87 Commits

Author SHA1 Message Date
Simon Pilgrim
3cee36c5ac [X86][SSE] X86ISD::FSETCC nodes (cmpss/cmpsd) return a 0/-1 allbits signbits result (REAPPLIED)
Annoyingly, i686 cmpsd handling still fails to remove the unnecessary neg(and(x,1))

Reapplied rGe4aa6ad13216 with fix for intrinsic variants of the opcode which uses a vector return type
2021-07-13 12:31:09 +01:00
Simon Pilgrim
afdae7c5d7 [X86][SSE] Add signbit tests to show cmpss/cmpsd intrinsics not recognised as 'allbits' results.
This adds test coverage for the crash reported on rGe4aa6ad13216
2021-07-13 11:25:52 +01:00
Vitaly Buka
606551ee98 Revert "[X86][SSE] X86ISD::FSETCC nodes (cmpss/cmpsd) return a 0/-1 allbits signbits result"
Fails here https://lab.llvm.org/buildbot/#/builders/37/builds/5267

This reverts commit e4aa6ad132164839a4a97dff0d433ea4766f77f1.
2021-07-12 22:26:54 -07:00
Simon Pilgrim
e4aa6ad132 [X86][SSE] X86ISD::FSETCC nodes (cmpss/cmpsd) return a 0/-1 allbits signbits result
Annoyingly, i686 cmpsd handling still fails to remove the unnecessary neg(and(x,1))
2021-07-12 09:56:59 +01:00
Simon Pilgrim
99718d5377 [X86][SSE] Add signbit tests to show cmpss/cmpsd ops not recognised as 'allbits' results. 2021-07-12 09:41:10 +01:00
Roman Lebedev
0aef747b84
[NFC][X86][Codegen] Megacommit: mass-regenerate all check lines that were already autogenerated
The motivation is that the update script has at least two deviations
(`<...>@GOT`/`<...>@PLT`/ and not hiding pointer arithmetics) from
what pretty much all the checklines were generated with,
and most of the tests are still not updated, so each time one of the
non-up-to-date tests is updated to see the effect of the code change,
there is a lot of noise. Instead of having to deal with that each
time, let's just deal with everything at once.

This has been done via:
```
cd llvm-project/llvm/test/CodeGen/X86
grep -rl "; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py" | xargs -L1 <...>/llvm-project/llvm/utils/update_llc_test_checks.py --llc-binary <...>/llvm-project/build/bin/llc
```

Not all tests were regenerated, however.
2021-06-11 23:57:02 +03:00
Craig Topper
0248e24071 [X86][update_llc_test_checks] Use a less greedy regular expression for replacing constant pool labels in tests.
While working on D97208 I noticed that these greedy regular
expressions prevent tests from failing when (%rip) appears after
a constant pool label when it didn't before.

Reviewed By: RKSimon, pengfei

Differential Revision: https://reviews.llvm.org/D99460
2021-03-28 11:39:46 -07:00
Simon Pilgrim
ffb2887103 [DAG] Fold shuffle(bop(shuffle(x,y),shuffle(z,w)),undef) -> bop(shuffle'(x,y),shuffle'(z,w))
Followup to D96345, handle unary shuffles of binops (as well as binary shuffles) if we can merge the shuffle with inner operand shuffles.

Differential Revision: https://reviews.llvm.org/D98646
2021-03-19 14:14:56 +00:00
Simon Pilgrim
814339454d [X86][SSE] canonicalizeShuffleWithBinOps - handle target shuffles.
Fold SHUFFLE(BINOP(SHUFFLE(X),SHUFFLE(Y))) -> BINOP(SHUFFLE'(X),SHUFFLE'(Y)) style patterns as well as the existing shuffles of constants.
2021-03-15 15:01:29 +00:00
Simon Pilgrim
75a184dacf Revert rG9ba577eca2e339726bfaad4e615c6324a705b292 "[X86][SSE] canonicalizeShuffleWithBinOps - handle target shuffles. NFCI."
Sorry this wasn't supposed to be committed yet (and certainly not tagged as NFCI....)
2021-03-15 12:23:44 +00:00
Simon Pilgrim
9ba577eca2 [X86][SSE] canonicalizeShuffleWithBinOps - handle target shuffles. NFCI.
Fold SHUFFLE(BINOP(SHUFFLE(X),SHUFFLE(Y))) -> BINOP(SHUFFLE'(X),SHUFFLE'(Y)) style patterns as well as the existing shuffles of constants.
2021-03-15 11:59:25 +00:00
Simon Pilgrim
2885d1251f [X86] Fold bitcast(logic(bitcast(X), Y)) --> logic'(X, bitcast(Y)) for int-int bitcasts
Extend the existing combine that handles bitcasting for fp-logic ops to also help remove logic ops across bitcasts to/from the same integer types.

This helps improve AVX512 predicate handling for D/Q logic ops and also allows DAGCombine's scalarizeExtractedBinop to remove some annoying gpr->simd->gpr transfers.

The concat_vectors regression in pr40891.ll will be addressed in a followup commit on this patch.

Differential Revision: https://reviews.llvm.org/D96206
2021-02-21 14:40:54 +00:00
Simon Pilgrim
ff51bcee4a [X86] KnownBits - use llvm min/max intrinsics instead of (deprecated) sse intrinsics. NFCI.
These are auto-upgraded to the equivalent llvm variants now.
2021-02-20 12:07:02 +00:00
Simon Pilgrim
c33d36e066 [X86][AVX] canonicalizeLaneShuffleWithRepeatedOps - handle unary vperm2x128(permute/shift(x,c),undef) cases
Fold vperm2x128(permute/shift(x,c),undef) -> permute/shift(vperm2x128(x,undef),c)
2021-01-22 15:47:23 +00:00
Simon Pilgrim
69bc0990a9 [DAGCombiner] Enable SimplifyDemandedBits vector support for TRUNCATE (REAPPLIED).
Add DemandedElts support inside the TRUNCATE analysis.

REAPPLIED - this was reverted by @hans at rGa51226057fc3 due to an issue with vector shift amount types, which was fixed in rG935bacd3a724 and an additional test case added at rG0ca81b90d19d

Differential Revision: https://reviews.llvm.org/D56387
2021-01-21 13:01:34 +00:00
Hans Wennborg
a51226057f Revert "[DAGCombiner] Enable SimplifyDemandedBits vector support for TRUNCATE"
It caused "Vector shift amounts must be in the same as their first arg"
asserts in Chromium builds. See the code review for repro instructions.

> Add DemandedElts support inside the TRUNCATE analysis.
>
> Differential Revision: https://reviews.llvm.org/D56387

This reverts commit cad4275d697c601761e0819863f487def73c67f8.
2021-01-20 20:06:55 +01:00
Simon Pilgrim
cad4275d69 [DAGCombiner] Enable SimplifyDemandedBits vector support for TRUNCATE
Add DemandedElts support inside the TRUNCATE analysis.

Differential Revision: https://reviews.llvm.org/D56387
2021-01-20 15:39:58 +00:00
Simon Pilgrim
21d02dc595 [X86][SSE] SimplifyDemandedVectorEltsForTargetNode - add general shuffle combining support
This patch uses partial DemandedElts masks to further simplify target shuffle chains and finally starts making target shuffle combining part of SimplifyDemandedBits/SimplifyDemandedVectorElts.

We already manage this for Depth == 0 cases, where combineX86ShuffleChain would early-out if the shuffle combined to the same op, but the patch generalizes this by manipulating the depth handling of combineX86ShufflesRecursively - calling with a new Depth = 0 and reducing the maximum shuffle combine depth accordingly.

Differential Revision: https://reviews.llvm.org/D66004
2020-09-02 09:24:46 +01:00
Simon Pilgrim
0c005be6eb [X86][SSE] getV4X86ShuffleImm8 - canonicalize broadcast masks
If the mask input to getV4X86ShuffleImm8 only refers to a single source element (+ undefs) then canonicalize to a full broadcast.

getV4X86ShuffleImm8 defaults to inline values for undefs, which can be useful for shuffle widening/narrowing but does leave SimplifyDemanded* calls thinking the shuffle depends on unnecessary elements.

I'm still investigating what we should do more generally to avoid these undemanded elements, but broadcast cases was a simpler win.
2020-07-29 11:32:44 +01:00
Simon Pilgrim
17eafe0841 [X86][SSE] lowerV2I64Shuffle - use undef elements in PSHUFD mask widening
If we lower a v2i64 shuffle to PSHUFD, we currently clamp undef elements to 0, (elements 0,1 of the v4i32) which can result in the shuffle referencing more elements of the source vector than expected, affecting later shuffle combines and KnownBits/SimplifyDemanded calls.

By ensuring we widen the undef mask element we allow getV4X86ShuffleImm8 to use inline elements as the default, which are more likely to fold.
2020-07-26 16:04:22 +01:00
Simon Pilgrim
f54402b63a [X86][AVX] Attempt to fold extract_subvector(shuffle(X)) -> extract_subvector(X)
If we're extracting a subvector from a shuffle that is shuffling entire subvectors we can peek through and extract the subvector from the shuffle source instead.

This helps remove some cases where concat_vectors(extract_subvector(),extract_subvector()) legalizations has resulted in BLEND/VPERM2F128 shuffles of the subvectors.
2020-07-09 14:09:24 +01:00
Simon Pilgrim
ecc5d7ee0d [DAG] SimplifyMultipleUseDemandedBits - drop unnecessary *_EXTEND_VECTOR_INREG cases
For little endian targets, if we only need the lowest element and none of the extended bits then we can just use the (bitcasted) source vector directly.

We already do this in SimplifyDemandedBits, this adds the SimplifyMultipleUseDemandedBits equivalent.
2020-06-22 12:35:32 +01:00
Simon Pilgrim
e53d4869a0 [X86][AVX] combineVectorSignBitsTruncation - avoid complex vXi64->vXi32 PACKSS truncations (PR45794)
Unless we're truncating an 'all-bits' result, using PACKSS for vXi64->vXi32 truncation causes problems with later combines as ComputeNumSignBits struggles to see through BITCASTs to smaller types. If we don't use PACKSS in these cases then we fallback to shuffles which are usually just as good.
2020-05-05 11:57:25 +01:00
Simon Pilgrim
371a69ac9a [X86][AVX] Add PR45794 sitofp v4i64-v4f32 test case 2020-05-05 11:32:48 +01:00
Simon Pilgrim
3daa71ee00 [SelectionDAG] ComputeNumSignBits - add DemandedElts support for MIN/MAX ops 2020-01-25 20:21:14 +00:00
Simon Pilgrim
481b79668c [X86] Add tests showing ComputeNumSignBits's failure to use DemandedElts for MIN/MAX opcodes 2020-01-25 19:28:57 +00:00
Simon Pilgrim
c6fcd5d115 [SelectionDAG] ComputeNumSignBits add getValidMaximumShiftAmountConstant() for ISD::SHL support
Allows us to handle non-uniform SHL shifts to determine the minimum number of sign bits remaining (based off the maximum shift amount value)
2020-01-13 18:02:37 +00:00
Simon Pilgrim
ffc05d0dbc [X86][SSE] Add sitofp(shl(sext(x),y)) test case with non-uniform shift value
Shows that for non-uniform SHL shifts we fail to determine the minimum number of sign bits remaining (based off the maximum shift amount value)
2020-01-13 17:34:40 +00:00
Simon Pilgrim
38e2c01221 [SelectionDAG] ComputeNumSignBits add getValidMinimumShiftAmountConstant() ISD::SRA support
Allows us to handle more non-uniform SRA sign bits cases
2020-01-13 16:55:02 +00:00
Simon Pilgrim
7afaa0099b [X86][SSE] Add sitofp(ashr(x,y)) test case with non-uniform shift value 2020-01-13 16:55:02 +00:00
Simon Pilgrim
ee4aa1a228 [X86] Add AVX2 known signbits codegen tests 2020-01-13 16:55:01 +00:00
Simon Pilgrim
03cde3a7cc [X86] Regenerate known-signbits-vector.ll tests.
Use X86 instead of X32 and add a common CHECK prefix
2019-11-04 15:12:01 +00:00
Sanjay Patel
eb99165b97 [x86] try to keep FP casted+truncated+extracted vector element out of GPRs
inttofp (trunc (extelt X, 0)) --> inttofp (extelt (bitcast X), 0)

We have pseudo-vectorization of scalar int to FP casts, so this tries to
make that more likely by replacing a truncate with a bitcast. I didn't see
any test diffs starting from 'uitofp', so I left that as a TODO. We can't
only match the shorter trunc+extract pattern because there's an opposing
transform somewhere, so we infinite loop. Waiting to try this during
lowering is another possibility.

A motivating case is shown in PR39975 and included in the test diffs here:
https://bugs.llvm.org/show_bug.cgi?id=39975

Differential Revision: https://reviews.llvm.org/D64710

llvm-svn: 366098
2019-07-15 18:17:23 +00:00
Simon Pilgrim
83e1a1e79b [TargetLowering] SimplifyDemandedVectorElts - add shift/rotate support.
llvm-svn: 364548
2019-06-27 14:25:54 +00:00
Simon Pilgrim
c692a8dc51 [TargetLowering] SimplifyDemandedBits - use DemandedElts to better identify partial splat shift amounts
llvm-svn: 364541
2019-06-27 13:48:43 +00:00
Sanjay Patel
d14389c0a5 [x86] split 256-bit vector selects if operands are vector concats
This is similar logic/motivation to the select splitting in D62969.

In D63233, the pattern changes so that we no longer have an extract_subvector of vselect,
but the operands of the select are still being concatenated.

The closest case is represented in either the first or last test diffs here - we have an
extra instruction, but we converted 3-4 ymm instructions into 4-5 xmm instructions.
I think that's the right trade-off for most AVX1 targets.

In the example based on PR37428:
https://bugs.llvm.org/show_bug.cgi?id=37428
...this makes the loop about 30% faster (tested on Haswell by compiling with -mavx).

Differential Revision: https://reviews.llvm.org/D63364

llvm-svn: 363508
2019-06-16 14:04:49 +00:00
Craig Topper
d10a200ceb [X86] Remove the suffix on vcvt[u]si2ss/sd register variants in assembly printing.
We require d/q suffixes on the memory form of these instructions to disambiguate the memory size.
We don't require it on the register forms, but need to support parsing both with and without it.

Previously we always printed the d/q suffix on the register forms, but it's redundant and
inconsistent with gcc and objdump.

After this patch we should support the d/q for parsing, but not print it when its unneeded.

llvm-svn: 360085
2019-05-06 21:39:51 +00:00
Simon Pilgrim
38a0616c1d [DAGCombiner] Fold truncate(build_vector(x,y)) -> build_vector(truncate(x),truncate(y))
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
2019-03-28 11:34:21 +00:00
Simon Pilgrim
e24441aab0 [TargetLowering] Add SimplifyDemandedBits support for ISD::INSERT_VECTOR_ELT
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
2019-03-26 12:32:01 +00:00
Simon Pilgrim
d33e62c826 [X86][SSE] Fold scalar_to_vector(i64 anyext(x)) -> bitcast(scalar_to_vector(i32 anyext(x)))
Reduce the size of an any-extended i64 scalar_to_vector source to i32 - the any_extend nodes are often introduced by SimplifyDemandedBits.

llvm-svn: 356292
2019-03-15 19:14:28 +00:00
Simon Pilgrim
8fbe439345 [SelectionDAG] Add SimplifyDemandedBits handling for ISD::SCALAR_TO_VECTOR
Fixes a lot of constant folding mismatches between i686 and x86_64

llvm-svn: 356273
2019-03-15 17:00:55 +00:00
Craig Topper
be9eeb5526 Recommit r354363 "[X86][SSE] Generalize X86ISD::BLENDI support to more value types"
And its follow ups r354511, r354640.

A follow patch will fix the issue that caused it to be reverted.

llvm-svn: 354737
2019-02-23 21:41:42 +00:00
Reid Kleckner
e3876637cf Revert r354363 & co "[X86][SSE] Generalize X86ISD::BLENDI support to more value types"
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
2019-02-23 01:19:42 +00:00
Sanjay Patel
234a5e8ea4 [x86] vectorize more cast ops in lowering to avoid register file transfers
This is a follow-up to D56864.

If we're extracting from a non-zero index before casting to FP,
then shuffle the vector and optionally narrow the vector before doing the cast:

cast (extelt V, C) --> extelt (cast (extract_subv (shuffle V, [C...]))), 0

This might be enough to close PR39974:
https://bugs.llvm.org/show_bug.cgi?id=39974

Differential Revision: https://reviews.llvm.org/D58197

llvm-svn: 354619
2019-02-21 20:40:39 +00:00
Simon Pilgrim
0b3b9424ca [X86][SSE] Generalize X86ISD::BLENDI support to more value types
D42042 introduced the ability for the ExecutionDomainFixPass to more easily change between BLENDPD/BLENDPS/PBLENDW as the domains required.

With this ability, we can avoid most bitcasts/scaling in the DAG that was occurring with X86ISD::BLENDI lowering/combining, blend with the vXi32/vXi64 vectors directly and use isel patterns to lower to the float vector equivalent vectors.

This helps the shuffle combining and SimplifyDemandedVectorElts be more aggressive as we lose track of fewer UNDEF elements than when we go up/down through bitcasts.

I've introduced a basic blend(bitcast(x),bitcast(y)) -> bitcast(blend(x,y)) fold, there are more generalizations I can do there (e.g. widening/scaling and handling the tricky v16i16 repeated mask case).

The vector-reduce-smin/smax regressions will be fixed in a future improvement to SimplifyDemandedBits to peek through bitcasts and support X86ISD::BLENDV.

Reapplied after reversion at rL353699 - AVX2 isel fix was applied at rL354358, additional test at rL354360/rL354361

Differential Revision: https://reviews.llvm.org/D57888

llvm-svn: 354363
2019-02-19 18:05:42 +00:00
Sam McCall
e825ba9165 Revert "[X86][SSE] Generalize X86ISD::BLENDI support to more value types"
This reverts commit r353610.
It causes a miscompile visible in macro expansion in a bootstrapped clang.

http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190211/626590.html

llvm-svn: 353699
2019-02-11 14:05:36 +00:00
Simon Pilgrim
690a2889d8 [X86][SSE] Generalize X86ISD::BLENDI support to more value types
D42042 introduced the ability for the ExecutionDomainFixPass to more easily change between BLENDPD/BLENDPS/PBLENDW as the domains required.

With this ability, we can avoid most bitcasts/scaling in the DAG that was occurring with X86ISD::BLENDI lowering/combining, blend with the vXi32/vXi64 vectors directly and use isel patterns to lower to the float vector equivalent vectors.

This helps the shuffle combining and SimplifyDemandedVectorElts be more aggressive as we lose track of fewer UNDEF elements than when we go up/down through bitcasts.

I've introduced a basic blend(bitcast(x),bitcast(y)) -> bitcast(blend(x,y)) fold, there are more generalizations I can do there (e.g. widening/scaling and handling the tricky v16i16 repeated mask case).

The vector-reduce-smin/smax regressions will be fixed in a future improvement to SimplifyDemandedBits to peek through bitcasts and support X86ISD::BLENDV.

Differential Revision: https://reviews.llvm.org/D57888

llvm-svn: 353610
2019-02-09 13:13:59 +00:00
Sanjay Patel
e84fbb67a1 [x86] vectorize cast ops in lowering to avoid register file transfers
The proposal in D56796 may cross the line because we're trying to avoid vectorization 
transforms in generic DAG combining. So this is an alternate, later, x86-specific 
translation of that patch.

There are several potential follow-ups to enhance this:
1. Allow extraction from non-zero element index.
2. Peek through extends of smaller width integers.
3. Support x86-specific conversion opcodes like X86ISD::CVTSI2P

Differential Revision: https://reviews.llvm.org/D56864

llvm-svn: 353302
2019-02-06 14:59:39 +00:00
Craig Topper
cfeb1cf9af [X86] Add INSERT_SUBVECTOR to ComputeNumSignBits
This adds support for calculating sign bits of insert_subvector. I based it on the computeKnownBits.

My motivating case is propagating sign bits information across basic blocks on AVX targets where concatenating using insert_subvector is common.

Differential Revision: https://reviews.llvm.org/D56283

llvm-svn: 350432
2019-01-04 20:50:59 +00:00
Craig Topper
58c61dce1d [X86] Add test case for D56283.
This tests a case where we need to be able to compute sign bits for two insert_subvectors that is a liveout of a basic block. The result is then used as a boolean vector in another basic block.

llvm-svn: 350359
2019-01-03 22:31:07 +00:00