The global-isel feature has been required for a long time and was
removed in c9455d3c579292e7ae5b7559ad0302d459e69a95, so this was
causing all tests to be skipped.
Apparently, we don't do this, neither in EarlyCSE, nor in InstSimplify,
nor in (old) GVN, but do in NewGVN and SimplifyCFG of all places..
While i could teach EarlyCSE how to hash PHI nodes,
we can't really do much (anything?) even if we find two identical
PHI nodes in different basic blocks, same-BB case is the interesting one,
and if we teach InstSimplify about it (which is what i wanted originally,
https://reviews.llvm.org/D86530), we get EarlyCSE support for free.
So i would think this is pretty uncontroversial.
On vanilla llvm test-suite + RawSpeed, this has the following effects:
```
| statistic name | baseline | proposed | Δ | % | \|%\| |
|----------------------------------------------------|-----------|-----------|-------:|---------:|---------:|
| instsimplify.NumPHICSE | 0 | 23779 | 23779 | 0.00% | 0.00% |
| asm-printer.EmittedInsts | 7942328 | 7942392 | 64 | 0.00% | 0.00% |
| assembler.ObjectBytes | 273069192 | 273084704 | 15512 | 0.01% | 0.01% |
| correlated-value-propagation.NumPhis | 18412 | 18539 | 127 | 0.69% | 0.69% |
| early-cse.NumCSE | 2183283 | 2183227 | -56 | 0.00% | 0.00% |
| early-cse.NumSimplify | 550105 | 542090 | -8015 | -1.46% | 1.46% |
| instcombine.NumAggregateReconstructionsSimplified | 73 | 4506 | 4433 | 6072.60% | 6072.60% |
| instcombine.NumCombined | 3640264 | 3664769 | 24505 | 0.67% | 0.67% |
| instcombine.NumDeadInst | 1778193 | 1783183 | 4990 | 0.28% | 0.28% |
| instcount.NumCallInst | 1758401 | 1758799 | 398 | 0.02% | 0.02% |
| instcount.NumInvokeInst | 59478 | 59502 | 24 | 0.04% | 0.04% |
| instcount.NumPHIInst | 330557 | 330533 | -24 | -0.01% | 0.01% |
| instcount.TotalInsts | 8831952 | 8832286 | 334 | 0.00% | 0.00% |
| simplifycfg.NumInvokes | 4300 | 4410 | 110 | 2.56% | 2.56% |
| simplifycfg.NumSimpl | 1019808 | 999607 | -20201 | -1.98% | 1.98% |
```
I.e. it fires ~24k times, causes +110 (+2.56%) more `invoke` -> `call`
transforms, and counter-intuitively results in *more* instructions total.
That being said, the PHI count doesn't decrease that much,
and looking at some examples, it seems at least some of them
were previously getting PHI CSE'd in SimplifyCFG of all places..
I'm adjusting `Instruction::isIdenticalToWhenDefined()` at the same time.
As a comment in `InstCombinerImpl::visitPHINode()` already stated,
there are no guarantees on the ordering of the operands of a PHI node,
so if we just naively compare them, we may false-negatively say that
the nodes are not equal when the only difference is operand order,
which is especially important since the fold is in InstSimplify,
so we can't rely on InstCombine sorting them beforehand.
Fixing this for the general case is costly (geomean +0.02%),
and does not appear to catch anything in test-suite, but for
the same-BB case, it's trivial, so let's fix at least that.
As per http://llvm-compile-time-tracker.com/compare.php?from=04879086b44348cad600a0a1ccbe1f7776cc3cf9&to=82bdedb888b945df1e9f130dd3ac4dd3c96e2925&stat=instructions
this appears to cause geomean +0.03% compile time increase (regression),
but geomean -0.01%..-0.04% code size decrease (improvement).
This is the first of a set of DAGCombiner changes enabling strictfp
optimizations. I want to test to waters with this to make sure changes
like these are acceptable for the strictfp case- this particular change
should preserve exception ordering and result precision perfectly, and
many other possible changes appear to be able to as well.
Copied from regular fadd combines but modified to preserve ordering via
the chain, this change allows strict_fadd x, (fneg y) to become
struct_fsub x, y and strict_fadd (fneg x), y to become strict_fsub y, x.
Differential Revision: https://reviews.llvm.org/D85548
AArch64, X86 and Mips currently directly consumes these and custom
lowering to produce a libcall, but really these should follow the
normal legalization process through the libcall/lower action.
We have a gap in our store merging capabilities for shift+truncate
patterns as discussed in:
https://llvm.org/PR46662
I generalized the code/comments for this function in earlier commits,
so we only need ease the type restriction and adjust the address/endian
checking to make this work.
AArch64 lets us switch endian to make sure that patterns are matched
either way.
Differential Revision: https://reviews.llvm.org/D86420
pointer.
mwaitx uses EBX as one of its argument.
Using this instruction clobbers RBX as it is defined to hold one of the
input. When the backend uses dynamically allocated stack, RBX is used as
a reserved register for the base pointer.
This patch is adapted from @qcolombet patch for cmpxchg at r263325.
This fixes PR43528.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D73475
The IsExtractedElement already called getOperand(0) so Extract
here is the source vector. We shouldn't call getOperand(0). This
worked for the original test cases because the result was a
bitcast so the getOperand(0) accidently peeked through the bitcast
which is what we wanted.
In the failing case here, the operand turns out to be undef so
the getOperand(0) asserts because undef has no operands.
Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=25184
Differential Revision: https://reviews.llvm.org/D86428
KMOVWkr produces VK16, there's no reason to copy it to VK16 again.
Test changes are presumably because we were scheduling based on
the COPY that is no longer there.
There are two ways .llvmbc can be produced:
* clang -c -fembed-bitcode=all (which also produces .llvmcmd)
* LTO backend: ld.lld -mllvm -lto-embed-bitcode or -plugin-opt=-lto-embed-bitcode
.llvmbc and .llvmcmd have the SHF_ALLOC flag, so they can be dropped by
--gc-sections.
This patch sets SectionKind::Metadata to drop the SHF_ALLOC flag. This
is conceptually correct: the two sections are not part of the process
image, so SHF_ALLOC is not appropriate.
`test/LTO/X86/embed-bitcode.ll`: changed `llvm-objcopy -O binary --only-section` to
`llvm-objcopy --dump-section`. `-O binary` does not dump non-SHF_ALLOC sections.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D86374
Support -march=sapphirerapids for x86.
Compare with Icelake Server, it includes 14 more new features. They are
amxtile, amxint8, amxbf16, avx512bf16, avx512vp2intersect, cldemote,
enqcmd, movdir64b, movdiri, ptwrite, serialize, shstk, tsxldtrk, waitpkg.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D86503
With FMF ( "nsz" and " reassoc") fold X/Sqrt(X) to Sqrt(X).
This is done after targets have the chance to produce a
reciprocal sqrt estimate sequence because that expansion
is probably more efficient than an expansion of a
non-reciprocal sqrt. That is also why we deferred doing
this transform in IR (D85709).
Differential Revision: https://reviews.llvm.org/D86403
This is preparation for making clang default to -mtune=generic when no -march is specified. This will allow the default tuning to be "generic" even though our default march is "pentium4" or "x86-64".
To avoid llc lit test regressions, if no mcpu is specified, I've defaulted tune to use i586 to match the old tuning settings of no CPU. Some tests explicitly used -mcpu=generic which I've removed so they instead get this default of architecture features from generic and tune from i586.
I updated one llvm-mca test to check a different CPU since generic has a scheduler model now
Differential Revision: https://reviews.llvm.org/D86312
The following program miscompiles because rL216012 added static
relocation model support but not for PIC.
```
// clang -fpic -mcmodel=large -O0 a.cc
double foo() { return 42.0; }
```
This patch adds PIC support.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D86024
In SelectionDAGBuilder always translate the fshl and fshr intrinsics to
FSHL and FSHR (or ROTL and ROTR) instead of lowering them to shifts and
ORs. Improve the legalization of FSHL and FSHR to avoid code quality
regressions.
Differential Revision: https://reviews.llvm.org/D77152
Add handling for storing the extracted lower (truncated bits) element from a X86ISD::VTRUNC node - this can be lowered to a generic truncated store directly.
Differential Revision: https://reviews.llvm.org/D86158
Allow non-VLX targets to use 512-bits VPERMV/VPERMV3 for 128/256-bit shuffles.
TBH I'm not sure these targets actually exist in the wild, but we're testing for them and its good test coverage for shuffle lowering/combines across different subvector widths.
This patch adds lowerShuffleWithVTRUNC to handle basic binary shuffles that can be lowered either as a pure ISD::TRUNCATE or a X86ISD::VTRUNC (with undef/zero values in the remaining upper elements).
We concat the binary sources together into a single 256-bit source vector. To avoid regressions we perform this after we've tried to lower with PACKS/PACKUS which typically does a cleaner job than a concat.
For non-AVX512VL cases we have to canonicalize VTRUNC cases to use a 512-bit source vectors (inserting undefs/zeros in the upper elements as necessary), truncate and then (possibly) extract the 128-bit result.
This should address the last regressions in D66004
Differential Revision: https://reviews.llvm.org/D86093
We can now enable this for AVX1 targets can now assist with canonicalizeShuffleMaskWithHorizOp cleanup.
There's still a few missed opportunities for merging subvector insert/extracts into shuffles, but they shouldn't cause any regressions now.
Instead of just attempting to fold shuffle(HOP,HOP) for a specific target shuffle, make this part of combineX86ShufflesRecursively so we can perform this on the combined shuffle chain, which is particularly useful for recognising more cases of where we're performing multiple HOPs that can be merged and pre-AVX where we don't have good blend/unary target shuffle support.
This is beginning to look like a canonicalization stage that could be performed as part of shuffle combining
Another step towards PR41813
Recommit of rG9bd97d036398 with fixed offset adjustments
Extend FixupStatepointCallerSaved pass with ability to spill
statepoint GC pointer arguments (optionally allowing them on CSRs).
Special handling is required for invoke statepoints, because at MI
level single landing pad may be shared by multiple statepoints, so
we must ensure we spill landing pad's live-ins into the same stack
slots.
Full statepoint refactoring change set is available at D81603.
Reviewed By: skatkov
Differential Revision: https://reviews.llvm.org/D81647
This patch restricts the behaviour of referencing via .Lfoo$local
local aliases, introduced in https://reviews.llvm.org/D73230, to
STV_DEFAULT globals only.
Hidden symbols via --fvisiblity=hidden (https://gcc.gnu.org/wiki/Visibility)
is an important scenario.
Benefits:
- Improves the size of object files by using fewer STT_SECTION symbols.
- The code reads a bit better (it was not obvious to me without going
back to the code reviews why the canBenefitFromLocalAlias function
currently doesn't consider visibility).
- There is also a side benefit in restoring the effectiveness of the
--wrap linker option and making the behavior of --wrap consistent
between LTO and normal builds for references within a translation-unit.
Note: this --wrap behavior (which is specific to LLD) should not be
considered reliable. See comments on https://reviews.llvm.org/D73230
for more.
Differential Revision: https://reviews.llvm.org/D85782
Similarly as for pointers, even for integers a == b is usually false.
GCC also uses this heuristic.
Reviewed By: ebrevnov
Differential Revision: https://reviews.llvm.org/D85781
Similarly as for pointers, even for integers a == b is usually false.
GCC also uses this heuristic.
Reviewed By: ebrevnov
Differential Revision: https://reviews.llvm.org/D85781
Similarly as for pointers, even for integers a == b is usually false.
GCC also uses this heuristic.
Reviewed By: ebrevnov
Differential Revision: https://reviews.llvm.org/D85781
We need to produce a setcc instruction which has an 8-bit result.
This gets rid of a bunch of cases that were using the s1->s8/s16/s32/s64
handling in selectZExt.
I'm not very familiar with GlobalISel yet so I'm not yet sure
the best way to do things. I'd especially like feedback on the
best way to handle the currently split 32-bit and 64-bit mode
handling.
Differential Revision: https://reviews.llvm.org/D85814
SUBREG_TO_REG is supposed to be used when we know the producing
instruction already zeroed the bits we're extending. But that's
not the case here. So INSERT_SUBREG with an IMPLICIT_DEF is the
correct thing to use.
