63852 Commits

Author SHA1 Message Date
Heejin Ahn
aa0b0fbbe6 [WebAssembly] Use SDValue::getConstantOperandVal (NFC)
Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D107499
2021-08-04 21:15:23 -07:00
Matt Jacobson
75abeb64ce [AVR] emit 'MCSA_Global' references to '__do_global_ctors' and '__do_global_dtors'
Emit references to '__do_global_ctors' and '__do_global_dtors' to allow
constructor/destructor routines to run.

Reviewed by: MaskRay

Differential Revision: https://reviews.llvm.org/D107133
2021-08-05 10:37:36 +08:00
Yonghong Song
e52946b9ab BPF: avoid NE/EQ loop exit condition
Kuniyuki Iwashima reported in [1] that llvm compiler may
convert a loop exit condition with "i < bound" to "i != bound", where
"i" is the loop index variable and "bound" is the upper bound.
In case that "bound" is not a constant, verifier will always have "i != bound"
true, which will cause verifier failure since to verifier this is
an infinite loop.

The fix is to avoid transforming "i < bound" to "i != bound".
In llvm, the transformation is done by IndVarSimplify pass.
The compiler checks loop condition cost (i = i + 1) and if the
cost is lower, it may transform "i < bound" to "i != bound".
This patch implemented getArithmeticInstrCost() in BPF TargetTransformInfo
class to return a higher cost for such an operation, which
will prevent the transformation for the test case
added in this patch.

 [1] https://lore.kernel.org/netdev/1994df05-8f01-371f-3c3b-d33d7836878c@fb.com/

Differential Revision: https://reviews.llvm.org/D107483
2021-08-04 16:54:16 -07:00
Jessica Paquette
ca2e053652 [AArch64][GlobalISel] Legalize wide vector G_PHIs
Clamp the max number of elements when legalizing G_PHI. This allows us to
legalize some common fallbacks like 4 x s64.

Here's an example: https://godbolt.org/z/6YocsEYTd

Had to add -global-isel-abort=0 to legalize-phi.mir to account for the
G_EXTRACT_VECTOR_ELT from the 32 x s8 G_PHI.

Differential Revision: https://reviews.llvm.org/D107508
2021-08-04 16:48:59 -07:00
Heejin Ahn
31a71a393f [WebAssembly] Make result of 'catch' inst variadic
`catch` instruction can have any number of result values depending on
its tag, but so far we have only needed a single i32 return value for
C++ exception so the instruction was specified that way. But using the
instruction for SjLj handling requires multiple return values.

This makes `catch` instruction's results variadic and moves selection of
`throw` and `catch` instruction from ISelLowering to ISelDAGToDAG.
Moving `catch` to ISelDAGToDAG is necessary because I am not aware of
a good way to do instruction selection for variadic output instructions
in TableGen. This also moves `throw` because 1. `throw` and `catch`
share the same utility function and 2. there is really no reason we
should do that in ISelLowering in the first place. What we do is mostly
the same in both places, and moving them to ISelDAGToDAG allows us to
remove unnecessary mid-level nodes for `throw` and `catch` in
WebAssemblyISD.def and WebAssemblyInstrInfo.td.

This also adds handling for new `catch` instruction to AsmTypeCheck.

Reviewed By: dschuff, tlively

Differential Revision: https://reviews.llvm.org/D107423
2021-08-04 14:05:33 -07:00
Fangrui Song
9c19b36f1c [X86] Remove -x86-experimental-pref-loop-alignment in favor of -align-loops 2021-08-04 13:23:57 -07:00
Michael Liao
5edc886e90 [amdgpu] Add an enhanced conversion from i64 to f32.
Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D107187
2021-08-04 15:33:12 -04:00
Reshabh Sharma
dce35ef104 Revert "[AMDGPU] Handle functions in llvm's global ctors and dtors list"
This reverts commit d42e70b3d315645e37f3b1455d39e68678e69525.
2021-08-04 23:33:31 +05:30
Craig Topper
643ce70a64 [RISCV] Remove the _COMMUTABLE and _TA versions of FMA and wide FMA vector instructions.
Use a tail policy operand instead. Inspired by the work in D105092,
but without the intrinsic interface changes.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D106512
2021-08-04 10:39:50 -07:00
Jessica Paquette
d9279843b1 [AArch64][GlobalISel] Widen G_PHI before clamping it during legalization
This allows us to handle weird types like s88; we first widen to s128, then
clamp back down to s64.

https://godbolt.org/z/9xqbP46Mz

Also this makes it possible for GISel to legalize the case in pr48188.ll. It
now does the same thing as SDAG, although regalloc chooses different registers.

Differential Revision: https://reviews.llvm.org/D107417
2021-08-04 10:25:14 -07:00
Jessica Paquette
7d97de60b3 [AArch64][GlobalISel] Widen G_FPTO*I before clamping
Going through our legalization rules and doing some cleanup.

Widening and then clamping is usually easier than clamping and then widening.

This allows us to legalize some weird types like s88.

Differential Revision: https://reviews.llvm.org/D107413
2021-08-04 10:19:26 -07:00
Andrea Di Biagio
7a1a35a1d1 [X86][SchedModel] Add missing ReadAdvance for some arithmetic ops (PR51318 and PR51322).
This fixes a bug where implicit uses of EFLAGS were not marked as ReadAdvance in
the RM/MR variants of ADC/SBB (PR51318)

This also fixes the absence of ReadAdvance for the register operand of
RMW arithmetic instructions (PR51322).

Differential Revision: https://reviews.llvm.org/D107367
2021-08-04 17:50:22 +01:00
Bradley Smith
d9cc5d84e4 [AArch64][SVE] Combine bitcasts of predicate types with vector inserts/extracts of loads/stores
An insert subvector that is inserting the result of a vector predicate
sized load into undef at index 0, whose result is casted to a predicate
type, can be combined into a direct predicate load. Likewise the same
applies to extract subvector but in reverse.

The purpose of this optimization is to clean up cases that will be
introduced in a later patch where casts to/from predicate types from i8
types will use insert subvector, rather than going through memory early.

This optimization is done in SVEIntrinsicOpts rather than InstCombine to
re-introduce scalable loads as late as possible, to give other
optimizations the best chance possible to do a good job.

Differential Revision: https://reviews.llvm.org/D106549
2021-08-04 15:51:14 +00:00
Simon Wallis
9269752671 [AArch64] Fix assert AArch64TargetLowering::ReplaceNodeResults
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
2021-08-04 16:18:19 +01:00
Reshabh Sharma
d42e70b3d3 [AMDGPU] Handle functions in llvm's global ctors and dtors list
This patch introduces a new code object metadata field, ".kind"
which is used to add support for init and fini kernels.

HSAStreamer will use function attributes, "device-init" and
"device-fini" to distinguish between init and fini kernels from
the regular kernels and will emit metadata with ".kind" set to
"init" and "fini" respectively.

To reduce the number of init and fini kernels, the ctors and
dtors present in the llvm's global.ctors and global.dtors lists
are called from a single init and fini kernel respectively.

Reviewed by: yaxunl

Differential Revision: https://reviews.llvm.org/D105682
2021-08-04 19:53:33 +05:30
Roman Lebedev
35c0848b57
[NFC][X86] combineX86ShuffleChain(): hoist Mask variable higher up
Having `NewMask` outside of an if and rebinding `BaseMask` `ArrayRef`
to it is confusing. Instead, just move the `Mask` vector higher up,
and change the code that earlier had no access to it but now does
to use `Mask` instead of `BaseMask`.

This has no other intentional changes.
2021-08-04 17:15:12 +03:00
Roman Lebedev
916cdc3d4b
[NFC][X86] combineX86ShuffleChain(): rename inner Mask to avoid future shadowing
I want to hoist `Mask` variable higher up,
but then it would clash with this one.
So let's rename this one first.

There are no other intentional changes here other than said rename.
2021-08-04 17:15:12 +03:00
Tomas Matheson
40650f27b5 [ARM][atomicrmw] Fix CMP_SWAP_32 expand assert
This assert is intended to ensure that the high registers are not
selected when it is passed to one of the thumb UXT instructions. However
it was triggering even for 32 bit where no UXT instruction is emitted.

Fixes PR51313.

Differential Revision: https://reviews.llvm.org/D107363
2021-08-04 15:02:02 +01:00
Roman Lebedev
f819e4c7d0
[X86] combineX86ShuffleChain(): canonicalize mask elts picking from splats
Given a shuffle mask, if it is picking from an input that is splat
given the current granularity of the shuffle, then adjust the mask
to pick from the same lane of the input as the mask element is in.
This may result in a shuffle being simplified into a blend.

I believe this is correct given that the splat detection matches the one
just above the new code,

My basic thought is that we might be able to get less regressions
by handling multiple insertions of the same value into a vector
if we form broadcasts+blend here, as opposed to D105390,
but i have not really thought this through,
and did not try implementing it yet.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D107009
2021-08-04 16:55:04 +03:00
Simon Pilgrim
8cd40ece70 [X86] Rename X86 tuning feature flag FeatureHasFastGather -> FeatureFastGather
Match the naming style used by the other 'FeatureFast/FeatureSlow' tuning flags.
2021-08-04 13:07:50 +01:00
Simon Pilgrim
17e8ac0703 [X86] Move FeatureFastBEXTR from bdver2 features to tuning
Noticed while looking at the feature flag renaming suggested in D107370
2021-08-04 13:07:49 +01:00
Serge Pavlov
0c28a7c990 Revert "Introduce intrinsic llvm.isnan"
This reverts commit 16ff91ebccda1128c43ff3cee104e2c603569fb2.
Several errors were reported mainly test-suite execution time. Reverted
for investigation.
2021-08-04 17:18:15 +07:00
Simon Pilgrim
fc8dee1ebb [X86] Split Subtarget ISA / Security / Tuning Feature Flags Definitions. NFC
Our list of slow/fast tuning feature flags has become pretty extensive and is randomly interleaved with ISA and Security (Retpoline etc.) flags, not even based on when the ISAs/flags were introduced, making it tricky to locate them. Plus we started treating tuning flags separately some time ago, so this patch tries to group the flags to match.

I've left them mostly in the same order within each group - I'm happy to rearrange them further if there are specific ISA or Tuning flags that you think should be kept closer together.

Differential Revision: https://reviews.llvm.org/D107370
2021-08-04 11:16:36 +01:00
Tim Northover
d7b0e5525a X86: fix frame offset calculation with mandatory tail calls
If there's a region of the stack reserved for potential tail call arguments
(only the case when we guarantee tail calls will be honoured), this is right
next to the incoming stored return address, not necessarily next to the
callee-saved area, so combining the two into a single figure leads to incorrect
offsets in some edge cases.
2021-08-04 10:02:42 +01:00
Serge Pavlov
16ff91ebcc Introduce intrinsic llvm.isnan
Clang has builtin function '__builtin_isnan', which implements C
library function 'isnan'. This function now is implemented entirely in
clang codegen, which expands the function into set of IR operations.
There are three mechanisms by which the expansion can be made.

* The most common mechanism is using an unordered comparison made by
  instruction 'fcmp uno'. This simple solution is target-independent
  and works well in most cases. It however is not suitable if floating
  point exceptions are tracked. Corresponding IEEE 754 operation and C
  function must never raise FP exception, even if the argument is a
  signaling NaN. Compare instructions usually does not have such
  property, they raise 'invalid' exception in such case. So this
  mechanism is unsuitable when exception behavior is strict. In
  particular it could result in unexpected trapping if argument is SNaN.

* Another solution was implemented in https://reviews.llvm.org/D95948.
  It is used in the cases when raising FP exceptions by 'isnan' is not
  allowed. This solution implements 'isnan' using integer operations.
  It solves the problem of exceptions, but offers one solution for all
  targets, however some can do the check in more efficient way.

* Solution implemented by https://reviews.llvm.org/D96568 introduced a
  hook 'clang::TargetCodeGenInfo::testFPKind', which injects target
  specific code into IR. Now only SystemZ implements this hook and it
  generates a call to target specific intrinsic function.

Although these mechanisms allow to implement 'isnan' with enough
efficiency, expanding 'isnan' in clang has drawbacks:

* The operation 'isnan' is hidden behind generic integer operations or
  target-specific intrinsics. It complicates analysis and can prevent
  some optimizations.

* IR can be created by tools other than clang, in this case treatment
  of 'isnan' has to be duplicated in that tool.

Another issue with the current implementation of 'isnan' comes from the
use of options '-ffast-math' or '-fno-honor-nans'. If such option is
specified, 'fcmp uno' may be optimized to 'false'. It is valid
optimization in general, but it results in 'isnan' always returning
'false'. For example, in some libc++ implementations the following code
returns 'false':

    std::isnan(std::numeric_limits<float>::quiet_NaN())

The options '-ffast-math' and '-fno-honor-nans' imply that FP operation
operands are never NaNs. This assumption however should not be applied
to the functions that check FP number properties, including 'isnan'. If
such function returns expected result instead of actually making
checks, it becomes useless in many cases. The option '-ffast-math' is
often used for performance critical code, as it can speed up execution
by the expense of manual treatment of corner cases. If 'isnan' returns
assumed result, a user cannot use it in the manual treatment of NaNs
and has to invent replacements, like making the check using integer
operations. There is a discussion in https://reviews.llvm.org/D18513#387418,
which also expresses the opinion, that limitations imposed by
'-ffast-math' should be applied only to 'math' functions but not to
'tests'.

To overcome these drawbacks, this change introduces a new IR intrinsic
function 'llvm.isnan', which realizes the check as specified by IEEE-754
and C standards in target-agnostic way. During IR transformations it
does not undergo undesirable optimizations. It reaches instruction
selection, where is lowered in target-dependent way. The lowering can
vary depending on options like '-ffast-math' or '-ffp-model' so the
resulting code satisfies requested semantics.

Differential Revision: https://reviews.llvm.org/D104854
2021-08-04 15:27:49 +07:00
hsmahesha
596e61c332 [AMDGPU] Ignore call graph node which does not have function info.
While collecting reachable callees (from kernels), ignore call graph node which
does not have associated function or associated function is not a definition.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D107329
2021-08-04 10:22:33 +05:30
Heejin Ahn
9bd02c433b [WebAssembly] Misc. cosmetic changes in EH (NFC)
- Rename `wasm.catch` intrinsic to `wasm.catch.exn`, because we are
  planning to add a separate `wasm.catch.longjmp` intrinsic which
  returns two values.
- Rename several variables
- Remove an unnecessary parameter from `canLongjmp` and `isEmAsmCall`
  from LowerEmscriptenEHSjLj pass
- Add `-verify-machineinstrs` in a test for a safety measure
- Add more comments + fix some errors in comments
- Replace `std::vector` with `SmallVector` for cases likely with small
  number of elements
- Renamed `EnableEH`/`EnableSjLj` to `EnableEmEH`/`EnableEmSjLj`: We are
  soon going to add `EnableWasmSjLj`, so this makes the distincion
  clearer

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D107405
2021-08-03 21:03:46 -07:00
Arthur Eubanks
ad25344620 [MC][CodeGen] Emit constant pools earlier
Previously we would emit constant pool entries for ldr inline asm at the
very end of AsmPrinter::doFinalization(). However, if we're emitting
dwarf aranges, that would end all sections with aranges. Then if we have
constant pool entries to be emitted in those same sections, we'd hit an
assert that the section has already been ended.

We want to emit constant pool entries before emitting dwarf aranges.
This patch splits out arm32/64's constant pool entry emission into its
own MCTargetStreamer virtual method.

Fixes PR51208

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D107314
2021-08-03 20:55:31 -07:00
Jessica Paquette
5643736378 [AArch64][GlobalISel] Widen G_SELECT before clamping it
This allows us to handle the s88 G_SELECTS:

https://godbolt.org/z/5s18M4erY

Weird types like this can result in weird merges.

Widening to s128 first and then clamping down avoids that situation.

Differential Revision: https://reviews.llvm.org/D107415
2021-08-03 18:31:17 -07:00
Evandro Menezes
63a5ac4e0d [RISCV] Add scheduling resources for V
Add the scheduling resources for the V extension instructions.

Differential Revision: https://reviews.llvm.org/D98002
2021-08-03 15:47:51 -05:00
David Green
bd07c2e266 [AArch64] Prefer fmov over orr v.16b when copying f32/f64
This changes the lowering of f32 and f64 COPY from a 128bit vector ORR to
a fmov of the appropriate type. At least on some CPU's with 64bit NEON
data paths this is expected to be faster, and shouldn't be slower on any
CPU that treats fmov as a register rename.

Differential Revision: https://reviews.llvm.org/D106365
2021-08-03 17:25:40 +01:00
Craig Topper
deaeb16d88 [RISCV] Indicate that RISCVMergeBaseOffsetOpt preserves the CFG.
Return false from runOnFunction if nothing changed. Curiously
we already returned a bool from detectAndFoldOffset, but didn't
use it.

Fix a couple breaks after returns that I saw while auditing
detectAndFoldOffset.

Differential Revision: https://reviews.llvm.org/D107303
2021-08-03 08:32:36 -07:00
Simon Pilgrim
d3917bbfc6 [X86] Add title comment to separate the "CPU Families" features from the other subtarget features. NFCI.
Hopefully we can get rid of these some day...
2021-08-03 12:53:57 +01:00
Fraser Cormack
cba6aab971 [RISCV] Support simple fractional steps in matching VID sequences
This patch extends the optimization of VID-sequence BUILD_VECTORs
introduced in D104921 to include simple fractional steps composed of a
separated integer numerator and denominator.

A notable limitation in this sequence detection is that only sequences
with steps N/1 or 1/D are found, meaning that the step between elements
and the frequency with which it changes is consistent across the whole
sequence. Fractional steps such as 2/3 won't be matched as those would
involve more complex tracking of state or some level of backtracking.

As is stands, however, this patch is sufficient to match common
interleave-type shuffle indices, for example matching `<0,0,1,1>` (or
commonly `<0,u,1,u>` or `<u,0,u,1>`) to an index sequence divided by 2.

While the optimization is relatively `undef`-tolerant, due to greedy
pattern-matching there even are some simple patterns which confuse the
sequence detection into identifying either a suboptimal sequence or no
sequence at all.

Currently only fractional-step sequences identified as having a
power-of-two denominator are actually lowered to RVV instructions. This
is to avoid introducing divisions into the generated code.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D106533
2021-08-03 10:38:24 +01:00
Jason Molenda
0d8cd4e2d5 [AArch64InstPrinter] Change printAddSubImm to comment imm value when shifted
Add a comment when there is a shifted value,
    add x9, x0, #291, lsl #12 ; =1191936
but not when the immediate value is unshifted,
    subs x9, x0, #256 ; =256
when the comment adds nothing additional to the reader.

Differential Revision: https://reviews.llvm.org/D107196
2021-08-03 02:28:46 -07:00
Cullen Rhodes
a02bbeeae7 [AArch64][AsmParser] NFC: Use helpers in matrix tile list parsing 2021-08-03 08:13:01 +00:00
Jay Foad
40202b13b2 [AMDGPU] Legalize operands of V_ADDC_U32_e32 and friends
These instructions have an implicit use of vcc which counts towards the
constant bus limit. Pre gfx10 this means that the explicit operands
cannot be sgprs. Use the custom inserter hook to call legalizeOperands
to enforce that restriction.

Fixes https://bugs.llvm.org/show_bug.cgi?id=51217

Differential Revision: https://reviews.llvm.org/D106868
2021-08-03 09:04:52 +01:00
Paulo Matos
d3a0a65bf0 Reland: "[WebAssembly] Add new pass to lower int/ptr conversions of reftypes"
Add new pass LowerRefTypesIntPtrConv to generate debugtrap
instruction for an inttoptr and ptrtoint of a reference type instead
of erroring, since calling these instructions on non-integral pointers
has been since allowed (see ac81cb7e6).

Differential Revision: https://reviews.llvm.org/D107102
2021-08-03 09:20:51 +02:00
jacquesguan
7900ee0b61 [RISCV] Teach VSETVLI insertion to merge the unused VSETVLI with the one need to be insert after it.
If a vsetvli instruction is not compatible with the next vector instruction,
and there is no other things that may update or use VL/VTYPE, we could merge
it with the next vsetvli instruction that should be insert for the vector
instruction.

This commit only merge VTYPE with the former vsetvli instruction which has
the same VL.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D106857
2021-08-03 12:06:59 +08:00
Roman Lebedev
6f6e9a867f
[BasicTTIImpl][LoopUnroll] getUnrollingPreferences(): emit ORE remark when advising against unrolling due to a call in a loop
I'm not sure this is the best way to approach this,
but the situation is rather not very detectable unless we explicitly call it out when refusing to advise to unroll.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D107271
2021-08-03 00:57:26 +03:00
Jessica Paquette
bd13c8e610 [AArch64][GlobalISel] Emit extloads for ZExt/SExt values in assignValueToAddress
When a value is expected to be extended, we should emit an extended load rather
than a normal G_LOAD.

Add checklines to arm64-abi.ll which show that we now emit the correct loads.

For ease of comparison: https://godbolt.org/z/8WvY6EfdE

Differential Revision: https://reviews.llvm.org/D107313
2021-08-02 14:48:44 -07:00
Paulo Matos
245f2ee647 Revert "[WebAssembly] Add new pass to lower int/ptr conversions of reftypes"
This reverts commit ce1c59dea6d01e8ec3d4cb911438254283e4646c.
2021-08-02 20:12:25 +02:00
Paulo Matos
ce1c59dea6 [WebAssembly] Add new pass to lower int/ptr conversions of reftypes
Add new pass LowerRefTypesIntPtrConv to generate trap
instruction for an inttoptr and ptrtoint of a reference type instead
of erroring, since calling these instructions on non-integral pointers
has been since allowed (see ac81cb7e6).

Differential Revision: https://reviews.llvm.org/D107102
2021-08-02 19:40:00 +02:00
Thomas Lively
417e500668 [WebAssembly] Compute known bits for SIMD bitmask intrinsics
This optimizes out the mask when the result of a bitmask is interpreted as an i8
or i16 value. Resolves PR50507.

Differential Revision: https://reviews.llvm.org/D107103
2021-08-02 09:52:34 -07:00
David Green
c423a586a7 [ARM] Remove setPreservesCFG from ARMBlockPlacement
As of 28293918409dd3a5a it no longer preserves the CFG, needing to
split blocks in order to add DLS instructions.
2021-08-02 14:15:45 +01:00
Irina Dobrescu
b01417d3c5 [AArch64] Optimise min/max lowering in ISel
Differential Revision: https://reviews.llvm.org/D106561
2021-08-02 13:40:21 +01:00
Carl Ritson
675c942373 [AMDGPU] Disable NSA for BVH instructions when appropriate
Check maximum NSA size when selecting NSA or non-NSA BVH instructions.

Differential Revision: https://reviews.llvm.org/D103230
2021-08-02 20:09:26 +09:00
Simon Pilgrim
7397dcb403 [TTI] Add basic SK_InsertSubvector shuffle mask recognition
This patch adds an initial ShuffleVectorInst::isInsertSubvectorMask helper to recognize 2-op shuffles where the lowest elements of one of the sources are being inserted into the "in-place" other operand, this includes "concat_vectors" patterns as can be seen in the Arm shuffle cost changes. This also helped fix a x86 issue with irregular/length-changing SK_InsertSubvector costs - I'm hoping this will help with D107188

This doesn't currently attempt to work with 1-op shuffles that could either be a "widening" shuffle or a self-insertion.

The self-insertion case is tricky, but we currently always match this with the existing SK_PermuteSingleSrc logic.

The widening case will be addressed in a follow up patch that treats the cost as 0.

Masks with a high number of undef elts will still struggle to match optimal subvector widths - its currently bounded by minimum-width possible insertion, whilst some cases would benefit from wider (pow2?) subvectors.

Differential Revision: https://reviews.llvm.org/D107228
2021-08-02 11:23:44 +01:00
Simon Pilgrim
0579050116 Fix MSVC signed/unsigned comparison warning. NFCI. 2021-08-02 11:23:43 +01:00
David Green
2829391840 [ARM] Revert WLSTP to DLSTP if the target block is out of range
If the block target for a WLSTP instruction is known to be out of range,
and cannot be fixed by the ARMBlockPlacementPass, we can relax it to a
DLSTP (and cmp/branch) to still allow the creation of tail predicated
loops. That is what this patch does, adding extra revert code to the
fallback path of ARMBlockPlacementPass.

Due to the code produced when reverting, this creates a DLSTP between a
Bcc and a Br. As a DLS isn't necessarily a terminator we need to split
the block to move the DLS/Br into.

Differential Revision: https://reviews.llvm.org/D104709
2021-08-02 10:59:52 +01:00