Commit Graph

695 Commits

Author SHA1 Message Date
Craig Topper 5625e6ab37 [X86] Improve min/max reduction costs.
This is similar to what I recently did for getArithmeticReductionCost.

I'm trying to account for the narrowing from 512->256->128 as we go.

I've also added a new helper method getMinMaxCost that tries to
handle the cases where we have native min/max instructions and
fall back to cmp+select when we don't.

Differential Revision: https://reviews.llvm.org/D76634
2020-04-09 17:28:50 -07:00
Matt Arsenault 66073953a5 AMDGPU: Allow vectorization of round intrinsic
There seems to be a small benefit to the legalized sequence for v2f16
round with packed instructions, so allow vectorizing it by reducing
the cost.

An unintended side effect is vectorization of f32 round also
happens. The current FMA logic seems off to me, and isn't checking for
packed instructions.
2020-03-23 17:00:41 -04:00
Craig Topper f4c67dfa92 [X86] More accurately model the cost of horizontal reductions.
This patch attempts to more accurately model the reduction of
power of 2 vectors of types we natively support. This takes into
account the narrowing of vectors that occur as we go from 512
bits to 256 bits, to 128 bits. It also takes into account the use
of wider elements in the shuffles for the first 2 steps of a
reduction from 128 bits. And uses a v8i16 shift for the final step
of vXi8 reduction.

The default implementation uses the legalized type for the arithmetic
for all levels. And uses the single source permute cost of the
legalized type for all levels. This penalizes things like
lack of v16i8 pshufb on pre-sse3 targets and the splitting and
joining that needs to be done for integer types on AVX1. We never
need v16i8 shuffle for a reduction and we only need split AVX1 ops
when type the type wide and needs to be split. I think we're still
over costing splits and joins for AVX1, but we're closer now.

I've also removed all pairwise special casing because I don't
think we ever want to generate that on X86. I've also adjusted
the add handling to more accurately account for any type splitting
that occurs before we reach a legal type.

Differential Revision: https://reviews.llvm.org/D76478
2020-03-22 14:20:15 -07:00
Huihui Zhang fc1f205745 [SLPVectorizer][SVE] Bail out early for scalable vector.
Summary:
SLPVectorizer try to vectorize list of scalar instructions of the same type,
instructions already vectorized are rejected through isValidElementType().

Without this patch, tryToVectorizeList() will first try to determine vectorization
factor of a list of Instructions before checking whether each instruction has unsupported
type or not. For instructions already vectorized for SVE, it will crash at getVectorElementSize(),
where it try to return a fixed size.

This patch make sure invalid element types are rejected before trying to get vectorization
factor. This make sure we are not trying to vectorize instructions already vectorized.

Reviewers: sdesmalen, efriedma, spatel, RKSimon, ABataev, apazos, rengolin

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76017
2020-03-13 11:23:31 -07:00
Simon Pilgrim a2db388dce [CostModel][X86] Improve ISD::CTTZ costs accounting for BSF/TZCNT implementations 2020-03-13 16:51:13 +00:00
Florian Hahn 2d6ecf4648 [SLP] Support vectorizing functions provided by vector libs.
It seems like the SLPVectorizer is currently not aware of vector
versions of functions provided by libraries like Accelerate [1].
This patch updates SLPVectorizer to use the same infrastructure
the LoopVectorizer uses to detect vectorizable library functions.

For calls, it computes the cost of an intrinsic call (existing behavior)
and the cost of a vector function library call, if available. Like
LoopVectorizer, it assumes the cost of the vector function is simply the
cost of a call to a vector function.

[1] https://developer.apple.com/documentation/accelerate

Reviewers: ABataev, RKSimon, spatel

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D75878
2020-03-10 13:10:50 +00:00
Simon Pilgrim 5cbddf7cbc [X86][SSE] Add more accurate costs for fmaxnum/fminnum codegen
Based off llvm-mca reports on codegen in llvm\test\CodeGen\X86\fmaxnum.ll + llvm\test\CodeGen\X86\fminnum.ll
2020-03-10 11:59:40 +00:00
Simon Pilgrim 9b05596eff [SLPVectorizer][X86] Add fmaxnum/fminnum tests 2020-03-10 11:18:28 +00:00
Florian Hahn b53907bfed [SLP] Precommit vector library test for D75878. 2020-03-10 10:17:34 +00:00
Alexey Bataev afa45d23e9 [SLP]Update test checks, NFC. 2020-02-28 13:25:44 -05:00
Simon Pilgrim 168a44a70e [CostModel][X86] Improve extract/insert element costs (PR43605)
This tries to improve the accuracy of extract/insert element costs by accounting for subvector extraction/insertion for >128-bit vectors and the shuffling of elements to/from the 0'th index.

It also adds INSERTPS for f32 types and PINSR/PEXTR costs for integer types (at the moment we assume the same cost as MOVD/MOVQ - which isn't always true).

Differential Revision: https://reviews.llvm.org/D74976
2020-02-27 15:54:13 +00:00
Simon Pilgrim b82438872b [CostModel][X86] We don't need a scale factor for SLM extract costs
D74976 will handle larger vector types, but since SLM doesn't support AVX+ then we will always be extracting from 128-bit vectors so don't need to scale the cost.
2020-02-24 14:23:04 +00:00
Florian Hahn e32522ca17 [SLPVectorizer] Do not assume extracelement idx is a ConstantInt.
The index of an ExtractElementInst is not guaranteed to be a
ConstantInt. It can be any integer value. Check explicitly for
ConstantInts.

The new test cases illustrate scenarios where we crash without
this patch. I've also added another test case to check the matching
of extractelement vector ops works.

Reviewers: RKSimon, ABataev, dtemirbulatov, vporpo

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D74758
2020-02-18 18:16:06 +01:00
Matt Arsenault b38940dfb9 TTI: Fix vectorization cost for bswap 2020-02-14 10:14:07 -08:00
Sanjay Patel bc1148e7bc [PATCH] D73727: [SLP] drop poison-generating flags for shuffle reduction ops (PR44536)
We may calculate reassociable math ops in arbitrary order when creating a shuffle reduction,
so there's no guarantee that things like 'nsw' hold on those intermediate values. Drop all
poison-generating flags for safety.

This change is limited to shuffle reductions because I don't think we have a problem in the
general case (where we intersect flags of each scalar op that goes into a vector op), but if
there's evidence of other cases being wrong, we can extend this fix to cover those cases.

https://bugs.llvm.org/show_bug.cgi?id=44536

Differential Revision: https://reviews.llvm.org/D73727
2020-01-31 09:54:35 -05:00
Andrei Elovikov e1d6d36852 [SLP] Don't allow Div/Rem as alternate opcodes
Summary:
We don't have control/verify what will be the RHS of the division, so it might
happen to be zero, causing UB.

Reviewers: Vasilis, RKSimon, ABataev

Reviewed By: ABataev

Subscribers: vporpo, ABataev, hiraditya, llvm-commits, vdmitrie

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72740
2020-01-21 15:21:17 -08:00
Andrei Elovikov 757fe53994 [SLP] Add a test showing miscompilation in AltOpcode support
Reviewers: Vasilis, RKSimon, ABataev

Reviewed By: RKSimon, ABataev

Subscribers: ABataev, inglorion, dexonsmith, llvm-commits, vdmitrie

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72739
2020-01-21 14:16:38 -08:00
James Henderson d68904f957 [NFC] Fix trivial typos in comments
Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D72143

Patch by Kazuaki Ishizaki.
2020-01-06 10:50:26 +00:00
Fangrui Song a36ddf0aa9 Migrate function attribute "no-frame-pointer-elim"="false" to "frame-pointer"="none" as cleanups after D56351 2019-12-24 16:27:51 -08:00
Fangrui Song 502a77f125 Migrate function attribute "no-frame-pointer-elim" to "frame-pointer"="all" as cleanups after D56351 2019-12-24 15:57:33 -08:00
Alexey Bataev 1edb3ea645 [SLP]Fix test arguments, NFC. 2019-12-19 13:36:21 -05:00
Alexey Bataev bc28f17e4f [SLP]Added test for gathering reused extracts from narrow vector, NFC. 2019-12-19 12:51:56 -05:00
Anton Afanasyev a315519c17 [SLP] Enhance SLPVectorizer to vectorize different combinations of aggregates
Summary:
Make SLPVectorize to recognize homogeneous aggregates like
`{<2 x float>, <2 x float>}`, `{{float, float}, {float, float}}`,
`[2 x {float, float}]` and so on.
It's a follow-up of https://reviews.llvm.org/D70068.
Merged `findBuildVector()` and `findBuildAggregate()` to
one `findBuildAggregate()` function making it recursive
to recognize multidimensional aggregates. Aggregates required
to be homogeneous.

Reviewers: RKSimon, ABataev, dtemirbulatov, spatel, vporpo

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70587
2019-12-03 19:29:27 +03:00
Sanjay Patel 5c166f1d19 [x86] make SLM extract vector element more expensive than default
I'm not sure what the effect of this change will be on all of the affected
tests or a larger benchmark, but it fixes the horizontal add/sub problems
noted here:
https://reviews.llvm.org/D59710?vs=227972&id=228095&whitespace=ignore-most#toc

The costs are based on reciprocal throughput numbers in Agner's tables for
PEXTR*; these appear to be very slow ops on Silvermont.

This is a small step towards the larger motivation discussed in PR43605:
https://bugs.llvm.org/show_bug.cgi?id=43605

Also, it seems likely that insert/extract is the source of perf regressions on
other CPUs (up to 30%) that were cited as part of the reason to revert D59710,
so maybe we'll extend the table-based approach to other subtargets.

Differential Revision: https://reviews.llvm.org/D70607
2019-11-27 14:08:56 -05:00
Anton Afanasyev 80cd6b6e04 [SLP] Enhance SLPVectorizer to vectorize vector aggregate
Summary:
Vector aggregate is homogeneous aggregate of vectors like `{ <2 x float>, <2 x float> }`.
This patch allows `findBuildAggregate()` to consider vector aggregates as
well as scalar ones. For instance, `{ <2 x float>, <2 x float> }` maps to `<4 x float>`.

Fixes vector part of llvm.org/PR42022

Reviewers: RKSimon

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70068
2019-11-22 20:01:59 +03:00
Anton Afanasyev 6d73265ad8 [SLP][Test] Precommit tests for D70068 and D70587. NFC. 2019-11-22 19:47:21 +03:00
Eric Christopher 714aabacfb Temporarily Revert "[SLP] allow forming 2-way reduction patterns" and update testcases.
After speaking with Sanjay - seeing a number of miscompiles and working
on tracking down a testcase. None of the follow on patches seem to
have helped so far.

This reverts commit 8a0aa5310b.
2019-11-20 16:00:53 -08:00
Eric Christopher 8a0aa5310b Temporarily Revert "Temporarily Revert "[SLP] allow forming 2-way reduction patterns""
as there were testcase changes after that need to also be reverted.

This reverts commit cd8748a15f.
2019-11-20 15:39:47 -08:00
Eric Christopher cd8748a15f Temporarily Revert "[SLP] allow forming 2-way reduction patterns"
After speaking with Sanjay - seeing a number of miscompiles and working
on tracking down a testcase. None of the follow on patches seem to
have helped so far.

This reverts commit 7ff57705ba.
2019-11-20 15:19:31 -08:00
Sanjay Patel b80033ef65 [SLP] reduce duplicate CHECK lines in tests; NFC 2019-11-20 10:12:54 -05:00
Sanjay Patel 0a8e7ca402 [SLP] fix miscompile on min/max reductions with extra uses (PR43948) (2nd try)
The 1st attempt was reverted because it revealed an existing
bug where we could produce invalid IR (use of value before
definition). That should be fixed with:
rG39de82ecc9c2

The bug manifests as replacing a reduction operand with an undef
value.

The problem appears to be limited to cases where a min/max reduction
has extra uses of the compare operand to the select.

In the general case, we are tracking "ExternallyUsedValues" and
an "IgnoreList" of the reduction operations, but those may not apply
to the final compare+select in a min/max reduction.

For that, we use replaceAllUsesWith (RAUW) to ensure that the new
vectorized reduction values are transferred to all subsequent users.

Differential Revision: https://reviews.llvm.org/D70148
2019-11-19 14:57:35 -05:00
Sanjay Patel 39de82ecc9 [SLP] fix insertion point for min/max reduction
As discussed in D70148 (and caused a revert of the original commit):
if we insert at the select, then we can produce invalid IR because
the replacement for the compare may have uses before the select.
2019-11-19 10:50:10 -05:00
Sanjay Patel 6265be2782 [SLP] add test for reduction miscompile; NFC
See D70148 for discussion.
2019-11-19 10:24:32 -05:00
Eric Christopher 6f1cc4151a Temporarily revert "[SLP] fix miscompile on min/max reductions with extra uses (PR43948)"
as it causes an ICE on valid. A testcase was followed up on the original thread.

This reverts commit a3e61946c5.
2019-11-18 14:41:37 -08:00
Sanjay Patel b763924bd0 [SLP] reduce duplicated check lines in tests; NFC 2019-11-18 17:03:07 -05:00
Alexey Bataev bfa32573bf Revert "Temporarily Revert:"
This reverts commit e511c4b0dff1692c267addf17dce3cebe8f97faa:

    Temporarily Revert:

     "[SLP] Generalization of stores vectorization."
     "[SLP] Fix -Wunused-variable. NFC"
     "[SLP] Vectorize jumbled stores."

after fixing the problem with compile time.
2019-11-14 16:38:20 -05:00
Sanjay Patel a3e61946c5 [SLP] fix miscompile on min/max reductions with extra uses (PR43948)
The bug manifests as replacing a reduction operand with an undef
value.

The problem appears to be limited to cases where a min/max reduction
has extra uses of the compare operand to the select.

In the general case, we are tracking "ExternallyUsedValues" and
an "IgnoreList" of the reduction operations, but those may not apply
to the final compare+select in a min/max reduction.

For that, we use replaceAllUsesWith (RAUW) to ensure that the new
vectorized reduction values are transferred to all subsequent users.

Differential Revision: https://reviews.llvm.org/D70148
2019-11-13 15:57:35 -05:00
Sanjay Patel 142cbe73e9 [SLP] improve test readability; NFC 2019-11-13 12:59:00 -05:00
Sanjay Patel 2d06375c3f [SLP] add test for miscompile with reduction (PR43948); NFC 2019-11-12 11:36:41 -05:00
Vasileios Porpodas 6a18a95487 [SLP] Look-ahead operand reordering heuristic.
Summary: This patch introduces a new heuristic for guiding operand reordering. The new "look-ahead" heuristic can look beyond the immediate predecessors. This helps break ties when the immediate predecessors have identical opcodes (see lit test for examples).

Reviewers: RKSimon, ABataev, dtemirbulatov, Ayal, hfinkel, rnk

Reviewed By: RKSimon, dtemirbulatov

Subscribers: xbolva00, Carrot, hiraditya, phosek, rnk, rcorcs, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60897
2019-11-11 21:06:51 -08:00
Sanjay Patel 7ff57705ba [SLP] allow forming 2-way reduction patterns
We have a vector compare reduction problem seen in PR39665 comment 2:
https://bugs.llvm.org/show_bug.cgi?id=39665#c2

Or slightly reduced here:

define i1 @cmp2(<2 x double> %a0) {
  %a = fcmp ogt <2 x double> %a0, <double 1.0, double 1.0>
  %b = extractelement <2 x i1> %a, i32 0
  %c = extractelement <2 x i1> %a, i32 1
  %d = and i1 %b, %c
  ret i1 %d
}

SLP would not attempt to turn this into a vector reduction because there is an
artificial lower limit on that transform. We can not completely remove that limit
without inducing regressions though, so this patch just hacks an extra attempt at
creating a 2-way reduction to the end of the analysis.

As shown in the test file, we are still not getting some of the motivating cases,
so follow-on patches will be needed to solve those cases.

Differential Revision: https://reviews.llvm.org/D59710
2019-11-07 06:08:42 -05:00
Eric Christopher e511c4b0df Temporarily Revert:
"[SLP] Generalization of stores vectorization."
 "[SLP] Fix -Wunused-variable. NFC"
 "[SLP] Vectorize jumbled stores."

As they're causing significant (10-30x) compile time regressions on
vectorizable code.

The primary cause of the compile-time regression is f228b53716.

This reverts commits:

f228b53716
5503455ccb
21d498c9c0
2019-11-06 16:06:15 -08:00
Sanjay Patel 7effd37b00 [SLP] add tests for 2-wide reductions; NFC 2019-11-05 17:18:37 -05:00
Alexey Bataev b80c41cd3c [SLP]Fix PR43799: Crash on different sizes of GEP indices.
Summary:
If the GEP instructions are going to be vectorized, the indices in those
GEP instructions must be of the same type. Otherwise, the compiler may
crash when trying to build the vector constant.

Reviewers: RKSimon, spatel

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69627
2019-11-04 10:36:26 -05:00
Sanjay Patel fc98907535 [SLP] avoid 'tmp' value name conflict with auto-generated CHECK script; NFC
The script uses 'TMP#' as its substitute for nameless values,
so if a test already contains 'tmp#' *named* values, then
there could be trouble. We should probably just fix the
script to avoid this problem going forward, but it's easy
enough to change a test too (and explicitly naming variables
'tmp' is always a sad choice).
2019-11-01 09:27:35 -04:00
Sanjay Patel 7faf33484e [SLP] avoid 'tmp' value name conflict with auto-generated CHECK script; NFC
The script uses 'TMP#' as its substitute for nameless values,
so if a test already contains 'tmp#' *named* values, then
there could be trouble. We should probably just fix the
script to avoid this problem going forward, but it's easy
enough to change a test too (and explicitly naming variables
'tmp' is always a sad choice).
2019-11-01 09:27:35 -04:00
Sanjay Patel 37628802be [SLP] avoid 'tmp' value name conflict with auto-generated CHECK script; NFC
The script uses 'TMP#' as its substitute for nameless values,
so if a test already contains 'tmp#' *named* values, then
there could be trouble. We should probably just fix the
script to avoid this problem going forward, but it's easy
enough to change a test too (and explicitly naming variables
'tmp' is always a sad choice).
2019-11-01 09:27:35 -04:00
Alexey Bataev 70ad617dd6 [SLP] Vectorize jumbled stores.
Summary:
Patch adds support for vectorization of the jumbled stores. The value
operands are vectorized and then shuffled in the right order before
store.

Reviewers: RKSimon, spatel, hfinkel, mkuper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43339
2019-10-31 16:02:25 -04:00
Haojian Wu e65ddcafee Revert "[SLP] Vectorize jumbled stores."
This reverts commit 21d498c9c0.

This commit causes some crashes on some targets.
2019-10-31 10:21:24 +01:00
Alexey Bataev 21d498c9c0 [SLP] Vectorize jumbled stores.
Summary:
Patch adds support for vectorization of the jumbled stores. The value
operands are vectorized and then shuffled in the right order before
store.

Reviewers: RKSimon, spatel, hfinkel, mkuper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43339
2019-10-30 13:33:52 -04:00
Alexey Bataev f228b53716 [SLP] Generalization of stores vectorization.
Stores are vectorized with maximum vectorization factor of 16. Patch
tries to improve the situation and use maximal vectorization factor.

Reviewers: spatel, RKSimon, mkuper, hfinkel

Differential Revision: https://reviews.llvm.org/D43582
2019-10-29 11:46:36 -04:00
Sanjay Patel 8cc6d42e8d [SLP] avoid reduction transform on patterns that the backend can load-combine (2nd try)
The 1st attempt at this modified the cost model in a bad way to avoid the vectorization,
but that caused problems for other users (the loop vectorizer) of the cost model.

I don't see an ideal solution to these 2 related, potentially large, perf regressions:
https://bugs.llvm.org/show_bug.cgi?id=42708
https://bugs.llvm.org/show_bug.cgi?id=43146

We decided that load combining was unsuitable for IR because it could obscure other
optimizations in IR. So we removed the LoadCombiner pass and deferred to the backend.
Therefore, preventing SLP from destroying load combine opportunities requires that it
recognizes patterns that could be combined later, but not do the optimization itself (
it's not a vector combine anyway, so it's probably out-of-scope for SLP).

Here, we add a cost-independent bailout with a conservative pattern match for a
multi-instruction sequence that can probably be reduced later.

In the x86 tests shown (and discussed in more detail in the bug reports), SDAG combining
will produce a single instruction on these tests like:

  movbe   rax, qword ptr [rdi]

or:

  mov     rax, qword ptr [rdi]

Not some (half) vector monstrosity as we currently do using SLP:

  vpmovzxbq       ymm0, dword ptr [rdi + 1] # ymm0 = mem[0],zero,zero,..
  vpsllvq ymm0, ymm0, ymmword ptr [rip + .LCPI0_0]
  movzx   eax, byte ptr [rdi]
  movzx   ecx, byte ptr [rdi + 5]
  shl     rcx, 40
  movzx   edx, byte ptr [rdi + 6]
  shl     rdx, 48
  or      rdx, rcx
  movzx   ecx, byte ptr [rdi + 7]
  shl     rcx, 56
  or      rcx, rdx
  or      rcx, rax
  vextracti128    xmm1, ymm0, 1
  vpor    xmm0, xmm0, xmm1
  vpshufd xmm1, xmm0, 78          # xmm1 = xmm0[2,3,0,1]
  vpor    xmm0, xmm0, xmm1
  vmovq   rax, xmm0
  or      rax, rcx
  vzeroupper
  ret

Differential Revision: https://reviews.llvm.org/D67841

llvm-svn: 375025
2019-10-16 18:06:24 +00:00
Simon Pilgrim 1385b27e92 [CostModel][X86] Add CTLZ scalar costs
Add specific scalar costs for CTLZ instructions, we can't discriminate between CTLZ and CTLZ_ZERO_UNDEF so we have to assume the worst. Given how BSR is often a microcoded nightmare on some older targets we might still be underestimating it.

For targets supporting LZCNT (Intel Haswell+ or AMD Fam10+), we provide overrides that assume 1cy costs.

llvm-svn: 374786
2019-10-14 16:30:17 +00:00
Simon Pilgrim 151bbba758 [CostModel][X86] Add CTPOP scalar costs (PR43656)
Add specific scalar costs for ctpop instructions, these are based on the llvm-mca's SLM throughput numbers (the oldest model we have).

For targets supporting POPCNT, we provide overrides that assume 1cy costs.

llvm-svn: 374775
2019-10-14 14:07:43 +00:00
Simon Pilgrim 1b59a16c0b [CostModel][X86] Improve sum reduction costs.
I can't see any notable differences in costs between SSE2 and SSE42 arches for FADD/ADD reduction, so I've lowered the target to just SSE2.

I've also added vXi8 sum reduction costs in line with the PSADBW codegen and discussions on PR42674.

llvm-svn: 374655
2019-10-12 13:21:50 +00:00
Sanjay Patel df14bd315d [SLP] respect target register width for GEP vectorization (PR43578)
We failed to account for the target register width (max vector factor)
when vectorizing starting from GEPs. This causes vectorization to
proceed to obviously illegal widths as in:
https://bugs.llvm.org/show_bug.cgi?id=43578

For x86, this also means that SLP can produce rogue AVX or AVX512
code even when the user specifies a narrower vector width.

The AArch64 test in ext-trunc.ll appears to be better using the
narrower width. I'm not exactly sure what getelementptr.ll is trying
to do, but it's testing with "-slp-threshold=-18", so I'm not worried
about those diffs. The x86 test is an over-reduction from SPEC h264;
this patch appears to restore the perf loss caused by SLP when using
-march=haswell.

Differential Revision: https://reviews.llvm.org/D68667

llvm-svn: 374183
2019-10-09 16:32:49 +00:00
Sanjay Patel 796a58107a [SLP] add test with prefer-vector-width function attribute; NFC (PR43578)
llvm-svn: 374090
2019-10-08 17:18:32 +00:00
Sanjay Patel 5cce533525 [SLP] add test with prefer-vector-width function attribute; NFC
llvm-svn: 374039
2019-10-08 12:43:46 +00:00
Martin Storsjo dfc1aee25b Revert "[SLP] avoid reduction transform on patterns that the backend can load-combine"
This reverts SVN r373833, as it caused a failed assert "Non-zero loop
cost expected" on building numerous projects, see PR43582 for details
and reproduction samples.

llvm-svn: 373882
2019-10-07 08:21:37 +00:00
Sanjay Patel e2321bb448 [SLP] avoid reduction transform on patterns that the backend can load-combine
I don't see an ideal solution to these 2 related, potentially large, perf regressions:
https://bugs.llvm.org/show_bug.cgi?id=42708
https://bugs.llvm.org/show_bug.cgi?id=43146

We decided that load combining was unsuitable for IR because it could obscure other
optimizations in IR. So we removed the LoadCombiner pass and deferred to the backend.
Therefore, preventing SLP from destroying load combine opportunities requires that it
recognizes patterns that could be combined later, but not do the optimization itself (
it's not a vector combine anyway, so it's probably out-of-scope for SLP).

Here, we add a scalar cost model adjustment with a conservative pattern match and cost
summation for a multi-instruction sequence that can probably be reduced later.
This should prevent SLP from creating a vector reduction unless that sequence is
extremely cheap.

In the x86 tests shown (and discussed in more detail in the bug reports), SDAG combining
will produce a single instruction on these tests like:

  movbe   rax, qword ptr [rdi]

or:

  mov     rax, qword ptr [rdi]

Not some (half) vector monstrosity as we currently do using SLP:

  vpmovzxbq       ymm0, dword ptr [rdi + 1] # ymm0 = mem[0],zero,zero,..
  vpsllvq ymm0, ymm0, ymmword ptr [rip + .LCPI0_0]
  movzx   eax, byte ptr [rdi]
  movzx   ecx, byte ptr [rdi + 5]
  shl     rcx, 40
  movzx   edx, byte ptr [rdi + 6]
  shl     rdx, 48
  or      rdx, rcx
  movzx   ecx, byte ptr [rdi + 7]
  shl     rcx, 56
  or      rcx, rdx
  or      rcx, rax
  vextracti128    xmm1, ymm0, 1
  vpor    xmm0, xmm0, xmm1
  vpshufd xmm1, xmm0, 78          # xmm1 = xmm0[2,3,0,1]
  vpor    xmm0, xmm0, xmm1
  vmovq   rax, xmm0
  or      rax, rcx
  vzeroupper
  ret

Differential Revision: https://reviews.llvm.org/D67841

llvm-svn: 373833
2019-10-05 18:03:58 +00:00
Sanjay Patel 3f4726b818 [SLP] add test for vectorization of different widths (PR28457); NFC
llvm-svn: 373483
2019-10-02 16:12:42 +00:00
Alexey Bataev 8b1eeafb91 [SLP] Fix for PR31847: Assertion failed: (isLoopInvariant(Operands[i], L) && "SCEVAddRecExpr operand is not loop-invariant!")
Initially SLP vectorizer replaced all going-to-be-vectorized
instructions with Undef values. It may break ScalarEvaluation and may
cause a crash.
Reworked SLP vectorizer so that it does not replace vectorized
instructions by UndefValue anymore. Instead vectorized instructions are
marked for deletion inside if BoUpSLP class and deleted upon class
destruction.

Reviewers: mzolotukhin, mkuper, hfinkel, RKSimon, davide, spatel

Subscribers: RKSimon, Gerolf, anemet, hans, majnemer, llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D29641

llvm-svn: 373166
2019-09-29 14:18:06 +00:00
Simon Pilgrim 756f5cfc2a [SLPVectorizer][X86] Regenerate arith-fp tests
llvm-svn: 373063
2019-09-27 10:04:25 +00:00
Jordan Rupprecht f98d2c099a Revert [SLP] Fix for PR31847: Assertion failed: (isLoopInvariant(Operands[i], L) && "SCEVAddRecExpr operand is not loop-invariant!")
This reverts r372626 (git commit 6a278d9073)

llvm-svn: 373019
2019-09-26 22:09:17 +00:00
Simon Pilgrim fc82c7a1b0 [SLPVectorizer][X86] Add SSE common check prefix to let us merge SSE2+SLM checks
llvm-svn: 372955
2019-09-26 10:23:57 +00:00
Simon Pilgrim d7f0207d73 [CostModel][X86] Fix SLM <2 x i64> icmp costs
SLM is 2 x slower for <2 x i64> comparison ops than other vector types, we should account for this like we do for SLM <2 x i64> add/sub/mul costs.

This should remove some of the SLM codegen diffs in D43582

llvm-svn: 372954
2019-09-26 10:14:38 +00:00
Alexey Bataev 6a278d9073 [SLP] Fix for PR31847: Assertion failed: (isLoopInvariant(Operands[i], L) && "SCEVAddRecExpr operand is not loop-invariant!")
Summary:
Initially SLP vectorizer replaced all going-to-be-vectorized
instructions with Undef values. It may break ScalarEvaluation and may
cause a crash.
Reworked SLP vectorizer so that it does not replace vectorized
instructions by UndefValue anymore. Instead vectorized instructions are
marked for deletion inside if BoUpSLP class and deleted upon class
destruction.

Reviewers: mzolotukhin, mkuper, hfinkel, RKSimon, davide, spatel

Subscribers: RKSimon, Gerolf, anemet, hans, majnemer, llvm-commits, sanjoy

Differential Revision: https://reviews.llvm.org/D29641

llvm-svn: 372626
2019-09-23 16:25:03 +00:00
Simon Pilgrim 665ccbff60 [Cost][X86] Add v2i64 truncation costs
We are missing costs for a lot of truncation cases, I'm hoping to address all the 'zero cost' cases in trunc.ll

I thought this was a vector widening side effect, but even before this we had some interesting LV decisions (notably over indvars) being made due to these zero costs.

llvm-svn: 372498
2019-09-22 12:04:38 +00:00
Sanjay Patel 4896f7243d [SLPVectorizer] add tests for bogus reductions; NFC
https://bugs.llvm.org/show_bug.cgi?id=42708
https://bugs.llvm.org/show_bug.cgi?id=43146

llvm-svn: 372393
2019-09-20 14:17:00 +00:00
Sanjay Patel b6a0faaa0c [SLP] limit vectorization of Constant subclasses (PR33958)
This is a fix for:
https://bugs.llvm.org/show_bug.cgi?id=33958

It seems universally true that we would not want to transform this kind of
sequence on any target, but if that's not correct, then we could view this
as a target-specific cost model problem. We could also white-list ConstantInt,
ConstantFP, etc. rather than blacklist Global and ConstantExpr.

Differential Revision: https://reviews.llvm.org/D67362

llvm-svn: 371931
2019-09-15 13:03:24 +00:00
Sanjay Patel 4ba6717c7e [SLP] add test for vectorization of constant expressions; NFC
Goes with D67362.

llvm-svn: 371879
2019-09-13 18:33:02 +00:00
Sanjay Patel c0728eac15 [SLP] add test for over-vectorization (PR33958); NFC
llvm-svn: 371426
2019-09-09 17:16:03 +00:00
Craig Topper 8cfff1e1bc [X86] Add prefer-128-bit subtarget feature.
Summary:
Similar to the previous prefer-256-bit flag. We might want to
enable this by default some CPUs. This just starts the initial
work to implement and prove that it effects TTI's vector width.

Reviewers: RKSimon, echristo, spatel, atdt

Reviewed By: RKSimon

Subscribers: lebedev.ri, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67311

llvm-svn: 371319
2019-09-07 19:54:22 +00:00
Craig Topper a31112e357 [X86] Replace -mcpu with -mattr on some tests.
llvm-svn: 371260
2019-09-06 21:48:44 +00:00
Sanjay Patel 0f9b5f86f1 [SLP] add test that requires shuffle of scalars; NFC
llvm-svn: 369255
2019-08-19 12:41:09 +00:00
Sanjay Patel 144903310f [SLP] add tests for PR16739; NFC
llvm-svn: 369127
2019-08-16 17:01:26 +00:00
Craig Topper 30d3e9c395 [X86][CostModel] Adjust the costs of ZERO_EXTEND/SIGN_EXTEND with less than 128-bit inputs
Now that we legalize by widening, the element types here won't change. Previously these were modeled as the elements being widened and then the instruction might become an AND or SHL/ASHR pair. But now they'll become something like a ZERO_EXTEND_VECTOR_INREG/SIGN_EXTEND_VECTOR_INREG.

For AVX2, when the destination type is legal its clear the cost should be 1 since we have extend instructions that can produce 256 bit vectors from less than 128 bit vectors. I'm a little less sure about AVX1 costs, but I think the ones I changed were definitely too high, but they might still be too high.

Differential Revision: https://reviews.llvm.org/D66169

llvm-svn: 368858
2019-08-14 14:52:39 +00:00
Craig Topper 8b5f2ab2a4 Recommit r367901 "[X86] Enable -x86-experimental-vector-widening-legalization by default."
The assert that caused this to be reverted should be fixed now.

Original commit message:

This patch changes our defualt legalization behavior for 16, 32, and
64 bit vectors with i8/i16/i32/i64 scalar types from promotion to
widening. For example, v8i8 will now be widened to v16i8 instead of
promoted to v8i16. This keeps the elements widths the same and pads
with undef elements. We believe this is a better legalization strategy.
But it carries some issues due to the fragmented vector ISA. For
example, i8 shifts and multiplies get widened and then later have
to be promoted/split into vXi16 vectors.

This has the potential to cause regressions so we wanted to get
it in early in the 10.0 cycle so we have plenty of time to
address them.

Next steps will be to merge tests that explicitly test the command
line option. And then we can remove the option and its associated
code.

llvm-svn: 368183
2019-08-07 16:24:26 +00:00
Mitch Phillips bd0d97e1c4 Revert "[X86] Enable -x86-experimental-vector-widening-legalization by default."
This reverts commit 3de33245d2.

This commit broke the MSan buildbots. See
https://reviews.llvm.org/rL367901 for more information.

llvm-svn: 368107
2019-08-06 23:00:43 +00:00
Craig Topper 3de33245d2 [X86] Enable -x86-experimental-vector-widening-legalization by default.
This patch changes our defualt legalization behavior for 16, 32, and
64 bit vectors with i8/i16/i32/i64 scalar types from promotion to
widening. For example, v8i8 will now be widened to v16i8 instead of
promoted to v8i16. This keeps the elements widths the same and pads
with undef elements. We believe this is a better legalization strategy.
But it carries some issues due to the fragmented vector ISA. For
example, i8 shifts and multiplies get widened and then later have
to be promoted/split into vXi16 vectors.

This has the potential to cause regressions so we wanted to get
it in early in the 10.0 cycle so we have plenty of time to
address them.

Next steps will be to merge tests that explicitly test the command
line option. And then we can remove the option and its associated
code.

llvm-svn: 367901
2019-08-05 18:25:36 +00:00
Hideto Ueno cc0a4cdc89 [FunctionAttrs] Annotate "willreturn" for intrinsics
Summary:
In D62801, new function attribute `willreturn` was introduced. In short, a function with `willreturn` is guaranteed to come back to the call site(more precise definition is in LangRef).

In this patch, willreturn is annotated for LLVM intrinsics.

Reviewers: jdoerfert

Reviewed By: jdoerfert

Subscribers: jvesely, nhaehnle, sstefan1, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64904

llvm-svn: 367184
2019-07-28 06:09:56 +00:00
Michael Liao 17a8a9277c [LAA] Re-check bit-width of pointers after stripping.
Summary:
- As the pointer stripping now tracks through `addrspacecast`, prepare
  to handle the bit-width difference from the result pointer.

Reviewers: jdoerfert

Subscribers: jvesely, nhaehnle, hiraditya, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64928

llvm-svn: 366470
2019-07-18 17:30:27 +00:00
Eric Christopher 93dfb93ad6 Temporarily Revert "[SLP] Recommit: Look-ahead operand reordering heuristic."
As there are some reported miscompiles with AVX512 and performance regressions
in Eigen. Verified with the original committer and testcases will be forthcoming.

This reverts commit r364964.

llvm-svn: 366154
2019-07-15 23:36:02 +00:00
Sanjay Patel c1c86adb16 [SLP] add tests for bitcasted vector pointer load; NFC
I'm not sure if this falls within the scope of SLP,
but we could create vector loads for some of these
patterns.

llvm-svn: 365055
2019-07-03 16:46:14 +00:00
Vasileios Porpodas cf47ff5ffb [SLP] Recommit: Look-ahead operand reordering heuristic.
Summary: This patch introduces a new heuristic for guiding operand reordering. The new "look-ahead" heuristic can look beyond the immediate predecessors. This helps break ties when the immediate predecessors have identical opcodes (see lit test for an example).

Reviewers: RKSimon, ABataev, dtemirbulatov, Ayal, hfinkel, rnk

Reviewed By: RKSimon, dtemirbulatov

Subscribers: hiraditya, phosek, rnk, rcorcs, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60897

llvm-svn: 364964
2019-07-02 20:20:28 +00:00
Jordan Rupprecht a7972dc04a Revert [SLP] Look-ahead operand reordering heuristic.
This reverts r364478 (git commit 574cb0eb3a)

The patch is causing compilation timeouts.

llvm-svn: 364846
2019-07-01 21:10:43 +00:00
Vasileios Porpodas 574cb0eb3a [SLP] Look-ahead operand reordering heuristic.
Summary: This patch introduces a new heuristic for guiding operand reordering. The new "look-ahead" heuristic can look beyond the immediate predecessors. This helps break ties when the immediate predecessors have identical opcodes (see lit test for an example).

Reviewers: RKSimon, ABataev, dtemirbulatov, Ayal, hfinkel, rnk

Reviewed By: RKSimon, dtemirbulatov

Subscribers: rnk, rcorcs, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60897

llvm-svn: 364478
2019-06-26 21:25:24 +00:00
Simon Pilgrim e98f8cf78f [SLPVectorizer] Precommit of supernode.ll test for D63661
This is a pre-commit of the tests introduced by the SuperNode SLP patch D63661.

Committed on behalf of @vporpo (Vasileios Porpodas)

Differential Revision: https://reviews.llvm.org/D63664

llvm-svn: 364320
2019-06-25 14:58:20 +00:00
Cameron McInally fe3f15cf90 [SLP] Support unary FNeg vectorization
Differential Revision: https://reviews.llvm.org/D63609

llvm-svn: 364219
2019-06-24 19:24:23 +00:00
Reid Kleckner 592a193285 Revert [SLP] Look-ahead operand reordering heuristic.
This reverts r364084 (git commit 5698921be2)

It caused crashes while compiling a file in Chrome. Reduction
forthcoming.

llvm-svn: 364111
2019-06-21 23:10:25 +00:00
Simon Pilgrim 5698921be2 [SLP] Look-ahead operand reordering heuristic.
This patch introduces a new heuristic for guiding operand reordering. The new "look-ahead" heuristic can look beyond the immediate predecessors. This helps break ties when the immediate predecessors have identical opcodes (see lit test for an example).

Committed on behalf of @vporpo (Vasileios Porpodas)

Differential Revision: https://reviews.llvm.org/D60897

llvm-svn: 364084
2019-06-21 17:57:01 +00:00
Cameron McInally 9589db7a98 [NFC][SLP] Pre-commit unary FNeg test to X86/propagate_ir_flags.ll
llvm-svn: 363978
2019-06-20 20:53:51 +00:00
Cameron McInally 4452c3b490 [NFC][SLP] Pre-commit unary FNeg test to X86/phi3.ll
llvm-svn: 363937
2019-06-20 15:17:17 +00:00
Simon Pilgrim 72186a2494 [SLP][X86] Add lookahead reordering tests from D60897
llvm-svn: 363925
2019-06-20 12:52:58 +00:00
Fangrui Song ac14f7b10c [lit] Delete empty lines at the end of lit.local.cfg NFC
llvm-svn: 363538
2019-06-17 09:51:07 +00:00
Sander de Smalen 51c2fa0e2a Improve reduction intrinsics by overloading result value.
This patch uses the mechanism from D62995 to strengthen the
definitions of the reduction intrinsics by letting the scalar
result/accumulator type be overloaded from the vector element type.

For example:

  ; The LLVM LangRef specifies that the scalar result must equal the
  ; vector element type, but this is not checked/enforced by LLVM.
  declare i32 @llvm.experimental.vector.reduce.or.i32.v4i32(<4 x i32> %a)

This patch changes that into:

  declare i32 @llvm.experimental.vector.reduce.or.v4i32(<4 x i32> %a)

Which has the type-constraint more explicit and causes LLVM to check
the result type with the vector element type.

Reviewers: RKSimon, arsenm, rnk, greened, aemerson

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D62996

llvm-svn: 363240
2019-06-13 09:37:38 +00:00
Dinar Temirbulatov b2f45ba1e8 [SLP] Update propagate_ir_flags.ll test to check that we do retain the common subset, NFC.
llvm-svn: 363218
2019-06-13 00:19:50 +00:00
Dinar Temirbulatov 15c657d13d [SLP] Fix regression in broadcasts caused by operand reordering patch D59973.
This patch fixes a regression caused by the operand reordering refactoring patch https://reviews.llvm.org/D59973 .
The fix changes the strategy to Splat instead of Opcode, if broadcast opportunities are found.
Please see the lit test for some examples.

Committed on behalf of @vporpo (Vasileios Porpodas)
    
Differential Revision: https://reviews.llvm.org/D62427

llvm-svn: 362613
2019-06-05 15:26:28 +00:00
Simon Pilgrim e6d1a80370 [SLPVectorizer][X86] Add other tests described in PR28474
llvm-svn: 362297
2019-06-01 12:35:03 +00:00
Simon Pilgrim 2ef83571f2 [SLPVectorizer][X86] This test was from PR28474
llvm-svn: 362296
2019-06-01 12:10:29 +00:00