Fix a couple of things that were causing stack protection to not work
correctly in functions that have scalable vectors on the stack:
* Use TypeSize when determining if accesses to a variable are
considered out-of-bounds so that the behaviour is correct for
scalable vectors.
* When stack protection is enabled move the stack protector location
to the top of the SVE locals, so that any overflow in them (or the
other locals which are below that) will be detected.
Fixes: https://github.com/llvm/llvm-project/issues/51137
Differential Revision: https://reviews.llvm.org/D111631
-(Za + Zm * Zn) != (-Za + Zm * (-Zn))
when the FMA produces a zero output (e.g. all zero inputs can produce -0
output)
Add a PatFrag to check presence of nsz on the fneg, add tests which
ensure the combine does not fire in the absense of nsz.
See https://reviews.llvm.org/D90901 for a similar discussion on X86.
Differential Revision: https://reviews.llvm.org/D109525
Restrict duplicate FP_EXTEND/FP_TRUNC -> LOAD/STORE DAG combines to only
larger than NEON types, as these are the ones for which there is custom
lowering.
Update tests so that they go through memory to improve validation.
Differential Revision: https://reviews.llvm.org/D115166
f526c600c0 had a concern raised because of an invalid typesize request
on a scalable vector, which this patch addresses.
Prevent shouldReduceLoadWidth from attempting to query the bit size, and
add a regression test in sve-extract-fixed-vector.ll.
Differential Revision: https://reviews.llvm.org/D115156
By duplicating these dag combines we can bypass the legality checks that
they do, this allows us to perform these combines on larger than legal
fixed types, which in turn allows us to bring the same benefits D114580
brought but to larger than legal fixed types.
Depends on D114580
Differential Revision: https://reviews.llvm.org/D114628
This adds a fold in DAGCombine to create fptosi_sat from sequences for
smin(smax(fptosi(x))) nodes, where the min/max saturate the output of
the fp convert to a specific bitwidth (say INT_MIN and INT_MAX). Because
it is dealing with smin(/smax) in DAG they may currently be ISD::SMIN,
ISD::SETCC/ISD::SELECT, ISD::VSELECT or ISD::SELECT_CC nodes which need
to be handled similarly.
A shouldConvertFpToSat method was added to control when converting may
be profitable. The original fptosi will have a less strict semantics
than the fptosisat, with less values that need to produce defined
behaviour.
This especially helps on ARM/AArch64 where the vcvt instructions
naturally saturate the result.
Differential Revision: https://reviews.llvm.org/D111976
It causes builds to fail with this assert:
llvm/include/llvm/ADT/APInt.h:990:
bool llvm::APInt::operator==(const llvm::APInt &) const:
Assertion `BitWidth == RHS.BitWidth && "Comparison requires equal bit widths"' failed.
See comment on the code review.
> This adds a fold in DAGCombine to create fptosi_sat from sequences for
> smin(smax(fptosi(x))) nodes, where the min/max saturate the output of
> the fp convert to a specific bitwidth (say INT_MIN and INT_MAX). Because
> it is dealing with smin(/smax) in DAG they may currently be ISD::SMIN,
> ISD::SETCC/ISD::SELECT, ISD::VSELECT or ISD::SELECT_CC nodes which need
> to be handled similarly.
>
> A shouldConvertFpToSat method was added to control when converting may
> be profitable. The original fptosi will have a less strict semantics
> than the fptosisat, with less values that need to produce defined
> behaviour.
>
> This especially helps on ARM/AArch64 where the vcvt instructions
> naturally saturate the result.
>
> Differential Revision: https://reviews.llvm.org/D111976
This reverts commit 52ff3b0093.
This adds a fold in DAGCombine to create fptosi_sat from sequences for
smin(smax(fptosi(x))) nodes, where the min/max saturate the output of
the fp convert to a specific bitwidth (say INT_MIN and INT_MAX). Because
it is dealing with smin(/smax) in DAG they may currently be ISD::SMIN,
ISD::SETCC/ISD::SELECT, ISD::VSELECT or ISD::SELECT_CC nodes which need
to be handled similarly.
A shouldConvertFpToSat method was added to control when converting may
be profitable. The original fptosi will have a less strict semantics
than the fptosisat, with less values that need to produce defined
behaviour.
This especially helps on ARM/AArch64 where the vcvt instructions
naturally saturate the result.
Differential Revision: https://reviews.llvm.org/D111976
I tried to exercise the existing combine patterns in performConcatVectorsCombine
for scalable vectors and at the moment it doesn't seem possible. Parts of
the code currently assume we're dealing with fixed-width vectors with calls
to getVectorNumElements(), therefore I've decided to simply bail out early
for scalable vectors.
Added a test here to show that we don't crash when attempting to combine
truncate + concat:
CodeGen/AArch64/concat_vector-truncate-combine.ll
Differential Revision: https://reviews.llvm.org/D114600
This allows the generic DAG combine to fold fp_extend/fp_trunc into
loads/stores which we can then lower into a integer extending
load/truncating store plus an FP_EXTEND/FP_ROUND.
The nuance here is that fixed-type FP_EXTEND/FP_ROUND require unpacked
types hence lowering them introduces an unpack/zip. By allowing these
nodes to be combined with loads/store we make it much easier to have
this unpack/zip combined into the load/store by our custom lowering.
Differential Revision: https://reviews.llvm.org/D114580
In most common cases the @llvm.get.active.lane.mask intrinsic maps directly
to the SVE whilelo instruction, which already takes overflow into account.
However, currently in SelectionDAGBuilder::visitIntrinsicCall we always lower
this immediately to a generic sequence of instructions that explicitly
take overflow into account. This makes it very difficult to then later
transform back into a single whilelo instruction. Therefore, this patch
introduces a new TLI function called shouldExpandGetActiveLaneMask that asks if
we should lower/expand this to a sequence of generic ISD nodes, or instead
just leave it as an intrinsic for the target to lower.
You can see the significant improvement in code quality for some of the
tests in this file:
CodeGen/AArch64/active_lane_mask.ll
Differential Revision: https://reviews.llvm.org/D114542
If we only demand bits from one half of a rotation pattern, see if we can simplify to a logical shift.
For the ARM/AArch64 rev16/32 patterns, I had to drop a fold to prevent srl(bswap()) -> rotr(bswap) -> srl(bswap) infinite loops. I've replaced this with an isel PatFrag which should do the same task.
Reapplied with fix for AArch64 rev patterns to matching the ARM fix.
https://alive2.llvm.org/ce/z/iroxki (rol -> shl by amt iff demanded bits has at least as many trailing zeros as the shift amount)
https://alive2.llvm.org/ce/z/4ez_U- (ror -> shl by revamt iff demanded bits has at least as many trailing zeros as the reverse shift amount)
https://alive2.llvm.org/ce/z/cD7dR- (ror -> lshr by amt iff demanded bits has at least as many leading zeros as the shift amount)
https://alive2.llvm.org/ce/z/_XGHtQ (rol -> lshr by revamt iff demanded bits has at least as many leading zeros as the reverse shift amount)
Differential Revision: https://reviews.llvm.org/D114354
This teaches AArch64TargetLowering::shouldSinkOperands to sink splat
shuffles to certain neon intrinsics, so that they can make use of the
lane variants of the instructions that are available.
Differential Revision: https://reviews.llvm.org/D112994
STATEPOINT instruction behavior is similar to call instruction.
In aarch64 BL instruction implicitly define lr register, so
STATEPOINT instruction should do the same.
However STATEPOINT is a general pseudo instruction and I could not find
a way to override list of implicit defs for specific target.
So this patch post processes inserting STATEPOINT instruction by
adding implisit dead def for lr.
Reviewers: reames, loicottet, ostannard
Reviewed By: reames
Subscribers: danilaml, hiraditya, kristof.beyls, llvm-commits, yrouban
Differential Revision: https://reviews.llvm.org/D111114
With fullfp16, it is cheaper to cast the {U,S}INT_TO_FP operand to i16
first, rather than promoting it to i32. The custom lowering for
{U,S}INT_TO_FP already supports that, it just needs to be used.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D113601
This extends performFpToIntCombine to work on FP16 vectors as well as
the f32 and f64 vectors it already supported.
Differential Revision: https://reviews.llvm.org/D113297
Similar to D113199 but dealing with the vector size, this extends the
fptosi+fmul to fixed point fold to handle fptosi.sat nodes that are
equally viable, so long as the saturation width matches the output
width.
Differential Revision: https://reviews.llvm.org/D113200
This adds FP type support to the SVE Container type list as a supplement to D112303.
Reviewed By: peterwaller-arm, paulwalker-arm
Differential Revision: https://reviews.llvm.org/D113333
When inserting an unpacked FP subvector into a packed vector we
can simply cast the unpacked value into a packed value, since
both types are legal for SVE. We can then use this as the input
for the UZP instruction. This avoids us expanding the operation
by going through the stack.
Differential Revision: https://reviews.llvm.org/D113270
Performing the rearrangement for add/sub and mul instructions to match the madd/msub pattern
Reviewed By: dmgreen, sdesmalen, david-arm
Differential Revision: https://reviews.llvm.org/D111862
When created a UUNPKLO/HI node with an undef input then the
output should also be undef. I've added a target DAG combine
function to ensure we avoid creating an unnecessary uunpklo/hi
instruction.
Differential Revision: https://reviews.llvm.org/D113266
This interface should not have existed in the first place, let alone
be a public member.
It allows calling `ElementCount::get(..)->getValue()`, which is ambiguous.
The interfaces to be used are either getFixedValue() or getKnownMinValue().
For NEON, FMA matching is done in the MachineCombiner, and not the
DAGCombiner. That causes problems with VLS lowering, since the
vectors are fixed width at the DAGCombiner, but are scalable in
the MachineCombiner. This patch corrects it by matching FMAs for
VLS vectors in the DAGCombiner.
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D112557
This adds support for SVE structured loads/stores to the relevant target
hooks, such that we can support these instructions in the InterleavedAccess
pass.
Depends on D112078
Differential Revision: https://reviews.llvm.org/D112303
This patch enables the use of reciprocal estimates for SVE
when both the -Ofast and -mrecip flags are used.
Reviewed By: david-arm, paulwalker-arm
Differential Revision: https://reviews.llvm.org/D111657
Inspired by D111968, provide a isNegatedPowerOf2() wrapper instead of obfuscating code with (-Value).isPowerOf2() patterns, which I'm sure are likely avenues for typos.....
Differential Revision: https://reviews.llvm.org/D111998
Try to widen element type to get a new mask value for a better permutation
sequence, so that we can use NEON shuffle instructions, such as zip1/2,
UZP1/2, TRN1/2, REV, INS, etc.
For example:
shufflevector <4 x i32> %a, <4 x i32> %b, <4 x i32> <i32 6, i32 7, i32 2, i32 3>
is equivalent to:
shufflevector <2 x i64> %a, <2 x i64> %b, <2 x i32> <i32 3, i32 1>
Finally, we can get:
mov v0.d[0], v1.d[1]
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D111619
Similar to D111236, this improves the lowering of vector fptosi.sat and
fptoui.sat, using legal converts and further saturating from there with
min/max. f64 are excluded for the moment due to producing worse code in
places compared to the unrolling.
Differential Revision: https://reviews.llvm.org/D111787
Improve the lowering of scalar fptosi.sat and fptoui.sat for saturating
widths smaller than legal types by using the fact that the legal type
will saturate under aarch64, and saturating the result further using
min/max.
Differential Revision: https://reviews.llvm.org/D111236
The lowering for EXTRACT_SUBVECTOR should not be called during type
legalization, only as part of lowering, hence return SDValue() when
called on illegal types.
This also adds missing tests for extracting fixed types from illegal
scalable types.
Differential Revision: https://reviews.llvm.org/D111412
AAPCS requires i1 argument to be zero-extended to 8-bits by the
caller. Emit a new AArch64ISD::ASSERT_ZEXT_BOOL hint (or AssertZExt
for GlobalISel) to enable some optimization opportunities. In
particular, when the argument is forwarded to the callee, we can avoid
zero-extension and use it as-is.
Differential Revision: https://reviews.llvm.org/D107160
Stop using APInt constructors and methods that were soft-deprecated in
D109483. This fixes all the uses I found in llvm, except for the APInt
unit tests which should still test the deprecated methods.
Differential Revision: https://reviews.llvm.org/D110807
Like normal atomicrmw operations, at -O0 the simple register-allocator can
insert spills into the LL/SC loop if it's expanded and visible when regalloc
runs. This can cause the operation to never succeed by repeatedly clearing the
monitor. Instead expand to a cmpxchg, which has a pseudo-instruction for -O0.
v8.4 says that normal loads/stores of 128-bytes are single-copy atomic if
they're properly aligned (which all LLVM atomics are) so we no longer need to
do a full RMW operation to guarantee we got a clean read.
This extends the custom lowering for extending loads on
fixed length vectors in SVE to support masked extending loads.
The existing tests for correct behaviour of masked extending loads
exhibit bad code generation due to the legalistaion of i1 vectors.
They have been left as-is and new tests have been added that do not
exhibit this behaviour.
Differential Revision: https://reviews.llvm.org/D108200
When combining 'and' of an unsigned unpack and shuffle instruction,
bail early if shuffle is not constructed from a constant integer.
Reviewed By: paulwalker-arm
Differential Revision: https://reviews.llvm.org/D109556
Soft deprecrate isNullValue/isAllOnesValue and update in tree
callers. This matches the changes to the APInt interface from
D109483.
Reviewed By: lattner
Differential Revision: https://reviews.llvm.org/D109535
This renames the primary methods for creating a zero value to `getZero`
instead of `getNullValue` and renames predicates like `isAllOnesValue`
to simply `isAllOnes`. This achieves two things:
1) This starts standardizing predicates across the LLVM codebase,
following (in this case) ConstantInt. The word "Value" doesn't
convey anything of merit, and is missing in some of the other things.
2) Calling an integer "null" doesn't make any sense. The original sin
here is mine and I've regretted it for years. This moves us to calling
it "zero" instead, which is correct!
APInt is widely used and I don't think anyone is keen to take massive source
breakage on anything so core, at least not all in one go. As such, this
doesn't actually delete any entrypoints, it "soft deprecates" them with a
comment.
Included in this patch are changes to a bunch of the codebase, but there are
more. We should normalize SelectionDAG and other APIs as well, which would
make the API change more mechanical.
Differential Revision: https://reviews.llvm.org/D109483
The isEssentiallyExtractHighSubvector function currently calls
getVectorNumElements on a type that in specific cases might be scalable.
Since this function only has correct behaviour at the moment on scalable
types anyway, the function can just return false when given a fixed type.
Differential Revision: https://reviews.llvm.org/D109163
When lowering a fixed length gather/scatter the index type is assumed to
be the same as the memory type, this is incorrect in cases where the
extension of the index has been folded into the addressing mode.
For now add a temporary workaround to fix the codegen faults caused by
this by preventing the removal of this extension. At a later date the
lowering for SVE gather/scatters will be redesigned to improve the way
addressing modes are handled.
As a short term side effect of this change, the addressing modes
generated for fixed length gather/scatters will not be optimal.
Differential Revision: https://reviews.llvm.org/D109145
For vectors that are exactly equal to getMaxSVEVectorSizeInBits, just use
AArch64SVEPredPattern::all, which can enable the use of unpredicated ptrue when available.
TestPlan: check-llvm
Differential Revision: https://reviews.llvm.org/D108706
This patch solely moves convert operation between SVE predicate pattern
and element number into two small functions. It's pre-commit patch for optimize
pture with known sve register width.
Differential Revision: https://reviews.llvm.org/D108705
This allows the instruction selector to realize that it can directly
broadcast the low byte of the memset value, rather than replicating
it to a 64-bit GPR before broadcasting.
This fixes PR50985.
Differential Revision: https://reviews.llvm.org/D108354
If Orig produces more than one value (rare) with different types (rarer) then
we need to make sure we check against the one that Orig actually represents,
not just the first type.
Unfortunately because of the combination of things that need to happen I wasn't
able to produce a test.
Follow-up to D107068, attempt to fold nested concat_vectors/undefs, as long as both the vector and inner subvector types are legal.
This exposed the same issue in ARM's MVE LowerCONCAT_VECTORS_i1 (raised as PR51365) and AArch64's performConcatVectorsCombine which both assumed concat_vectors only took 2 subvector operands.
Differential Revision: https://reviews.llvm.org/D107597
This patch enables extending loads for fixed length SVE code generation.
There is a slight regression here in the mulh tests; since these tests
load the parameter and then extend it these are treated as extending
loads which are merged, preventing the mulh instruction from being
generated. As this affects scalable SVE codegen as well this should be
addressed in a separate patch.
Reviewed By: bsmith
Differential Revision: https://reviews.llvm.org/D107057
This was checking extends as shuffles, where as we should be checking
the operands. This helps sink the shuffles, creating more addl/subl
instructions.
Differential Revision: https://reviews.llvm.org/D107623
I was originally going to try to implement this in target-independent
code, but it's actually sort of tricky to generate the correct sequence
for vectors like nxv2f32. So just stick this in target-specific code,
at least for now.
Differential Revision: https://reviews.llvm.org/D107608
The patterns for fixed length gather/scatter with 32-bit offsets and
64-bit memory type are slightly different that the rest of the patterns,
as such the lowering needs to be slightly different to ensure the
correct types are used.
Differential Revision: https://reviews.llvm.org/D107576
IR typically creates INSERT_SUBVECTOR patterns as a widening of the subvector with undefs to pad to the destination size, followed by a shuffle for the actual insertion - SelectionDAGBuilder has to do something similar for shuffles when source/destination vectors are different sizes.
This combine attempts to recognize these patterns by looking for a shuffle of a subvector (from a CONCAT_VECTORS) that starts at a modulo of its size into an otherwise identity shuffle of the base vector.
This uncovered a couple of target-specific issues as we haven't often created INSERT_SUBVECTOR nodes in generic code - aarch64 could only handle insertions into the bottom of undefs (i.e. a vector widening), and x86-avx512 vXi1 insertion wasn't keeping track of undef elements in the base vector.
Fixes PR50053
Differential Revision: https://reviews.llvm.org/D107068
Don't know how to custom expand this
UNREACHABLE executed at llvm-project/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp:16788
The fix is to provide missing expansions for:
case ISD::STRICT_FP_TO_UINT:
case ISD::STRICT_FP_TO_SINT:
A test case is provided.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D107452
This patch legalizes the Machine Value Type introduced in D94096 for loads
and stores. A new target hook named getAsmOperandValueType() is added which
maps i512 to MVT::i64x8. GlobalISel falls back to DAG for legalization.
Differential Revision: https://reviews.llvm.org/D94097
An incorrect mask type when lowering an SVE gather/scatter was causing
a codegen fault which manifested as the incorrect predicate size being
used for an SVE gather/scatter, (e.g.. p0.b rather than p0.d).
Fixes PR51182.
Differential Revision: https://reviews.llvm.org/D106943
This patch implements vector_splice in tablegen for all cases when the
Immediate is positive and lower than the known minimum value of
a scalable vector.
Vector_splice can be implemented using SVE instruction EXT.
For instance :
@llvm.experimental.vector.splice(Vector_1, Vector_2, Imm)
@llvm.experimental.vector.splice(<A,B,C,D>, <E,F,G,H>, 1) ==> <B, C, D, E>
EXT Vector_1, Vector_2, Imm // Vector_1 = B, C, D + Vector_2 = E
Depends on D105633
Differential Revision: https://reviews.llvm.org/D106273
This patch implements vector_splice in tablegen for:
a) when the immediate is equal to -1 (Imm==1) and uses:
INSR + LASTB
For instance :
@llvm.experimental.vector.splice(Vector_1, Vector_2, -1)
@llvm.experimental.vector.splice(<A,B,C,D>, <E,F,G,H>, 1) ==> <D, E, F, G>
LAST RegLast, Vector_1 // RegLast = D
INSR Res, (Vector_1 >> 1), RegLast // Res = D + E, F, G
Differential Revision: https://reviews.llvm.org/D105633
This adds custom lowering for truncating stores when operating on
fixed length vectors in SVE. It also includes a DAG combine to
fold extends followed by truncating stores into non-truncating
stores in order to prevent this pattern appearing once truncating
stores are supported.
Currently truncating stores are not used in certain cases where
the size of the vector is larger than the target vector width.
Differential Revision: https://reviews.llvm.org/D104471
Basically two parts to this fix:
1. Stop using AtomicExpand to expand cmpxchg i128
2. Fix AArch64ExpandPseudoInsts to use a correct expansion.
From ARM architecture reference:
To atomically load two 64-bit quantities, perform a Load-Exclusive
pair/Store-Exclusive pair sequence of reading and writing the same value
for which the Store-Exclusive pair succeeds, and use the read values
from the Load-Exclusive pair.
Fixes https://bugs.llvm.org/show_bug.cgi?id=51102
Differential Revision: https://reviews.llvm.org/D106039
This removes the promotion of NEON AND, OR and XOR nodes to v2i32/v4i32,
treating them the same as the AArch64 and MVE backends where we just add
the relevant patterns for each legal type. This prevents a lot of
bitcasts from being added to the DAG, which have the potential to make
optimizations more difficult. It does mean adding extra patterns, and
some codegen can change due to the types now being legal, not promoted.
Differential Revision: https://reviews.llvm.org/D105588
The case for nxv2f32/nxv2i32 was already covered by D104573.
This patch builds on top of that by making the mechanism work for
nxv2[b]f16/nxv2i16, nxv4[b]f16/nxv4i16 as well.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D106138
This is mostly a minor convenience, but the pattern seems frequent
enough to be worthwhile (and we'll probably add more uses in the
future).
Differential Revision: https://reviews.llvm.org/D105850
This adds custom lowering for truncating stores when operating on
fixed length vectors in SVE. It also includes a DAG combine to
fold extends followed by truncating stores into non-truncating
stores in order to prevent this pattern appearing once truncating
stores are supported.
Currently truncating stores are not used in certain cases where
the size of the vector is larger than the target vector width.
Differential Revision: https://reviews.llvm.org/D104471
Additionally, lower the floating point compare SVE intrinsics to
SETCC_MERGE_ZERO ISD nodes to avoid duplicating ISel patterns.
Differential Revision: https://reviews.llvm.org/D105486
This patch adds a new ShuffleKind SK_Splice and then handle the cost in
getShuffleCost, as in experimental.vector.reverse.
Differential Revision: https://reviews.llvm.org/D104630
Improve codegen when lowering the common vector shuffle case from the
vectorizer (op1[last]:op2[0:last-1]). This patch only handles this
common case as it is difficult to handle this more generally when using
fixed length vectors, due to being unable to use the SVE ext instruction.
Differential Revision: https://reviews.llvm.org/D105289
Target-independent code only knows how to spill to the stack; instead,
use AArch64ISD::REINTERPRET_CAST.
Differential Revision: https://reviews.llvm.org/D104573
Inserting into a smaller-than-legal scalable vector would result in an
internal compiler error. For example, inserting a <vscale x 4 x i8> into
a <vscale x 8 x i8> (both illegal vector types for SVE) would cause a
crash.
This crash was happening because there was no code to promote (legalise)
the result of an INSERT_SUBVECTOR node.
This patch implements PromoteIntRes_INSERT_SUBVECTOR, which legalises
the ISD node. This is currently done by going through memory. This is
necessary because of the requirement that the SubVec parameter of the
INSERT_SUBVECTOR node must be smaller than the Vec parameter, which
means that INSERT_SUBVECTOR cannot always have a legal result/operand
types.
Co-Authored-by: Joe Ellis <joe.ellis@arm.com>
Differential Revision: https://reviews.llvm.org/D102766
Since gather lowering can now lower to nodes that may need expansion via
the vector legalizer, do MGATHER lowering via vector legalizer.
Additionally, as part of adding passthru support for fixed typed
gathers, fix passthru support for scalable types.
Depends on D104910
Differential Revision: https://reviews.llvm.org/D104217
This ports the AArch64 SABD and USBD over to DAG Combine, where they can be
used by more backends (notably MVE in a follow-up patch). The matching code
has changed very little, just to handle legal operations and types
differently. It selects from (ABS (SUB (EXTEND a), (EXTEND b))), producing
a ubds/abdu which is zexted to the original type.
Differential Revision: https://reviews.llvm.org/D91937
This custom lowers <4 x i8> vector loads using a 32-bit load, followed by 2
SSHLL instructions to extend it to e.g. a <4 x i32> vector. Before, it was
really inefficient and expensive to construct a <4 x i32> for this as 4 byte
loads and 4 moves were used. With this improvement SLP vectorisation might for
example become profitable, see D103629.
Differential Revision: https://reviews.llvm.org/D104782
This is a mechanical change. This actually also renames the
similarly named methods in the SmallString class, however these
methods don't seem to be used outside of the llvm subproject, so
this doesn't break building of the rest of the monorepo.
This also adds new interfaces for the fixed- and scalable case:
* LLT::fixed_vector
* LLT::scalable_vector
The strategy for migrating to the new interfaces was as follows:
* If the new LLT is a (modified) clone of another LLT, taking the
same number of elements, then use LLT::vector(OtherTy.getElementCount())
or if the number of elements is halfed/doubled, it uses .divideCoefficientBy(2)
or operator*. That is because there is no reason to specifically restrict
the types to 'fixed_vector'.
* If the algorithm works on the number of elements (as unsigned), then
just use fixed_vector. This will need to be fixed up in the future when
modifying the algorithm to also work for scalable vectors, and will need
then need additional tests to confirm the behaviour works the same for
scalable vectors.
* If the test used the '/*Scalable=*/true` flag of LLT::vector, then
this is replaced by LLT::scalable_vector.
Reviewed By: aemerson
Differential Revision: https://reviews.llvm.org/D104451
This only applies to FastIsel. GlobalIsel seems to sidestep
the issue.
This fixes https://bugs.llvm.org/show_bug.cgi?id=46996
One of the things we do in llvm is decide if a type needs
consecutive registers. Previously, we just checked if it
was an array or not.
(plus an SVE specific check that is not changing here)
This causes some confusion when you arbitrary IR like:
```
%T1 = type { double, i1 };
define [ 1 x %T1 ] @foo() {
entry:
ret [ 1 x %T1 ] zeroinitializer
}
```
We see it is an array so we call CC_AArch64_Custom_Block
which bails out when it sees the i1, a type we don't want
to put into a block.
This leaves the location of the double in some kind of
intermediate state and leads to odd codegen. Which then crashes
the backend because it doesn't know how to implement
what it's been asked for.
You get this:
```
renamable $d0 = FMOVD0
$w0 = COPY killed renamable $d0
```
Rather than this:
```
$d0 = FMOVD0
$w0 = COPY $wzr
```
The backend knows how to copy 64 bit to 64 bit registers,
but not 64 to 32. It can certainly be taught how but the real
issue seems to be us even trying to assign a register block
in the first place.
This change makes the logic of
AArch64TargetLowering::functionArgumentNeedsConsecutiveRegisters
a bit more in depth. If we find an array, also check that all the
nested aggregates in that array have a single member type.
Then CC_AArch64_Custom_Block's assumption of a type that looks
like [ N x type ] will be valid and we get the expected codegen.
New tests have been added to exercise these situations. Note that
some of the output is not ABI compliant. The aim of this change is
to simply handle these situations and not to make our processing
of arbitrary IR ABI compliant.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D104123
Currently, Loop strengh reduce is not handling loops with scalable stride very well.
Take loop vectorized with scalable vector type <vscale x 8 x i16> for instance,
(refer to test/CodeGen/AArch64/sve-lsr-scaled-index-addressing-mode.ll added).
Memory accesses are incremented by "16*vscale", while induction variable is incremented
by "8*vscale". The scaling factor "2" needs to be extracted to build candidate formula
i.e., "reg(%in) + 2*reg({0,+,(8 * %vscale)}". So that addrec register reg({0,+,(8*vscale)})
can be reused among Address and ICmpZero LSRUses to enable optimal solution selection.
This patch allow LSR getExactSDiv to recognize special cases like "C1*X*Y /s C2*X*Y",
and pull out "C1 /s C2" as scaling factor whenever possible. Without this change, LSR
is missing candidate formula with proper scaled factor to leverage target scaled-index
addressing mode.
Note: This patch doesn't fully fix AArch64 isLegalAddressingMode for scalable
vector. But allow simple valid scale to pass through.
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D103939
Given a vecreduce_add node, detect the below pattern and convert it to the node
sequence with UABDL, [S|U]ADB and UADDLP.
i32 vecreduce_add(
v16i32 abs(
v16i32 sub(
v16i32 [sign|zero]_extend(v16i8 a), v16i32 [sign|zero]_extend(v16i8 b))))
=================>
i32 vecreduce_add(
v4i32 UADDLP(
v8i16 add(
v8i16 zext(
v8i8 [S|U]ABD low8:v16i8 a, low8:v16i8 b
v8i16 zext(
v8i8 [S|U]ABD high8:v16i8 a, high8:v16i8 b
Differential Revision: https://reviews.llvm.org/D104042
Don't require a specific kind of IRBuilder for TargetLowering hooks.
This allows us to drop the IRBuilder.h include from TargetLowering.h.
Differential Revision: https://reviews.llvm.org/D103759
This NEG node is just a vector negation, easily represented as a SUB
zero. Removing it from the one place it is generated is essentially an
NFC, but can allow some extra folding. The updated tests are now loading
different constant literals, which have already been negated.
Differential Revision: https://reviews.llvm.org/D103703
setcc (csel 0, 1, cond, X), 1, ne ==> csel 0, 1, !cond, X
Where X is a condition code setting instruction.
Co-authored-by: Paul Walker <paul.walker@arm.com>
Differential Revision: https://reviews.llvm.org/D103256
If a cmpxchg specifies acquire or seq_cst on failure, make sure we
generate code consistent with that ordering even if the success ordering
is not acquire/seq_cst.
At one point, it was ambiguous whether this sort of construct was valid,
but the C++ standad and LLVM now accept arbitrary combinations of
success/failure orderings.
This doesn't address the corresponding issue in AtomicExpand. (This was
reported as https://bugs.llvm.org/show_bug.cgi?id=33332 .)
Fixes https://bugs.llvm.org/show_bug.cgi?id=50512.
Differential Revision: https://reviews.llvm.org/D103284
SwiftTailCC has a different set of requirements than the C calling convention
for a tail call. The exact argument sequence doesn't have to match, but fewer
ABI-affecting attributes are allowed.
Also make sure the musttail diagnostic triggers if a musttail call isn't
actually a tail call.
This adds custom lowering for the MLOAD and MSTORE ISD nodes when
passed fixed length vectors in SVE. This is done by converting the
vectors to VLA vectors and using the VLA code generation.
Fixed length extending loads and truncating stores currently produce
correct code, but do not use the built in extend/truncate in the
load and store instructions. This will be fixed in a future patch.
Differential Revision: https://reviews.llvm.org/D101834
bswap.v2i16 + sitofp in LLVM IR generate a sequence of:
- REV32 + USHR for bswap.v2i16
- SHL + SSHR + SCVTF for sext to v2i32 and scvt
The shift instructions are excessive as noted in PR24820, and they can
be optimized to just SSHR.
Differential Revision: https://reviews.llvm.org/D102333
The implementation just extends the vector to a larger element type, and
extracts from that. Not fancy, but generates reasonable code.
There was discussion in the review of doing the promotion in
target-independent code, but I'm sticking with this to avoid making
LegalizeDAG infrastructure more complicated.
Differential Revision: https://reviews.llvm.org/D87651
Adding lowering support for bitreverse.
Previously, lowering bitreverse would expand it into a series of other instructions. This patch makes it so this produces a single rbit instruction instead.
Reviewed By: dmgreen
Differential Revision: https://reviews.llvm.org/D102397
Swift's new concurrency features are going to require guaranteed tail calls so
that they don't consume excessive amounts of stack space. This would normally
mean "tailcc", but there are also Swift-specific ABI desires that don't
naturally go along with "tailcc" so this adds another calling convention that's
the combination of "swiftcc" and "tailcc".
Support is added for AArch64 and X86 for now.
AArch64's fctv* instructions implement the saturating behaviour that the
fpto*i.sat intrinsics require, in cases where the destination width
matches the saturation width. Lowering them removes a lot of unnecessary
generated code.
Only scalar lowerings are supported for now.
Differential Revision: https://reviews.llvm.org/D102353
Addition of this node allows us to better utilize the different forms of
the SVE BIC instructions, including using the alias to an AND (immediate).
Differential Revision: https://reviews.llvm.org/D101831
This extends any frame record created in the function to include that
parameter, passed in X22.
The new record looks like [X22, FP, LR] in memory, and FP is stored with 0b0001
in bits 63:60 (CodeGen assumes they are 0b0000 in normal operation). The effect
of this is that tools walking the stack should expect to see one of three
values there:
* 0b0000 => a normal, non-extended record with just [FP, LR]
* 0b0001 => the extended record [X22, FP, LR]
* 0b1111 => kernel space, and a non-extended record.
All other values are currently reserved.
If compiling for arm64e this context pointer is address-discriminated with the
discriminator 0xc31a and the DB (process-specific) key.
There is also an "i8** @llvm.swift.async.context.addr()" intrinsic providing
front-ends access to this slot (and forcing its creation initialized to nullptr
if necessary).
The sve.convert.to.svbool lowering has the effect of widening a logical
<M x i1> vector representing lanes into a physical <16 x i1> vector
representing bits in a predicate register.
In general, if converting to svbool, the contents of lanes in the
physical register might not be known. For sve.convert.to.svbool the new
lanes are specified to be zeroed, requiring 'and' instructions to mask
off the new lanes. For lanes coming from a ptrue or a comparison,
however, they are known to be zero.
CodeGen Before:
ptrue p0.s, vl16
ptrue p1.s
ptrue p2.b
and p0.b, p2/z, p0.b, p1.b
ret
After:
ptrue p0.s, vl16
ret
Differential Revision: https://reviews.llvm.org/D101544
Expanding a fixed length operation involves wrapping the operation in an
insert/extract subvector pair, as such, when this is done to bitcast we
end up with an extract_subvector of a bitcast. DAGCombine tries to
convert this into a bitcast of an extract_subvector which restores the
initial fixed length bitcast, causing an infinite loop of legalization.
As part of this patch, we must make sure the above DAGCombine does not
trigger after legalization if the created bitcast would not be legal.
Differential Revision: https://reviews.llvm.org/D101990
When using predicated intrinsics, if the predicate used is all lanes active,
use an unpredicated form of the instruction, additionally this allows for
better use of immediate forms.
This only includes instructions where the unpredicated/predicated forms
matched in such a way that instruction selection would not introduce extra
ptrue instructions. This allows us to convert the intrinsics directly to
architecture independent ISD nodes.
Depends on D101062
Differential Revision: https://reviews.llvm.org/D101828
When using predicated arithmetic intrinsics, if the predicate used is all
lanes active, use an unpredicated form of the instruction, additionally
this allows for better use of immediate forms.
This also includes a new complex isel pattern which allows matching an
all active predicate when the types are different but the predicate is a
superset of the type being used. For example, to allow a b8 ptrue for a
b32 predicate operand.
This only includes instructions where the unpredicated/predicated forms
are mismatched between variants, meaning that the removal of the
predicate is done during instruction selection in order to prevent
spurious re-introductions of ptrue instructions.
Co-authored-by: Paul Walker <paul.walker@arm.com>
Differential Revision: https://reviews.llvm.org/D101062
DAGCombiner tries to combine a (fpext (load)) to (fround (extload))
but SVE has no FP-extending loads. By marking these as expand,
the combine no longer happens.
This also fixes a similar issue for fptrunc, where the source type
is not a legal type.
Reviewed By: bsmith, kmclaughlin
Differential Revision: https://reviews.llvm.org/D102053
Since index_vector is lowered into step_vector in D100816, we can just remove
index_vector, use step_vector for codegen directly.
Differential Revision: https://reviews.llvm.org/D101593
Based off a discussion on D89281 - where the AARCH64 implementations were being replaced to use funnel shifts.
Any target that has efficient funnel shift lowering can handle the shift parts expansion using the same expansion, avoiding a lot of duplication.
I've generalized the X86 implementation and moved it to TargetLowering - so far I've found that AARCH64 and AMDGPU benefit, but many other targets (ARM, PowerPC + RISCV in particular) could easily use this with a few minor improvements to their funnel shift lowering (or the folding of their target ops that funnel shifts lower to).
NOTE: I'm trying to avoid adding full SHIFT_PARTS legalizer handling as I think it might actually be possible to remove these opcodes in the medium-term and use funnel shift / libcall expansion directly.
Differential Revision: https://reviews.llvm.org/D101987
Specifically, this allow us to rely on the lane zero'ing behaviour of
SVE reduce instructions.
Co-authored-by: Paul Walker <paul.walker@arm.com>
Differential Revision: https://reviews.llvm.org/D101369
This can come up in rare situations, where a csel is created with
identical operands. These can be folded simply to the original value,
allowing the csel to be removed and further simplification to happen.
This patch also removes FCSEL as it is unused, not being produced
anywhere or lowered to anything.
Differential Revision: https://reviews.llvm.org/D101687
Apply the same logic used to check if CMPXCHG nodes should be expanded
at -O0: the register allocator may end up spilling some register in
between the atomic load/store pairs, breaking the atomicity and possibly
stalling the execution.
Fixes PR48017
Reviewed By: efriedman
Differential Revision: https://reviews.llvm.org/D101163
These operations don't exist natively, so just let the
target-independent code expand to plain shifts.
The generated sequences could probably be optimized a bit more, but
they seem good enough for now.
Differential Revision: https://reviews.llvm.org/D101574
As discussed in D100107, this patch first convert index_vector to
step_vector, and convert step_vector back to index_vector after LegalizeDAG.
Differential Revision: https://reviews.llvm.org/D100816
John Brawn