When given the -experimental-debug-variable-locations option (via -Xclang
or to llc), have SelectionDAG generate DBG_INSTR_REF instructions instead
of DBG_VALUE. For now, this only happens in a limited circumstance: when
the value referred to is not a PHI and is defined in the current block.
Other situations introduce interesting problems, addresed in later patches.
Practically, this patch hooks into InstrEmitter and if it can find a
defining instruction for a value, gives it an instruction number, and
points the DBG_INSTR_REF at that <instr, operand> pair.
Differential Revision: https://reviews.llvm.org/D85747
This passes existing X86 test but I'm not sure if it handles all type
legalization cases it needs to.
Alternative to D89200
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D89222
Based on a discussion on D88783, if we're promoting a funnel shift to a width at least twice the size as the original type, then we can use the 'double shift' patterns (shifting the concatenated sources).
Differential Revision: https://reviews.llvm.org/D89139
I have introduced a new template PolySize class, where the template
parameter determines the type of quantity, i.e. for an element
count this is just an unsigned value. The ElementCount class is
now just a simple derivation of PolySize<unsigned>, whereas TypeSize
is more complicated because it still needs to contain the uint64_t
cast operator, since there are still many places in the code that
rely upon this implicit cast. As such the class also still needs
some of it's own operators.
I've tried to minimise the amount of code in the base PolySize
class, which led to a couple of changes:
1. In some places we were relying on '==' operator comparisons
between ElementCounts and the scalar value 1. I didn't put this
operator in the new PolySize class, and thought it was actually
clearer to use the isScalar() function instead.
2. I removed the isByteSized function and replaced it with calls
to isKnownMultipleOf(8).
I've also renamed NextPowerOf2 to be coefficientNextPowerOf2 so
that it's more consistent with coefficientDivideBy.
Differential Revision: https://reviews.llvm.org/D88409
Currently we allow passing pointers from deopt bundle on VReg only if
they were seen in list of gc-live pointers passed on VRegs.
This means that for the case of empty gc-live bundle we spill deopt
bundle's pointers. This change allows lowering deopt pointers to VRegs
in case of empty gc-live bundle. In case of non-empty gc-live bundle,
behavior does not change.
Reviewed By: skatkov
Differential Revision: https://reviews.llvm.org/D88999
Summary: This patch is derived from D87384.
In this patch we expand the existing decomposition of mul-by-constant to be more general by implementing 2 patterns:
```
mul x, (2^N + 2^M) --> (add (shl x, N), (shl x, M))
mul x, (2^N - 2^M) --> (sub (shl x, N), (shl x, M))
```
The conversion will be trigged if the multiplier is a big constant that the target can't use a single multiplication instruction to handle. This is controlled by the hook `decomposeMulByConstant`.
More over, the conversion benefits from an ILP improvement since the instructions are independent. A case with the sequence like following also gets benefit since a shift instruction is saved.
```
*res1 = a * 0x8800;
*res2 = a * 0x8080;
```
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D88201
The STRICT was causing unnecessary confusion. I think SEQ is a more accurate
name for what they actually do, and the other obvious option of "ORDERED"
has the issue of already having a meaning in FP contexts.
Differential Revision: https://reviews.llvm.org/D88791
We were already doing this for integer constants. This patch implements
the same thing for floating point constants.
Differential Revision: https://reviews.llvm.org/D88570
Current Statepoint MI format is this:
STATEPOINT
<id>, <num patch bytes >, <num call arguments>, <call target>,
[call arguments...],
<StackMaps::ConstantOp>, <calling convention>,
<StackMaps::ConstantOp>, <statepoint flags>,
<StackMaps::ConstantOp>, <num deopt args>, [deopt args...],
<gc base/derived pairs...> <gc allocas...>
Note that GC pointers are listed in pairs <base,derived>.
This causes base pointers to appear many times (at least twice) in
instruction, which is bad for us when VReg lowering is ON.
The problem is that machine operand tiedness is 1-1 relation, so
it might look like this:
%vr2 = STATEPOINT ... %vr1, %vr1(tied-def0)
Since only one instance of %vr1 is tied, that may lead to incorrect
codegen (see PR46917 for more details), so we have to always spill
base pointers. This mostly defeats new VReg lowering scheme.
This patch changes statepoint instruction format so that every
gc pointer appears only once in operand list. That way they all can
be tied. Additional set of operands is added to preserve base-derived
relation required to build stackmap.
New statepoint has following format:
STATEPOINT
<id>, <num patch bytes>, <num call arguments>, <call target>,
[call arguments...],
<StackMaps::ConstantOp>, <calling convention>,
<StackMaps::ConstantOp>, <statepoint flags>,
<StackMaps::ConstantOp>, <num deopt args>, [deopt args...],
<StackMaps::ConstantOp>, <num gc pointers>, [gc pointers...],
<StackMaps::ConstantOp>, <num gc allocas>, [gc allocas...]
<StackMaps::ConstantOp>, <num entries in gc map>, [base/derived indices...]
Changes are:
- every gc pointer is listed only once in a flat length-prefixed list;
- alloca list is prefixed with its length too;
- following alloca list is length-prefixed list of base-derived
indices of pointers from gc pointer list. Note that indices are
logical (number of pointer), not absolute (index of machine operand).
Differential Revision: https://reviews.llvm.org/D87154
In DAGCombiner::ForwardStoreValueToDirectLoad I have fixed up some
implicit casts from TypeSize -> uint64_t and replaced calls to
getVectorNumElements() with getVectorElementCount(). There are some
simple cases of forwarding that we can definitely support for
scalable vectors, i.e. when the store and load are both scalable
vectors and have the same size. I have added tests for the new
code paths here:
CodeGen/AArch64/sve-forward-st-to-ld.ll
Differential Revision: https://reviews.llvm.org/D87098
getNode handling for ISD:SETCC calls FoldSETCC which can canonicalize
FP constants to the RHS. When this happens we should create the node
with the FMF that was requested. By using FlagInserter when can ensure
any calls to getNode/getSetcc during canonicalization will also get the flags.
Differential Revision: https://reviews.llvm.org/D88063
I have fixed up a number of warnings resulting from TypeSize -> uint64_t
casts and calling getVectorNumElements() on scalable vector types. I
think most of the changes are fairly trivial except for those in
DAGTypeLegalizer::SplitVecRes_MSTORE I've tried to ensure we create
the MachineMemoryOperands in a sensible way for scalable vectors.
I have added a CHECK line to the following test:
CodeGen/AArch64/sve-split-store.ll
that ensures no new warnings are added.
Differential Revision: https://reviews.llvm.org/D86928
This reverts partial of a2fb5446 (actually, 2508ef01) about removing
negated FP constant immediately if it has no uses. However, as discussed
in bug 47517, there're cases when NegX is folded into constant from
other places while NegY is removed by that line of code and NegX is
equal to NegY. In these cases, NegX is deleted before used and crash
happens. So revert the code and add necessary test case.
In the motivating case from https://llvm.org/PR47517
we create a node that does not get constant folded
before getNegatedExpression is attempted from some
other node, and we crash.
By moving the fold into SelectionDAG::simplifyFPBinop(),
we get the constant fold sooner and avoid the problem.
This is similar to D87251, but for CopyFromRegs nodes.
Even for local statepoint uses we generate CopyToRegs/CopyFromRegs
nodes. When generating CopyFromRegs in visitGCRelocate, we must chain
to current DAG root, not EntryNode, to ensure proper ordering of copy
w.r.t. statepoint node producing result for it.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D88639
When we know that a particular type is always going to be fixed
width we have so far been writing code like this:
getSizeInBits().getFixedSize()
Since we are doing this in quite a few places now it seems to make
sense to add a new helper function that allows us to replace
these calls with a single getFixedSizeInBits() call.
Differential Revision: https://reviews.llvm.org/D88649
This patch adds FP_EXTEND_MERGE_PASSTHRU & FP_ROUND_MERGE_PASSTHRU
ISD nodes, used to lower scalable vector fp_extend/fp_round operations.
fp_round has an additional argument, the 'trunc' flag, which is an integer of zero or one.
This also fixes a warning introduced by the new tests added to sve-split-fcvt.ll,
resulting from an implicit TypeSize -> uint64_t cast in SplitVecOp_FP_ROUND.
Reviewed By: sdesmalen, paulwalker-arm
Differential Revision: https://reviews.llvm.org/D88321
After some recent upstream discussion we decided that it was best
to avoid having the / operator for both ElementCount and TypeSize,
since this could give the impression that these classes can be used
in the same way as basic integer integer types. However, division
for scalable types is a bit odd because we are only dividing the
minimum quantity by a value, as opposed to something like:
(MinSize * Vscale) / SomeValue
This is why when performing division it's important the caller
first establishes whether the operation makes sense, perhaps by
calling isKnownMultipleOf() prior to division. The caller must now
explictly call divideCoefficientBy() on the class to perform the
operation.
Differential Revision: https://reviews.llvm.org/D87700
Use +/-Inf or +/-Largest as neutral element for nnan fmin/fmax
reductions. This avoids dropping any FMF flags. Preserving the
nnan flag in particular is important to get a good lowering on X86.
Differential Revision: https://reviews.llvm.org/D87586
If we're multiplying all elements of a vector by '0' or '1' then we can more efficiently perform this as a clearing mask (that is likely to further simplify to a shuffle blend).
This was noticed when reviewing D87502 but seems to help idiv/irem by constant cases even more as '0'/'1' values are often used for 'passthrough' cases.
Differential Revision: https://reviews.llvm.org/D88225
This is like FastMathFlagGuard in IR. Since we use SDAG instance to get
values, it's with SelectionDAG. By creating a FlagInserter in current
scope, all values created by getNode will get the flags if no Flags
argument provided.
In this patch, I applied it to floating point operations folding part in
DAG combiner, and removed Flags passing to getNode to show its effect.
Other places in DAG combiner and other helper methods similar to getNode
also need this. They can be done in follow-up patches.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D87361
When processing PHI nodes after a callbr, we need to make sure that the
PHI nodes on the default branch are resolved after the callbr
(inserted after INLINEASM_BR). The PHI node values on the indirect
branches are processed before the INLINEASM_BR.
Differential Revision: https://reviews.llvm.org/D86260
Previously, if a floating-point type was legal, but FNEG wasn't legal,
we would use FSUB. Instead, we should use integer ops, to preserve the
semantics. (Alternatively, there's a compiler-rt call we could use, but
there isn't much reason to use that.)
It turns out we actually are still using this obscure codepath in a few
cases: on some targets, we have "legal" floating-point types that don't
actually support any floating-point operations. In particular, ARM and
AArch64 are using this path.
The implementation for SelectionDAG is pretty simple because we can
reuse the infrastructure from FCOPYSIGN.
See also 9a3dc3e, the corresponding change to type legalization.
Also includes a "bonus" change to STRICT_FSUB legalization, so we can
lower a STRICT_FSUB to a float libcall.
Includes the changes to both LegalizeDAG and GlobalISel so we don't have
inconsistent results in the future.
Fixes https://bugs.llvm.org/show_bug.cgi?id=46792 .
Differential Revision: https://reviews.llvm.org/D84287
An existing function Type::getScalarSizeInBits returns a uint64_t
instead of a TypeSize class because the caller is requesting a
scalar size, which cannot be scalable. This patch makes other
similar functions requesting a scalar size consistent with that,
thereby eliminating more than 1000 implicit TypeSize -> uint64_t
casts.
Differential revision: https://reviews.llvm.org/D87889
Just scalarize trunc stores - GenWidenVectorTruncStores does the same thing but is flawed (PR42046) and unused.
Differential Revision: https://reviews.llvm.org/D87708
When exporting statepoint results to virtual registers we try to avoid
generating exports for duplicated inputs. But we erroneously use
IR Value* to check if inputs are duplicated. Instead, we should use
SDValue, because even different IR values can get lowered to the same
SDValue.
I'm adding a (degenerate) test case which emphasizes importance of this
feature for invoke statepoints.
If we fail to export only unique values we will end up with something
like that:
%0 = STATEPOINT
%1 = COPY %0
landing_pad:
<use of %1>
And when exceptional path is taken, %1 is left uninitialized (COPY is never
execute).
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D87695
This reverts commit 0345d88de6.
Google internal backend uses EntrySU, we are looking into removing
dependency on it.
Differential Revision: https://reviews.llvm.org/D88018
SelectionDAGBuilder was inconsistently mangling values based on ABI
Calling Conventions when getting them through copyFromRegs in
SelectionDAGBuilder, causing duplicate value type convertions for
function arguments. The checking for the mangling requirement was based
on the value's originating instruction and was performed outside of, and
inspite of, the regular Calling Convention Lowering.
The issue could be observed in a scenario such as:
```
%arg1 = load half, half* %const, align 2
%arg2 = call fastcc half @someFunc()
call fastcc void @otherFunc(half %arg1, half %arg2)
; Here, %arg2 was incorrectly mangled twice, as the CallConv data from
; the call to @someFunc() was taken into consideration for the check
; when getting the value for processing the call to @otherFunc(...),
; after the proper convertion had taken place when lowering the return
; value of the first call.
```
This patch fixes the issue by disregarding the Calling Convention
information for such copyFromRegs, making sure the ABI mangling is
properly contanined in the Calling Convention Lowering.
This fixes Bugzilla #47454.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D87844
This is a follow-up of D86605. For strict DAG FP node, if its FP
exception behavior metadata is ignore, it should have nofpexcept flag.
But during custom lowering, this flag isn't passed down.
This is also seen on X86 target.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D87390
2508ef01 fixed a bug about constant removal in negation. But after
sanitizing check I found there's still some issue about it so it's
reverted.
Temporary nodes will be removed if useless in negation. Before the
removal, they'd be checked if any other nodes used it. So the removal
was moved after getNode. However in rare cases the node to be removed is
the same as result of getNode. We missed that and will be fixed by this
patch.
Reviewed By: steven.zhang
Differential Revision: https://reviews.llvm.org/D87614
If we have an all ones mask, we can just a regular masked load. InstCombine already gets this in IR. But the all ones mask can appear after type legalization.
Only avx512 test cases are affected because X86 backend already looks for element 0 and the last element being 1. It replaces this with an unmasked load and blend. The all ones mask is a special case of that where the blend will be removed. That transform is only enabled on avx2 targets. I believe that's because a non-zero passthru on avx2 already requires a separate blend so its more profitable to handle mixed constant masks.
This patch adds a dedicated all ones handling to the target independent DAG combiner. I've skipped extending, expanding, and index loads for now. X86 doesn't use index so I don't know much about it. Extending made me nervous because I wasn't sure I could trust the memory VT had the right element count due to some weirdness in vector splitting. For expanding I wasn't sure if we needed different undef handling.
Differential Revision: https://reviews.llvm.org/D87788
Fix lowering and instruction selection for v3x16 types
and enable InstCombine to emit them.
This patch only implements it for the selection dag.
GlobalISel tests in GlobalISel/llvm.amdgcn.image.load.1d.d16.ll and
GlobalISel/llvm.amdgcn.image.store.2d.d16.ll still don't work.
Differential Revision: https://reviews.llvm.org/D84420
2508ef01 doesn't totally fix the issue since we did not handle the case
when unused temporary negated result is the same with the result, which
is found by address sanitizer.
960cbc53 immediately removes nodes that won't be used to avoid
compilation time explosion. This patch adds the removal to constants to
fix PR47517.
Reviewed By: RKSimon, steven.zhang
Differential Revision: https://reviews.llvm.org/D87614
The versions that take 'unsigned' will be removed in the future.
I tried to use getOriginalAlign instead of getAlign in some
places. getAlign factors in the minimum alignment implied by
the offset in the pointer info. Since we're also passing the
pointer info we can use the original alignment.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D87592
The code that decomposes the GEP into ADD/MUL doesn't work properly
for vector GEPs. It can create bad COPY instructions or possibly
assert.
For now just bail out to SelectionDAG.
Fixes PR45906
This adds SoftenFloatRes, PromoteFloatRes and SoftPromoteHalfRes
legalizations for VECREDUCE, to fill the remaining hole in the SDAG
legalization. These legalizations simply expand the reduction and
let it be recursively legalized. For the PromoteFloatRes case at
least it is possible to do better than that, but it's pretty tricky
(because we need to consider the interaction of three different
vector legalizations and the type promotion) and probably not
really worthwhile.
I haven't added ExpandFloatRes support, as I am not familiar with
ppc_fp128.
Differential Revision: https://reviews.llvm.org/D87569
Similar to D87415, this folds the various float min/max opcodes
with a constant INF or -INF operand, or FLT_MAX / -FLT_MAX operand
if the ninf flag is set. Some of the folds are only possible under
nnan.
The fminnum(X, INF) with nnan and fmaxnum(X, -INF) with nnan cases
are needed to improve the VECREDUCE_FMIN/FMAX lowerings on X86,
the rest is here for the sake of completeness.
Differential Revision: https://reviews.llvm.org/D87571
In an earlier patch I meant to add the correct flags to the ADD
node when incrementing the pointer, but forgot to pass them to
SelectionDAG::getNode.
Differential Revision: https://reviews.llvm.org/D87496
Previously, we formed ISD::PARITY by looking for (and (ctpop X), 1)
but the AND might be separated from the ctpop. For example if the
parity result is multiplied by 2, we'll pull the AND through the
shift.
So to handle more cases, move to SimplifyDemandedBits where we
can handle more cases that result in only the LSB of the CTPOP
being used.
DAG combiner folds (fma a 1.0 b) into (fadd a b) but the flag isn't
propagated into new fadd. This patch fixes that.
Some code in visitFMA is redundant and such support for vector constants
is missing. Need follow-up patch to clean.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D87037
CTTZ, CTLZ, CTPOP, and FCANONICALIZE all have the same input and
output types so the operand should have already been legalized when the
result type was legalized.
Clang emits (and (ctpop X), 1) for __builtin_parity. If ctpop
isn't natively supported by the target, this leads to poor codegen
due to the expansion of ctpop being more complex than what is needed
for parity.
This adds a DAG combine to convert the pattern to ISD::PARITY
before operation legalization. Type legalization is updated
to handled Expanding and Promoting this operation. If after type
legalization, CTPOP is supported for this type, LegalizeDAG will
turn it back into CTPOP+AND. Otherwise LegalizeDAG will emit a
series of shifts and xors followed by an AND with 1.
I've avoided vectors in this patch to avoid more legalization
complexity for this patch.
X86 previously had a custom DAG combiner for this. This is now
moved to Custom lowering for the new opcode. There is a minor
regression in vector-reduce-xor-bool.ll, but a follow up patch
can easily fix that.
Fixes PR47433
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D87209
As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2020-April/140729.html
This is hopefully the final remaining showstopper before we can remove
the 'experimental' from the reduction intrinsics.
No behavior was specified for the FP min/max reductions, so we have a
mess of different interpretations.
There are a few potential options for the semantics of these max/min ops.
I think this is the simplest based on current behavior/implementation:
make the reductions inherit from the existing llvm.maxnum/minnum intrinsics.
These correspond to libm fmax/fmin, and those are similar to the (now
deprecated?) IEEE-754 maxNum/minNum functions (NaNs are treated as missing
data). So the default expansion creates calls to libm functions.
Another option would be to inherit from llvm.maximum/minimum (NaNs propagate),
but most targets just crash in codegen when given those nodes because no
default expansion was ever implemented AFAICT.
We could also just assume 'nnan' semantics by default (we are already
assuming 'nsz' semantics in the maxnum/minnum intrinsics), but some targets
(AArch64, PowerPC) support the more defined behavior, so it doesn't make much
sense to not allow a tighter spec. Fast-math-flags (nnan) can be used to
loosen the semantics.
(Note that D67507 was proposed to update the LangRef to acknowledge the more
recent IEEE-754 2019 standard, but that patch seems to have stalled. If we do
update based on the new standard, the reduction instructions can seamlessly
inherit from whatever updates are made to the max/min intrinsics.)
x86 sees a regression here on 'nnan' tests because we have underlying,
longstanding bugs in FMF creation/propagation. Those need to be fixed apart
from this change (for example: https://llvm.org/PR35538). The expansion
sequence before this patch may not have been correct.
Differential Revision: https://reviews.llvm.org/D87391
Truncating from an illegal SVE type to a legal type, e.g.
`trunc <vscale x 4 x i64> %in to <vscale x 4 x i32>`
fails after PromoteIntOp_CONCAT_VECTORS attempts to
create a BUILD_VECTOR.
This patch changes the promote function to create a sequence of
INSERT_SUBVECTORs if the return type is scalable, and replaces
these with UNPK+UZP1 for AArch64.
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D86548
fminnum(X, NaN) is X, fminimum(X, NaN) is NaN. This mirrors the
behavior of existing InstSimplify folds.
This is expected to improve the reduction lowerings in D87391,
which use NaN as a neutral element.
Differential Revision: https://reviews.llvm.org/D87415
During the main DAGCombine loop, whenever a node gets replaced, the new
node and all its users are pushed onto the worklist. Omit this if the
new node is the EntryToken (e.g. if a store managed to get optimized
out), because re-visiting the EntryToken and its users will not uncover
any additional opportunities, but there may be a large number of such
users, potentially causing compile time explosion.
This compile time explosion showed up in particular when building the
SingleSource/UnitTests/matrix-types-spec.cpp test-suite case on any
platform without SIMD vector support.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D86963
Since we always generate CopyToRegs for statepoint results,
we must update DAG root after emitting statepoint, so that
these copies are scheduled before any possible local uses.
Note: getControlRoot() flushes all PendingExports, not only
those we generates for relocates. If that'll become a problem,
we can change it to flushing relocate exports only.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D87251
Current code in InstEmitter assumes all GC pointers are either
VRegs or stack slots - hence, taking only one operand.
But it is possible to have constant base, in which case it
occupies two machine operands.
Add a convinience function to StackMaps to get index of next
meta argument and use it in InsrEmitter to properly advance to
the next statepoint meta operand.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D87252
This removes the after the fact FMF handling from D46854 in favor of passing fast math flags to getNode. This should be a superset of D87130.
This required adding a SDNodeFlags to SelectionDAG::getSetCC.
Now we manage to contant fold some stuff undefs during the
initial getNode that we don't do in later DAG combines.
Differential Revision: https://reviews.llvm.org/D87200
On SystemZ, a ZERO_EXTEND of an i1 vector handled by WidenVecRes_Convert()
always ended up being scalarized, because the type action of the input is
promotion which was previously an unhandled case in this method.
This fixes https://bugs.llvm.org/show_bug.cgi?id=47132.
Differential Revision: https://reviews.llvm.org/D86268
Patch by Eli Friedman.
Review: Ulrich Weigand
Rather than using SELECT instructions, use SRA, UADDO/ADDCARRY and
XORs to expand ABS. This is the multi-part version of the sequence
we use in LegalizeDAG.
It's also the same as the Custom sequence uses for i64 on 32-bit
and i128 on 64-bit. So we can remove the X86 customization.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D87215
This is a follow-up suggested in D86420 - if we have a pair of stores
in inverted order for the target endian, we can rotate the source
bits into place.
The "be_i64_to_i16_order" test shows a limitation of the current
function (which might be avoided if we integrate this function with
the other cases in mergeConsecutiveStores). In the earlier
"be_i64_to_i16" test, we skip the first 2 stores because we do not
match the full set as consecutive or rotate-able, but then we reach
the last 2 stores and see that they are an inverted pair of 16-bit
stores. The "be_i64_to_i16_order" test alters the program order of
the stores, so we miss matching the sub-pattern.
Differential Revision: https://reviews.llvm.org/D87112
In getMemcpyLoadsAndStores(), a memcpy where the source is a zero constant is expanded to a MemOp::Set instead of a MemOp::Copy, even when the memcpy is volatile.
This is incorrect.
The fix is to add a check for volatile, and expand to MemOp::Copy in the volatile case.
Reviewed By: chill
Differential Revision: https://reviews.llvm.org/D87134
Previously SDNodeFlags::instersectWith(Flags) would do nothing if Flags was
in an undefined state, which is very bad given that this is the default when
getNode() is called without passing an explicit SDNodeFlags argument.
This meant that if an already existing and reused node had a flag which the
second caller to getNode() did not set, that flag would remain uncleared.
This was exposed by https://bugs.llvm.org/show_bug.cgi?id=47092, where an NSW
flag was incorrectly set on an add instruction (which did in fact overflow in
one of the two original contexts), so when SystemZElimCompare removed the
compare with 0 trusting that flag, wrong-code resulted.
There is more that needs to be done in this area as discussed here:
Differential Revision: https://reviews.llvm.org/D86871
Review: Ulrich Weigand, Sanjay Patel
I have fixed up some more ElementCount/TypeSize related warnings in
the following tests:
CodeGen/AArch64/sve-split-extract-elt.ll
CodeGen/AArch64/sve-split-insert-elt.ll
In SelectionDAG::CreateStackTemporary we were relying upon the implicit
cast from TypeSize -> uint64_t when calling MachineFrameInfo::CreateStackObject.
I've fixed this by passing in the known minimum size instead, which I
believe is fine because the associated stack id indicates whether this
is a scalable object or not.
I've also fixed up a case in TargetLowering::SimplifyDemandedBits when
extracting a vector element from a scalable vector. The result is a scalar,
hence it wasn't caught at the start of the function. If the vector is
scalable we just bail out for now.
Differential Revision: https://reviews.llvm.org/D86431
Use forward declarations and move the include down to dependent files that actually use it.
This also exposes a number of implicit dependencies on KnownBits.h
When lowering fixed length vector operations for SVE the subvector
operations are used extensively to marshall data between scalable
and fixed-length vectors. This means that sequences like:
extract_subvec(binop(insert_subvec(a), insert_subvec(b)))
are very common. DAGCombine only checks if the resulting binop is
legal or can be custom lowered when undoing such sequences. When
it's custom lowering that is introducing them the result is an
infinite legalise->combine->legalise loop.
This patch extends the isOperationLegalOr... functions to include
a "LegalOnly" parameter to restrict the check to legal operations
only. Although isOperationLegal could be used it's common for
the affected code paths to be visited pre and post legalisation,
so the extra parameter keeps the code tidy.
Differential Revision: https://reviews.llvm.org/D86450
Unwinders may only preserve the lower 64bits of Neon and SVE registers,
as only the registers in the base ABI are guaranteed to be preserved
over the exception edge. The caller will need to preserve additional
registers for when the call throws an exception and the unwinder has
tried to recover state.
For e.g.
svint32_t bar(svint32_t);
svint32_t foo(svint32_t x, bool *err) {
try { bar(x); } catch (...) { *err = true; }
return x;
}
`z0` needs to be spilled before the call to `bar(x)` and reloaded before
returning from foo, as the exception handler may have clobbered z0.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D84737
I have fixed up a number of warnings resulting from TypeSize -> uint64_t
casts and calling getVectorNumElements() on scalable vector types. I
think most of the changes are fairly trivial except for those in
DAGTypeLegalizer::SplitVecRes_MLOAD I've tried to ensure we create
the MachineMemoryOperands in a sensible way for scalable vectors.
I have added a CHECK line to the following test:
CodeGen/AArch64/sve-split-load.ll
that ensures no new warnings are added.
Differential Revision: https://reviews.llvm.org/D86697
fabs and fneg share a common transformation:
(fneg (bitconvert x)) -> (bitconvert (xor x sign))
(fabs (bitconvert x)) -> (bitconvert (and x ~sign))
This patch separate the code into a single method.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D86862
I tried to fix this in:
rG716e35a0cf53
...but that patch depends on the order that we encounter the
magic "x/sqrt(x)" expression in the combiner's worklist.
This patch should improve that by waiting until we walk the
user list to decide if there's a use to skip.
The AArch64 test reveals another (existing) ordering problem
though - we may try to create an estimate for plain sqrt(x)
before we see that it is part of a 1/sqrt(x) expression.
In general, we probably want to try the multi-use reciprocal
transform before sqrt transforms, but x/sqrt(x) is a special-case
because that will always reduce to plain sqrt(x) or an estimate.
The AArch64 tests show that the transform is limited by TLI
hook to patterns where there are 3 or more uses of the divisor.
So this change can result in an extra division compared to
what we had, but that's the intended behvior based on the
current setting of that hook.
Current `v:t = zext(setcc x,y,cc)` will be transformed to `select x, y, 1:t, 0:t, cc`. It misses some opportunities if x's type size is less than `t`'s size. This patch enhances the above transformation.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D86687
There is a subtle problem with new statepoint lowering scheme
when base and pointers are the same (see PR46917 for more context):
%1 = STATEPOINT ... %0, %0(tied-def 0)...
if, for some reason, register allocator desides to put two instances
of %0 into two different objects (registers or spill slots), we may
end up with
$reg3 = STATEPOINT ... $reg2, $reg1(tied-def 0)...
and nothing will prevent later passes to sink uses of $reg2 below
statepoint, which is incorrect.
As a short term solution, always put base pointers on stack during
lowering.
A longer term solution may be to rework MIR statepoint format to
avoid GC pointer duplication in statepoint argument list.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D86712
This is the follow up patch for https://reviews.llvm.org/D86183 as we miss to delete the node if NegX == NegY, which has use after we create the node.
```
if (NegX && (CostX <= CostY)) {
Cost = std::min(CostX, CostZ);
RemoveDeadNode(NegY);
return DAG.getNode(Opcode, DL, VT, NegX, Y, NegZ, Flags); #<-- NegY is used here if NegY == NegX.
}
```
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D86689
This patch changes ElementCount so that the Min and Scalable
members are now private and can only be accessed via the get
functions getKnownMinValue() and isScalable(). In addition I've
added some other member functions for more commonly used operations.
Hopefully this makes the class more useful and will reduce the
need for calling getKnownMinValue().
Differential Revision: https://reviews.llvm.org/D86065
When joining the legal parts of vector arguments into its original value
during the lower of Formal Arguments in SelectionDAGBuilder, the Calling
Convention information was not being propagated for the handling of each
individual parts. The same did not happen when lowering calls, causing a
mismatch.
This patch fixes the issue by properly propagating the Calling
Convention details.
This fixes Bugzilla #47001.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D86715
This is the first of a set of DAGCombiner changes enabling strictfp
optimizations. I want to test to waters with this to make sure changes
like these are acceptable for the strictfp case- this particular change
should preserve exception ordering and result precision perfectly, and
many other possible changes appear to be able to as well.
Copied from regular fadd combines but modified to preserve ordering via
the chain, this change allows strict_fadd x, (fneg y) to become
struct_fsub x, y and strict_fadd (fneg x), y to become strict_fsub y, x.
Differential Revision: https://reviews.llvm.org/D85548
We have a gap in our store merging capabilities for shift+truncate
patterns as discussed in:
https://llvm.org/PR46662
I generalized the code/comments for this function in earlier commits,
so we only need ease the type restriction and adjust the address/endian
checking to make this work.
AArch64 lets us switch endian to make sure that patterns are matched
either way.
Differential Revision: https://reviews.llvm.org/D86420
This adapts legalization of intrinsic get.active.lane.mask to the new semantics
as described in D86147. Because the second argument is now the loop tripcount,
we legalize this intrinsic to an 'icmp ULT' instead of an ULE when it was the
backedge-taken count.
Differential Revision: https://reviews.llvm.org/D86302
Also updates isConstOrConstSplatFP to allow the mul(A,-1) -> neg(A)
transformation when -1 is expressed as an ISD::SPLAT_VECTOR.
Differential Revision: https://reviews.llvm.org/D86415
With FMF ( "nsz" and " reassoc") fold X/Sqrt(X) to Sqrt(X).
This is done after targets have the chance to produce a
reciprocal sqrt estimate sequence because that expansion
is probably more efficient than an expansion of a
non-reciprocal sqrt. That is also why we deferred doing
this transform in IR (D85709).
Differential Revision: https://reviews.llvm.org/D86403
D77152 tried to do this but got it wrong in the shift-by-zero case.
D86430 reverted the wrong code. Reimplement the optimization with
different code depending on whether the shift amount is known to be
non-zero (modulo bitwidth).
This improves code quality for fshl tests on AMDGPU, which only has an
fshr instruction.
Differential Revision: https://reviews.llvm.org/D86438
This is a fixup of commit 0819a6416f (D77152) which could
result in miscompiles. The miscompile could only happen for targets
where isOperationLegalOrCustom could return different values for
FSHL and FSHR.
The commit mentioned above added logic in expandFunnelShift to
convert between FSHL and FSHR by swapping direction of the
funnel shift. However, that transform is only legal if we know
that the shift count (modulo bitwidth) isn't zero.
Basically, since fshr(-1,0,0)==0 and fshl(-1,0,0)==-1 then doing a
rewrite such as fshr(X,Y,Z) => fshl(X,Y,0-Z) would be incorrect if
Z modulo bitwidth, could be zero.
```
$ ./alive-tv /tmp/test.ll
----------------------------------------
define i32 @src(i32 %x, i32 %y, i32 %z) {
%0:
%t0 = fshl i32 %x, i32 %y, i32 %z
ret i32 %t0
}
=>
define i32 @tgt(i32 %x, i32 %y, i32 %z) {
%0:
%t0 = sub i32 32, %z
%t1 = fshr i32 %x, i32 %y, i32 %t0
ret i32 %t1
}
Transformation doesn't verify!
ERROR: Value mismatch
Example:
i32 %x = #x00000000 (0)
i32 %y = #x00000400 (1024)
i32 %z = #x00000000 (0)
Source:
i32 %t0 = #x00000000 (0)
Target:
i32 %t0 = #x00000020 (32)
i32 %t1 = #x00000400 (1024)
Source value: #x00000000 (0)
Target value: #x00000400 (1024)
```
It could be possible to add back the transform, given that logic
is added to check that (Z % BW) can't be zero. Since there were
no test cases proving that such a transform actually would be useful
I decided to simply remove the faulty code in this patch.
Reviewed By: foad, lebedev.ri
Differential Revision: https://reviews.llvm.org/D86430
D70867 introduced support for expanding most ppc_fp128 operations. But
sitofp/uitofp is missing. This patch adds that after D81669.
Reviewed By: uweigand
Differntial Revision: https://reviews.llvm.org/D81918
The pattern matching does not account for truncating stores,
so it is unlikely to work at later stages. So we are likely
wasting compile-time with no hope of improvement by running
this later.
This should be NFC in terms of output because the endian
check further down would bail out too, but we are wasting
time by waiting to that point to give up. If we generalize
that function to deal with more than i8 types, we should
not have to deal with the degenerate case.
In SelectionDAGBuilder always translate the fshl and fshr intrinsics to
FSHL and FSHR (or ROTL and ROTR) instead of lowering them to shifts and
ORs. Improve the legalization of FSHL and FSHR to avoid code quality
regressions.
Differential Revision: https://reviews.llvm.org/D77152
In DAGTypeLegalizer::GenWidenVectorLoads the algorithm assumes it only
ever deals with fixed width types, hence the offsets for each individual
store never take 'vscale' into account. I've changed the code in that
function to use TypeSize instead of unsigned for tracking the remaining
load amount. In addition, I've changed the load loop to use the new
IncrementPointer helper function for updating the addresses in each
iteration, since this handles scalable vector types.
Also, I've added report_fatal_errors in GenWidenVectorExtLoads,
TargetLowering::scalarizeVectorLoad and TargetLowering::scalarizeVectorStores,
since these functions currently use a sequence of element-by-element
scalar loads/stores. In a similar vein, I've also added a fatal error
report in FindMemType for the case when we decide to return the element
type for a scalable vector type.
I've added new tests in
CodeGen/AArch64/sve-split-load.ll
CodeGen/AArch64/sve-ld-addressing-mode-reg-imm.ll
for the changes in GenWidenVectorLoads.
Differential Revision: https://reviews.llvm.org/D85909
The "isa" checks were less constrained because they allow
target constants, but the later matching code would bail
out on those anyway, so this should be slightly more
efficient.
This patch changes SplitVecOp_EXTRACT_VECTOR_ELT to work correctly
for scalable vectors and also fixes an a bug in DAGCombiner where
the scalable property is dropped in visitTRUNCATE when attempting
to fold an extract + a truncate.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D85754
In DAGTypeLegalizer::GenWidenVectorStores the algorithm assumes it only
ever deals with fixed width types, hence the offsets for each individual
store never take 'vscale' into account. I've changed the main loop in
that function to use TypeSize instead of unsigned for tracking the
remaining store amount and offset increment. In addition, I've changed
the loop to use the new IncrementPointer helper function for updating
the addresses in each iteration, since this handles scalable vector
types.
Whilst fixing this function I also fixed a minor issue in
IncrementPointer whereby we were not adding the no-unsigned-wrap flag
for the add instruction in the same way as the fixed width case does.
Also, I've added a report_fatal_error in GenWidenVectorTruncStores,
since this code currently uses a sequence of element-by-element scalar
stores.
I've added new tests in
CodeGen/AArch64/sve-intrinsics-stores.ll
CodeGen/AArch64/sve-st1-addressing-mode-reg-imm.ll
for the changes in GenWidenVectorStores.
Differential Revision: https://reviews.llvm.org/D84937
In narrowExtractedVectorLoad there is an optimisation that tries to
combine extract_subvector with a narrowing vector load. At the moment
this produces warnings due to the incorrect calls to
getVectorNumElements() for scalable vector types. I've got this
working for scalable vectors too when the extract subvector index
is a multiple of the minimum number of elements. I have added a
new variant of the function:
MachineFunction::getMachineMemOperand
that copies an existing MachineMemOperand, but replaces the pointer
info with a null version since we cannot currently represent scaled
offsets.
I've added a new test for this particular case in:
CodeGen/AArch64/sve-extract-subvector.ll
Differential Revision: https://reviews.llvm.org/D83950
In this patch I have fixed two issues:
1. Our SVE tuple get/set intrinsics were using the wrong constant type
for the index passed to EXTRACT_SUBVECTOR. I have fixed this by using the
function SelectionDAG::getVectorIdxConstant to create the value. Also, I
have updated the documentation for EXTRACT_SUBVECTOR describing what type
the constant index should be and we now enforce this when creating the
node.
2. The AArch64 backend was missing the appropriate patterns for
extracting certain subvectors (nxv4f16 and nxv2f32) from legal SVE types.
I have added them as part of this patch.
The only way that I could find to test the new patterns was to use the
SVE tuple get intrinsics, although I realise it looks a bit unusual.
Tests added here:
test/CodeGen/AArch64/sve-extract-subvector.ll
Differential Revision: https://reviews.llvm.org/D85516
When the result type of insertelement needs to be split,
SplitVecRes_INSERT_VECTOR_ELT will try to store the vector to a
stack temporary, store the element at the location of the stack
temporary plus the index, and reload the Lo/Hi parts.
This patch does the following to ensure this works for scalable vectors:
- Sets the StackID with getStackIDForScalableVectors() in CreateStackTemporary
- Adds an IsScalable flag to getMemBasePlusOffset() and scales the
offset by VScale when this is true
- Ensures the immediate is clamped correctly by clampDynamicVectorIndex
so that we don't try to use an out of range index
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D84874
Changes the Offset arguments to both functions from int64_t to TypeSize
& updates all uses of the functions to create the offset using TypeSize::Fixed()
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D85220
These aren't the canonical forms we'd get from InstCombine, but
we do have X86 tests for them. Recognizing them is pretty cheap.
While there make use of APInt:isSignedMinValue/isSignedMaxValue
instead of creating a new APInt to compare with. Also use
SelectionDAG::getAllOnesConstant helper to hide the all ones
APInt creation.
Follow-up to D82716 / rGea71ba11ab11
We do not have the fabs removal fold in IR yet for the case
where the sqrt operand is repeated, so that's another potential
improvement.
As mentioned on D85463, we should be using SimplifyMultipleUseDemandedBits (which is the default fallback).
The minor regression in illegal-bitfield-loadstore.ll will be addressed properly by D77804.
One of the callers only wants the condition, but the vselect can
be simplified by getNode making it hard or impossible to retrieve
the condition.
Instead, return the condition and make the other 2 callers
responsible for creating the vselect node using the condition.
Rename the function to WidenVSELECTMask accordingly.
Differential Revision: https://reviews.llvm.org/D85468
This allows us to remove extra patterns from AArch64SVEInstrInfo.td
because we can reuse those required for fixed length vectors.
Differential Revision: https://reviews.llvm.org/D85328
We currently don't do anything to fold any_extend vector loads as no target has such an instruction.
Instead I've added support for folding to a zextload, SimplifyDemandedBits does a good job of adjusting the zext(truncate(()) stages as required later on.
We still need the custom scalar extload handling instead of using the tryToFoldExtOfLoad helper as it has different legality tests - we can probably tweak that to reduce most of the code duplication.
Fixes the regression I mentioned in rG99a971cadff7
Differential Revision: https://reviews.llvm.org/D85129
This corresponds with the SelectionDAGISel change in D84056.
Also, rename some poorly named tests in CodeGen/X86/fast-isel-fneg.ll with NFC.
Differential Revision: https://reviews.llvm.org/D85149
The custom lowering saves an instruction over the generic expansion, by
taking advantage of the fact that PowerPC shift instructions are well
defined in the shift-by-bitwidth case.
Differential Revision: https://reviews.llvm.org/D83948
This patch stops unconditionally transforming FSUB(-0,X) into an FNEG(X) while building the DAG. There is also one small change to handle the new FSUB(-0,X) similarly to FNEG(X) in the AMDGPU backend.
Differential Revision: https://reviews.llvm.org/D84056
Try to be more consistent with the SDLoc param in the TargetLowering methods.
This also exposes an issue where we were passing a SDNode as a SDLoc, relying on the implicit SDLoc(SDNode) constructor.
Just the obvious implementation that rewrites the result type. Also fix
warning from EXTRACT_SUBVECTOR legalization that triggers on the test.
Differential Revision: https://reviews.llvm.org/D84706
This fixes an assertion failure that was being triggered in
SelectionDAG::getZeroExtendInReg(), where it was trying to extend the <2xi32>
to i64 (which should have been <2xi64>).
Fixes: rdar://66016901
Differential Revision: https://reviews.llvm.org/D84884
This change is mechanical, it just removes the restriction and updates tests. The key building blocks were submitted in 31342eb and 8fe2abc.
Note that this (and preceeding changes) entirely subsumes D83965. I did includes a couple of it's tests.
From the codegen changes, an interesting observation: this doesn't actual reduce spilling, it just let's the register allocator do it's job. That results in a slightly different overall result which has both pros and cons over the eager spill lowering. (i.e. We'll have some perf tuning to do once this is stable.)
Change the way we track how a particular pointer was relocated at a statepoint in selection dag. Previously, we used an optional<location> for the spill lowering, and a block local Register for the newly introduced vreg lowering. Combine all three lowerings (norelocate, spill, and vreg) into a single helper class, and keep a single copy of the information.
This is submitted separately as it really does make the code more readible on it's own, but the indirect motivation is to move vreg tracking from StatepointLowering to FunctionLoweringInfo. This is the last piece needed to support cross block relocations with vregs; that will follow in a separate (non-NFC) patch.
This builds on 3da1a96 on the path towards supporting invokes and cross block relocations. The actual change attempts to be NFC, but does fail in one corner-case explained below.
The change itself is fairly mechanical. Rather than remember SDValues - which are inherently block local - immediately produce a virtual register copy and remember that.
Once this lands, we'll update the FunctionLoweringInfo::StatepointSpillMap map to allow register based lowerings, delete VirtRegs from StatepointLowering, and drop the restriction against cross block relocations. I deliberately separate the semantic part into it's own change for easy of understanding and fault isolation.
The corner-case which isn't quite NFC is that the old implementation implicitly CSEd gc.relocates of the same SDValue regardless of type. The new implementation still only relocates once, but it produces distinct vregs for the bitcast and it's source, whereas SelectionDAG's generic CSE was able to remove the bitcast in the old implementation. Note that the final assembly doesn't change (at least in the test), as our MI level optimizations catch the duplication.
I assert that this is an uninteresting corner-case. It's functionally correct, and if we find a case where this influences performance, we should really be canonicalizing types to i8* at the IR level.
Differential Revision: https://reviews.llvm.org/D84692
I have added tests to:
CodeGen/AArch64/sve-intrinsics-int-arith.ll
for doing simple integer add operations on tuple types. Since these
tests introduced new warnings due to incorrect use of
getVectorNumElements() I have also fixed up these warnings in the
same patch. These fixes are:
1. In narrowExtractedVectorBinOp I have changed the code to bail out
early for scalable vector types, since we've not yet hit a case that
proves the optimisations are profitable for scalable vectors.
2. In DAGTypeLegalizer::WidenVecRes_CONCAT_VECTORS I have replaced
calls to getVectorNumElements with getVectorMinNumElements in cases
that work with scalable vectors. For the other cases I have added
asserts that the vector is not scalable because we should not be
using shuffle vectors and build vectors in such cases.
Differential revision: https://reviews.llvm.org/D84016
In DAGTypeLegalizer::SplitVecOp_EXTRACT_SUBVECTOR I have replaced
calls to getVectorNumElements with getVectorMinNumElements, since
this code path works for both fixed and scalable vector types. For
scalable vectors the index will be multiplied by VSCALE.
Fixes warnings in this test:
sve-sext-zext.ll
Differential revision: https://reviews.llvm.org/D83198
Summary:
In parallelizeChainedStores, a TokenFactor was created with the size greater than 3000.
We found that DAGCombiner::visitTokenFactor will consume a huge amount of time on
such nodes. Since the number of operands already exceeds TokenFactorInlineLimit, we propose
to give up simplification with the consideration of compile time.
Reviewers:
@spatel, @arsenm
Differential Revision:
https://reviews.llvm.org/D84204
(Disabled under flag for the moment)
This is part of a larger project wherein we are finally integrating lowering of gc live operands with the register allocator. Today, we force spill all operands in SelectionDAG. The code to do so is distinctly non-optimal. The approach this patch is working towards is to instead lower the relocations directly into the MI form, and let the register allocator pick which ones get spilled and which stack slots they get spilled to. In terms of performance, the later part is actually more important as it avoids redundant shuffling of values between stack slots.
This particular change adds ISEL support to produce the variadic def STATEPOINT form required by the above. In particular, the first N are lowered to variadic tied def/use pairs. So new statepoint looks like this:
reloc1,reloc2,... = STATEPOINT ..., base1, derived1<tied-def0>, base2, derived2<tied-def1>, ...
N is limited by the maximal number of tied registers machine instruction can have (15 at the moment).
The current patch is restricted to handling relocations within a single basic block. Cross block relocations (e.g. invokes) are handled via the legacy mechanism. This restriction will be relaxed in future patches.
Patch By: dantrushin
Differential Revision: https://reviews.llvm.org/D81648
In the included test case the align 16 allowed the v23f32 load to handled as load v16f32, load v4f32, and load v4f32(one element not used). These loads all need to be concatenated together into a final vector. In this case we tried to concatenate the two v4f32 loads to match the type of the v16f32 load so we could do a second concat_vectors, but those loads alone only add up to v8f32. So we need to two v4f32 undefs to pad it.
It appears we've tried to hack around a similar issue in this code before by adding undef padding to loads in one of the earlier loops in this function. Originally in r147964 by padding all loads narrower than previous loads to the same size. Later modifed to only the last load in r293088. This patch removes that earlier code and just handles it on demand where we know we need it.
Fixes PR46820
Differential Revision: https://reviews.llvm.org/D84463
This adds the llvm.abs(), llvm.umin(), llvm.umax(), llvm.smin(),
and llvm.smax() intrinsics specified in D81829. For SelectionDAG,
the ISD opcodes and all the legalization and lowering already exist,
so this just wires them up to the intrinsic in the SDAG builder and
adds rudimentary tests. For GlobalISel only the min/max intrinsics
are wired up, as llvm.abs() will require the addition of a G_ABS op,
and corresponding legalization support.
Differential Revision: https://reviews.llvm.org/D84125
On systems where size() doesn't return unsigned long, this leads to an
overloading mismatch. Convert the constant to whatever type is used for
Q.size() on the system.
Currently popFromQueueImpl iterates over all candidates to find the best
one. While the candidate queue is small, this is not a problem. But it
becomes a problem once the queue gets larger. For example, the snippet
below takes 330s to compile with llc -O0, but completes in 3s with this
patch.
define void @test(i4000000* %ptr) {
entry:
store i4000000 0, i4000000* %ptr, align 4
ret void
}
This patch limits the number of candidates to check to 1000. This limit
ensures that it never triggers for test-suite/SPEC2000/SPEC2006 on X86
and AArch64 with -O3, while still drastically limiting the compile-time
in case of very large queues.
It would be even better to use a binary heap to manage to queue
(D83335), but some heuristics change the score of a node in the queue
after another node has been scheduled. I plan to address this for
backends that use the MachineScheduler in the future, but that requires
a more careful evaluation. In the meantime, the limit should help users
impacted by this issue.
The patch includes a slightly smaller version of the motivating example
as test case, to guard against the issue.
Reviewers: efriedma, paquette, niravd
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D84328
The AMDGPU handling of f16 vectors is terrible still since it gets
scalarized even when the vector operation is legal.
The code is is essentially duplicated between the non-strict and
strict case. Apparently no other expansions are currently trying to do
this. This is mostly because I found the behavior of
getStrictFPOperationAction to be confusing. In the ARM case, it would
expand strict_fsub even though it shouldn't due to the later check. At
that point, the logic required to check for legality was more complex
than just duplicating the 2 instruction expansion.
This isn't a natively supported operation, so convert it to a
mask+compare.
In addition to the operation itself, fix up some surrounding stuff to
make the testcase work: we need concat_vectors on i1 vectors, we need
legalization of i1 vector truncates, and we need to fix up all the
relevant uses of getVectorNumElements().
Differential Revision: https://reviews.llvm.org/D83811
MBBs are not allowed to have non-terminator instructions after the first
terminator. Currently in some cases (see the modified test),
EmitSchedule can add DBG_VALUEs after the last terminator, for example
when referring a debug value that gets folded into a TCRETURN
instruction on ARM.
This patch updates EmitSchedule to move inserted DBG_VALUEs just before
the first terminator. I am not sure if there are terminators produce
values that can in turn be used by a DBG_VALUE. In that case, moving the
DBG_VALUE might result in referencing an undefined register. But in any
case, it seems like currently there is no way to insert a proper DBG_VALUEs
for such registers anyways.
Alternatively it might make sense to just remove those extra DBG_VALUES.
I am not too familiar with the details of debug info in the backend and
would appreciate any suggestions on how to address the issue in the best
possible way.
Reviewers: vsk, aprantl, jpaquette, efriedma, paquette
Reviewed By: aprantl
Differential Revision: https://reviews.llvm.org/D83561
In an upcoming AMDGPU patch, the scalar cases will be legal and vector
ops should be scalarized, rather than producing a long sequence of
vector ops which will also need to be scalarized.
Use a lazy heuristic that seems to work and improves the thumb2 MVE
test.
When the byref attribute is added, there will need to be two similar
functions for the existing cases which have an associate value copy,
and byref which does not. Most, but not all of the existing uses will
use the existing version.
The associated size function added by D82679 also needs to
contextually differ, and will help eliminate a few places still
relying on pointee element types.
Summary:
This patch modifies IncrementMemoryAddress to use a vscale
when calculating the new address if the data type is scalable.
Also adds tablegen patterns which match an extract_subvector
of a legal predicate type with zip1/zip2 instructions
Reviewers: sdesmalen, efriedma, david-arm
Reviewed By: efriedma, david-arm
Subscribers: tschuett, hiraditya, psnobl, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D83137
The operands of a BUILD_VECTOR must all have the same type, so we can hoist this invariant condition out of the loop.
Differential Revision: https://reviews.llvm.org/D83882
Some of the system registers readable on AArch64 and ARM platforms
return different values with each read (for example a timer counter),
these shouldn't be hoisted outside loops or otherwise interfered with,
but the normal @llvm.read_register intrinsic is only considered to read
memory.
This introduces a separate @llvm.read_volatile_register intrinsic and
maps all system-registers on ARM platforms to use it for the
__builtin_arm_rsr calls. Registers declared with asm("r9") or similar
are unaffected.
The existing code already considered this case. Unfortunately a typo in
the condition prevents it from triggering. Also the existing code, had
it run, forgot to do the folding.
This fixes PR42876.
Differential Revision: https://reviews.llvm.org/D65802
ComputeNumSignBits and computeKnownBits both trigger "Scalable flag
may be dropped" warnings when a fixed length vector is extracted
from a scalable vector. This patch assumes nothing about the
demanded elements thus matching the behaviour when extracting a
scalable vector from a scalable vector.
Differential Revision: https://reviews.llvm.org/D83642
In DAGCombiner::TransformFPLoadStorePair we were dropping the scalable
property of TypeSize when trying to create an integer type of equivalent
size. In fact, this optimisation makes no sense for scalable types
since we don't know the size at compile time. I have changed the code
to bail out when encountering scalable type sizes.
I've added a test to
llvm/test/CodeGen/AArch64/sve-fp.ll
that exercises this code path. The test already emits an error if it
encounters warnings due to implicit TypeSize->uint64_t conversions.
Differential Revision: https://reviews.llvm.org/D83572
We have this generic transform in IR (instcombine),
but as shown in PR41098:
http://bugs.llvm.org/PR41098
...the pattern may emerge in codegen too.
x86 has a potential refinement/reversal opportunity here,
but that should come later or needs a target hook to
avoid the transform. Converting to bswap is the more
specific form, so we should use it if it is available.
This carves out an exception for a pair of consecutive loads that are
reversed from the consecutive order of a pair of stores. All of the
existing profitability/legality checks for the memops remain between
the 2 altered hunks of code.
This should give us the same x86 base-case asm that gcc gets in
PR41098 and PR44895:
http://bugs.llvm.org/PR41098http://bugs.llvm.org/PR44895
I think we are missing a potential subsequent conversion to use "movbe"
if the target supports that. That might be similar to what AArch64
would use to get "rev16".
Differential Revision: https://reviews.llvm.org/D83567
This carves out an exception for a pair of consecutive loads that are
reversed from the consecutive order of a pair of stores. All of the
existing profitability/legality checks for the memops remain between
the 2 altered hunks of code.
This should give us the same x86 base-case asm that gcc gets in
PR41098 and PR44895:i
http://bugs.llvm.org/PR41098http://bugs.llvm.org/PR44895
I think we are missing a potential subsequent conversion to use "movbe"
if the target supports that. That might be similar to what AArch64
would use to get "rev16".
Differential Revision:
Summary:
Helper used when splitting load & store operations to calculate
the pointer + offset for the high half of the split
Reviewers: efriedma, sdesmalen, david-arm
Reviewed By: efriedma
Subscribers: tschuett, hiraditya, psnobl, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D83577
fadd (fma A, B, (fmul C, D)), E --> fma A, B, (fma C, D, E)
This is only allowed when "reassoc" is present on the fadd.
As discussed in D80801, this transform goes beyond
what is allowed by "contract" FMF (-ffp-contract=fast).
That is because we are fusing the trailing add of 'E' with a
multiply, but without "reassoc", the code mandates that the
products A*B and C*D are added together before adding in 'E'.
I've added this example to the LangRef to try to clarify the
meaning of "contract". If that seems reasonable, we should
probably do something similar for the clang docs because
there does not appear to be any formal spec for the behavior
of -ffp-contract=fast.
Differential Revision: https://reviews.llvm.org/D82499
In DAGTypeLegalizer::SetSplitVector I have changed calls in the assert
from getVectorNumElements() to getVectorElementCount(), since this
code path works for both fixed and scalable vectors.
This fixes up one warning in the test:
sve-sext-zext.ll
Differential Revision: https://reviews.llvm.org/D83196
This patch replaces some invalid calls to getVectorNumElements() with calls
to getVectorMinNumElements() instead, since the code paths changed in this
patch work for both fixed and scalable vector types.
Fixes warnings in this test:
sve-sext-zext.ll
Differential Revision: https://reviews.llvm.org/D83203
Summary:
When legalizing a biscast operation from an fp16 operand to an i16 on a
target that requires both input and output types to be promoted to
32-bits, an assertion can fail when building the new node due to a
mismatch between the the operation's result size and the type specified to
the node.
This patches fix the issue by making sure the bit width of the types
match for the FP_TO_FP16 node, covering the difference with an extra
ANYEXTEND operation.
Reviewers: ostannard, efriedma, pirama, jmolloy, plotfi
Reviewed By: efriedma
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82552
This should be a typo introduced in D69275, which may cause an unknown
segment fault in getNode.
Reviewed By: uweigand
Differential Revision: https://reviews.llvm.org/D83376
9cac4e6d1403554b06ec2fc9d834087b1234b695/D32628 intended to eliminate
this, and move all isel pseudo expansion to FinalizeISel. This was a
bad rebase or something, and failed to actually delete this call.
GlobalISel also has a redundant call of finalizeLowering. However, it
requires more work to remove it since it currently triggers a lot of
verifier errors in tests.
It looks like 9cac4e6d14 accidentally
added a second copy of this from a bad rebase or something. This
second copy was added, and the finalizeLowering call was not deleted
as intended.
This removes existing code duplication and allows us to
assert that we are handling the expected cases.
We have a list of outstanding bugs that could benefit by
handling truncated source values, so that's a possible
addition going forward.
ExpandVectorBuildThroughStack is also used for CONCAT_VECTORS.
However, when calculating the offsets for each of the operands we
incorrectly use the element size rather than actual size and thus
the stores overlap.
Differential Revision: https://reviews.llvm.org/D83303
Summary:
The following combine currently breaks in the DAGCombiner:
```
extract_vector_elt (concat_vectors v4i16:a, v4i16:b), x
-> extract_vector_elt a, x
```
This happens because after we have combined these nodes we have inserted nodes
that use individual instances of the vector element type. In the above example
i16. However this isn't a legal type on all backends, and when the combining pass calls
the legalizer it breaks as it expects types to already be legal. The type legalizer has
already been run, and running it again would make a mess of the nodes.
In the example code at least, the generated code is still efficient after the change.
Reviewers: miyuki, arsenm, dmgreen, lebedev.ri
Reviewed By: miyuki, lebedev.ri
Subscribers: lebedev.ri, wdng, hiraditya, steven.zhang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D83231
In DAGTypeLegalizer::SplitVecRes_ExtendOp I have replaced an invalid
call to getVectorNumElements() with a call to getVectorMinNumElements(),
since the code path works for both fixed and scalable vectors.
This fixes up a warning in the following test:
sve-sext-zext.ll
Differential Revision: https://reviews.llvm.org/D83197
Calling getVectorNumElements() is not safe for scalable vectors and we
should normally use getVectorElementCount() instead. However, for the
code changed in this patch I decided to simply move the instantiation of
the variable 'OutNumElems' lower down to the place where only fixed-width
vectors are used, and hence it is safe to call getVectorNumElements().
Fixes up one warning in this test:
sve-sext-zext.ll
Differential Revision: https://reviews.llvm.org/D83195
`__stack_chk_fail` does not return, but `unreachable` was not generated
following `call __stack_chk_fail`. This had a possibility to generate an
invalid binary for functions with a return type, because
`__stack_chk_fail`'s return type is void and `call __stack_chk_fail` can
be the last instruction in the function whose return type is non-void.
Generating `unreachable` after it makes sure CFGStackify's
`fixEndsAtEndOfFunction` handles it correctly.
Reviewed By: tlively
Differential Revision: https://reviews.llvm.org/D83277
This is inspired by D81648. The basic idea is to have the set of SDValues which are lowered as either constants or direct frame references explicit in one place, and to separate them clearly from the spilling logic.
This is not NFC in that the handling of constants larger than > 64 bit has changed. The old lowering would crash on values which could not be encoded as a sign extended 64 bit value. The new lowering just spills all constants > 64 bits. We could be consistent about doing the sext(Con64) optimization, but I happen to know that this code path is utterly unexercised in practice, so simple is better for now.
Summary:
When splitting a store of a scalable type, the new address is
calculated in SplitVecOp_STORE using a vscale and an add instruction.
Reviewers: sdesmalen, efriedma, david-arm
Reviewed By: david-arm
Subscribers: tschuett, hiraditya, psnobl, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D83041
Summary:
When splitting a load of a scalable type, the new address is
calculated in SplitVecRes_LOAD using a vscale and an add instruction.
This patch also adds a DAG combiner fold to visitADD for vscale:
- Fold (add (vscale(C0)), (vscale(C1))) to (add (vscale(C0 + C1)))
Reviewers: sdesmalen, efriedma, david-arm
Reviewed By: david-arm
Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82792
This patch fixes all remaining warnings in:
llvm/test/CodeGen/AArch64/sve-trunc.ll
llvm/test/CodeGen/AArch64/sve-vector-splat.ll
I hit some warnings related to getCopyPartsToVector. I fixed two
issues:
1. In widenVectorToPartType() we assumed that we'd always be
using BUILD_VECTOR nodes to expand from one vector type to another,
which is incorrect for scalable vector types. I've fixed this for now
by simply bailing out immediately for scalable vectors.
2. In getCopyToPartsVector() I've changed the code to compare
the element counts of different types.
Differential Revision: https://reviews.llvm.org/D83028
X / (fabs(A) * sqrt(Z)) --> X / sqrt(A*A*Z) --> X * rsqrt(A*A*Z)
In the motivating case from PR46406:
https://bugs.llvm.org/show_bug.cgi?id=46406
...this is restoring the sequence that was originally in the source code.
We extracted a term from within the sqrt because we do not know in
instcombine whether a target will expand a sqrt call.
Note: we could say that the transform in IR should be restricted, but
that would not solve the problem if the source was originally in the
pattern shown here.
This is a gray area for fast-math-flag requirements. I think we should at
least check fast-math-flags on the fdiv and fmul because I view this
transform as 2 pieces: reassociate the fmul operands and form reciprocal
from the fdiv (as with the existing transform). We could argue that the
sqrt also needs FMF, but that was not required before, so we should change
that in a follow-up patch if that seems better.
We don't currently have a way to check that the target will produce a sqrt
or recip estimate without actually creating nodes (the APIs are SDValue
getSqrtEstimate() and SDValue getRecipEstimate()), so we clean up
speculatively created nodes if we are not able to create an estimate.
The x86 test with doubles verifies that we are not changing a test with
no estimate sequence.
Differential Revision: https://reviews.llvm.org/D82716
Use a simpler code sequence when the shift amount is known not to be
zero modulo the bit width.
Nothing much uses this until D77152 changes the translation of fshl and
fshr intrinsics.
Differential Revision: https://reviews.llvm.org/D82540
Using a negation instead of a subtraction from a constant can save an
instruction on some targets.
Nothing much uses this until D77152 changes the translation of fshl and
fshr intrinsics.
Differential Revision: https://reviews.llvm.org/D82539
We need to ensure that the sign bits of the result all match
so we can't fold to undef.
Similar to PR46585.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D83163
zext_vector_inreg needs to produces 0s in the extended bits and
sext_vector_inreg needs to produce upper bits that are all the
same. So we should fold them to a 0 vector instead of undef.
Fixes PR46585.
Currently matchBinOpReduction only handles shufflevector reduction patterns, but in many cases these only occur in the final stages of a reduction, once we're down to legal vector widths.
Before this its likely that we are performing reductions using subvector extractions to repeatedly split the source vector in half and perform the binop on the halves.
Assuming we've found a non-partial reduction, this patch continues looking for subvector reductions as far as it can beyond the last shufflevector.
Fixes PR37890
SelectionDAGBuilder converts logic-of-compares into multiple branches based
on a boolean TLI setting in isJumpExpensive(). But that probably never
considered the pattern of extracted bools from a vector compare - it seems
unlikely that we would want to turn vector logic into control-flow.
The motivating x86 reduction case is shown in PR44565:
https://bugs.llvm.org/show_bug.cgi?id=44565
...and that test shows the expected improvement from using pmovmsk codegen.
For AArch64, I modified the test to include an extra op because the simpler
test gets transformed by a codegen invocation of SimplifyCFG.
Differential Revision: https://reviews.llvm.org/D82602
There was a rogue 'assert' in AArch64ISelLowering for the tuple.get intrinsics,
that shouldn't really have been there (I suspect this was a remnant from when
we expected the wider vector always to have come from a vector CONCAT).
When I tried to create a more minimal reproducer, I found a bug in
DAGCombiner where it drops the scalable flag when trying to fold:
extract_subv (bitcast X), Index --> bitcast (extract_subv X, Index')
This patch fixes both issues.
Reviewers: david-arm, efriedma, spatel
Reviewed By: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D82910
Whilst trying to assemble the following test:
clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_set2.c
I discovered we were hitting some warnings about possible invalid
calls to getVectorNumElements() in getCopyToPartsVector(). I've
tried to fix these by using ElementCount types where possible and
I've made the assumption that we don't support using a fixed width
vector to copy parts of a scalable vector, and vice versa. Looking
at how the copy is implemented I think that's the right thing for
now.
Differential Revision: https://reviews.llvm.org/D82744
The caller can't handle the node having multiple results like a
masked load does. So we need to detect the case and do our own
result replacement.
Fixes PR46532.
In visitSCALAR_TO_VECTOR we try to optimise cases such as:
scalar_to_vector (extract_vector_elt %x)
into vector shuffles of %x. However, it led to numerous warnings
when %x is a scalable vector type, so for now I've changed the
code to only perform the combination on fixed length vectors.
Although we probably could change the code to work with scalable
vectors in certain cases, without a proper profit analysis it
doesn't seem worth it at the moment.
This change fixes up one of the warnings in:
llvm/test/CodeGen/AArch64/sve-merging-stores.ll
I've also added a simplified version of the same test to:
llvm/test/CodeGen/AArch64/sve-fp.ll
which already has checks for no warnings.
Differential Revision: https://reviews.llvm.org/D82872
Before this instruction supported output values, it fit fairly
naturally as a terminator. However, being a terminator while also
supporting outputs causes some trouble, as the physreg->vreg COPY
operations cannot be in the same block.
Modeling it as a non-terminator allows it to be handled the same way
as invoke is handled already.
Most of the changes here were created by auditing all the existing
users of MachineBasicBlock::isEHPad() and
MachineBasicBlock::hasEHPadSuccessor(), and adding calls to
isInlineAsmBrIndirectTarget or mayHaveInlineAsmBr, as appropriate.
Reviewed By: nickdesaulniers, void
Differential Revision: https://reviews.llvm.org/D79794
As per documentation of `hasPairLoad`:
"`RequiredAlignment` gives the minimal alignment constraints that must be met to be able to select this paired load."
In this sense, `0` is strictly equivalent to `1`. We make this obvious by using `Align` instead of unsigned.
There is only one implementor of this interface.
Differential Revision: https://reviews.llvm.org/D82958
It's perfectly valid to do certain DAG combines where we extract
subvectors from a concat vector when we have scalable vector types.
However, we can do this in a way that avoids generating compiler
warnings by replacing calls to getVectorNumElements() with
getVectorMinNumElements(). Due to the way subvector extracts are
designed to work with scalable vector types this is ok.
This eliminates some warnings from existing tests in this file:
llvm/test/CodeGen/AArch64/sve-intrinsics-loads.ll
Differential Revision: https://reviews.llvm.org/D82655
Fix a warning in getNode() when extracting a subvector from a
concat vector. We can simply replace the call to getVectorNumElements
with getVectorMinNumElements as this follows the defined behaviour
for EXTRACT_SUBVECTOR.
Differential Revision: https://reviews.llvm.org/D82746
When trying to reduce a BUILD_VECTOR to a SHUFFLE_VECTOR it's
important that we carefully check the vector types that led to
that BUILD_VECTOR. In the test I have attached to this commit
there is a case where the results of two SVE faddv instructions
are being stored to consecutive memory locations. With my fix,
as part of merging those stores we discover that each BUILD_VECTOR
element came from an extract of a SVE vector element and
therefore bail out.
Differential Revision: https://reviews.llvm.org/D82564
If a constant is only allsignbits in the demanded/active bits, then sign extend it to an allsignbits bool pattern for OR/XOR ops.
This also requires SimplifyDemandedBits XOR handling to be modified to call ShrinkDemandedConstant on any (non-NOT) XOR pattern to account for non-splat cases.
Next step towards fixing PR45808 - with this patch we now get a <-1,-1,0,0> v4i64 constant instead of <1,1,0,0>.
Differential Revision: https://reviews.llvm.org/D82257
Pre-commit for D82257, this adds a DemandedElts arg to ShrinkDemandedConstant/targetShrinkDemandedConstant which will allow future patches to (optionally) add vector support.
reduceBuildVecExtToExtBuildVec was breaking a splat(zext(x)) pattern into buildvector(x, 0, x, 0, ..) resulting in much more complex insert+shuffle codegen.
We already go to some lengths to avoid this in SimplifyDemandedVectorElts etc. when we encounter splat buildvectors.
It should be OK to fold all splat(aext(x)) patterns - we might need to tighten this if we find a case where we mustn't introduce a buildvector(x, undef, x, undef, ..) but I can't find one.
Fixes PR46461.
This lowers intrinsic @llvm.get.active.lane.mask to a setcc node, i.e. an icmp
ule, and creates vectors for its 2 arguments on which the comparison is
performed.
Differential Revision: https://reviews.llvm.org/D82292
Implement them on top of sdiv/udiv, similar to what we do for integer
types.
Potential future work: implementing i8/i16 srem/urem, optimizations for
constant divisors, optimizing the mul+sub to mls.
Differential Revision: https://reviews.llvm.org/D81511
Summary:
This patch adds base support for code generating fixed length
vector operations targeting a known SVE vector length. To achieve
this we lower fixed length vector operations to equivalent scalable
vector operations, whereby SVE predication is used to limit the
elements processed to those present within the fixed length vector.
Specifically this patch implements load and store operations, which
get lowered to their masked counterparts thusly:
V = load(Addr) =>
V = extract_fixed_vector(masked_load(make_pred(V.NumElts), Addr))
store(V, (Addr)) =>
masked_store(insert_fixed_vector(V), make_pred(V.NumElts), Addr))
Reviewers: rengolin, efriedma
Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80385
Summary:
- AssertAlign node records the guaranteed alignment on its source node,
where these alignments are retrieved from alignment attributes in LLVM
IR. These tracked alignments could help DAG combining and lowering
generating efficient code.
- In this patch, the basic support of AssertAlign node is added. So far,
we only generate AssertAlign nodes on return values from intrinsic
calls.
- Addressing selection in AMDGPU is revised accordingly to capture the
new (base + offset) patterns.
Reviewers: arsenm, bogner
Subscribers: jvesely, wdng, nhaehnle, tpr, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81711
We have many cases where we call SimplifyMultipleUseDemandedBits and demand specific vector elements, but all the bits from them - this adds a helper wrapper to handle this.
For little endian targets, if we only need the lowest element and none of the extended bits then we can just use the (bitcasted) source vector directly.
We already do this in SimplifyDemandedBits, this adds the SimplifyMultipleUseDemandedBits equivalent.
For now I have changed SimplifyDemandedBits and it's various callers
to assume we know nothing for scalable vectors and to ignore the
demanded bits completely. I have also done something similar for
SimplifyDemandedVectorElts. These changes fix up lots of warnings
due to calls to EVT::getVectorNumElements() for types with scalable
vectors. These functions are all used for optimisations, rather than
functional requirements. In future we can revisit this code if
there is a need to improve code quality for SVE.
Differential Revision: https://reviews.llvm.org/D80537
When trying to calculate the number of sign bits for scalable vectors
we should just bail out for now and pretend we know nothing.
Differential Revision: https://reviews.llvm.org/D81093
Summary:
Half-precision floating point arguments and returns are currently
promoted to either float or int32 in clang's CodeGen and there's
no existing support for the lowering of `half` arguments and returns
from IR in AArch32's backend.
Such frontend coercions, implemented as coercion through memory
in clang, can cause a series of issues in argument lowering, as causing
arguments to be stored on the wrong bits on big-endian architectures
and incurring in missing overflow detections in the return of certain
functions.
This patch introduces the handling of half-precision arguments and returns in
the backend using the actual "half" type on the IR. Using the "half"
type the backend is able to properly enforce the AAPCS' directions for
those arguments, making sure they are stored on the proper bits of the
registers and performing the necessary floating point convertions.
Reviewers: rjmccall, olista01, asl, efriedma, ostannard, SjoerdMeijer
Reviewed By: ostannard
Subscribers: stuij, hiraditya, dmgreen, llvm-commits, chill, dnsampaio, danielkiss, kristof.beyls, cfe-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D75169
Instead of asserting the number of elements is the same, we should be
comparing the element counts instead. In addition, when looking at
concats of extract_subvectors it's fine to use getVectorMinNumElements()
for scalable vectors.
I discovered these warnings when compiling the structured loads tests in
this file:
test/CodeGen/AArch64/sve-intrinsics-loads.ll
Differential Revision: https://reviews.llvm.org/D81936
Current implementation of division estimation isn't correct for some
cases like 1.0/0.0 (result is nan, not expected inf).
And this change exposes a potential infinite loop: we use
isConstOrConstSplatFP in combineRepeatedFPDivisors to look up if the
divisor is some constant. But it doesn't work after legalized on some
platforms. This patch restricts the method to act before LegalDAG.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D80542
Until we have a real need for computing known bits for scalable
vectors I have simply changed the code to bail out for now and
pretend we know nothing. I've also fixed up some simple callers of
computeKnownBits too.
Differential Revision: https://reviews.llvm.org/D80437
If fmul and fadd are separated by an fma, we can fold them together
to save an instruction:
fadd (fma A, B, (fmul C, D)), N1 --> fma(A, B, fma(C, D, N1))
The fold implemented here is actually a specialization - we should
be able to peek through >1 fma to find this pattern. That's another
patch if we want to try that enhancement though.
This transform was guarded by the TLI hook enableAggressiveFMAFusion(),
so it was done for some in-tree targets like PowerPC, but not AArch64
or x86. The hook is protecting against forming a potentially more
expensive computation when fma takes longer to execute than a single
fadd. That hook may be needed for other transforms, but in this case,
we are replacing fmul+fadd with fma, and the fma should never take
longer than the 2 individual instructions.
'contract' FMF is all we need to allow this transform. That flag
corresponds to -ffp-contract=fast in Clang, so we are allowed to form
fma ops freely across expressions.
Differential Revision: https://reviews.llvm.org/D80801
Summary:
The naked function attribute is meant to suppress all function
prologue/epilogue instructions.
On ARM, some are still emitted if an argument greater than 64 bytes in size
(the threshold for using the byval attribute in IR) is passed partially
in registers.
Perform the check for Attribute::Naked and early exit in
SelectionDAGISel::LowerArguments().
Checking in ARMFrameLowering::determineCalleeSaves() is too late.
A test case is included.
Reviewers: llvm-commits, olista01, danielkiss
Reviewed By: danielkiss
Subscribers: kristof.beyls, hiraditya, danielkiss
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80715
Change-Id: Icedecf2a4ad31bc3c35ab0df7489a9d346e1f7cc
Summary:
Note to downstream target maintainers: this might silently change the semantics of your code if you override `TargetLowering::allowsMemoryAccess` without marking it override.
This patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D81379
In two instances of CreateStackTemporary we are sometimes promoting
alignments beyond the stack alignment. I have introduced a new function
called getReducedAlign that will return the alignment for the broken
down parts of illegal vector types. For example, on NEON a <32 x i8>
type is made up of two <16 x i8> types - in this case the sensible
alignment is 16 bytes, not 32.
In the legalization code wherever we create stack temporaries I have
started using the reduced alignments instead for illegal vector types.
I added a test to
CodeGen/AArch64/build-one-lane.ll
that tries to insert an element into an illegal fixed vector type
that involves creating a temporary stack object.
Differential Revision: https://reviews.llvm.org/D80370
Just computing the alignment makes sense without caring about the
general known bits, such as for non-integral pointers. Separate the
two and start calling into the TargetLowering hooks for frame indexes.
Start calling the TargetLowering implementation for FrameIndexes,
which improves the AMDGPU matching for stack addressing modes. Also
introduce a new hook for returning known alignment of target
instructions. For AMDGPU, it would be useful to report the known
alignment implied by certain intrinsic calls.
Also stop using MaybeAlign.
This patch updates TargetLoweringBase::computeRegisterProperties and
TargetLoweringBase::getTypeConversion to support scalable vectors,
and make the right calls on how to legalise them. These changes are required
to legalise both MVTs and EVTs.
Reviewers: efriedma, david-arm, ctetreau
Reviewed By: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80640
Summary:
This patch adds legalisation of extensions where the operand
of the extend is a legal scalable type but the result is not.
EXTRACT_SUBVECTOR is used to split the result, before
being replaced by target-specific [S|U]UNPK[HI|LO] operations.
For example:
```
zext <vscale x 16 x i8> %a to <vscale x 16 x i16>
```
should emit:
```
uunpklo z2.h, z0.b
uunpkhi z1.h, z0.b
```
Reviewers: sdesmalen, efriedma, david-arm
Reviewed By: efriedma
Subscribers: tschuett, hiraditya, rkruppe, psnobl, huihuiz, cfe-commits, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79587
This wasn't getting much value from the DAG or depth arguments, since
it's only called on the frame index root nodes. FrameIndexes can also
only return a scalar value, so it also didn't need DemandedElts.
D79003/rG9fa58d1bf2f8 exposed an issue with scalarizeBinOpOfSplats that we were extracting from the splatted vector result instead of the source, the splat index is only valid for the source vector not the result, which may contain undefs, including at the splat index.
This reverts commit 21dadd774f.
In at least PromoteIntBinOps, they wanted to know about users of *all* values
produced by the node not just the integer being promoted. For example not
replacing chain users if the operation was a load breaks the ordering of the
DAG.
Summary:
This patch adds support for dumping .dot
representation of SelectionDAG. It is inspired from the fact that,
a developer may want to just dump the graph at
a predictable path with a simple name to compare.
The exisitng utility (i.e. viewGraph) are overkill
for this motive hence this patch adds the requires support
while using the core routines from GraphWriter.
Example usage: DAG.dumpDotGraph("/tmp/graph.dot", "MyGraph")
will create /tmp/graph.dot file when DAG is an
object of SelectionDAG class.
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D80711
To do so, I had to sink the old school inline operand handling into GCStatepointInst which is non ideal. This code should be removed shortly and I was able to at least clean it up a bunch.
If we're only demanding the (shifted) sign bits of the shift source value, then we can use the value directly.
This handles SimplifyDemandedBits/SimplifyMultipleUseDemandedBits for both ISD::SHL and X86ISD::VSHLI.
Differential Revision: https://reviews.llvm.org/D80869
This patch implements a target independent DAG combine to produce multiply-high
instructions from shifts. This DAG combine will combine shifts for any type as
long as the MULH on the narrow type is legal.
For now, it is enabled on PowerPC as PowerPC is the only target that has an
implementation of the isMulhCheaperThanMulShift TLI hook introduced in
D78271.
Moreover, this DAG combine focuses on catching the pattern:
(shift (mul (ext <narrow_type>:$a to <wide_type>), (ext <narrow_type>:$b to <wide_type>)), <narrow_width>)
to produce mulhs when we have a sign-extend, and mulhu when we have
a zero-extend.
The patch performs the following checks:
- Operation is a right shift arithmetic (sra) or logical (srl)
- Input to the shift is a multiply
- Both operands to the shift are sext/zext nodes
- The extends into the multiply are both the same
- The narrow type is half the width of the wide type
- The shift amount is the width of the narrow type
- The respective mulh operation is legal
Differential Revision: https://reviews.llvm.org/D78272
Do not spill UNDEF GC values. Instead, replace corresponding
gc.relocate intrinsic with an (arbitrary, but recognizable) constant.
Reviewed By: reames
Differential Revision: https://reviews.llvm.org/D80714
The AMDGPU non-strict fdiv lowering needs to introduce an FP mode
switch in some cases, and has custom nodes to provide chain/glue for
the intermediate FP operations. We need to propagate nofpexcept here,
but getNode was dropping the flags.
Adding nofpexcept in the AMDGPU custom lowering is left to a future
patch.
Also fix a second case where flags were dropped, but in this case it
seems it just didn't handle this number of operands.
Test will be included in future AMDGPU patch.
In some cases ScheduleDAGRRList has to add new nodes to resolve problems
with interfering physical registers. When new nodes are added, it
completely re-computes the topological order, which can take a long
time, but is unnecessary. We only add nodes one by one, and initially
they do not have any predecessors. So we can just insert them at the end
of the vector. Later we add predecessors, but the helper function
properly updates the topological order much more efficiently. With this
change, the compile time for the program below drops from 300s to 30s on
my machine.
define i11129 @test1() {
%L1 = load i11129, i11129* undef
%B30 = ashr i11129 %L1, %L1
store i11129 %B30, i11129* undef
ret i11129 %L1
}
This should be generally beneficial, as we can skip a large amount of
work. Theoretically there are some scenarios where we might not safe
much, e.g. when we add a dependency between the first and last node.
Then we would have to shift all nodes. But we still do not have to spend
the time re-computing the initial order.
Reviewers: MatzeB, atrick, efriedma, niravd, paquette
Reviewed By: paquette
Differential Revision: https://reviews.llvm.org/D59722
This code was repeated in two callers of CommitTargetLoweringOpt.
But CommitTargetLoweringOpt is also called from TargetLowering.
We should print a message for those calls to. So sink the
repeated code into CommitTargetLoweringOpt to catch those calls.
We are calling getValidShiftAmountConstant first followed by getValidMinimumShiftAmountConstant/getValidMaximumShiftAmountConstant if that failed. But both are used in the same way in ComputeNumSignBits and the Min/Max variants call getValidShiftAmountConstant internally anyhow.
Summary:
This caused incorrect debug information for parameters:
Previously, after a COPY of a parameter that changes the width,
we would emit a DBG_VALUE that continues to be associated to that
parameter, even though it now used a different width.
This made the LiveDebugValues pass assume the parameter value
got clobbered and it stopped tracking the parameter entry
value, leading to incorrect debug information.
Fixes https://bugs.llvm.org/show_bug.cgi?id=39715
Subscribers: aprantl, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80819
Let the codegen recognized the nomerge attribute and disable branch folding when the attribute is given
Differential Revision: https://reviews.llvm.org/D79537
optimizations
As discussed in the thread http://lists.llvm.org/pipermail/llvm-dev/2020-May/141838.html,
some bit field access width can be reduced by ReduceLoadOpStoreWidth, some
can't. If two accesses are very close, and the first access width is reduced,
the second is not. Then the wide load of second access will be stalled for long
time.
This patch add command line options to guard ReduceLoadOpStoreWidth and
ShrinkLoadReplaceStoreWithStore, so users can use them to disable these
store width reduction optimizations.
Differential Revision: https://reviews.llvm.org/D80745
Currently combineInsertEltToShuffle turns insert_vector_elt into a
vector_shuffle, even if the inserted element is a vector with a single
element. In this case, it should be unlikely that the additional shuffle
would be more efficient than a insert_vector_elt.
Additionally, this fixes a infinite cycle in DAGCombine, where
combineInsertEltToShuffle turns a insert_vector_elt into a shuffle,
which gets turned back into a insert_vector_elt/extract_vector_elt by
a custom AArch64 lowering (in visitVECTOR_SHUFFLE).
Such insert_vector_elt and extract_vector_elt combinations can be
lowered efficiently using mov on AArch64.
There are 2 test changes in arm64-neon-copy.ll: we now use one or two
mov instructions instead of a single zip1. The reason that we need a
second mov in ins1f2 is that we have to move the result to the result
register and is not really related to the DAGCombine fold I think.
But in any case, on most uarchs, mov should be cheaper than zip1. On a
Cortex-A75 for example, zip1 is twice as expensive as mov
(https://developer.arm.com/docs/101398/latest/arm-cortex-a75-software-optimization-guide-v20)
Reviewers: spatel, efriedma, dmgreen, RKSimon
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D80710
Summary:
The description of EXTACT_SUBVECTOR and INSERT_SUBVECTOR has been
changed to accommodate scalable vectors (see ISDOpcodes.h). This
patch updates the asserts used to verify these requirements when
using SelectionDAG's getNode interface.
This patch introduces the MVT function getVectorMinNumElements
that can be used against fixed-length and scalable vectors when
only the known minimum vector length is required.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D80709
We should be using getVectorElementCount() to assert that two types
have the same numbers of elements. I encountered the warnings while
compiling this test:
CodeGen/AArch64/sve-intrinsics-ld1.ll
Differential Revision: https://reviews.llvm.org/D80616
I have tried to ensure that SelectionDAG and DAGCombiner do
sensible things for scalable vectors, and added support for a
limited number of simple folds. Codegen support for the vector
extract patterns have also been added to the AArch64 backend.
New vector extract tests have been added here:
CodeGen/AArch64/sve-extract-element.ll
and I have also added new folds using inserts and extracts here:
CodeGen/AArch64/sve-insert-element.ll
Differential Revision: https://reviews.llvm.org/D80208
These are the two operand sets which are expected to survive more than another week or so. Instead of bothering to update the deopt and gc-transition operands, we'll just wait until those are removed and delete the code.
For those following along, this is likely to be the last (major) change in this sequence for about a week. I want to wait until all of this has been merged downstream to ensure I haven't introduced any bugs (and migrate some downstream code to the new interfaces). Once that's done, we should be able to delete Statepoint/ImmutableStatepoint without too much work.
I'd apparently only grepped in the lib directories and missed a few used in the Statepoint header itself. Beyond simple mechanical cleanup, changed the type of one routine to reflect the fact it also returns a statepoint.
Sinking logic around actual callee from Statepoint to GCStatepointInst. While doing so, adjust naming to be consistent about refering to "actual" callee and follow precedent on naming from CallBase otherwise.
Use the result to simplify one consumer. This is mostly just to ensure the new code is exercised, but is also a helpful cleanup on it's own.
While LazyBlockFrequencyInfo itself is lazy, the dominator tree
and loop info analyses it requires are not. Drop the dependency
on this pass in SelectionDAGIsel at O0.
This makes for a ~0.6% O0 compile-time improvement.
Differential Revision: https://reviews.llvm.org/D80387
Now that all of the statepoint related routines have classes with isa support, let's cleanup.
I'm leaving the (dead) utitilities in tree for a few days so that I can do the same cleanup downstream without breakage.
Can't test this since I can't directly use the default expansion for
AMDGPU. It needs to scale the amount by the wave size, rather than use
the raw byte size value.
In the current statepoint design, we have four distinct groups of operands to the call: call args, gc transition args, deopt args, and gc args. This format prexisted the support in IR for operand bundles and was in fact one of the inspirations for the extension. However, we never went back and rearchitected statepoints to fully leverage bundles.
This change is the first in a small sequence to do so. All this does is extend the SelectionDAG lowering code to allow deopt and gc transition operands to be specified in either inline argument bundles or operand bundles.
Differential Revision: https://reviews.llvm.org/D8059
This intrinsic implements IEEE-754 operation roundToIntegralTiesToEven,
and performs rounding to the nearest integer value, rounding halfway
cases to even. The intrinsic represents the missed case of IEEE-754
rounding operations and now llvm provides full support of the rounding
operations defined by the standard.
Differential Revision: https://reviews.llvm.org/D75670
binop (splat X), (splat C) --> splat (binop X, C)
binop (splat C), (splat X) --> splat (binop C, X)
We do this in IR, and there's a similar fold for the case with 2
non-constant operands just above the code diff in this patch.
This was discussed in D79718, and the extra shuffle in the test
(llvm/test/CodeGen/X86/vector-fshl-128.ll::sink_splatvar) where it
was noticed disappears because demanded elements analysis is no
longer blocked. The large majority of the test diffs seem to be
benign code scheduling changes, but I do see another type of win:
moving the splat later allows binop narrowing in some cases.
Regressions were avoided on x86 and ARM with the INSERT_VECTOR_ELT
restriction.
Differential Revision: https://reviews.llvm.org/D79886
For the supported binops (basic arithmetic, logicals + shifts), if we fail to simplify the demanded vector elts, then call SimplifyMultipleUseDemandedBits and try to peek through ops to remove unnecessary dependencies.
This helps with PR40502.
Differential Revision: https://reviews.llvm.org/D79003
For the 'inverse shift', we currently always perform a subtraction of the original (masked) shift amount.
But for the case where we are handling power-of-2 type widths, we can replace:
(sub bw-1, (and amt, bw-1) ) -> (and (xor amt, bw-1), bw-1) -> (and ~amt, bw-1)
This allows x86 shifts to fold away the and-mask.
Followup to D77301 + D80466.
http://volta.cs.utah.edu:8080/z/Nod0Gr
Differential Revision: https://reviews.llvm.org/D80489
This patch introduces a TargetLowering query, isMulhCheaperThanMulShift.
Currently in DAG Combine, it will transform mulhs/mulhu into a
wider multiply and a shift if the wide multiply is legal.
This TLI function is implemented on 64-bit PowerPC, as it is more desirable to
have multiply-high over multiply + shift for words and doublewords. Having
multiply-high can also aid in further transformations that can be done.
Differential Revision: https://reviews.llvm.org/D78271
Replace with forward declaration and move dependency down to source files that actually need it.
Both TargetLowering.h and TargetMachine.h are 2 of the most expensive headers (top 10) in the ClangBuildAnalyzer report when building llc.
If the caller needs to reponsible for making sure the MaybeAlign
has a value, then we should just make the caller convert it to an Align
with operator*.
I explicitly deleted the relational comparison operators that
were being inherited from Optional. It's unclear what the meaning
of two MaybeAligns were one is defined and the other isn't
should be. So make the caller reponsible for defining the behavior.
I left the ==/!= operators from Optional. But now that exposed a
weird quirk that ==/!= between Align and MaybeAlign required the
MaybeAlign to be defined. But now we use the operator== from
Optional that takes an Optional and the Value.
Differential Revision: https://reviews.llvm.org/D80455
Summary:
For some targets generic combines don't really do much and they
consume a disproportionate amount of time.
There's not really a mechanism in SDISel to tactically disable
combines, but we can have a switch to disable all of them and
let the targets just implement what they specifically need.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D79112
We do not have any special handling for constant FP deopt arguments.
They are just spilled to stack or generated in register by MOVS
instruction. This is inefficient and, when we have too many such
constant arguments, may result in register allocation failure.
Instead, we can bitcast such constant FP operands to appropriately
sized integer and record as constant into statepoint and later, into
StackMap.
Reviewed By: skatkov
Differential Revision: https://reviews.llvm.org/D80318
Will make it easier to pass the pointer info and alignment
correctly to the loads/stores.
While there also make the i32 stores independent and use a token
factor to join before the load.
Previously this code just used a default constructed
MachinePointerInfo. But we know the accesses are to a fixed stack
object or at least somewhere on the stack.
While there fix the alignment passed to the full vector load/stores.
I don't think this function is currently exercised in tree so I
don't know how to test it. I just noticed it when I removed
non-constant index support in this function.
Differential Revision: https://reviews.llvm.org/D80058
See https://reviews.llvm.org/D74651 for the preallocated IR constructs
and LangRef changes.
In X86TargetLowering::LowerCall(), if a call is preallocated, record
each argument's offset from the stack pointer and the total stack
adjustment. Associate the call Value with an integer index. Store the
info in X86MachineFunctionInfo with the integer index as the key.
This adds two new target independent ISDOpcodes and two new target
dependent Opcodes corresponding to @llvm.call.preallocated.{setup,arg}.
The setup ISelDAG node takes in a chain and outputs a chain and a
SrcValue of the preallocated call Value. It is lowered to a target
dependent node with the SrcValue replaced with the integer index key by
looking in X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to an
%esp adjustment, the exact amount determined by looking in
X86MachineFunctionInfo with the integer index key.
The arg ISelDAG node takes in a chain, a SrcValue of the preallocated
call Value, and the arg index int constant. It produces a chain and the
pointer fo the arg. It is lowered to a target dependent node with the
SrcValue replaced with the integer index key by looking in
X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to a
lea of the stack pointer plus an offset determined by looking in
X86MachineFunctionInfo with the integer index key.
Force any function containing a preallocated call to use the frame
pointer.
Does not yet handle a setup without a call, or a conditional call.
Does not yet handle musttail. That requires a LangRef change first.
Tried to look at all references to inalloca and see if they apply to
preallocated. I've made preallocated versions of tests testing inalloca
whenever possible and when they make sense (e.g. not alloca related,
inalloca edge cases).
Aside from the tests added here, I checked that this codegen produces
correct code for something like
```
struct A {
A();
A(A&&);
~A();
};
void bar() {
foo(foo(foo(foo(foo(A(), 4), 5), 6), 7), 8);
}
```
by replacing the inalloca version of the .ll file with the appropriate
preallocated code. Running the executable produces the same results as
using the current inalloca implementation.
Reverted due to unexpectedly passing tests, added REQUIRES: asserts for reland.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77689
See https://reviews.llvm.org/D74651 for the preallocated IR constructs
and LangRef changes.
In X86TargetLowering::LowerCall(), if a call is preallocated, record
each argument's offset from the stack pointer and the total stack
adjustment. Associate the call Value with an integer index. Store the
info in X86MachineFunctionInfo with the integer index as the key.
This adds two new target independent ISDOpcodes and two new target
dependent Opcodes corresponding to @llvm.call.preallocated.{setup,arg}.
The setup ISelDAG node takes in a chain and outputs a chain and a
SrcValue of the preallocated call Value. It is lowered to a target
dependent node with the SrcValue replaced with the integer index key by
looking in X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to an
%esp adjustment, the exact amount determined by looking in
X86MachineFunctionInfo with the integer index key.
The arg ISelDAG node takes in a chain, a SrcValue of the preallocated
call Value, and the arg index int constant. It produces a chain and the
pointer fo the arg. It is lowered to a target dependent node with the
SrcValue replaced with the integer index key by looking in
X86MachineFunctionInfo. In
X86TargetLowering::EmitInstrWithCustomInserter() this is lowered to a
lea of the stack pointer plus an offset determined by looking in
X86MachineFunctionInfo with the integer index key.
Force any function containing a preallocated call to use the frame
pointer.
Does not yet handle a setup without a call, or a conditional call.
Does not yet handle musttail. That requires a LangRef change first.
Tried to look at all references to inalloca and see if they apply to
preallocated. I've made preallocated versions of tests testing inalloca
whenever possible and when they make sense (e.g. not alloca related,
inalloca edge cases).
Aside from the tests added here, I checked that this codegen produces
correct code for something like
```
struct A {
A();
A(A&&);
~A();
};
void bar() {
foo(foo(foo(foo(foo(A(), 4), 5), 6), 7), 8);
}
```
by replacing the inalloca version of the .ll file with the appropriate
preallocated code. Running the executable produces the same results as
using the current inalloca implementation.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77689
We have the getNegatibleCost/getNegatedExpression to evaluate the cost and negate the expression.
However, during negating the expression, the cost might change as we are changing the DAG,
and then, hit the assertion if we negated the wrong expression as the cost is not trustful anymore.
This patch is target to remove the getNegatibleCost to avoid the out of sync with getNegatedExpression,
and check the cost during negating the expression. It also reduce the duplicated code between
getNegatibleCost and getNegatedExpression. And fix the crash for the test in D76638
Reviewed By: RKSimon, spatel
Differential Revision: https://reviews.llvm.org/D77319
Now that load/store alignment is required, we no longer need most
of them. Also switch the getLoadStoreAlignment() helper to return
Align instead of MaybeAlign.
We know the pointer somewhere on the stack, we just don't know
exactly where since the index may be variable.
Differential Revision: https://reviews.llvm.org/D80060
Along the lines of D77454 and D79968. Unlike loads and stores, the
default alignment is getPrefTypeAlign, to match the existing handling in
various places, including SelectionDAG and InstCombine.
Differential Revision: https://reviews.llvm.org/D80044
The code was calculating an offset from a stack pointer SDValue.
This is exactly what getMemBasePlusOffset does. I also replaced
sizeof(int) with a hardcoded 4. We know the type we're operating
on is 4 bytes. But the size of int that the source code is being
compiled with isn't guaranteed to be 4 bytes.
While here replace another use of getMemBasePlusOffset that was
proceeded with a call to getConstant with the other signature
that call getConstant internally.
This is D77454, except for stores. All the infrastructure work was done
for loads, so the remaining changes necessary are relatively small.
Differential Revision: https://reviews.llvm.org/D79968
For now I have changed FoldConstantVectorArithmetic to return early
if we encounter a scalable vector, since the subsequent code assumes
you can perform lane-wise constant folds. However, in future work we
should be able to extend this to look at splats of a constant value
and fold those if possible. I have also added the same code to
FoldConstantArithmetic, since that deals with vectors too.
The warnings I fixed in this patch were being generated by this
existing test:
CodeGen/AArch64/sve-int-arith.ll
Differential Revision: https://reviews.llvm.org/D79421
I've created a new variant of CreateStackTemporary that takes
TypeSize and Align arguments, and made the older instances of
CreateStackTemporary call this new function. This refactoring is
in preparation for more patches in this area related to scalable
vectors and improving the alignment calculations.
Differential Revision: https://reviews.llvm.org/D79933
The fact that loads and stores can have the alignment missing is a
constant source of confusion: code that usually works can break down in
rare cases. So fix the LoadInst API so the alignment is never missing.
To reduce the number of changes required to make this work, IRBuilder
and certain LoadInst constructors will grab the module's datalayout and
compute the alignment automatically. This is the same alignment
instcombine would eventually apply anyway; we're just doing it earlier.
There's a minor risk that the way we're retrieving the datalayout
could break out-of-tree code, but I don't think that's likely.
This is the last in a series of patches, so most of the necessary
changes have already been merged.
Differential Revision: https://reviews.llvm.org/D77454
Use an extra shift-by-1 instead of a compare and select to handle the
shift-by-zero case. This sometimes saves one instruction (if the compare
couldn't be combined with a previous instruction). It also works better
on targets that don't have good select instructions.
Note that currently this change doesn't affect most targets because
expandFunnelShift is not used because funnel shift intrinsics are
lowered early in SelectionDAGBuilder. But there is work afoot to change
that; see D77152.
Differential Revision: https://reviews.llvm.org/D77301
It sounds like an interesting idea in theory, but nothing is actually
taking advantage of it, and specifying/implementing the edge cases is
painful. So just forbid it.
Differential Revision: https://reviews.llvm.org/D79814
I have fixed up some places in SelectionDAG::getNode() where we
used to assert that the number of vector elements for two types
are the same. I have changed such cases to assert that the
element counts are the same instead. I've added new tests that
exercise the code paths for all the truncations. All the extend
operations are covered by this existing test:
CodeGen/AArch64/sve-sext-zext.ll
For the ISD::SETCC case I fixed this code path is exercised by
these existing tests:
CodeGen/AArch64/sve-fcmp.ll
CodeGen/AArch64/sve-intrinsics-int-compares-with-imm.ll
Differential Revision: https://reviews.llvm.org/D79399
allocas in LLVM IR have a specified alignment. When that alignment is
specified, the alloca has at least that alignment at runtime.
If the specified type of the alloca has a higher preferred alignment,
SelectionDAG currently ignores that specified alignment, and increases
the alignment. It does this even if it would trigger stack realignment.
I don't think this makes sense, so this patch changes that.
I was looking into this for SVE in particular: for SVE, overaligning
vscale'ed types is extra expensive because it requires realigning the
stack multiple times, or using dynamic allocation. (This currently isn't
implemented.)
I updated the expected assembly for a couple tests; in particular, for
arg-copy-elide.ll, the optimization in question does not increase the
alignment the way SelectionDAG normally would. For the rest, I just
increased the specified alignment on the allocas to match what
SelectionDAG was inferring.
Differential Revision: https://reviews.llvm.org/D79532
We have the getNegatibleCost/getNegatedExpression to evaluate the cost and negate the expression.
However, during negating the expression, the cost might change as we are changing the DAG,
and then, hit the assertion if we negated the wrong expression as the cost is not trustful anymore.
This patch is target to remove the getNegatibleCost to avoid the out of sync with getNegatedExpression,
and check the cost during negating the expression. It also reduce the duplicated code between
getNegatibleCost and getNegatedExpression. And fix the crash for the test in D76638
Reviewed By: RKSimon, spatel
Differential Revision: https://reviews.llvm.org/D77319
This patch stores the alignment for ConstantPoolSDNode as an
Align and updates the getConstantPool interface to take a MaybeAlign.
Removing getAlignment() will be done as a follow up.
Differential Revision: https://reviews.llvm.org/D79436
If the SimplifyMultipleUseDemandedBits calls BITCASTs that peek through back to the original type then we can remove the BITCASTs entirely.
Differential Revision: https://reviews.llvm.org/D79572
Summary:
This patch handles illegal scalable types when lowering IR operations,
addressing several places where the value of isScalableVector() is
ignored.
For types such as <vscale x 8 x i32>, this means splitting the
operations. In this example, we would split it into two
operations of type <vscale x 4 x i32> for the low and high halves.
In cases such as <vscale x 2 x i32>, the elements in the vector
will be promoted. In this case they will be promoted to
i64 (with a vector of type <vscale x 2 x i64>)
Reviewers: sdesmalen, efriedma, huntergr
Reviewed By: efriedma
Subscribers: david-arm, tschuett, hiraditya, rkruppe, psnobl, cfe-commits, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78812
Calling getShiftAmountTy with LegalTypes set may return a type that's too narrow to hold the shift amount for integer type it's applied to.
Fixes the regression introduced by D79096
Differential Revision: https://reviews.llvm.org/D79405
Try to combine N short vector cast ops into 1 wide vector cast op:
concat (cast X), (cast Y)... -> cast (concat X, Y...)
This is part of solving PR45794:
https://bugs.llvm.org/show_bug.cgi?id=45794
As noted in the code comment, this is uglier than I was hoping because
the opcode determines whether we pass the source or destination type
to isOperationLegalOrCustom(). Also IIUC, there's no way to validate
what the other (dest or src) type is. Without the extra legality check
on that, there's an ARM regression test in:
test/CodeGen/ARM/isel-v8i32-crash.ll
...that will crash trying to lower an unsupported v8f32 to v8i16.
Differential Revision: https://reviews.llvm.org/D79360
Summary:
I have fixed several places in getSplatSourceVector and isSplatValue
to work correctly with scalable vectors. I added new support for
the ISD::SPLAT_VECTOR DAG node as one of the obvious cases we can
support with scalable vectors. In other places I have tried to do
the sensible thing, such as bail out for vector types we don't yet
support or don't intend to support.
It's not possible to add IR test cases to cover these changes, since
they are currently only ever exercised on certain targets, e.g.
only X86 targets use the result of getSplatSourceVector. I've
assumed that X86 tests already exist to test these code paths for
fixed vectors. However, I have added some AArch64 unit tests that
test the specific functions I have changed.
Differential revision: https://reviews.llvm.org/D79083
We allocated a suitably aligned frame index so we know that all the values
have ABI alignment.
For MIPS this avoids using pair of lwl + lwr instructions instead of a
single lw. I found this when compiling CHERI pure capability code where
we can't use the lwl/lwr unaligned loads/stores and and were to falling
back to a byte load + shift + or sequence.
This should save a few instructions for MIPS and possibly other backends
that don't have fast unaligned loads/stores.
It also improves code generation for CodeGen/X86/pr34653.ll and
CodeGen/WebAssembly/offset.ll since they can now use aligned loads.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D78999
The two code paths have the same goal, legalizing a load of a non-byte-sized vector by loading the "flattened" representation in memory, slicing off each single element and then building a vector out of those pieces.
The technique employed by `ExpandLoad` is slightly more convoluted and produces slightly better codegen on ARM, AMDGPU and x86 but suffers from some bugs (D78480) and is wrong for BE machines.
Differential Revision: https://reviews.llvm.org/D79096
rL368553 added SimplifyMultipleUseDemandedBits handling for ISD::TRUNCATE to SimplifyDemandedBits so we don't need to duplicate this (and it gets rid of another GetDemandedBits call which is slowly being replaced with SimplifyMultipleUseDemandedBits anyhow).
Also fix some cost tables for vXi1 types to match the costs entries for the types they will be promoted to.
Differential Revision: https://reviews.llvm.org/D79045
X86 matches several 'shift+xor' funnel shift patterns:
fold (or (srl (srl x1, 1), (xor y, 31)), (shl x0, y)) -> (fshl x0, x1, y)
fold (or (shl (shl x0, 1), (xor y, 31)), (srl x1, y)) -> (fshr x0, x1, y)
fold (or (shl (add x0, x0), (xor y, 31)), (srl x1, y)) -> (fshr x0, x1, y)
These patterns are also what we end up with the proposed expansion changes in D77301.
This patch moves these to DAGCombine's generic MatchFunnelPosNeg.
All existing X86 test cases still pass, and we just have a small codegen change in pr32282.ll.
Reviewed By: @spatel
Differential Revision: https://reviews.llvm.org/D78935
Summary:
This patch tries to ensure that we do something sensible when
generating code for the ISD::INSERT_VECTOR_ELT DAG node when operating
on scalable vectors. Previously we always returned 'undef' when
inserting an element into an out-of-bounds lane index, whereas now
we only do this for fixed length vectors. For scalable vectors it
is assumed that the backend will do the right thing in the same way
that we have to deal with variable lane indices.
In this patch I have permitted a few basic combinations for scalable
vector types where it makes sense, but in general avoided most cases
for now as they currently require the use of BUILD_VECTOR nodes.
This patch includes tests for all scalable vector types when inserting
into lane 0, but I've only included one or two vector types for other
cases such as variable lane inserts.
Differential Revision: https://reviews.llvm.org/D78992
Call getNegatedExpression(Cost) and check the Cost to make the code more clear.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D78347
This method has been commented as deprecated for a while. Remove
it and replace all uses with the equivalent getCalledOperand().
I also made a few cleanups in here. For example, to removes use
of getElementType on a pointer when we could just use getFunctionType
from the call.
Differential Revision: https://reviews.llvm.org/D78882
Summary:
When generating code for the LLVM IR zeroinitialiser operation, if
the vector type is scalable we should be using SPLAT_VECTOR instead
of BUILD_VECTOR.
Differential Revision: https://reviews.llvm.org/D78636
This is a NFC patch for D77319. The idea is to hide the getNegatibleCost inside the getNegatedExpression()
to have it return null if the cost is expensive, and add some helper function for easy to use. And
rename the old getNegatedExpression to negateExpression to avoid the semantic conflict.
Reviewed By: RKSimon
Differential revision: https://reviews.llvm.org/D78291
Summary:
Given a VL=14 that is enveloped by a proper VL=16, splitting the
masked load using the enveloping halving VL=8/8 should yields
should eventually yield V=8/5. This fixes various assert failures
in getHalfNumVectorElementsVT() and IncrementMemoryAddress().
Note, I suspect similar fixes will be needed for other masked
operations, but for now I send out a fix for masked load only.
Bugzilla issue 45563
https://bugs.llvm.org/show_bug.cgi?id=45563
Reviewers: craig.topper, mehdi_amini, nicolasvasilache
Reviewed By: craig.topper
Subscribers: hiraditya, dmgreen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D78608
Using getValueType() is not correct for architectures extended with CHERI since
we need a pointer type and not the value that is loaded. While stack
protector is useless when you have CHERI (since CHERI provides much
stronger security guarantees), we still have a test to check that we can
generate correct code for checks. Merging b281138a1b
into our tree broke this test. Fix by using TLI.getFrameIndexTy().
Reviewed By: arsenm
Differential Revision: https://reviews.llvm.org/D77785
Summary:
The patch D29014 has added the new ISD::FREEZE and can deal with the
integer.
The patch D76980 has added SoftenFloatRes_FREEZE for float point.
But we still lack of expand for ppc_fp128, this will cause assertion for
some cases.
This patch is to support freeze expand for ppc_fp128.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D78278
Summary:
Remove asserting vector getters from Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.
Reviewers: dexonsmith, sdesmalen, efriedma
Reviewed By: efriedma
Subscribers: cfe-commits, hiraditya, llvm-commits
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D77278
This allows targets to know exactly which operands are contributing to
the dependency, which is required for targets with per-operand
scheduling models.
Differential Revision: https://reviews.llvm.org/D77135
I've always found the "findValue" a little odd and
inconsistent with other things in SDB.
This simplfifies the code in SDB to just handle a splat constant
address or a 2 operand GEP in the same BB. This removes the
need for "findValue" since the operands to the GEP are
guaranteed to be available. The splat constant handling is
new, but was needed to avoid regressions due to constant
folding combining GEPs created in CGP.
CGP is now responsible for canonicalizing gather/scatters into
this form. The pattern I'm using for scalarizing, a scalar GEP
followed by a GEP with an all zeroes index, seems to be subject
to constant folding that the insertelement+shufflevector was not.
Differential Revision: https://reviews.llvm.org/D76947
The "Align" passed into getMachineMemOperand etc. is the alignment of
the MachinePointerInfo, not the alignment of the memory operation.
(getAlign() on a MachineMemOperand automatically reduces the alignment
to account for this.)
We were passing on wrong (overconservative) alignment in a bunch of
places. Fix a bunch of these, mostly in legalization. And while I'm
here, switch to the new Align APIs.
The test changes are all scheduling changes: the biggest effect of
preserving large alignments is that it improves alias analysis, so the
scheduler has more freedom.
(I was originally just trying to do a minor cleanup in
SelectionDAGBuilder, but I accidentally went deeper down the rabbit
hole.)
Differential Revision: https://reviews.llvm.org/D77687
Summary:
No error or warning is emitted when specific reserved registers are
written to in inline assembly. Therefore, writes to the program counter
or to the frame pointer, for instance, were permitted, which could have
led to undesirable behaviour.
Example:
int foo() {
register int a __asm__("r7"); // r7 = frame-pointer in M-class ARM
__asm__ __volatile__("mov %0, r1" : "=r"(a) : : );
return a;
}
In contrast, GCC issues an error in the same scenario.
This patch detects writes to specific reserved registers in inline
assembly for ARM and emits an error in such case. The detection works
for output and input operands. Clobber operands are not handled here:
they are already covered at a later point in
AsmPrinter::emitInlineAsm(const MachineInstr *MI). The registers
covered are: program counter, frame pointer and base pointer.
This is ARM only. Therefore the implementation of other targets'
counterparts remain open to do.
Reviewers: efriedma
Reviewed By: efriedma
Subscribers: kristof.beyls, hiraditya, danielkiss, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76848
This is a minor NFC change to make the code more clear. We have the NegatibleCost that
has cheaper, neutral, and expensive. Typically, the smaller one means the less cost.
It is inverse for current implementation, which makes following code not easy to read.
If (CostX > CostY) negate(X)
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D77993
Since 1725f28841, this should check
isFMADLegalForFAddFSub rather than the the plain isOperationLegal.
This would assert in a subset of cases due to an oddity in how FMAD is
selected. We will allow FMA formation pre-legalize, but not FMAD even
in cases where it would be valid.
The current hook requires passing in the root fadd/fsub. However, in
this distributed case, this would be far more complicated to pass in
the relevant operand. AMDGPU doesn't get any value from the node, and
only needs the type and is the only implementor, so I'm not sure why
we have this complexity. Just rename and expand the assert to avoid
the more complicated checks spread through the distribution logic.
Sometimes LegalizeTypes knows about common subexpressions before SelectionDAG
does, leading to accidental SDValue removal before its reference count was
truly zero.
Differential Revision: https://reviews.llvm.org/D76994
Reviewed-By: bjope
Fixes: https://bugs.llvm.org/show_bug.cgi?id=45049
Reverted in 3ce77142a6 because the previous patch
broke the expensive-checks bots. The new patch removes the broken check.
As proposed in D77881, we'll have the related widening operation,
so this name becomes too vague.
While here, change the function signature to take an 'int' rather
than 'size_t' for the scaling factor, add an assert for overflow of
32-bits, and improve the documentation comments.
This is the same as what was done to the CallLoweringInfo in
TargetLowering.h in r309159.
This is just a step on the way to replacing this with CallBase.
I only left it at the interface to ParseConstraints since that
needs updates to other callers in different files. I'll do that
as a follow up.
Differential Revision: https://reviews.llvm.org/D77892
Summary:
Remove usages of asserting vector getters in Type in preparation for the
VectorType refactor. The existence of these functions complicates the
refactor while adding little value.
Reviewers: stoklund, sdesmalen, efriedma
Reviewed By: sdesmalen
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77272
Remove a number of includes that aren't necessary (nor are we relying on the remaining includes to provide the declarations), we just needed a llvm::Instruction forward declaration.
This exposed a couple of source files that were implicitly replying on the includes for their use of llvm::SmallSet or std::set, requiring local includes to be added there instead.
The change introduces the usage of physical registers for non-gc deopt values.
This require runtime support to know how to take a value from register.
By default usage is off and can be switched on by option.
The change also introduces additional fix-up patch which forces the spilling
of caller saved registers (clobbered after the call) and re-writes statepoint
to use spill slots instead of caller saved registers.
Reviewers: reames, danstrushin
Reviewed By: dantrushin
Subscribers: mgorny, hiraditya, mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D77797
The change introduces the usage of physical registers for non-gc deopt values.
This require runtime support to know how to take a value from register.
By default usage is off and can be switched on by option.
The change also introduces additional fix-up patch which forces the spilling
of caller saved registers (clobbered after the call) and re-writes statepoint
to use spill slots instead of caller saved registers.
Reviewers: reames, dantrushin
Reviewed By: reames, dantrushin
Subscribers: mgorny, hiraditya, mgrang, llvm-commits
Differential Revision: https://reviews.llvm.org/D77371
Summary:
There are at least three clients for KnownBits calculations:
ValueTracking, SelectionDAG and GlobalISel. To reduce duplication the
common logic should be moved out of these clients and into KnownBits
itself.
This patch does this for AND, OR and XOR calculations by implementing
and using appropriate operator overloads KnownBits::operator& etc.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74060
This removes a call to getScalarType from a bunch of call sites.
It also makes the behavior consistent with SIGN_EXTEND_INREG.
Differential Revision: https://reviews.llvm.org/D77631
These should not be assuming address space 0. Calling getPointerTy is
generally the wrong thing to do, since you should already know the
type from the incoming IR.
Move the logic whether lowering of deopt value requires a spill slot in
a separate lambda.
Reviewers: reames, dantrushin
Reviewed By: dantrushin
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D77629
Summary:
A bug report mentioned that LLVM was producing jumps off the end of a
function when using "asm goto with outputs". Further digging pointed to
MachineBasicBlocks that had their address taken and were indirect
targets of INLINEASM_BR being removed by BranchFolder, because their
predecessor list was empty, so they appeared to have no entry.
This was a cascading failure caused earlier, during Pre-RA instruction
scheduling. We have a few special cases in Pre-RA instruction scheduling
where we split a MachineBasicBlock in two. This requires careful
handing of predecessor and successor lists for a MachineBasicBlock that
was split, and careful handing of PHI MachineInstrs that referred to the
MachineBasicBlock before it was split.
The clue that led to this fix was the observation that many callers of
MachineBasicBlock::splice() frequently call
MachineBasicBlock::transferSuccessorsAndUpdatePHIs() to update their PHI
nodes after a splice. We don't want to reuse that method, as we have
custom successor transferring logic for this block split.
This patch fixes 2 pre-existing bugs, and adds tests.
The first bug was that MachineBasicBlock::splice() correctly handles
updating most successors and predecessors; we don't need to do anything
more than removing the previous fallthrough block from the first half of
the split block post splice. Previously, we were updating the successor
list incorrectly (updating successors updates predecessors).
The second bug was that PHI nodes that needed registers from the first
half of the split block were not having entries populated. The register
live out information was correct, and the FuncInfo->PHINodesToUpdate was
correct. Specifically, the check in SelectionDAGISel::FinishBasicBlock:
for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; ++i) {
MachineInstrBuilder PHI(*MF, FuncInfo->PHINodesToUpdate[i].first);
if (!FuncInfo->MBB->isSuccessor(PHI->getParent()))
continue;
PHI.addReg(FuncInfo->PHINodesToUpdate[i].second).addMBB(FuncInfo->MBB);
was `continue`ing because FuncInfo->MBB tracks the second half of
the post-split block; no one was updating PHI entries for the first half
of the post-split block.
SelectionDAGBuilder::UpdateSplitBlock() already expects to perform
special handling for MachineBasicBlocks that were split post calls to
ScheduleDAGSDNodes::EmitSchedule(), so I'm confident that it's both
correct for ScheduleDAGSDNodes::EmitSchedule() to return the second half
of the split block `CopyBB` which updates `FuncInfo->MBB` (ie. the
current MachineBasicBlock being processed), and perform special handling
for this in SelectionDAGBuilder::UpdateSplitBlock().
Reviewers: void, craig.topper, efriedma
Reviewed By: void, efriedma
Subscribers: hfinkel, fhahn, MatzeB, efriedma, hiraditya, llvm-commits, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76961
The previous code used the type of the first field for the VT
passed to getNode for every field.
I've based the implementation here off what is done in visitSelect
as it removes the need to special case aggregates.
Differential Revision: https://reviews.llvm.org/D77093
Summary:
This is a roll forward of D77394 minus AlignmentFromAssumptions (which needs to be addressed separately)
Differences from D77394:
- DebugStr() now prints the alignment value or `None` and no more `Align(x)` or `MaybeAlign(x)`
- This is to keep Warning message consistent (CodeGen/SystemZ/alloca-04.ll)
- Removed a few unneeded headers from Alignment (since it's included everywhere it's better to keep the dependencies to a minimum)
Reviewers: courbet
Subscribers: sdardis, hiraditya, jrtc27, atanasyan, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77537
We're ANDing with 1 right after which will cause the SIGN_EXTEND to
be combined to ANY_EXTEND later. Might as well just start with an
ANY_EXTEND.
While there replace create the AND using the getZeroExtendInReg
helper to remove the need to explicitly create the VecOnes constant.
This code is replacing a shift with a new shift on an extended type.
If the shift amount type can't represent the maximum shift amount
for the new type, the amount needs to be extended to a type that
can.
Previously, the code just hardcoded a check for 256 bits which
seems to have been an assumption that the original shift amount
was MVT::i8. But that seems more catered to a specific target
like X86 that uses i8 as its legal shift amount type. Other
targets may use different types.
This commit changes the code to look at the real type of the shift
amount and makes sure it has enough bits for the Log2 of the
new type. There are similar checks to this in SelectionDAGBuilder
and LegalizeIntegerTypes.
The newly-created constant zero will need an extra register to hold it
in the current statepoint lowering implementation. Remove it if there
exists one.
isGCValue should detect whether the deopt value is a GC pointer.
Currently it checks by finding the value in SI.Bases and SI.Ptrs.
However these data structures contain only those values which
have corresponding gc.relocate call. So we can miss GC value if it
does not have gc.relocate call (dead after the call).
Check GC strategy whether pointer is GC one or consider any pointer
to be GC one conservatively.
Reviewers: reames, dantrushin
Reviewed By: reames
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D77130
Summary:
Currently, the comparison argument used for ATOMIC_CMP_XCHG is legalised
with GetPromotedInteger, which leaves the upper bits of the value
undefind. Since this is used for comparing in an LR/SC loop with a
full-width comparison, we must sign extend it. We introduce a new
getExtendForAtomicCmpSwapArg to complement getExtendForAtomicOps, since
many targets have compare-and-swap instructions (or pseudos) that
correctly handle an any-extend input, and the existing function
determines the extension of the result, whereas we are concerned with
the input.
This is related to https://reviews.llvm.org/D58829, which solved the
issue for ATOMIC_CMP_SWAP_WITH_SUCCESS, but not the simpler
ATOMIC_CMP_SWAP.
Reviewers: asb, lenary, efriedma
Reviewed By: asb
Subscribers: arichardson, hiraditya, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, jfb, PkmX, jocewei, psnobl, benna, Jim, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, evandro, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74453
Currently, DAG combiner uses (fmul (rsqrt x) x) to estimate square
root of x. However, this method would return NaN if x is +Inf, which
is incorrect.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D76853
Summary: These were templated due to SelectionDAG using int masks for shuffles and IR using unsigned masks for shuffles. But now that D72467 has landed we have an int mask version of IRBuilder::CreateShuffleVector. So just use int instead of a template
Reviewers: spatel, efriedma, RKSimon
Reviewed By: efriedma
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D77183
Instead, represent the mask as out-of-line data in the instruction. This
should be more efficient in the places that currently use
getShuffleVector(), and paves the way for further changes to add new
shuffles for scalable vectors.
This doesn't change the syntax in textual IR. And I don't currently plan
to change the bitcode encoding in this patch, although we'll probably
need to do something once we extend shufflevector for scalable types.
I expect that once this is finished, we can then replace the raw "mask"
with something more appropriate for scalable vectors. Not sure exactly
what this looks like at the moment, but there are a few different ways
we could handle it. Maybe we could try to describe specific shuffles.
Or maybe we could define it in terms of a function to convert a fixed-length
array into an appropriate scalable vector, using a "step", or something
like that.
Differential Revision: https://reviews.llvm.org/D72467
Summary:
In method SelectionDAGBuilder::LowerStatepoint, array SI.GCTransitionArgs
is initialized from wrong part of ImmutableStatepoint class.
We copy gc args instead of transitions args.
Reviewers: reames, skatkov
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77075
Summary:
This code was throwing away the opcode for a boolean, which was then
reconstructing the opcode from that boolean. Just pass the opcode, and
forget the boolean.
Reviewers: srhines
Reviewed By: srhines
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77100
Summary:
This change adds amdgcn.reloc.constant intrinsic to the amdgpu backend, which will compile into a relocation entry in the resulting elf.
The intrinsics takes a MetadataNode (String) as its only argument, which specifies the symbol name of the relocation entry.
`SelectionDAGBuilder::getValueImpl` is changed to allow metadata operands passed through to ISel.
Author: csyonghe <yonghe@google.com>
Reviewers: tpr, nhaehnle
Reviewed By: nhaehnle
Subscribers: arsenm, kzhuravl, jvesely, wdng, yaxunl, dstuttard, t-tye, hiraditya, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76440
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: jyknight, sdardis, nemanjai, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, jfb, PkmX, jocewei, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D77059
Summary:
Also deprecate getOriginalAlignment, getAlignment will take much more time as it is pervasive through the codebase (including TableGened files).
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76933
There was already a test case for landingpads to handle this case, but I
had forgotten to consider PHI instructions preceding the EH_LABEL in the
landingpad.
PR45261
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: arsenm, dschuff, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, jrtc27, atanasyan, jfb, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76925
Summary: This patch is the first effort to adding basic optimizations for FREEZE in SelDag.
Reviewers: spatel, lebedev.ri
Reviewed By: spatel
Subscribers: xbolva00, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76707
These transforms rely on a vector reduction flag on the SDNode
set by SelectionDAGBuilder. This flag exists because SelectionDAG
can't see across basic blocks so SelectionDAGBuilder is looking
across and saving the info. X86 is the only target that uses this
flag currently. By removing the X86 code we can remove the flag
and the SelectionDAGBuilder code.
This pass adds a dedicated IR pass for X86 that looks across the
blocks and transforms the IR into a form that the X86 SelectionDAG
can finish.
An advantage of this new approach is that we can enhance it to
shrink the phi nodes and final reduction tree based on the zeroes
that we need to concatenate to bring the partially reduced
reduction back up to the original width.
Differential Revision: https://reviews.llvm.org/D76649
In some scalarize/split result methods (unary, binary, ...), flags in
SDNode were not passed down, which may lead to unexpected results in
unsafe float-point optimization. This patch fixes them. (maybe not
complete)
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D76832
I think we can save the MRI argument from these since it's in
GISelKnownBits already, but currently not accessible.
Implementation deferred to avoid dependency on other patches.
We have some long-standing missing shuffle optimizations that could
use this transform via VectorCombine now:
https://bugs.llvm.org/show_bug.cgi?id=35454
(and we still don't get that case in the backend either)
This function is apparently templated because there's existing code
in IR that treats mask values as unsigned and backend code that
treats masks values as signed.
The mask values are not endian-dependent (as shown by the existing
bitcast transform from DAGCombiner).
Differential Revision: https://reviews.llvm.org/D76508
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: dylanmckay, sdardis, nemanjai, hiraditya, kbarton, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76551
When decided whether to generate a post-inc load/store, look at the
other memory nodes that use the same base address and, if any proceed
the current node, then don't do the combine.
The change only seems to be affecting the Arm backend, which I was
surprised at, but it appears to fix a lot of our issues around MVE
masked load/stores having to store a temporary address after an early
post-increment on a shared base address.
Differential Revision: https://reviews.llvm.org/D75847
Extract the decision to combine into a post-inc address into a
couple of functions to make the logic more clear and re-usable.
Differential Revision: https://reviews.llvm.org/D76060
For folding pattern `x-(fma y,z,u*v) -> (fma -y,z,(fma -u,v,x))`, if
`yz` is 1, `uv` is -1 and `x` is -0, sign of result would be changed.
Differential Revision: https://reviews.llvm.org/D76419
Technically we can permit EXTLOAD of the LHS operand but only if all the extended bits are shifted out. Until we test coverage for that case, I'm just disabling this to fix PR45265.
Summary:
It can be the case that a vector type is legal but the corresponding
scalar type is not legal for an architecture (i8 vs. v16i8 on AArch64).
Check if the scalar type created when folding
truncate(build_vector(x,y)) -> build_vector(truncate(x),truncate(y))
is legal if we are running after the type legalizer.
This fixes https://github.com/android/ndk/issues/1207.
Reviewers: RKSimon, srhines
Subscribers: kristof.beyls, hiraditya, danielkiss, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76312
Summary:
For some reason the order in which we call getNegatedExpression
for the involved operands, after a call to isCheaperToUseNegatedFPOps,
seem to matter. This patch includes a new test case in
test/CodeGen/X86/fdiv.ll that crashes if we reverse the order of
those calls. Before this patch that could happen depending on
which compiler that were used when buildind llvm. With my GCC
version (7.4.0) I got the crash, because it seems like it is
using a different order for the argument evaluation compared
to clang.
All other users of isCheaperToUseNegatedFPOps already used this
pattern with unfolded/ordered calls to getNegatedExpression, so
this patch is aligning visitFDIV with the other use cases.
This patch simply deals with the non-determinism for FDIV. While
the underlying problem with getNegatedExpression is discussed
further in D76439.
Reviewers: spatel, RKSimon
Reviewed By: spatel
Subscribers: hiraditya, mgrang, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76319
Summary:
* Remove a bunch of asserts checking for unsupported scalable types and
add some more now that they are supported.
* Propagate the scalable flag where necessary.
* Add another `EVT::getExtendedVectorVT` method that takes an
ElementCount parameter.
* Add `EVT::isExtendedScalableVector` and
`EVT::getExtendedVectorElementCount` - latter is currently unused.
Reviewers: sdesmalen, efriedma, rengolin, craig.topper, huntergr
Reviewed By: efriedma
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75672
Gather/scatter don't access one memory location, they access multiple disjoint locations. So using a fixed size isn't accurate. But we don't have a way to represent the true behavior so just use UnknownSize.
Previously we "split" the memory VT and use that size for the MMO of each half. But the memory VT is scalar so splitting usually just returned the original scalar VT, but on 32-bit X86 if the scalar VT was i64 it probably returned i32?
Differential Revision: https://reviews.llvm.org/D76388
SelectionDAG CSEs nodes based on their result type and operands, but not their flags. The flags are expected to be intersected when they are CSEd. In SelectionDAGBuilder, for FP nodes we manage both the fast math flags and the nofpexcept flag after the nodes have already been CSEd when they were created with getNode. The management of the fastmath flags before the constrained nodes prevents the nofpexcept management from working correctly.
This commit moves the FMF handling for constrained intrinsics into their visitor and disables the common FMF handling for these nodes.
Differential Revision: https://reviews.llvm.org/D75224
If it is a*b-c*d, it could be also folded into fma(a, b, -c*d) or fma(-c, d, a*b).
This patch is trying to respect the uses of a*b and c*d to make the best choice.
Differential Revision: https://reviews.llvm.org/D75982
ISD::ROTL/ROTR rotation values are guaranteed to act as a modulo amount, so for power-of-2 bitwidths we only need the lowest bits.
Differential Revision: https://reviews.llvm.org/D76201
I believe we were previously calculating a pointer info with the scalar base and an offset of 0. But that's not really where the gather is pointing. The offset is a function of the indices of the GEP we looked through.
Also set the size of the MachineMemOperand to UnknownSize
Differential Revision: https://reviews.llvm.org/D76157
Under certain circumstances we'll end up in the position where the negated shift amount will get truncated to the type specified getScalarShiftAmountTy(), so we need to test for a truncated version of the shift amount as well.
This allows us to remove half of the remaining patterns tested for by X86ISelLowering's combineOrShiftToFunnelShift.
Followup to D75114, this patch reuses the existing MatchRotate ROTL/ROTR rotation pattern code to also recognize the more general FSHL/FSHR funnel shift patterns when we have variable shift amounts, matched with MatchFunnelPosNeg which acts in an (almost) equivalent manner to MatchRotatePosNeg.
Summary:
Using the default DAG.UnrollVectorOp on v16i8 and v8i16 vectors
results in i8 or i16 nodes being inserted into the SelectionDAG. Since
those are illegal types, this causes a legalization assertion failure
for some code patterns, as uncovered by PR45178. This change unrolls
shifts manually to avoid this issue by adding and using a new optional
EVT argument to DAG.ExtractVectorElements to control the type of the
extract_element nodes.
Reviewers: aheejin, dschuff
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76043
Summary:
This patch adds the following intrinsics for non-temporal gather loads
and scatter stores:
* aarch64_sve_ldnt1_gather_index
* aarch64_sve_stnt1_scatter_index
These intrinsics implement the "scalar + vector of indices" addressing
mode.
As opposed to regular and first-faulting gathers/scatters, there's no
instruction that would take indices and then scale them. Instead, the
indices for non-temporal gathers/scatters are scaled before the
intrinsics are lowered to `ldnt1` instructions.
The new ISD nodes, GLDNT1_INDEX and SSTNT1_INDEX, are only used as
placeholders so that we can easily identify the cases implemented in
this patch in performGatherLoadCombine and performScatterStoreCombined.
Once encountered, they are replaced with:
* GLDNT1_INDEX -> SPLAT_VECTOR + SHL + GLDNT1
* SSTNT1_INDEX -> SPLAT_VECTOR + SHL + SSTNT1
The patterns for lowering ISD::SHL for scalable vectors (required by
this patch) were missing, so these are added too.
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D75601
This is a reimplementation of the optimization removed in D75964. The actual spill/fill optimization is handled by D76013, this one just worries about reducing the stackmap section size itself by eliminating redundant entries. As noted in the comments, we could go a lot further here, but avoiding the degenerate invoke case as we did before is probably "enough" in practice.
Differential Revision: https://reviews.llvm.org/D76021
Summary:
callbr's indirect branches aren't expected to be taken, so reduce their
probabilities to 0 while increasing the default destination to 1. This
allows some code improvements through block placement.
Reviewers: nickdesaulniers
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72656
We just removed a broken duplicate elimination algorithm in D75964, and after landed that it occurred to me that duplicate elimination is simply CSE. SelectionDAG has a build in CSE, so why wasn't that triggering? Well, it turns out we were overly conservative in the memory states for our reloads and CSE (rightly) considers the incoming memory state for a load part of the identity of the load.
By loosening the chain and allowing reordering, we also allow CSE. As shown in the test case, doing iterative CSE as we go is enough to eliminate duplicate stores in later statepoints as well. We key our (block local) slot map by SDValue, so commoning a previous pair of loads at construction time means we also common following stores.
Differential Revision: https://reviews.llvm.org/D76013
This patch reuses the existing MatchRotate ROTL/ROTR rotation pattern code to also recognize the more general FSHL/FSHR funnel shift patterns when we have constant shift amounts.
Differential Revision: https://reviews.llvm.org/D75114
A downstream test case (see included reduced test) revealed that we have a bug in how we handle duplicate relocations. If we have the same SDValue relocated twice, and that value happens to be a constant (such as null), we only export one of the two llvm::Values. Exporting on a per llvm::Value basis is required to allow lowering of gc.relocates in following basic blocks (e.g. invokes). Without it, we end up with a use of an undefined vreg and bad things happen.
Rather than fixing the optimization - which appears to be hard - I propose we simply remove it. There are no tests in tree that change with this code removed. If we find out later that this did matter for something, we can reimplement a variation of this in CodeGenPrepare to catch the easy cases without complicating the lowering code.
Thanks to Denis and Serguei who did all the hard work of figuring out what went wrong here. The patch is by far the easy part. :)
Differential Revision: https://reviews.llvm.org/D75964
As noted on D75114, if both arguments of a funnel shift are consecutive loads we are missing the opportunity to combine them into a single load.
Differential Revision: https://reviews.llvm.org/D75624
PowerPC hits an assertion due to somewhat the same reason as https://reviews.llvm.org/D70975.
Though there are already some hack, it still failed with some case, when the operand 0 is NOT
a const fp, it is another fma that with const fp. And that const fp is negated which result in multi-uses.
A better fix is to check the uses of the negated const fp. If there are already use of its negated
value, we will have benefit as no extra Node is added.
Differential revision: https://reviews.llvm.org/D75501
As discussed in the commit thread for rGa253a2a and D73978, we can do more undef folding for FP ops.
The nnan and ninf fast-math-flags specify that if an operand is the disallowed value, the result is
poison, so we can produce an undef result.
But this doesn't work as expected (the undef operand cases remain) because of a Flags propagation
problem in SelectionDAGBuilder.
I've added DAGCombiner calls to enable these for the other cases because we've shown in other
patches that (because of the limited way that SDAG iterates), it is possible to miss simplifications
like this if they are done only at node creation time.
Several potential follow-ups to expand on this patch are possible.
Differential Revision: https://reviews.llvm.org/D75576
Summary:
Follow up from D75377. If the subvector is byte sized and the
index is aligned to the subvector size, we can shrink the load.
Reviewers: spatel, RKSimon
Reviewed By: RKSimon
Subscribers: dbabokin, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D75434
I expect that the isCondCodeLegal checks should match that CC of
the node that we're going to create.
Rewriting to a switch to minimize repeated mentions of the same
constants.
The address calculation for the offset assumes that you can calculate the offset by multiplying the index by the store size of the element. But that only works if the element's store size is exactly its real size since we store vectors tightly packed in memory. There are improvements we could make to this like special casing extracting element 0. I think we could also handle cases where the extracted VT is byte sized and the index is aligned with the extract element count.
Differential Revision: https://reviews.llvm.org/D75377
Select_cc isn't used by all targets. X86 doesn't have optimizations
for it.
Since we already know the input to the sint_to_fp/uint_to_fp is
a setcc we can just emit a plain select using that setcc as the
condition. Other DAG combines can turn that into a select_cc on
targets that support it.
Differential Revision: https://reviews.llvm.org/D75415
We get the simple cases of this via demanded elements and other folds,
but that doesn't work if the values have >1 use, so add a dedicated
match for the pattern.
We already have this transform in IR, but it doesn't help the
motivating x86 tests (based on PR42024) because the shuffles don't
exist until after legalization and other combines have happened.
The AArch64 test shows a minimal IR example of the problem.
Differential Revision: https://reviews.llvm.org/D75348
The alias analysis in DAG Combine looks at the BaseAlign, the Offset and
the Size of two accesses, and determines if they are known to access
different parts of memory by the fact that they are different offsets
from inside that "alignment window". It does not seem to account for
accesses that are not a multiple of the size, and may overflow from one
alignment window into another.
For example in the test case we have a 19byte memset that is splits into
a 16 byte neon store and an unaligned 4 byte store with a 15 byte
offset. This 15byte offset (with a base align of 8) wraps around to the
next alignment windows. When compared to an access that is a 16byte
offset (of the same 4byte size and 8byte basealign), the two accesses
are said not to alias.
I've fixed this here by just ensuring that the offsets are a multiple of
the size, ensuring that they don't overlap by wrapping. Fixes PR45035,
which was exposed by the UseAA changes in the arm backend.
Differential Revision: https://reviews.llvm.org/D75238
We can only report the knownbits for a SCALAR_TO_VECTOR node if we only demand the 0'th element - the upper elements are undefined and shouldn't be trusted.
This is causing a number of regressions that need addressing but we need to get the bugfix in first.
According to Joseph Myers, a libm maintainer
> They were only ever an ABI (selected by use of -ffinite-math-only or
> options implying it, which resulted in the headers using "asm" to redirect
> calls to some libm functions), not an API. The change means that ABI has
> turned into compat symbols (only available for existing binaries, not for
> anything newly linked, not included in static libm at all, not included in
> shared libm for future glibc ports such as RV32), so, yes, in any case
> where tools generate direct calls to those functions (rather than just
> following the "asm" annotations on function declarations in the headers),
> they need to stop doing so.
As a consequence, we should no longer assume these symbols are available on the
target system.
Still keep the TargetLibraryInfo for constant folding.
Differential Revision: https://reviews.llvm.org/D74712
This may inhibit vector narrowing in general, but there's
already an inconsistency in the way that we deal with this
pattern as shown by the test diff.
We may want to add a dedicated function for narrowing fneg.
It's often folded into some other op, so moving it away from
other math ops may cause regressions that we would not see
for normal binops.
See D73978 for more details.
This node reads the rounding control which means it needs to be ordered properly with operations that change the rounding control. So it needs to be chained to maintain order.
This patch adds a chain input and output to the node and connects it to the chain in SelectionDAGBuilder. I've update all in-tree targets to connect their chain through their lowering code.
Differential Revision: https://reviews.llvm.org/D75132
Summary:
Terminators in LLVM aren't prohibited from returning values. This means that
the "callbr" instruction, which is used for "asm goto", can support "asm goto
with outputs."
This patch removes all restrictions against "callbr" returning values. The
heavy lifting is done by the code generator. The "INLINEASM_BR" instruction's
a terminator, and the code generator doesn't allow non-terminator instructions
after a terminator. In order to correctly model the feature, we need to copy
outputs from "INLINEASM_BR" into virtual registers. Of course, those copies
aren't terminators.
To get around this issue, we split the block containing the "INLINEASM_BR"
right before the "COPY" instructions. This results in two cheats:
- Any physical registers defined by "INLINEASM_BR" need to be marked as
live-in into the block with the "COPY" instructions. This violates an
assumption that physical registers aren't marked as "live-in" until after
register allocation. But it seems as if the live-in information only
needs to be correct after register allocation. So we're able to get away
with this.
- The indirect branches from the "INLINEASM_BR" are moved to the "COPY"
block. This is to satisfy PHI nodes.
I've been told that MLIR can support this handily, but until we're able to
use it, we'll have to stick with the above.
Reviewers: jyknight, nickdesaulniers, hfinkel, MaskRay, lattner
Reviewed By: nickdesaulniers, MaskRay, lattner
Subscribers: rriddle, qcolombet, jdoerfert, MatzeB, echristo, MaskRay, xbolva00, aaron.ballman, cfe-commits, JonChesterfield, hiraditya, llvm-commits, rnk, craig.topper
Tags: #llvm, #clang
Differential Revision: https://reviews.llvm.org/D69868
This is the second patch as part of https://bugs.llvm.org/show_bug.cgi?id=36544
Merging in the ConstantSDNode variant of FoldConstantArithmetic. After this, I will begin merging in FoldConstantVectorArithmetic
I've ensured this patch can build & pass all lit tests in Windows and Linux environments.
Patch by @justice_adams (Justice Adams)
Differential Revision: https://reviews.llvm.org/D74881
Summary:
This patch adds intrinsics and ISelDAG nodes for signed
and unsigned fixed-point division:
```
llvm.sdiv.fix.sat.*
llvm.udiv.fix.sat.*
```
These intrinsics perform scaled, saturating division
on two integers or vectors of integers. They are
required for the implementation of the Embedded-C
fixed-point arithmetic in Clang.
Reviewers: bjope, leonardchan, craig.topper
Subscribers: hiraditya, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71550
A question about this behavior came up on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139003.html
...and as part of backend improvements in D73978.
We decided not to implement a more general change that would have
folded any FP binop with nearly arbitrary constant + undef operand
to undef because that is not theoretically correct (even if it is
practically correct).
This is the SDAG-equivalent to the IR change in D74713.
Use the SelectionDAG::getValidShiftAmountConstant helper to get const/constsplat shift amounts, which allows us to drop the out of range shift amount early-out.
First step towards better non-uniform shift amount support in SimplifyDemandedBits.
This includes both GEPs where the indexed type is a scalable vector, and
GEPs where the result type is a scalable vector.
Differential Revision: https://reviews.llvm.org/D73602
Similar to what we already do with SimplifyDemandedVectorElts, call SimplifyDemandedBits across all the extracted elements of the source vector, treating it as single use.
There's a minor regression in store-weird-sizes.ll which will be addressed in an upcoming SimplifyDemandedBits patch.
This reverts commit 649aba93a2, now that
the approach started there has been shown to be workable in the patch
series culminating in https://reviews.llvm.org/D74192.
This patch enables the debug entry values feature.
- Remove the (CC1) experimental -femit-debug-entry-values option
- Enable it for x86, arm and aarch64 targets
- Resolve the test failures
- Leave the llc experimental option for targets that do not
support the CallSiteInfo yet
Differential Revision: https://reviews.llvm.org/D73534
Summary:
Backends should fold the subtraction into the comparison, but not all
seem to. Moreover, on targets where pointers are not integers, such as
CHERI, an integer subtraction is not appropriate. Instead we should just
compare the two pointers directly, as this should work everywhere and
potentially generate more efficient code.
Reviewers: bogner, lebedev.ri, efriedma, t.p.northover, uweigand, sunfish
Reviewed By: lebedev.ri
Subscribers: dschuff, sbc100, arichardson, jgravelle-google, hiraditya, aheejin, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74454
These are going to be useful in TargetLowering::SimplifyDemandedBits, so expose these helpers outside of SelectionDAG.cpp
Also add an getValidShiftAmountConstant early-out to getValidMinimumShiftAmountConstant/getValidMaximumShiftAmountConstant so we can use them for scalar cases as well.
Summary:
This patch implements the part of the calling convention
where SVE Vectors are passed by reference. This means the
caller must allocate stack space for these objects and
pass the address to the callee.
Reviewers: efriedma, rovka, cameron.mcinally, c-rhodes, rengolin
Reviewed By: efriedma
Subscribers: tschuett, kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71216
This adds another pattern to the combiner for a case that we were not handling
to generate the REV16 instruction for ARM/Thumb2 and a bswap+ror on X86.
Differential Revision: https://reviews.llvm.org/D74032
Summary:
When using strict fp, it is required to update the
chain when performing integer type promotion of a
operand to a integer to floating point conversion.
Reviewers: craig.topper, john.brawn
Reviewed By: craig.topper
Subscribers: kristof.beyls, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74597
Patchable statepoint is lowered into sequence of nops, so zeroed call target
should not be on register. It is better to use getTargetConstant instead
of getConstant to select zero constant for call target.
Reviewers: reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D74465
Summary:
This was a very odd API, where you had to pass a flag into a zext
function to say whether the extended bits really were zero or not. All
callers passed in a literal true or false.
I think it's much clearer to make the function name reflect the
operation being performed on the value we're tracking (rather than on
the KnownBits Zero and One fields), so zext means the value is being
zero extended and new function anyext means the value is being extended
with unknown bits.
NFC.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74482
The isNegatibleForFree/getNegatedExpression methods currently rely on a raw char value to indicate whether a negation is beneficial or not.
This patch replaces the char return value with an NegatibleCost enum to more clearly demonstrate what is implied.
It also renames isNegatibleForFree to getNegatibleCost to more accurately reflect whats going on.
Differential Revision: https://reviews.llvm.org/D74221
This patch enables the debug entry values feature.
- Remove the (CC1) experimental -femit-debug-entry-values option
- Enable it for x86, arm and aarch64 targets
- Resolve the test failures
- Leave the llc experimental option for targets that do not
support the CallSiteInfo yet
Differential Revision: https://reviews.llvm.org/D73534
Summary:
The method attempts to find loads that can be legally clustered by
looking for loads consuming the same chain glue token.
However, the old code looks at _all_ users of values produced by the
chain node -- including uses of the loaded/returned value of volatile
loads or atomics. This could lead to circular dependencies which then
failed during scheduling.
With this change, we filter out users by getResNo, i.e. by which
SDValue value they use, to ensure that we only look at users of the
chain glue token.
This appears to be a rather old bug, which is perhaps surprising.
However, the test case is actually quite fragile (i.e., it is hidden
by fairly small changes), and the test _must_ use volatile loads for
the bug to manifest.
Reviewers: arsenm, bogner, craig.topper, foad
Subscribers: MatzeB, jvesely, wdng, hiraditya, javed.absar, jfb, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D74253
This adds a strict version of FP16_TO_FP and FP_TO_FP16 and uses
them to implement soft promotion for the half type. This is
enough to provide basic support for __fp16 with strictfp.
Add the necessary X86 support to use VCVTPS2PH/VCVTPH2PS when F16C
is enabled.
Add a simplification to fuse a manual vector extract with shifts and
truncate into a bitcast.
Unpacking and packing values into vectors is only optimized with
extractelement instructions, not when manually unpacked using shifts
and truncates.
This patch simplifies shifts and truncates into a bitcast if possible.
Simplify (build_vec (trunc $1)
(trunc (srl $1 width))
(trunc (srl $1 (2 * width))) ...)
to (bitcast $1)
Differential Revision: https://reviews.llvm.org/D73892
Remove code from LegalizeTypes that allowed this to work.
We were already using BUILD_PAIR for this in some places so this
standardizes on a single way to do this.
Summary:
For CTTZ we place a set bit just past where the non-promoted type
stopped so the extended bits won't be used for the count. For
CTTZ_ZERO_UNDEF we don't care what happens if no bits are set in
the original type and we end up counting into the extended bits.
So we can just use ANY_EXTEND for both cases.
This matches what is done in type legalization for these operations.
We make no effort to force the upper bits to zero.
Differential Revision: https://reviews.llvm.org/D74111
Add the isCandidateForCallSiteEntry predicate to MachineInstr to
determine whether a DWARF call site entry should be created for an
instruction.
For now, it's enough to have any call instruction that doesn't belong to
a blacklisted set of opcodes. For these opcodes, a call site entry isn't
meaningful.
Differential Revision: https://reviews.llvm.org/D74159
Summary: This patch introduces an API for MemOp in order to simplify and tighten the client code.
Reviewers: courbet
Subscribers: arsenm, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jsji, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73964
This reverts commit ed29dbaafa.
I'm backing out D68945, which as the discussion for D73526 shows, doesn't
seem to handle the -O0 path through the codegen backend correctly. I'll
reland the patch when a fix is worked out, apologies for all the churn.
The two parent commits are part of this revert too.
Conflicts:
llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/test/DebugInfo/X86/dbg-addr-dse.ll
SelectionDAGBuilder conflict is due to a nearby change in e39e2b4a79
that's technically unrelated. dbg-addr-dse.ll conflicted because
41206b61e3 (legitimately) changes the order of two lines.
There are further modifications to dbg-value-func-arg.ll: it landed after
the patch being reverted, and I've converted indirection to be represented
by the isIndirect field rather than DW_OP_deref.
This reverts commit 3137fe4d23.
I'm backing out D68945, which this patch is a follow up for. It'll be
re-landed when D68945 is fixed.
The changes to dbg-value-func-arg.ll occur because our handling of certain
kinds of location now mixes up indirection that happens at different points
in a DIExpression. While this is a regression, it's a return to the prior
behaviour while a better patch is sought.
This reverts commit 2d3174c4df.
The overall solution for this problem is reverting D68945, which wasn't
handling the -O0 path through the codegen backend correctly. See:
discussion in D73526.
Summary:
This reverts commit 3ef169e586. The
purpose of this commit was to allow stack machines to perform
instruction selection for instructions with variadic defs. However,
MachineInstrs fundamentally cannot support variadic defs right now, so
this change does not turn out to be useful.
Depends on D73927.
Reviewers: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73928
The CATCHPAD node mostly existed to be selected into the EH_RESTORE
instruction, which sets the frame back up when 32-bit Windows exceptions
return to the parent function. However, creating this MachineInstr early
increases the risk that other passes will come along and insert
instructions that use the stack before ESP and EBP are restored. That
happened in PR44697.
Instead of representing these in the instruction stream early, delay it
until PEI. Mark the blocks where this needs to happen as EHPads, but not
funclet entry blocks. Passes after PEI have to be careful not to hoist
instructions that can use stack across frame setup instructions, so this
should be relatively reliable.
Fixes PR44697
Reviewed By: hans
Differential Revision: https://reviews.llvm.org/D73752
AMDGPU and x86 at least both have separate controls for whether
denormal results are flushed on output, and for whether denormals are
implicitly treated as 0 as an input. The current DAGCombiner use only
really cares about the input treatment of denormals.
Ensure that OptLevelChanger::SavedFastISel is initialized in the constructor.
This should be NFC - as the equivalent 'same opt level' early-out is used in the destructor as well, so SavedFastISel is only actually referenced in the general case.
Differential Revision: https://reviews.llvm.org/D73875
Under MVE, we do not have any lowering for fminimum, which a
vector_reduce_fmin without NoNan will be expanded into. As with the
other recent patches, force this to expand in the pre-isel pass. Note
that Neon lowering would be OK because the scalar fminimum uses the
vector VMIN instruction, but is probably better to just rely on the
scalar operations, which is what is done here.
Also fixes what appears to be the reversal of INF vs -INF in the
vector_reduce_fmin widening code.
We have to be careful in SimplifyDemandedBits with loads in case we attempt to combine back to a constant (which then gets turned into a constant pool load again), but we can at least set the upper KnownBits for a ZEXTLoad to zero.
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: arsenm, dschuff, jyknight, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73885
Summary:
A Copy with a source that is zeros is the same as a Set of zeros.
This fixes the invariant that SrcAlign should always be non-null.
Reviewers: courbet
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73791
This is based on this llvm-dev thread http://lists.llvm.org/pipermail/llvm-dev/2019-December/137521.html
The current strategy for f16 is to promote type to float every except where the specific width is required like loads, stores, and bitcasts. This results in rounding occurring in odd places instead of immediately after arithmetic operations. This interacts in weird ways with the __fp16 type in clang which is a storage only type where arithmetic is always promoted to float. InstCombine can remove some fpext/fptruncs around such arithmetic and turn it into arithmetic on half. This wouldn't be so bad if SelectionDAG was able to put those fpext/fpround back in when it promotes.
It is also not obvious how to handle to make the existing strategy work with STRICT fp. We need to use STRICT versions of the conversions which require chain operands. But if the conversions are created for a bitcast, there is no place to get an appropriate chain from.
This patch implements a different strategy where conversions are emitted directly around arithmetic operations. And otherwise its passed around as an i16 including in arguments and return values. This can result in more conversions between arithmetic operations, but is closer to matching the IR the frontend generates for __fp16. And it will allow us to use the chain from constrained arithmetic nodes to link the STRICT_FP_TO_FP16/STRICT_FP16_TO_FP that will need to be added. I've set it up so that each target can opt into the new behavior. Converting all the targets myself was more than I was able to handle.
Differential Revision: https://reviews.llvm.org/D73749
This allows SimplifyDemandedBits to call SimplifyMultipleUseDemandedBits to create a simpler ISD::INSERT_SUBVECTOR, which is particularly useful for cases where we're splitting into subvectors anyhow.
Summary: This is a first step before changing the types to llvm::Align and introduce functions to ease client code.
Reviewers: courbet
Subscribers: arsenm, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, kerbowa, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73785
This patch addresses the issue found in https://bugs.llvm.org/show_bug.cgi?id=44585
where a DW_OP_deref was placed at the end of a dwarf expression, resulting in corrupt
symbols when debugging.
This is an attempt to reland with a few fixes for buildbot since I
haven't merged from master in a bit.
Differential Revision: https://reviews.llvm.org/D73526
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Summary:
This is a follow up on D61634. It adds an LLVM IR intrinsic to allow better implementation of memcpy from C++.
A follow up CL will add the intrinsics in Clang.
Reviewers: courbet, theraven, t.p.northover, jdoerfert, tejohnson
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71710
This allows SimplifyDemandedBits to call SimplifyMultipleUseDemandedBits to create a simpler ISD::EXTRACT_SUBVECTOR, which is particularly useful for cases where we're splitting into subvectors anyhow.
Differential Revision: This allows SimplifyDemandedBits to call SimplifyMultipleUseDemandedBits to create a simpler ISD::EXTRACT_SUBVECTOR, which is particularly useful for cases where we're splitting into subvectors anyhow.
and macro FUNCTION likewise. NFCI.
Some functions like fmuladd don't really have a node, we should divide
the declaration form those have node to avoid introducing fake nodes.
Differential Revision: https://reviews.llvm.org/D72871
Updated FoldConstantArithmetic method signature to match that of
FoldConstantVectorArithmetic in preparation for merging the two
functions together
https://bugs.llvm.org/show_bug.cgi?id=36544
This is the first step in combining the various
FoldConstantVectorArithmetic and FoldConstantVectorArithmetic
functions into one FoldConstantArithmetic function.
Differential Revision: https://reviews.llvm.org/D72870
Unlike the existing code that I modified here, I only handle the
case where the strict_fsetcc has a single use. Not sure exactly
how to handle multiples uses.
Testing this on X86 is hard because we already have a other
combines that get rid of lowered version of the integer setcc that
this xor will eventually become. So this combine really just
saves a bunch of extra nodes being created. Not sure about other
targets.
Differential Revision: https://reviews.llvm.org/D71816
Summary:
This is a follow up on https://reviews.llvm.org/D71473#inline-647262.
There's a caveat here that `Align(1)` relies on the compiler understanding of `Log2_64` implementation to produce good code. One could use `Align()` as a replacement but I believe it is less clear that the alignment is one in that case.
Reviewers: xbolva00, courbet, bollu
Subscribers: arsenm, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, hiraditya, kbarton, jrtc27, atanasyan, jsji, Jim, kerbowa, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D73099
Match the approach in SimplifyDemandedBits where we calculate the demanded elts and then have a common path for the ComputeKnownBits/ComputeNumSignBits call.
Match the approach in SimplifyDemandedBits/ComputeNumSignBits where we calculate the demanded elts and then have a common path for the ComputeKnownBits call.
Match the approach in SimplifyDemandedBits where we calculate the demanded elts and then have a common path for the ComputeKnownBits/ComputeNumSignBits call, additionally we only ever need original demanded elts of the base vector even if the index is unknown.
This patch also fixes up a number of cases in DAGCombine and
SelectionDAGBuilder where the size of a scalable vector is used in a
fixed-width context (thus triggering an assertion failure).
Reviewers: efriedma, c-rhodes, rovka, cameron.mcinally
Reviewed By: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71215
In LLVM IR, vscale can be represented with an intrinsic. For some targets,
this is equivalent to the constexpr:
getelementptr <vscale x 1 x i8>, <vscale x 1 x i8>* null, i32 1
This can be used to propagate the value in CodeGenPrepare.
In ISel we add a node that can be legalized to one or more
instructions to materialize the runtime vector length.
This patch also adds SVE CodeGen support for VSCALE, which maps this
node to RDVL instructions (for scaled multiples of 16bytes) or CNT[HSD]
instructions (scaled multiples of 2, 4, or 8 bytes, respectively).
Reviewers: rengolin, cameron.mcinally, hfinkel, sebpop, SjoerdMeijer, efriedma, lattner
Reviewed by: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D68203
Summary:
WebAssembly is unique among upstream targets in that it does not at
any point use physical registers to store values. Instead, it uses
virtual registers to model positions in its value stack. This means
that some target-independent lowering activities that would use
physical registers need to use virtual registers instead for
WebAssembly and similar downstream targets. This CL generalizes the
existing `usesPhysRegsForPEI` lowering hook to
`usesPhysRegsForValues` in preparation for using it in more places.
One such place is in InstrEmitter for instructions that have variadic
defs. On register machines, it only makes sense for these defs to be
physical registers, but for WebAssembly they must be virtual registers
like any other values. This CL changes InstrEmitter to check the new
target lowering hook to determine whether variadic defs should be
physical or virtual registers.
These changes are necessary to support a generalized CALL instruction
for WebAssembly that is capable of returning an arbitrary number of
arguments. Fully implementing that instruction will require additional
changes that are described in comments here but left for a follow up
commit.
Reviewers: aheejin, dschuff, qcolombet
Subscribers: sbc100, jgravelle-google, hiraditya, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D71484
This was unconditionally folding this to the source operand, even if the access was out of bounds. Use undef instead of the extract is not the first element.
This helps with some cases where 3-vectors are legalized and avoids processing the 4th component.
Original Patch by: arsenm (Matt Arsenault)
Differential Revision: https://reviews.llvm.org/D51589
Add DemandedElts handling to ISD::ANY_EXTEND and add missing ISD::ANY_EXTEND_VECTOR_INREG handling. Despite the lack of test changes this code IS being used - its just that the ANY_EXTEND ops are legalized later on (typically to ZERO_EXTEND equivalents) so we typically manage to combine later on.
The algorithm here only works if the sint_to_fp doesn't do any
rounding. Otherwise it can round before the offset fixup is
applied. Add an assert to protect this.
To avoid breaking the one test in tree that tested this code
with a set of types that fail the assert, I've enabled i32->f32
to use the i64->f32 algorithm. This only occurs when f64 isn't
a legal type. If f64 is legal then we do i32->f64->f32 instead.
Differential Revision: https://reviews.llvm.org/D72794
This was dropping the invariant metadata on dead argument loads, so
they weren't deleted.
Atomics still need to be fixed the same way. Also, apparently store
was never preserving dereferencable which should also be fixed.
Testing compiler-rt, a new assertion failure occurs when building
the GwpAsanTestObjects object. I'm uploading a reproducer to D70597.
This reverts commit 75188b01e9.
If there are DBG_VALUEs between phi and label (after phi and before label),
DBG_VALUE will block PHI lowering after the LABEL. Moving all DBG_VALUEs
after Labels in the function ScheduleDAGSDNodes::EmitSchedule to avoid
impacting PHI lowering.
before:
PHI
DBG_VALUE
LABEL
after: (move DBG_VALUE after label)
PHI
LABEL
DBG_VALUE
then: (phi lowering after label)
LABEL
COPY
DBG_VALUE
Fixes the issue: https://bugs.llvm.org/show_bug.cgi?id=43859
Differential Revision: https://reviews.llvm.org/D70597
This was moved in October 2018, but we don't appear to be using
this for vectors on any in tree target.
Moving it back simplifies D72794 so we can share the code for i32->f32.
This code is untested in tree because the "APFloat::semanticsPrecision(sem) >= SrcVT.getSizeInBits() - 1" check is false for most combinations for int and fp types except maybe i32 and f64. For that you would need i32 to be an illegal type, but f64 to be legal and have custom handling for legalizing the split sint_to_fp. The precision check itself was added in 2010 to fix a double rounding issue in the algorithm that would occur if the sint_to_fp was not able to do the conversion without rounding.
Differential Revision: https://reviews.llvm.org/D72728
Code in getRoot made the assumption that every node in PendingLoads
must always itself have a dependency on the current DAG root node.
After the changes in 04a8696, it turns out that this assumption no
longer holds true, causing wrong codegen in some cases (e.g. stores
after constrained FP intrinsics might get deleted).
To fix this, we now need to make sure that the TokenFactor created
by getRoot always includes the previous root, if there is no implicit
dependency already present.
The original getControlRoot code already has exactly this check,
so this patch simply reuses that code now for getRoot as well.
This fixes the regression.
NFC if no constrained FP intrinsic is present.
As mentioned by @nikic on rGef5debac4302, we can merge the guaranteed bottom zero bits from the shifted value, and then, if a min shift amount is known, zero out the bottom bits as well.
As mentioned by @nikic on rGef5debac4302 (although that was just about SHL), we can merge the guaranteed top zero bits from the shifted value, and then, if a min shift amount is known, zero out the top bits as well.
SHL tests / handling will be added in a follow up patch.
Summary:
be15dfa88f broke GlobalISel's usage of getSetCCInverse() which currently
appears to be limited to our out-of-tree backend. GlobalISel doesn't use
EVT's and isn't able to derive them from the information it has as it
doesn't distinguish between integer and floating point types (that
distinction is made by operations rather than values). Bring back the
bool version of getSetCCInverse() in a way that doesn't break the intent
of be15dfa88f but also allows GlobalISel to continue using it.
Reviewers: spatel, bogner, arichardson
Reviewed By: arichardson
Subscribers: rovka, hiraditya, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72309
Some target like arm/riscv with soft-float will have compiling crash when using -fno-unsafe-math-optimization option.
This patch will add the missing strict FP support to SoftenFloatRes_XINT_TO_FP.
Differential Revision: https://reviews.llvm.org/D72277
We need to ensure that fpexcept.strict nodes are not optimized away even if
the result is unused. To do that, we need to chain them into the block's
terminator nodes, like already done for PendingExcepts.
This patch adds two new lists of pending chains, PendingConstrainedFP and
PendingConstrainedFPStrict to hold constrained FP intrinsic nodes without
and with fpexcept.strict markers. This allows not only to solve the above
problem, but also to relax chains a bit further by no longer flushing all
FP nodes before a store or other memory access. (They are still flushed
before nodes with other side effects.)
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D72341
As detailed in https://blog.regehr.org/archives/1709 we don't make use of the known leading/trailing zeros for shifted values in cases where we don't know the shift amount value.
This patch adds support to SelectionDAG::ComputeKnownBits to use KnownBits::countMinTrailingZeros and countMinLeadingZeros to set the minimum guaranteed leading/trailing known zero bits.
Differential Revision: https://reviews.llvm.org/D72573
Custom legalization can produce MERGE_VALUES to return multiple
results. We can expand them immediately instead of leaving them
around for DAG combine to clean up.
Some of the simplest handlers just call TLI and if that fails,
they fall back to unrolling. For those just inline the TLI call
and share the unrolling call with the default case of Expand.
For ExpandFSUB and ExpandBITREVERSE so that its obvious they
don't return results sometimes and want to defer to LegalizeDAG.
Summary:
This always just used the same libcall as unordered, but the comparison predicate was different. This change appears to have been made when targets were given the ability to override the predicates. Before that they were hardcoded into the type legalizer. At that time we never inverted predicates and we handled ugt/ult/uge/ule compares by emitting an unordered check ORed with a ogt/olt/oge/ole checks. So only ordered needed an inverted predicate. Later ugt/ult/uge/ule were optimized to only call a single libcall and invert the compare.
This patch removes the ordered entries and just uses the inverting logic that is now present. This removes some odd things in both the Mips and WebAssembly code.
Reviewers: efriedma, ABataev, uweigand, cameron.mcinally, kpn
Reviewed By: efriedma
Subscribers: dschuff, sdardis, sbc100, arichardson, jgravelle-google, kristof.beyls, hiraditya, aheejin, sunfish, atanasyan, Petar.Avramovic, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D72536
ONE is currently softened to OGT | OLT. But the libcalls for OGT and OLT libcalls will trigger an exception for QNAN. At least for X86 with libgcc. UEQ on the other hand uses UO | OEQ. The UO and OEQ libcalls will not trigger an exception for QNAN.
This patch changes ONE to use the inverse of the UEQ lowering. So we now produce O & UNE. Technically the existing behavior was correct for a signalling ONE, but since I don't know how to generate one of those from clang that seemed like something we can deal with later as we would need to fix other predicates as well. Also removing spurious exceptions seemed better than missing an exception.
There are also problems with quiet OGT/OLT/OLE/OGE, but those are harder to fix.
Differential Revision: https://reviews.llvm.org/D72477
This system wasn't very well designed for multi-result nodes. As
a consequence they weren't consistently registered in the
LegalizedNodes map leading to nodes being revisited for different
results.
I've removed the "Result" variable from the main LegalizeOp method
and used a SDNode* instead. The result number from the incoming
Op SDValue is only used for deciding which result to return to the
caller. When LegalizeOp is called it should always register a
legalized result for all of its results. Future calls for any other
result should be pulled for the LegalizedNodes map.
Legal nodes will now register all of their results in the map
instead of just the one we were called for.
The Expand and Promote handling to use a vector of results similar
to LegalizeDAG. Each of the new results is then re-legalized and
logged in the LegalizedNodes map for all of the Results for the
node being legalized. None of the handles register their own
results now. And none call ReplaceAllUsesOfValueWith now.
Custom handling now always passes result number 0 to LowerOperation.
This matches what LegalizeDAG does. Since the introduction of
STRICT nodes, I've encountered several issues with X86's custom
handling being called with an SDValue pointing at the chain and
our custom handlers using that to get a VT instead of result 0.
This should prevent us from having any more of those issues. On
return we will update the LegalizedNodes map for all results so
we shouldn't call the custom handler again for each result number.
I want to push SDNode* further into the Expand and Promote
handlers, but I've left that for a follow to keep this patch size
down. I've created a dummy SDValue(Node, 0) to keep the handlers
working.
Differential Revision: https://reviews.llvm.org/D72224
In D71841 we inverted the sense of the SDNode-level flag to ensure all nodes
default to potentially raising FP exceptions unless otherwise specified --
i.e. if we forget to propagate the flag somewhere, the effect is now only
lost performance, not incorrect code.
However, the related flag at the MI level still defaults to nodes not raising
FP exceptions unless otherwise specified. To be fully on the (conservatively)
safe side, we should invert that flag as well.
This patch does so by replacing MIFlag::FPExcept with MIFlag::NoFPExcept.
(Note that this does also introduce an incompatible change in the MIR format.)
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D72466
Only PPC seems to be using it, and only checks some simple cases and
doesn't distinguish between FP. Just switch to using LLT to simplify
use from GlobalISel.
If we're doing a compare that only tests the sign bit and only the sign bit is demanded, we can just bypass the node. This removes one of the blend dependencies in our v2i64->v2f32 uint_to_fp codegen on pre-sse4.2 targets.
Differential Revision: https://reviews.llvm.org/D72356
If we are extracting a chunk of a vector that's a fraction of an
operand of the concatenated vector operand, we can extract directly
from one of those original operands.
This is another suggestion from PR42024:
https://bugs.llvm.org/show_bug.cgi?id=42024#c2
But I'm not sure yet if it will make any difference on those patterns.
It seems to help a few existing AVX512 tests though.
Differential Revision: https://reviews.llvm.org/D72361
This is a positive combination as long as the NEG is NOT free,
as we are reducing the number of NEG from two to one.
Differential Revision: https://reviews.llvm.org/D72312
Summary:
Added MIRFormatter for target specific MIR formating and parsing with
immediate and custom pseudo source values. Target machine can subclass
MIRFormatter and implement custom logic for printing and parsing
immediate and custom pseudo source values for better readability.
* Target specific immediate mnemonic need to start with "." follows by
identifier string. When MIR parser sees immediate it will call target
specific parsing function.
* Custom pseudo source value need to start with custom follows by
double-quoted string. MIR parser will pass the quoted string to target
specific PSV parsing function.
* MIRFormatter have 2 helper functions to facilitate LLVM value printing
and parsing for custom PSV if they refers LLVM values.
Patch by Peng Guo
Reviewers: dsanders, arsenm
Reviewed By: dsanders
Subscribers: wdng, jvesely, nhaehnle, hiraditya, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69836
Summary:
Added MIRFormatter for target specific MIR formating and parsing with
immediate and custom pseudo source values. Target machine can subclass
MIRFormatter and implement custom logic for printing and parsing
immediate and custom pseudo source values for better readability.
* Target specific immediate mnemonic need to start with "." follows by
identifier string. When MIR parser sees immediate it will call target
specific parsing function.
* Custom pseudo source value need to start with custom follows by
double-quoted string. MIR parser will pass the quoted string to target
specific PSV parsing function.
* MIRFormatter have 2 helper functions to facilitate LLVM value printing
and parsing for custom PSV if they refers LLVM values.
Reviewers: dsanders, arsenm
Reviewed By: dsanders
Subscribers: wdng, jvesely, nhaehnle, hiraditya, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69836
Summary:
This patch adds intrinsics and ISelDAG nodes for
signed and unsigned fixed-point division:
llvm.sdiv.fix.*
llvm.udiv.fix.*
These intrinsics perform scaled division on two
integers or vectors of integers. They are required
for the implementation of the Embedded-C fixed-point
arithmetic in Clang.
Patch by: ebevhan
Reviewers: bjope, leonardchan, efriedma, craig.topper
Reviewed By: craig.topper
Subscribers: Ka-Ka, ilya, hiraditya, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70007
Summary:
Remove the restrictions that preventing "asm goto" from returning non-void
values. The values returned by "asm goto" are only valid on the "fallthrough"
path.
Reviewers: jyknight, nickdesaulniers, hfinkel
Reviewed By: jyknight, nickdesaulniers
Subscribers: rsmith, hiraditya, llvm-commits, cfe-commits, craig.topper, rnk
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D69876
This is possibly a small part towards solving PR42024:
https://bugs.llvm.org/show_bug.cgi?id=42024
The vectorizer is creating shuffles of concat like this:
%63 = shufflevector <4 x i64> %x, <4 x i64> undef, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 0, i32 1, i32 2, i32 3>
%64 = shufflevector <8 x i64> %63, <8 x i64> undef, <8 x i32> <i32 0, i32 4, i32 1, i32 5, i32 2, i32 6, i32 3, i32 7>
That might be fixable in the vectorizers, but we're not allowed to fold that into a single shuffle in instcombine,
so we should have a backend backstop to convert that into the likely simpler form:
%64 = shufflevector <4 x i64> %x, <4 x i64> undef, <8 x i32> <i32 0, i32 0, i32 1, i32 1, i32 2, i32 2, i32 3, i32 3>
Differential Revision: https://reviews.llvm.org/D72300
This patch adds widening which really just scalarizes because we don't have a strategy for the extra elements we would need to pad with.
Differential Revision: https://reviews.llvm.org/D72193
This isn't a functonal change since we also check the bit width is the
same and the input type is integer. This guarantees the input and
output type are the same. But passing the input type makes the code
more readable.
This is the DAG node for SIGN_EXTEND_INREG :
t21: v4i32 = sign_extend_inreg t18, ValueType:ch:v4i16
It has two operands. The first one is the value it want to extend, and the second
one is the type to specify how to extend the value. For this example, it means
that, it is signed extend the t18(v4i32) from v4i16 to v4i32. That is
the semantics of c code:
vector int foo(vector int m) {
return m << 16 >> 16;
}
And it could be any vector type that hardware support the operation, though
the type 'v4i16' is NOT legal for the target. When we are trying to combine
the srl + sra, what we did now is calling the TLI.isOperationLegal(), which
will also check the legality of the type. That doesn't make sense.
Differential Revision: https://reviews.llvm.org/D70230
The code here isn't great in all caess. Particularly v4f64->v4i32
on 64-bit AVX targets. But there is some improvement in some
configurations.
There's definitely some issues with computeNumSignBits with
X86ISD::STRICT_FCMP. As well as not being able to propagate sign
bits through merge_values nodes that get created during custom
legalization.
Previously, for vectors we created a vselect with a condition that
didn't match what the target wanted according to getSetCCResultType.
To make up for this, X86 had a special DAG combine to detect if
the condition was all sign bits and then insert its own truncate
or extend. By adding the extend/truncate here explicitly we can
avoid that.
ExpandStrictFPOp calls ExpandUINT_TO_FLOAT. Previously, ExpandUINT_TO_FLOAT
returned SDValue() if it wasn't able to handle and needed to unroll.
Then ExpandStrictFPOp would detect his SDValue() and do the unroll.
After this change, ExpandUINT_TO_FLOAT will directly call
UnrollStrictFPOp and return the unrolled result.
This patch attempts to peek through vectors based on the demanded bits/elt of a particular ISD::EXTRACT_VECTOR_ELT node, allowing us to avoid dependencies on ops that have no impact on the extract.
In particular this helps remove some unnecessary scalar->vector->scalar patterns.
The wasm shift patterns are annoying - @tlively has indicated that the wasm vector shift codegen are to be refactored in the near-term and isn't considered a major issue.
Reapplied after reversion at rL368660 due to PR42982 which was fixed at rGca7fdd41bda0.
Differential Revision: https://reviews.llvm.org/D65887
UpdateNodeOperands might CSE to another existing node. So we should make sure we're legalizing that node otherwise we might fail to hook up the operands properly. I've moved the result registration up to the caller to avoid having to pass both Result and Op into the functions where it might be confusing which is which.
This address 2 other issues pointed out in D71861.
Differential Revision: https://reviews.llvm.org/D72021
When the "disable-tail-calls" attribute was added, checks were added for
it in various backends. Now this code has proliferated, and it is
something the target is responsible for checking. Move that
responsibility back to the ISels (fast, global, and SD).
There's no major functionality change, except for targets that never
implemented this check.
This LLVM attribute was originally added in
d9699bc7bd (2015).
Reviewers: echristo, MaskRay
Differential Revision: https://reviews.llvm.org/D72118
The fold 'A - (A & (B - 1))' -> 'A & (0 - B)'
added in 8dab0a4a7d
is too specific. It should/can just be 'A - (A & B)' -> 'A & (~B)'
Even if we don't manage to fold `~` into B,
we have likely formed `ANDN` node.
Also, this way there's less similar-but-duplicate folds.
Name: X - (X & Y) -> X & (~Y)
%o = and i32 %X, %Y
%r = sub i32 %X, %o
=>
%n = xor i32 %Y, -1
%r = and i32 %X, %n
https://rise4fun.com/Alive/kOUl
See
https://bugs.llvm.org/show_bug.cgi?id=44448https://reviews.llvm.org/D71499
The fold 'A - (A & (B - 1))' -> 'A & (0 - B)'
added in 8dab0a4a7d
is too specific. It should just be 'A - (A & B)' -> 'A & (~B)',
but we currently fail to sink that '~' into `(B - 1)`.
Name: ~(X - 1) -> (0 - X)
%o = add i32 %X, -1
%r = xor i32 %o, -1
=>
%r = sub i32 0, %X
https://rise4fun.com/Alive/rjU
While we do manage to fold integer-typed IR in middle-end,
we can't do that for the main motivational case of pointers.
There is @llvm.ptrmask() intrinsic which may or may not be helpful,
but i'm not sure it is fully considered canonical yet,
not everything is fully aware of it likely.
Name: PR44448 ptr - (ptr & C) -> ptr & (~C)
%bias = and i32 %ptr, C
%r = sub i32 %ptr, %bias
=>
%r = and i32 %ptr, ~C
See
https://bugs.llvm.org/show_bug.cgi?id=44448https://reviews.llvm.org/D71499
While we do manage to fold integer-typed IR in middle-end,
we can't do that for the main motivational case of pointers.
There is @llvm.ptrmask() intrinsic which may or may not be helpful,
but i'm not sure it is fully considered canonical yet,
not everything is fully aware of it likely.
https://rise4fun.com/Alive/ZVdp
Name: ptr - (ptr & (alignment-1)) -> ptr & (0 - alignment)
%mask = add i64 %alignment, -1
%bias = and i64 %ptr, %mask
%r = sub i64 %ptr, %bias
=>
%highbitmask = sub i64 0, %alignment
%r = and i64 %ptr, %highbitmask
See
https://bugs.llvm.org/show_bug.cgi?id=44448https://reviews.llvm.org/D71499
The NoFPExcept bit in SDNodeFlags currently defaults to true, unlike all
other such flags. This is a problem, because it implies that all code that
transforms SDNodes without copying flags can introduce a correctness bug,
not just a missed optimization.
This patch changes the default to false. This makes it necessary to move
setting the (No)FPExcept flag for constrained intrinsics from the
visitConstrainedIntrinsic routine to the generic visit routine at the
place where the other flags are set, or else the intersectFlagsWith
call would erase the NoFPExcept flag again.
In order to avoid making non-strict FP code worse, whenever
SelectionDAGISel::SelectCodeCommon matches on a set of orignal nodes
none of which can raise FP exceptions, it will preserve this property
on all results nodes generated, by setting the NoFPExcept flag on
those result nodes that would otherwise be considered as raising
an FP exception.
To check whether or not an SD node should be considered as raising
an FP exception, the following logic applies:
- For machine nodes, check the mayRaiseFPException property of
the underlying MI instruction
- For regular nodes, check isStrictFPOpcode
- For target nodes, check a newly introduced isTargetStrictFPOpcode
The latter is implemented by reserving a range of target opcodes,
similarly to how memory opcodes are identified. (Note that there a
bit of a quirk in identifying target nodes that are both memory nodes
and strict FP nodes. To simplify the logic, right now all target memory
nodes are automatically also considered strict FP nodes -- this could
be fixed by adding one more range.)
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D71841
This was increasing the number of instructions when fsub was legalized
on AMDGPU with no signed zeros enabled. This fold should be guarded by
hasOneUse, and I don't think getNode should be doing that. The same
fold is already done as a regular combine through isNegatibleForFree.
This does require duplicating, even though isNegatibleForFree does
this combine already (and properly checks hasOneUse) to avoid one PPC
regression. In the regression, the outer fneg has nsz but the fsub
operand does not. isNegatibleForFree only sees the operand, and
doesn't see it's used from a nsz context. A nsz parameter needs to be
added and threaded through isNegatibleForFree to avoid this.
These operations are needed as building blocks for promoting so they
can't be promoted themselves.
This appeared to work because the fp_extend query type for operation
actions is the result type, not the input type so it never triggered
in the legalizer.
For fp_round, the vector op legalizer just ended up creating a
nop fp_extend that was elided by getNode, followed by a nop
fp_round that was also elided by getNode. This was followed by
a final fp_round from v4f32 back to vf416 which was CSEd to the
original node. Then legalize vector ops just believed that node
legalized to itself. LegalizeDAG took another crack at promoting
it, but didn't have a handler so just skipped it with a debug
message saying it wasn't promoted.
This patch just removes the operation actions to avoid this
non-sense. Found while trying to refactor LegalizeVectorOps to
handle multiple result nodes better.
This allows us to clean up some places that were peeking through
the MERGE_VALUES node after the call. By returning the SDValues
directly, we can clean that up.
Unfortunately, there are several call sites in AMDGPU that wanted
the MERGE_VALUES and now need to create their own.
This allows us to delete InlineAsm::Constraint_i workarounds in
SelectionDAGISel::SelectInlineAsmMemoryOperand overrides and
TargetLowering::getInlineAsmMemConstraint overrides.
They were introduced to X86 in r237517 to prevent crashes for
constraints like "=*imr". They were later copied to other targets.
Jeremy Morse