Refactor DIExpression::With* into a flag enum in order to be less
error-prone to use (as discussed on D60866).
Patch by Djordje Todorovic.
Differential Revision: https://reviews.llvm.org/D61943
llvm-svn: 361137
Summary:
That check claims that the transform is illegal otherwise.
That isn't true:
1. For `ISD::ADD`, we only process `ISD::SHL` outer shift => sign bit does not matter
https://rise4fun.com/Alive/K4A
2. For `ISD::AND`, there is no restriction on constants:
https://rise4fun.com/Alive/Wy3
3. For `ISD::OR`, there is no restriction on constants:
https://rise4fun.com/Alive/GOH
3. For `ISD::XOR`, there is no restriction on constants:
https://rise4fun.com/Alive/ml6
So, why is it there then?
This changes the testcase that was touched by @spatel in rL347478,
but i'm not sure that test tests anything particular?
Reviewers: RKSimon, spatel, craig.topper, jojo, rengolin
Reviewed By: spatel
Subscribers: javed.absar, llvm-commits, spatel
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61918
llvm-svn: 361044
The recent introduction of v3i32 etc as an MVT, and its use in AMDGPU
3-dword memory instructions, caused a de-optimization problem for code
with such a load that then bitcasts via vector of i8, because v12i8 is
not an MVT so it legalizes the bitcast by widening it.
This commit adds the ability to widen a bitcast using extract_subvector
on the result, so the value does not need to go via memory.
Differential Revision: https://reviews.llvm.org/D60457
Change-Id: Ie4abb7760547e54a2445961992eafc78e80d4b64
llvm-svn: 360942
This patch add the ISD::LROUND and ISD::LLROUND along with new
intrinsics. The changes are straightforward as for other
floating-point rounding functions, with just some adjustments
required to handle the return value being an interger.
The idea is to optimize lround/llround generation for AArch64
in a subsequent patch. Current semantic is just route it to libm
symbol.
llvm-svn: 360889
Before this change, they were erroneously constructed with the EH_LABEL
SDNode opcode, which caused other passes to interact with them in
incorrect ways. See the FIXME about fastisel that this addresses in the
existing test case.
Fixes PR41890
llvm-svn: 360818
Summary:
X86TargetLowering::LowerAsmOperandForConstraint had better support than
TargetLowering::LowerAsmOperandForConstraint for arbitrary depth
getelementpointers for "i", "n", and "s" extended inline assembly
constraints. Hoist its support from the derived class into the base
class.
Link: https://github.com/ClangBuiltLinux/linux/issues/469
Reviewers: echristo, t.p.northover
Reviewed By: t.p.northover
Subscribers: t.p.northover, E5ten, kees, jyknight, nemanjai, javed.absar, eraman, hiraditya, jsji, llvm-commits, void, craig.topper, nathanchance, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61560
llvm-svn: 360604
We catch most of these patterns (on x86 at least) by matching
a concat vectors opcode early in combining, but the pattern may
emerge later using insert subvector instead.
The AVX1 diffs for add/sub overflow show another missed narrowing
pattern. That one may be falling though the cracks because of
combine ordering and multiple uses.
llvm-svn: 360585
The new fptrunc and fpext intrinsics are constrained versions of the
regular fptrunc and fpext instructions.
Reviewed by: Andrew Kaylor, Craig Topper, Cameron McInally, Conner Abbot
Approved by: Craig Topper
Differential Revision: https://reviews.llvm.org/D55897
llvm-svn: 360581
Summary:
When we know for sure whether two addresses do or do not alias, we
should immediately return from DAGCombiner::isAlias().
I think this comes from a bad copy/paste, Sorry for not catching that during the
code review.
Fixes PR41855.
Reviewers: niravd, gchatelet, EricWF
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61846
llvm-svn: 360566
I've included a new fix in X86RegisterInfo to prevent PR41619 without
reintroducing r359392. We might be able to improve that in the base class
implementation of shouldRewriteCopySrc somehow. But this hopefully enables
forward progress on SimplifyDemandedBits improvements for now.
Original commit message:
This patch adds support for BigBitWidth -> SmallBitWidth bitcasts, splitting the DemandedBits/Elts accordingly.
The AMDGPU backend needed an extra (srl (and x, c1 << c2), c2) -> (and (srl(x, c2), c1) combine to encourage BFE creation, I investigated putting this in DAGComb
but it caused a lot of noise on other targets - some improvements, some regressions.
The X86 changes are all definite wins.
llvm-svn: 360552
I noticed that we were failing to narrow an x86 ymm math op in a case similar
to the 'madd' test diff. That is because a bitcast is sitting between the math
and the extract subvector and thwarting our pattern matching for narrowing:
t56: v8i32 = add t59, t58
t68: v4i64 = bitcast t56
t73: v2i64 = extract_subvector t68, Constant:i64<2>
t96: v4i32 = bitcast t73
There are a few wins and neutral diffs in the other tests.
Differential Revision: https://reviews.llvm.org/D61806
llvm-svn: 360541
We already updated the LegalizedNodes map at the end of the Expand call. This
would have marked the new node as being mapped to itself. So the LegalizeOp
call will find that an immediately return.
llvm-svn: 360472
Split out from D61692 per RKSimon's suggestion. Vector op
legalization will automatically recursively legalize the returned
SDValue, but we need to take care of the other results ourselves.
Otherwise it will end up getting legalized only during op
legalization, by which point it might be too late (though I'm not
aware of any specific cases right now).
There are codegen differences because expansion occurs earlier now
and we don't get a DAGCombiner run in between.
Differential Revision: https://reviews.llvm.org/D61744
llvm-svn: 360470
To find the candidates to merge stores we iterate over all nodes in a chain
for each store, which leads to quadratic compile times for large basic blocks
with a large number of stores.
Reviewers: niravd, spatel, craig.topper
Reviewed By: niravd
Differential Revision: https://reviews.llvm.org/D61511
llvm-svn: 360357
This patch allows for expansion of ADDCARRY and SUBCARRY when the target does not support it.
Differential Revision: https://reviews.llvm.org/D61411
llvm-svn: 360303
This is extracted from the original draft of D61419 with some additional tests.
We don't currently get this in IR (it's conservatively turned into a NaN),
but presumably that'll get updated as we add real IR support for 'fneg'
rather than 'fsub -0.0, x'.
The x86-32 run shows the following, and I haven't looked further to see why,
but that seems to be independent:
Legalizing: t1: f32 = undef
Trying to expand node
Creating fp constant: t4: f32 = ConstantFP<0.000000e+00>
Differential Revision: https://reviews.llvm.org/D61516
llvm-svn: 360296
This patch adds support for calling selectFNeg for FNeg instructions in addition to the fsub idiom
Differential Revision: https://reviews.llvm.org/D61624
llvm-svn: 360273
Add a new function to do the endian check, as I will commit another patch later, which will also need the endian check.
Differential Revision: https://reviews.llvm.org/D61236
llvm-svn: 360226
When simplifying TokenFactors, we potentially iterate over all
operands of a large number of TokenFactors. This causes quadratic
compile times in some cases and the large token factors cause additional
scalability problems elsewhere.
This patch adds some limits to the number of nodes explored for the
cases mentioned above.
Reviewers: niravd, spatel, craig.topper
Reviewed By: niravd
Differential Revision: https://reviews.llvm.org/D61397
llvm-svn: 360171
Summary:
If fneg lowering for fsub -0.0, x fails we currently fall back to treating it as an fsub. This has different behavior for nans than the xor with sign bit trick we normally try to do. On X86, the xor trick for double fails fast-isel in 32-bit mode with sse2 due to 64 bit integer types not being available. With -O2 we would always use an xorpd for this case. If we use subsd, this creates an observable behavior difference between -O0 and -O2. So fall back to SelectionDAG if we can't fast-isel it, that way SelectionDAG will use the xorpd.
I believe this patch is restoring the behavior prior to r345295 from last October. This was missed then because our fast isel case in 32-bit mode aborted fast-isel earlier for another reason. But I've added new tests to cover that.
Reviewers: andrew.w.kaylor, cameron.mcinally, spatel, efriedma
Reviewed By: cameron.mcinally
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61622
llvm-svn: 360111
The problem was that we were creating a CMOV64rr <TargetFrameIndex>, <TargetFrameIndex>. The entire point of a TFI is that address code is not generated, so there's no way to legalize/lower this. Instead, simply prevent it's creation.
Arguably, we shouldn't be using *Target*FrameIndices in StatepointLowering at all, but that's a much deeper change.
llvm-svn: 360090
It's possible to use the 'y' mmx constraint with a type narrower than 64-bits.
This patch supports this by bitcasting the mmx type to 64-bits and then
truncating to the desired type.
There are probably other missing type combinations we need to support, but this
is the case we have a bug report for.
Fixes PR41748.
Differential Revision: https://reviews.llvm.org/D61582
llvm-svn: 360069
Reverts "[X86] Remove (V)MOV64toSDrr/m and (V)MOVDI2SSrr/m. Use 128-bit result MOVD/MOVQ and COPY_TO_REGCLASS instead"
Reverts "[TargetLowering][AMDGPU][X86] Improve SimplifyDemandedBits bitcast handling"
Eric Christopher and Jorge Gorbe Moya reported some issues with these patches to me off list.
Removing the CodeGenOnly instructions has changed how fneg is handled during fast-isel with sse/sse2. We're now emitting fsub -0.0, x instead
moving to the integer domain(in a GPR), xoring the sign bit, and then moving back to xmm. This is because the fast isel table no longer
contains an entry for (f32/f64 bitcast (i32/i64)) so the target independent fneg code fails. The use of fsub changes the behavior of nan with
respect to -O2 codegen which will always use a pxor. NOTE: We still have a difference with double with -m32 since the move to GPR doesn't work
there. I'll file a separate PR for that and add test cases.
Since removing the CodeGenOnly instructions was fixing PR41619, I'm reverting r358887 which exposed that PR. Though I wouldn't be surprised
if that bug can still be hit independent of that.
This should hopefully get Google back to green. I'll work with Simon and other X86 folks to figure out how to move forward again.
llvm-svn: 360066
This addresses one half of https://bugs.llvm.org/show_bug.cgi?id=41635
by combining a VECREDUCE_AND/OR into VECREDUCE_UMIN/UMAX (if latter is
legal but former is not) for zero-or-all-ones boolean reductions (which
are detected based on sign bits).
Differential Revision: https://reviews.llvm.org/D61398
llvm-svn: 360054
Based on PR41748, not all cases are handled in this function.
llvm_unreachable is treated as an optimization hint than can prune code paths
in a release build. This causes weird behavior when PR41748 is encountered on a
release build. It appears to generate an fp_round instruction from the floating
point code.
Making this a report_fatal_error prevents incorrect optimization of the code
and will instead generate a message to file a bug report.
llvm-svn: 360008
As a result of the underlying cause of PR41678 we created an ANY_EXTEND node with a scalar result type and v1i1 input type. Ideally we would have asserted for this instead of letting it go through to instruction selection and generate bad machine IR
Differential Revision: https://reviews.llvm.org/D61463
llvm-svn: 359836
The original patch was committed at rL359398 and reverted at rL359695 because of
infinite looping.
This includes a fix to check for a vector splat of "1.0" to avoid the infinite loop.
Original commit message:
This was originally part of D61028, but it's an independent diff.
If we try the repeated divisor reciprocal transform before producing an estimate sequence,
then we have an opportunity to use scalar fdiv. On x86, the trade-off is 1 divss vs. 5
vector FP ops in the default estimate sequence. On recent chips (Skylake, Ryzen), the
full-precision division is only 3 cycle throughput, so that's probably the better perf
default option and avoids problems from x86's inaccurate estimates.
The last 2 tests show that users still have the option to override the defaults by using
the function attributes for reciprocal estimates, but those patterns are potentially made
faster by converting the vector ops (including ymm ops) to scalar math.
Differential Revision: https://reviews.llvm.org/D61149
llvm-svn: 359793
We don't have FP exception limits in the IR constant folder for the binops (apart from strict ops),
so it does not make sense to have them here in the DAG either. Nothing else in the backend tries
to preserve exceptions (again outside of strict ops), so I don't see how this could have ever
worked for real code that cares about FP exceptions.
There are still cases (examples: unary opcodes in SDAG, FMA in IR) where we are trying (at least
partially) to preserve exceptions without even asking if the target supports FP exceptions. Those
should be corrected in subsequent patches.
Real support for FP exceptions requires several changes to handle the constrained/strict FP ops.
Differential Revision: https://reviews.llvm.org/D61331
llvm-svn: 359791
In preparation for supporting ILP32 on AArch64, this modifies the SelectionDAG
builder code so that pointers are allowed to have a larger type when "live" in
the DAG compared to memory.
Pointers get zero-extended whenever they are loaded, and truncated prior to
stores. In addition, a few not quite so obvious locations need updating:
* A GEP that has not been marked inbounds needs to enforce the IR-documented
2s-complement wrapping at the memory pointer size. Inbounds GEPs are
undefined if they overflow the address space, so no additional operations
are needed.
* Signed comparisons would give incorrect results if performed on the
zero-extended values.
This shouldn't affect CodeGen for now, but will become active when the AArch64
ILP32 support is committed.
llvm-svn: 359676
We don't have this restriction in IR, so it should not be here
either simply out of consistency. Code that wants to handle FP
exceptions is expected to use the 'strict' variants of these
nodes.
We don't get the frem case because frem by 0.0 produces NaN (invalid),
and that's the remaining check here (so the removed check for frem
was dead code AFAIK).
This is the only place in SDAG that uses "HasFPExceptions", so I
think we should remove that entirely as a follow-up patch.
llvm-svn: 359566
This was a local static funtion in SelectionDAG, which I've promoted to
TargetLowering so that I can reuse it to estimate the cost of a memory
operation in D59787.
Differential Revision: https://reviews.llvm.org/D59766
llvm-svn: 359543
The MachineFunction wasn't used in getOptimalMemOpType, but more importantly,
this allows reuse of findOptimalMemOpLowering that is calling getOptimalMemOpType.
This is the groundwork for the changes in D59766 and D59787, that allows
implementation of TTI::getMemcpyCost.
Differential Revision: https://reviews.llvm.org/D59785
llvm-svn: 359537
Do not combine (trunc adde(X, Y, Carry)) into (adde trunc(X), trunc(Y), Carry),
if adde is not legal for the target. Even it's at type-legalize phase.
Because adde is special and will not be legalized at operation-legalize phase later.
This fixes: PR40922
https://bugs.llvm.org/show_bug.cgi?id=40922
Differential Revision: https://reviews.llvm.org//D60854
llvm-svn: 359532
Summary:
Extract the logic for doing reassociations
from DAGCombiner::reassociateOps into a helper
function DAGCombiner::reassociateOpsCommutative,
and use that helper to trigger reassociation
on the original operand order, or the commuted
operand order.
Codegen is not identical since the operand order will
be different when doing the reassociations for the
commuted case. That causes some unfortunate churn in
some test cases. Apart from that this should be NFC.
Reviewers: spatel, craig.topper, tstellar
Reviewed By: spatel
Subscribers: dmgreen, dschuff, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, hiraditya, aheejin, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61199
llvm-svn: 359476
This was originally part of D61028, but it's an independent diff.
If we try the repeated divisor reciprocal transform before producing an estimate sequence,
then we have an opportunity to use scalar fdiv. On x86, the trade-off is 1 divss vs. 5
vector FP ops in the default estimate sequence. On recent chips (Skylake, Ryzen), the
full-precision division is only 3 cycle throughput, so that's probably the better perf
default option and avoids problems from x86's inaccurate estimates.
The last 2 tests show that users still have the option to override the defaults by using
the function attributes for reciprocal estimates, but those patterns are potentially made
faster by converting the vector ops (including ymm ops) to scalar math.
Differential Revision: https://reviews.llvm.org/D61149
llvm-svn: 359398
As detailed on PR40758, Bobcat/Jaguar can perform vector immediate shifts on the same pipes as vector ANDs with the same latency - so it doesn't make sense to replace a shl+lshr with a shift+and pair as it requires an additional mask (with the extra constant pool, loading and register pressure costs).
Differential Revision: https://reviews.llvm.org/D61068
llvm-svn: 359293
We had special case handling here, but it uses a scalar any_extend for the
promotion then bitcasts to the final type. This won't split up the input data
into multiple promoted elements like we need.
This patch falls back to doing the conversion through memory.
Fixes PR41594 which I believe was reflected in the bitcast-vector-bool.ll
changes. The changes to vector-half-conversions.ll are fixing a previously
unknown miscompile from this issue.
Differential Revision: https://reviews.llvm.org/D61114
llvm-svn: 359219
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.
Reviewers: rnk
Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D61083
llvm-svn: 359149
If we have a vector FP division with a splatted divisor, use the existing transform
that converts 'x/y' into 'x * (1.0/y)' to allow more conversions. This can then
potentially be converted into a scalar FP division by existing combines (rL358984)
as seen in the tests here.
That can be a potentially big perf difference if scalar fdiv has better timing
(including avoiding possible frequency throttling for vector ops).
Differential Revision: https://reviews.llvm.org/D61028
llvm-svn: 359147
Summary:
Both the input Value pointer and the returned Value
pointers in GetUnderlyingObjects are now declared as
const.
It turned out that all current (in-tree) uses of
GetUnderlyingObjects were trivial to update, being
satisfied with have those Value pointers declared
as const. Actually, in the past several of the users
had to use const_cast, just because of ValueTracking
not providing a version of GetUnderlyingObjects with
"const" Value pointers. With this patch we get rid
of those const casts.
Reviewers: hfinkel, materi, jkorous
Reviewed By: jkorous
Subscribers: dexonsmith, jkorous, jholewinski, sdardis, eraman, hiraditya, jrtc27, atanasyan, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61038
llvm-svn: 359072
If we only match build vectors, we can miss some patterns
that use shuffles as seen in the affected tests.
Note that the underlying calls within getSplatSourceVector()
have the potential for compile-time explosion because of
exponential recursion looking through binop opcodes, but
currently the list of supported opcodes is very limited.
Both of those problems should be addressed in follow-up
patches.
llvm-svn: 358984
Summary:
The DAGCombiner is rewriting (canonicalizing) an ISD::ADD
with no common bits set in the operands as an ISD::OR node.
This could sometimes result in "missing out" on some
combines that normally are performed for ADD. To be more
specific this could happen if we already have rewritten an
ADD into OR, and later (after legalizations or combines)
we expose patterns that could have been optimized if we
had seen the OR as an ADD (e.g. reassociations based on ADD).
To make the DAG combiner less sensitive to if ADD or OR is
used for these "no common bits set" ADD/OR operations we
now apply most of the ADD combines also to an OR operation,
when value tracking indicates that the operands have no
common bits set.
Reviewers: spatel, RKSimon, craig.topper, kparzysz
Reviewed By: spatel
Subscribers: arsenm, rampitec, lebedev.ri, jvesely, nhaehnle, hiraditya, javed.absar, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59758
llvm-svn: 358965
This was supposed to be NFC, but the change in SDLoc
definitions causes instruction scheduling changes.
There's nothing x86-specific in this code, and it can
likely be used from DAGCombiner's simplifyVBinOp().
llvm-svn: 358930
This patch adds support for BigBitWidth -> SmallBitWidth bitcasts, splitting the DemandedBits/Elts accordingly.
The AMDGPU backend needed an extra (srl (and x, c1 << c2), c2) -> (and (srl(x, c2), c1) combine to encourage BFE creation, I investigated putting this in DAGCombine but it caused a lot of noise on other targets - some improvements, some regressions.
The X86 changes are all definite wins.
Differential Revision: https://reviews.llvm.org/D60462
llvm-svn: 358887
Summary:
This emits labels around heapallocsite calls and S_HEAPALLOCSITE debug
info in codeview. Currently only changes FastISel, so emitting labels still
needs to be implemented in SelectionDAG.
Reviewers: hans, rnk
Subscribers: aprantl, hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D60800
llvm-svn: 358783
These are general queries, so they should not die when given
a degenerate input like an all undef mask. Callers should be
able to deal with an op that will eventually be simplified away.
llvm-svn: 358761
Currently there is a single point in ScheduleDAGRRList, where we
actually query the topological order (besides init code). Currently we
are recomputing the order after adding a node (which does not have
predecessors) and then we add predecessors edge-by-edge.
We can avoid adding edges one-by-one after we added a new node. In that case, we can
just rebuild the order from scratch after adding the edges to the DAG
and avoid all the updates to the ordering.
Also, we can delay updating the DAG until we query the DAG, if we keep a
list of added edges. Depending on the number of updates, we can either
apply them when needed or recompute the order from scratch.
This brings down the geomean compile time for of CTMark with -O1 down 0.3% on X86,
with no regressions.
Reviewers: MatzeB, atrick, efriedma, niravd, paquette
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D60125
llvm-svn: 358583
As discussed on PR41359, this patch renames the pair of shift-mask target feature functions to make their purposes more obvious.
shouldFoldShiftPairToMask -> shouldFoldConstantShiftPairToMask
preferShiftsToClearExtremeBits -> shouldFoldMaskToVariableShiftPair
llvm-svn: 358526
The checks in `canFoldInAddressingMode` tested for addressing modes that have a
base register but didn't set the `HasBaseReg` flag to true (it's false by
default). This patch fixes that. Although the omission of the flag was
technically incorrect it had no known observable impact, so no tests were
changed by this patch.
Differential Revision: https://reviews.llvm.org/D60314
llvm-svn: 358502
Arguments already have a flag to inform backends when they have been split up.
The AArch64 arm64_32 ABI makes use of these on return types too, so that code
emitted for armv7k can be ABI-compliant.
There should be no CodeGen changes yet, just making more information available.
llvm-svn: 358399
The arm64_32 ABI specifies that pointers (despite being 32-bits) should be
zero-extended to 64-bits when passed in registers for efficiency reasons. This
means that the SelectionDAG needs to be able to tell the backend that an
argument was originally a pointer, which is implmented here.
Additionally, some memory intrinsics need to be declared as taking an i8*
instead of an iPTR.
There should be no CodeGen change yet, but it will be triggered when AArch64
backend support for ILP32 is added.
llvm-svn: 358398
Summary:
Use KnownBits::computeForAddSub/computeForAddCarry
in SelectionDAG::computeKnownBits when doing value
tracking for addition/subtraction.
This should improve the precision of the known bits,
as we only used to make a simple estimate of known
zeroes. The KnownBits support functions are also
able to deduce bits that are known to be one in the
result.
Reviewers: spatel, RKSimon, nikic, lebedev.ri
Reviewed By: nikic
Subscribers: nikic, javed.absar, lebedev.ri, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60460
llvm-svn: 358372
// shuffle (concat X, undef), (concat Y, undef), Mask -->
// concat (shuffle X, Y, Mask0), (shuffle X, Y, Mask1)
The ARM changes with 'vtrn' and narrowed 'vuzp' are improvements.
The x86 changes look neutral or better. There's one test with an
extra instruction, but that could be reversed for a subtarget with
the right attributes. But by default, we want to avoid the 256-bit
op when possible (in my motivating benchmark, a handful of ymm ops
sprinkled into a sequence of xmm ops are triggering frequency
throttling on Haswell resulting in significantly worse perf).
Differential Revision: https://reviews.llvm.org/D60545
llvm-svn: 358291
If the upper bits of the SHL result aren't used, we might be able to use a narrower shift. For example, on X86 this can turn a 64-bit into 32-bit enabling a smaller encoding.
Differential Revision: https://reviews.llvm.org/D60358
llvm-svn: 358257
// bo (build_vec ...undef, x, undef...), (build_vec ...undef, y, undef...) -->
// build_vec ...undef, (bo x, y), undef...
The lifetime of the nodes in these examples is different for variables versus constants,
but they are all build vectors briefly, so I'm proposing to catch them in this form to
handle all of the leading examples in the motivating test file.
Before we have build vectors, we might have insert_vector_element. After that, we might
have scalar_to_vector and constant pool loads.
It's going to take more work to ensure that FP vector operands are getting simplified
with undef elements, so this transform can apply more widely. In a non-loose FP environment,
we are likely simplifying FP elements to NaN values rather than undefs.
We also need to allow more opcodes down this path. Eg, we don't handle FP min/max flavors
yet.
Differential Revision: https://reviews.llvm.org/D60514
llvm-svn: 358172
Certain optimisations from ConstantHoisting and CGP rely on Selection DAG not
seeing through to the constant in other blocks. Revert this patch while we come
up with a better way to handle that.
I will try to follow this up with some better tests.
llvm-svn: 358113
This lines up with what we do for regular subtract and it matches up better with X86 assumptions in isel patterns that add with immediate is more canonical than sub with immediate.
Differential Revision: https://reviews.llvm.org/D60020
llvm-svn: 358027
When bitcasting from a source op to a larger bitwidth op, split the demanded bits and OR them on top of one another and demand those merged bits in the SimplifyDemandedBits call on the source op.
llvm-svn: 357992
Second half of PR40800, this patch adds DAG undef handling to fcmp instructions to match the behavior in llvm::ConstantFoldCompareInstruction, this permits constant folding of vector comparisons where some elements had been reduced to UNDEF (by SimplifyDemandedVectorElts etc.).
This involves a lot of tweaking to reduced tests as bugpoint loves to reduce fcmp arguments to undef........
Differential Revision: https://reviews.llvm.org/D60006
llvm-svn: 357765
There are a variety of vector patterns that may be profitably reduced to a
scalar op when scalar ops are performed using a subset (typically, the
first lane) of the vector register file.
For x86, this is true for float/double ops and element 0 because
insert/extract is just a sub-register rename.
Other targets should likely enable the hook in a similar way.
Differential Revision: https://reviews.llvm.org/D60150
llvm-svn: 357760
Summary:
Teach SelectionDAG how to compute known bits of ISD::CopyFromReg if
the virtual reg used has one def only.
This can be particularly useful when calling isBaseWithConstantOffset()
with the ISD::CopyFromReg argument, as more optimizations may get enabled
in the result.
Also add a missing truncation on X86, found by testing of this patch.
Change-Id: Id1c9fceec862d118c54a5b53adf72ada5d6daefa
Reviewers: bogner, craig.topper, RKSimon
Reviewed By: RKSimon
Subscribers: lebedev.ri, nemanjai, jvesely, nhaehnle, javed.absar, jsji, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59535
llvm-svn: 357745
Lowering safepoint checks that all gc.relocaes observed in safepoint
must be lowered. However Fast-Isel is able to skip dead gc.relocate.
To resolve this issue we just ignore dead gc.relocate in the check.
Reviewers: reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D60184
llvm-svn: 357742
The Fast ISel has a fallback to SelectionDAGISel in case it cannot handle the instruction.
This works as follows:
Using reverse order, try to select instruction using Fast ISel, if it cannot handle instruction it fallbacks to SelectionDAGISel
for these instructions if it is a call and continue fast instruction selections.
However if unhandled instruction is not a call or statepoint related instruction it fallbacks to SelectionDAGISel for all remaining
instructions in basic block.
However gc.result instruction is missed and as a result it is possible that gc.result is processed earlier than statepoint
causing breakage invariant the gc.results should be handled after statepoint.
Test is updated because in the current form fast-isel cannot handle ret instruction (due to i1 ret type without explicit ext)
and as a result test does not check fast-isel at all.
Reviewers: reames
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D60182
llvm-svn: 357672
There are 3 changes to make this correspond to the same transform in instcombine:
1. Remove the legality check - we can't create anything less legal than we started with.
2. Ease the use restriction, so we only bail out if both operands have >1 use.
3. Ease the use restriction for binops with a repeated operand (eg, mul x, x).
As discussed in D60150, there's a scalarization opportunity that will be made
easier by allowing this transform more generally.
llvm-svn: 357580
Summary:
Nodes that have no uses are eventually pruned when they are selected
from the worklist. Record nodes newly added to the worklist or DAG and
perform pruning after every combine attempt.
Reviewers: efriedma, RKSimon, craig.topper, spatel, jyknight
Reviewed By: jyknight
Subscribers: jdoerfert, jyknight, nemanjai, jvesely, nhaehnle, javed.absar, hiraditya, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58070
llvm-svn: 357283
Summary:
Various SelectionDAG non-combine operations (e.g. the getNode smart
constructor and legalization) may leave dangling nodes by applying
optimizations without fully pruning unused result values. This results
in nodes that are never added to the worklist and therefore can not be
pruned.
Add a node inserter for the combiner to make sure such nodes have the
chance of being pruned. This allows a number of additional peephole
optimizations.
Reviewers: efriedma, RKSimon, craig.topper, jyknight
Reviewed By: jyknight
Subscribers: msearles, jyknight, sdardis, nemanjai, javed.absar, hiraditya, jrtc27, atanasyan, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58068
llvm-svn: 357279
After investigating the examples from D59777 targeting an SSE4.1 machine,
it looks like a very different problem due to how we map illegal types (256-bit in these cases).
We're missing a shuffle simplification that maps elements of a vector back to a shuffled operand.
We have a more general version of this transform in DAGCombiner::visitVECTOR_SHUFFLE(), but that
generality means it is limited to patterns with a one-use constraint, and the examples here have
2 uses. We don't need any uses or legality limitations for a simplification (no new value is
created).
It looks like we miss this pattern in IR too.
In one of the zext examples here, we have shuffle masks like this:
Shuf0 = vector_shuffle<0,u,3,7,0,u,3,7>
Shuf = vector_shuffle<4,u,6,7,u,u,u,u>
...so that's moving the high half of the 1st vector into the low half. But the high half of the
1st vector is already identical to the low half.
Differential Revision: https://reviews.llvm.org/D59961
llvm-svn: 357258
This is a sibling to rL357178 that I noticed we'd hit if we chose
an alternate transform in D59818.
%z = zext i8 %x to i32
%dec = add i32 %z, -1
%r = sext i32 %dec to i64
=>
%z2 = zext i8 %x to i64
%r = add i64 %z2, -1
https://rise4fun.com/Alive/kPP
The x86 vector diffs show a slight regression, so there's a chance
that we should limit this and the previous transform to scalars.
But given that we allowed vectors before, I'm matching that behavior
here. We should change both transforms together if that's the right
thing to do.
llvm-svn: 357254
In the example below, we would previously emit two range checks, one for cases
1--3 and one for 4--6. This patch makes us exploit the fact that the
fall-through is unreachable and only one range check is necessary.
switch i32 %i, label %default [
i32 1, label %bb1
i32 2, label %bb1
i32 3, label %bb1
i32 4, label %bb2
i32 5, label %bb2
i32 6, label %bb2
]
default: unreachable
llvm-svn: 357252
If scalar truncates are free, attempt to pre-truncate build_vectors source operands.
Only attempt to do this before legalization as we often end up with truncations/extensions during build_vector lowering.
Differential Revision: https://reviews.llvm.org/D59654
llvm-svn: 357161
When lowering a load or store for TypeWidenVector, the type legalizer
would use a single load or store if the associated integer type was legal
or promoted. E.g. it loads a v4i8 as an i32 if i32 is legal/promotable.
(See https://reviews.llvm.org/rL236528 for reference.)
This applies that behaviour to vector types. If the vector type is
TypePromoteInteger, the element type is going to be TypePromoteInteger
as well, which will lead to have a single promoting load rather than N
individual promoting loads. For instance, if we have a v3i1, we would
now have a load of v4i1 instead of 3 loads of i1.
Patch by Guillaume Marques. Thanks!
Differential Revision: https://reviews.llvm.org/D56201
llvm-svn: 357120
Split out from D59749. The current implementation of isWrappedSet()
doesn't do what it says on the tin, and treats ranges like
[X, Max] as wrapping, because they are represented as [X, 0) when
using half-inclusive ranges. This also makes it inconsistent with
the semantics of isSignWrappedSet().
This patch renames isWrappedSet() to isUpperWrapped(), in preparation
for the introduction of a new isWrappedSet() method with corrected
behavior.
llvm-svn: 357107
Rework BaseIndexOffset and isAlias to fully work with lifetime nodes
and fold in lifetime alias analysis.
This is mostly NFC.
Reviewers: courbet
Reviewed By: courbet
Subscribers: hiraditya, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59794
llvm-svn: 357070
Original commit by Ayonam Ray.
This commit adds a regression test for the issue discovered in the
previous commit: that the range check for the jump table can only be
omitted if the fall-through destination of the jump table is
unreachable, which isn't necessarily true just because the default of
the switch is unreachable.
This addresses the missing optimization in PR41242.
> During the lowering of a switch that would result in the generation of a
> jump table, a range check is performed before indexing into the jump
> table, for the switch value being outside the jump table range and a
> conditional branch is inserted to jump to the default block. In case the
> default block is unreachable, this conditional jump can be omitted. This
> patch implements omitting this conditional branch for unreachable
> defaults.
>
> Differential Revision: https://reviews.llvm.org/D52002
> Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev
llvm-svn: 357067
getAsCarry() checks that the input argument is a carry-producing node before
allowing a transformation to addcarry. This patch adds a check to make sure
that the carry-producing node is legal. If it is not, it may not remain in a
form that is manageable by the target backend. The test case caused a
compilation failure during instruction selection for this reason on SystemZ.
Patch by Ulrich Weigand.
Review: Sanjay Patel
https://reviews.llvm.org/D59822
llvm-svn: 357052
We have the folds for fadd/fsub/fmul already in DAGCombiner,
so it may be possible to remove that code if we can guarantee that
these ops are zapped before they can exist.
llvm-svn: 357029
Various SelectionDAG non-combine operations (e.g. the getNode smart
constructor and legalization) may leave dangling nodes by applying
optimizations or not fully pruning unused result values. This can
result in nodes that are never added to the worklist and therefore can
not be pruned.
Add a node inserter as the current node deleter to make sure such
nodes have the chance of being pruned.
Many minor changes, mostly positive.
llvm-svn: 356996
This helps us relax the extension of a lot of scalar elements before they are inserted into a vector.
Its exposes an issue in DAGCombiner::convertBuildVecZextToZext as some/all the zero-extensions may be relaxed to ANY_EXTEND, so we need to handle that case to avoid a couple of AVX2 VPMOVZX test regressions.
Once this is in it should be easier to fix a number of remaining failures to fold loads into VBROADCAST nodes.
Differential Revision: https://reviews.llvm.org/D59484
llvm-svn: 356989
DenseMap iteration order is not guaranteed, use MapVector instead.
Fix provided by srhines.
Differential Revision: https://reviews.llvm.org/D59807
llvm-svn: 356988
First half of PR40800, this patch adds DAG undef handling to icmp instructions to match the behaviour in llvm::ConstantFoldCompareInstruction and SimplifyICmpInst, this permits constant folding of vector comparisons where some elements had been reduced to UNDEF (by SimplifyDemandedVectorElts etc.).
This involved a lot of tweaking to reduced tests as bugpoint loves to reduce icmp arguments to undef........
Differential Revision: https://reviews.llvm.org/D59363
llvm-svn: 356938
An i16 bswap can be implemented with an i16 rotate by 8. We previously emitted
a shift and OR sequence that DAG combine should be able to turn back into
rotate. But we might as well go there directly. If rotate isn't legal,
LegalizeDAG should further legalize it to either the opposite rotate, or the
shift and OR pattern.
I don't know of any way to get the existing DAG combine reliance to fail. So
I don't know any way to add new tests for this that wouldn't have worked
previously.
llvm-svn: 356860
SDNodes can only have 64k operands and for some inputs (e.g. large
number of stores), we can reach this limit when creating TokenFactor
nodes. This patch is a follow up to D56740 and updates a few more places
that potentially can create TokenFactors with too many operands.
Reviewers: efriedma, craig.topper, aemerson, RKSimon
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D59156
llvm-svn: 356668
The actual code change is fairly straight forward, but exercising it isn't. First, it turned out we weren't adding the appropriate flags in SelectionDAG. Second, it turned out that we've got some optimization gaps, so obvious test cases don't work.
My first attempt (in atomic-unordered.ll) points out a deficiency in our peephole-opt folding logic which I plan to fix separately. Instead, I'm exercising this through MachineLICM.
Differential Revision: https://reviews.llvm.org/D59375
llvm-svn: 356494
In r311255 we added a case where we split vectors whose elements are
all derived from the same input vector so that we could shuffle it
more efficiently. In doing so, createBuildVecShuffle was taught to
adjust for the fact that all indices would be based off of the first
vector when this happens, but it's possible for the code that checked
that to fire incorrectly if we happen to have a BUILD_VECTOR of
extracts from subvectors and don't hit this new optimization.
Instead of trying to detect if we've split the vector by checking if
we have extracts from the same base vector, we can just pass that
information into createBuildVecShuffle, avoiding the miscompile.
Differential Revision: https://reviews.llvm.org/D59507
llvm-svn: 356476
These changes are related to PR37743 and include:
SelectionDAGBuilder::visitSelect handles the unary SelectPatternFlavor::SPF_ABS case to build ABS node.
Delete the redundant recognizer of the integer ABS pattern from the DAGCombiner.
Add promoting the integer ABS node in the LegalizeIntegerType.
Expand-based legalization of integer result for the ABS nodes.
Expand-based legalization of ABS vector operations.
Add some integer abs testcases for different typesizes for Thumb arch
Add the custom ABS expanding and change the SAD pattern recognizer for X86 arch: The i64 result of the ABS is expanded to:
tmp = (SRA, Hi, 31)
Lo = (UADDO tmp, Lo)
Hi = (XOR tmp, (ADDCARRY tmp, hi, Lo:1))
Lo = (XOR tmp, Lo)
The "detectZextAbsDiff" function is changed for the recognition of pattern with the ABS node. Given a ABS node, detect the following pattern:
(ABS (SUB (ZERO_EXTEND a), (ZERO_EXTEND b))).
Change integer abs testcases for codegen with the ABS node support for AArch64.
Indicate that the ABS is legal for the i64 type when the NEON is supported.
Change the integer abs testcases to show changing of codegen.
Add combine and legalization of ABS nodes for Thumb arch.
Extend 'matchSelectPattern' to recognize the ABS patterns with ICMP_SGE condition.
For discussion, see https://bugs.llvm.org/show_bug.cgi?id=37743
Patch by: @ikulagin (Ivan Kulagin)
Differential Revision: https://reviews.llvm.org/D49837
llvm-svn: 356468
This allows better code size for aarch64 floating point materialization
in a future patch.
Reviewers: evandro
Differential Revision: https://reviews.llvm.org/D58690
llvm-svn: 356389
Delete temporarily constructed node uses for analysis after it's use,
holding onto original input nodes. Ideally this would be rewritten
without making nodes, but this appears relatively complex.
Reviewers: spatel, RKSimon, craig.topper
Subscribers: jdoerfert, hiraditya, deadalnix, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57921
llvm-svn: 356382
Summary:
Look past bitcasts when looking for parameter debug values that are
described by frame-index loads in `EmitFuncArgumentDbgValue()`.
In the attached test case we would be left with an undef `DBG_VALUE`
for the parameter without this patch.
A similar fix was done for parameters passed in registers in D13005.
This fixes PR40777.
Reviewers: aprantl, vsk, jmorse
Reviewed By: aprantl
Subscribers: bjope, javed.absar, jdoerfert, llvm-commits
Tags: #debug-info, #llvm
Differential Revision: https://reviews.llvm.org/D58831
llvm-svn: 356363
AMDGPU would like to have MVTs for v3i32, v3f32, v5i32, v5f32. This
commit does not add them, but makes preparatory changes:
* Exclude non-legal non-power-of-2 vector types from ComputeRegisterProp
mechanism in TargetLoweringBase::getTypeConversion.
* Cope with SETCC and VSELECT for odd-width i1 vector when the other
vectors are legal type.
Some of this patch is from Matt Arsenault, also of AMD.
Differential Revision: https://reviews.llvm.org/D58899
Change-Id: Ib5f23377dbef511be3a936211a0b9f94e46331f8
llvm-svn: 356350
Fold (x & ~y) | y and it's four commuted variants to x | y. This pattern
can in particular appear when a vselect c, x, -1 is expanded to
(x & ~c) | (-1 & c) and combined to (x & ~c) | c.
This change has some overlap with D59066, which avoids creating a
vselect of this form in the first place during uaddsat expansion.
Differential Revision: https://reviews.llvm.org/D59174
llvm-svn: 356333
This is a subset of what was proposed in:
D59006
...and may overlap with test changes from:
D59174
...but it seems like a good general optimization to turn selects
into bitwise-logic when possible because we never know exactly
what can happen at this stage of DAG combining depending on how
the target has defined things.
Differential Revision: https://reviews.llvm.org/D59066
llvm-svn: 356332
rL356292 reduces the size of scalar_to_vector if we know the upper bits are undef - which means that shuffles may find they are suddenly referencing scalar_to_vector elements other than zero - so make sure we handle this as undef.
llvm-svn: 356327
Summary:
In the new wasm EH proposal, `rethrow` takes an `except_ref` argument.
This change was missing in r352598.
This patch adds `llvm.wasm.rethrow.in.catch` intrinsic. This is an
intrinsic that's gonna eventually be lowered to wasm `rethrow`
instruction, but this intrinsic can appear only within a catchpad or a
cleanuppad scope. Also this intrinsic needs to be invokable - otherwise
EH pad successor for it will not be correctly generated in clang.
This also adds lowering logic for this intrinsic in
`SelectionDAGBuilder::visitInvoke`. This routine is basically a
specialized and simplified version of
`SelectionDAGBuilder::visitTargetIntrinsic`, but we can't use it
because if is only for `CallInst`s.
This deletes the previous `llvm.wasm.rethrow` intrinsic and related
tests, which was meant to be used within a `__cxa_rethrow` library
function. Turned out this needs some more logic, so the intrinsic for
this purpose will be added later.
LateEHPrepare takes a result value of `catch` and inserts it into
matching `rethrow` as an argument.
`RETHROW_IN_CATCH` is a pseudo instruction that serves as a link between
`llvm.wasm.rethrow.in.catch` and the real wasm `rethrow` instruction. To
generate a `rethrow` instruction, we need an `except_ref` argument,
which is generated from `catch` instruction. But `catch` instrutions are
added in LateEHPrepare pass, so we use `RETHROW_IN_CATCH`, which takes
no argument, until we are able to correctly lower it to `rethrow` in
LateEHPrepare.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59352
llvm-svn: 356316
Summary:
A number of optimizations are inhibited by single-use TokenFactors not
being merged into the TokenFactor using it. This makes we consider if
we can do the merge immediately.
Most tests changes here are due to the change in visitation causing
minor reorderings and associated reassociation of paired memory
operations.
CodeGen tests with non-reordering changes:
X86/aligned-variadic.ll -- memory-based add folded into stored leaq
value.
X86/constant-combiners.ll -- Optimizes out overlap between stores.
X86/pr40631_deadstore_elision -- folds constant byte store into
preceding quad word constant store.
Reviewers: RKSimon, craig.topper, spatel, efriedma, courbet
Reviewed By: courbet
Subscribers: dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, eraman, hiraditya, kbarton, jrtc27, atanasyan, jsji, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59260
llvm-svn: 356068
First step towards PR40800 - I intend to move the float case in a separate future patch.
I had to tweak the (overly reduced) thumb2 test and the x86 widening test change is annoying (no longer rematerializable) but we should address this separately.
Differential Revision: https://reviews.llvm.org/D59244
llvm-svn: 356040
The existing statepoint lowering code does something odd; it adds machine memory operands post instruction selection. This was copied from the stackmap/patchpoint implementation, but appears to be non-idiomatic.
This change is largely NFC. It moves the MMO creation logic into SelectionDAG building. It ends up not quite being NFC because the size of the stack slot is reflected in the MMO. The old code blindly used pointer size for the MMO size, which appears to have always been incorrect for larger values. It just happened nothing actually relied on the MMOs, so it worked out okay.
For context, I'm planning on removing the MOVolatile flag from these in a future commit, and then removing the MOStore flag from deopt spill slots in a separate one. Doing so is motivated by a small test case where we should be able to better schedule spill slots, but don't do so due to a memory use/def implied by the statepoint.
Differential Revision: https://reviews.llvm.org/D59106
llvm-svn: 355953
Expand MULO with constant power of two operand into a shift. The
overflow is checked with (x << shift) >> shift == x, where the right
shift will be logical for umulo and arithmetic for smulo (with
exception for multiplications by signed_min).
Differential Revision: https://reviews.llvm.org/D59041
llvm-svn: 355937
Fixes https://bugs.llvm.org/show_bug.cgi?id=36796.
Implement basic legalizations (PromoteIntRes, PromoteIntOp,
ExpandIntRes, ScalarizeVecOp, WidenVecOp) for VECREDUCE opcodes.
There are more legalizations missing (esp float legalizations),
but there's no way to test them right now, so I'm not adding them.
This also includes a few more changes to make this work somewhat
reasonably:
* Add support for expanding VECREDUCE in SDAG. Usually
experimental.vector.reduce is expanded prior to codegen, but if the
target does have native vector reduce, it may of course still be
necessary to expand due to legalization issues. This uses a shuffle
reduction if possible, followed by a naive scalar reduction.
* Allow the result type of integer VECREDUCE to be larger than the
vector element type. For example we need to be able to reduce a v8i8
into an (nominally) i32 result type on AArch64.
* Use the vector operand type rather than the scalar result type to
determine the action, so we can control exactly which vector types are
supported. Also change the legalize vector op code to handle
operations that only have vector operands, but no vector results, as
is the case for VECREDUCE.
* Default VECREDUCE to Expand. On AArch64 (only target using VECREDUCE),
explicitly specify for which vector types the reductions are supported.
This does not handle anything related to VECREDUCE_STRICT_*.
Differential Revision: https://reviews.llvm.org/D58015
llvm-svn: 355860
Includes a fix to emit a CheckOpcode for build_vector when immAllZerosV/immAllOnesV is used as a pattern root. This means it can't be used to look through bitcasts when used as a root, but that's probably ok. This extra CheckOpcode will ensure that the first match in the isel table will be a SwitchOpcode which is needed by the caching optimization in the ISel Matcher.
Original commit message:
Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.
By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.
This removes something like 40,000 bytes from the X86 isel table.
Differential Revision: https://reviews.llvm.org/D58595
llvm-svn: 355784
This avoids breaking possible value dependencies when sorting loads by
offset.
AMDGPU has some load instructions that write into the high or low bits
of the destination register, and have a tied input for the other input
bits. These can easily have the same base pointer, but be a swizzle so
the high address load needs to come first. This was inserting glue
forcing the opposite ordering, producing a cycle the InstrEmitter
would assert on. It may be potentially expensive to look for the
dependency between the other loads, so just skip any where this could
happen.
Fixes bug 40936 by reverting r351379, which added a hacky attempt to
fix this by adding chains in this case, which I think was just working
around broken glue before the InstrEmitter. The core of the patch is
re-implementing the fix for that problem.
llvm-svn: 355728
Move the x86 combine from D58974 into the DAGCombine VSELECT code and update the SELECT version to use the isBooleanFlip helper as well.
Requested by @spatel on D59006
llvm-svn: 355533
During the lowering of a switch that would result in the generation of a
jump table, a range check is performed before indexing into the jump
table, for the switch value being outside the jump table range and a
conditional branch is inserted to jump to the default block. In case the
default block is unreachable, this conditional jump can be omitted. This
patch implements omitting this conditional branch for unreachable
defaults.
Differential Revision: https://reviews.llvm.org/D52002
Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev
llvm-svn: 355490
During the lowering of a switch that would result in the generation of a
jump table, a range check is performed before indexing into the jump
table, for the switch value being outside the jump table range and a
conditional branch is inserted to jump to the default block. In case the
default block is unreachable, this conditional jump can be omitted. This
patch implements omitting this conditional branch for unreachable
defaults.
Differential Revision: https://reviews.llvm.org/D52002
Reviewers: Hans Wennborg, Eli Freidman, Roman Lebedev
llvm-svn: 355483
This caused the first matcher in the isel table for many targets to Opc_Scope instead of Opc_SwitchOpcode. This leads to a significant increase in isel match failures.
llvm-svn: 355433
This patch enables combining integer bitcasts of integer build vectors when the new scalar type is legal. I've avoided floating point because the implementation bitcasts float to int along the way and we would need to check the intermediate types for legality
Differential Revision: https://reviews.llvm.org/D58884
llvm-svn: 355324
Summary:
Before when we implemented the first EH proposal, 'catch <tag>'
instruction may not catch an exception so there were multiple EH pads an
exception can unwind to. That means a BB could have multiple EH pad
successors.
Now after we switched to the new proposal, every 'catch' instruction
catches an exception, and there is only one catchpad per catchswitch, so
we at most have one EH pad successor, making `ThrowUnwindDest` map in
`WasmEHInfo` unnecessary.
Keeping `ThrowUnwindDest` map in `WasmEHInfo` has its own problems,
because other optimization passes can split a BB that contains possibly
throwing calls (previously invokes), and we have to update the map every
time that happens, which is not easy for common CodeGen passes.
This also correctly updates successor info in LateEHPrepare when we add
a rethrow instruction.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58486
llvm-svn: 355296
Previously we had build_vector PatFrags that called ISD::isBuildVectorAllZeros/Ones. Internally the ISD::isBuildVectorAllZeros/Ones look through bitcasts, but we aren't able to take advantage of that in isel. Instead of we have to canonicalize the types of the all zeros/ones build_vectors and insert bitcasts. Then we have to pattern match those exact bitcasts.
By emitting specific matchers for these 2 nodes, we can make isel look through any bitcasts without needing to explicitly match them. We should also be able to remove the canonicalization to vXi32 from lowering, but I've left that for a follow up.
This removes something like 40,000 bytes from the X86 isel table.
Differential Revision: https://reviews.llvm.org/D58595
llvm-svn: 355224
Summary:
The description of KnownBits::zext() and
KnownBits::zextOrTrunc() has confusingly been telling
that the operation is equivalent to zero extending the
value we're tracking. That has not been true, instead
the user has been forced to explicitly set the extended
bits as known zero afterwards.
This patch adds a second argument to KnownBits::zext()
and KnownBits::zextOrTrunc() to control if the extended
bits should be considered as known zero or as unknown.
Reviewers: craig.topper, RKSimon
Reviewed By: RKSimon
Subscribers: javed.absar, hiraditya, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58650
llvm-svn: 355099
At the moment, we mark every atomic memory access as being also volatile. This is unnecessarily conservative and prohibits many legal transforms (DCE, folding, etc..).
This patch removes MOVolatile from the MachineMemOperands of atomic, but not volatile, instructions. This should be strictly NFC after a series of previous patches which have gone in to ensure backend code is conservative about handling of isAtomic MMOs. Once it's in and baked for a bit, we'll start working through removing unnecessary bailouts one by one. We applied this same strategy to the middle end a few years ago, with good success.
To make sure this patch itself is NFC, it is build on top of a series of other patches which adjust code to (for the moment) be as conservative for an atomic access as for a volatile access and build up a test corpus (mostly in test/CodeGen/X86/atomics-unordered.ll)..
Previously landed
D57593 Fix a bug in the definition of isUnordered on MachineMemOperand
D57596 [CodeGen] Be conservative about atomic accesses as for volatile
D57802 Be conservative about unordered accesses for the moment
rL353959: [Tests] First batch of cornercase tests for unordered atomics.
rL353966: [Tests] RMW folding tests w/unordered atomic operations.
rL353972: [Tests] More unordered atomic lowering tests.
rL353989: [SelectionDAG] Inline a single use helper function, and remove last non-MMO interface
rL354740: [Hexagon, SystemZ] Be super conservative about atomics
rL354800: [Lanai] Be super conservative about atomics
rL354845: [ARM] Be super conservative about atomics
Attention Out of Tree Backend Owners: This patch may break you. If it does, you can use the TLI getMMOFlags hook to restore the MOVolatile to any instruction you need to. (See llvm-dev thread titled "PSA: Changes to how atomics are handled in backends" started Feb 27, 2019.)
Differential Revision: https://reviews.llvm.org/D57601
llvm-svn: 355025
If SADDSAT/SSUBSAT are legal, then we can expand SADDO/SSUBO by performing a ADD/SUB and a SADDO/SSUBO and then compare the results.
I looked at doing this for UADDO/USUBO as well but as we don't have to do as many range comparisons I didn't see any/much benefit.
Differential Revision: https://reviews.llvm.org/D58637
llvm-svn: 354866
These helpers extend the existing isConstOrConstSplat helper checks to support DemandedElts masks as well.
We already had a local version of this in SelectionDAG that computeKnownBits/ComputeNumSignBits made use of, but this adds the functionality directly to the BuildVectorSDNode node and extends isConstOrConstSplat etc. to use that.
This will allow us to reuse the functionality in SimplifyDemandedVectorElts/SimplifyDemandedBits.
Differential Revision: https://reviews.llvm.org/D58503
llvm-svn: 354797
Support undef shuffle mask indices in the shuffle(concat_vectors, concat_vectors) -> concat_vectors fold
Differential Revision: https://reviews.llvm.org/D58585
llvm-svn: 354793
OPC_CheckCondCode is always used as operand 2 of a setcc. And its always surrounded by a MoveChild2 and a MoveParent. By having a dedicated opcode for this case we can reduce the number of bytes needed for this pattern from 4 bytes to 2.
This saves ~3000 bytes in the X86 table.
llvm-svn: 354763
Summary:
When promoting the over flow vector for these ops we should use the target's desired setcc result type. This way a v8i32 result type will use a v8i32 overflow vector instead of a v8i16 overflow vector. A v8i16 overflow vector will cause LegalizeDAG/LegalizeVectorOps to have to use v8i32 and truncate to v8i16 in its expansion. By doing this in type legalization instead, we get the truncate into the DAG earlier and give DAG combine more of a chance to optimize it.
We also have to fix unrolling to use the scalar setcc result type for the scalarized operation, and convert it to the required vector element type after the scalar operation. We have to observe the vector boolean contents when doing this conversion. The previous code was just taking the scalar result and putting it in the vector. But for X86 and AArch64 that would have only put a the boolean value in bit 0 of the element and left all other bits in the element 0. We need to ensure all bits in the element are the same. I'm using a select with constants here because that's what setcc unrolling in LegalizeVectorOps used.
Reviewers: spatel, RKSimon, nikic
Reviewed By: nikic
Subscribers: javed.absar, kristof.beyls, dmgreen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D58567
llvm-svn: 354753
r354648 was a follow up to fix a regression "[X86] Add a DAG combine for (aext_vector_inreg (aext_vector_inreg X)) -> (aext_vector_inreg X) to fix a regression from my previous commit."
These were reverted in r354713 as their context depended on other patches that were reverted for a bug.
llvm-svn: 354734
r354363 caused https://crbug.com/934963#c1, which has a plain C reduced
test case.
I also had to revert some dependent changes:
- r354648
- r354647
- r354640
- r354511
llvm-svn: 354713
Guillaume Chatelet