Commit Graph

91 Commits

Author SHA1 Message Date
Simon Pilgrim 6e5350a367 [X86][SSE] SimplifyDemandedBitsForTargetNode - PCMPGT(0,X) sign mask
For PCMPGT(0, X) patterns where we only demand the sign bit (e.g. BLENDV or MOVMSK) then we can use X directly.

Differential Revision: https://reviews.llvm.org/D57667

llvm-svn: 353051
2019-02-04 15:43:36 +00:00
Craig Topper 5b69b5e20a [X86] Add a few more fptosi test cases to demonstrate -x86-experimental-vector-widening legalization not combining vpacksswb+vpmovdw.
We are able to combine vpackuswb+vpmovdw, but we didn't have packsswb+vpmovdw at the time that combine was added.

llvm-svn: 348909
2018-12-12 05:55:59 +00:00
Craig Topper 333ab7d08b [X86] Add more tests for -x86-experimental-vector-widening-legalization
I'm looking into whether we can make this the default legalization strategy. Adding these tests to help cover the changes that will be necessary.

This patch adds copies of some tests with the command line switch enabled. By making copies its easier to compare the two legalization strategies.

I've also removed RUN lines from some of these tests that already had -x86-experimental-vector-widening-legalization

llvm-svn: 346745
2018-11-13 07:47:52 +00:00
Sanjay Patel 0a515595a7 [x86] allow vector load narrowing with multi-use values
This is a long-awaited follow-up suggested in D33578. Since then, we've picked up even more
opportunities for vector narrowing from changes like D53784, so there are a lot of test diffs.
Apart from 2-3 strange cases, these are all wins.

I've structured this to be no-functional-change-intended for any target except for x86
because I couldn't tell if AArch64, ARM, and AMDGPU would improve or not. All of those
targets have existing regression tests (4, 4, 10 files respectively) that would be
affected. Also, Hexagon overrides the shouldReduceLoadWidth() hook, but doesn't show
any regression test diffs. The trade-off is deciding if an extra vector load is better
than a single wide load + extract_subvector.

For x86, this is almost always better (on paper at least) because we often can fold
loads into subsequent ops and not increase the official instruction count. There's also
some unknown -- but potentially large -- benefit from using narrower vector ops if wide
ops are implemented with multiple uops and/or frequency throttling is avoided.

Differential Revision: https://reviews.llvm.org/D54073

llvm-svn: 346595
2018-11-10 20:05:31 +00:00
Simon Pilgrim 838eb24014 [TargetLowering] Improve vXi64 UINT_TO_FP vXf64 support (P38226)
As suggested on D52965, this patch moves the i64 to f64 UINT_TO_FP expansion code from LegalizeDAG into TargetLowering and makes it available to LegalizeVectorOps as well.

Not only does this help perform X86 lowering as a true vectorization instead of (partially vectorized) scalar conversions, it avoids the HADDPD op from the scalar code which can be slow on most targets.

The AVX512F does have the vcvtusi2sdq scalar operation but we don't unroll to use it as it seems to only help for the v2f64 case - otherwise the unrolling cost will certainly be too high. My feeling is that we should leave it to the vectorizers - and if it generates the vector UINT_TO_FP we should use it.

Differential Revision: https://reviews.llvm.org/D53649

llvm-svn: 345256
2018-10-25 11:15:57 +00:00
Craig Topper 2140a8e307 [X86] Add -x86-experimental-vector-widening-legalization run line to avx512-cvt.ll
This will cover the (v2i32 (setcc v2f32)) case in replaceNodeResults. That code shouldn't be needed at all in this mode. A future patch will skip it.

llvm-svn: 341171
2018-08-31 07:05:36 +00:00
Craig Topper cdb0ed2910 [X86] Add custom execution domain fixing for 128/256-bit integer logic operations with AVX512F, but not AVX512DQ.
AVX512F only has integer domain logic instructions. AVX512DQ added FP domain logic instructions.

Execution domain fixing runs before EVEX->VEX. So if we have AVX512F and not AVX512DQ we fail to do execution domain switching of the logic operations. This leads to mismatches in execution domain and more test differences.

This patch adds custom domain fixing that switches EVEX integer logic operations to VEX fp logic operations if XMM16-31 are not used.

llvm-svn: 337137
2018-07-15 23:32:36 +00:00
Craig Topper b195ed8ce3 [X86] Use vpmovq2m/vpmovd2m for truncate to vXi1 when possible.
Previously we used vptestmd, but the scheduling data for SKX says vpmovq2m/vpmovd2m is lower latency. We already used vpmovb2m/vpmovw2m for byte/word truncates. So this is more consistent anyway.

llvm-svn: 325534
2018-02-19 22:07:31 +00:00
Craig Topper 9121eb575e [X86] Custom legalize (v2i32 (setcc (v2f32))) so that we don't end up with a (v4i1 (setcc (v4f32)))
Undef VLX, getSetCCResultType returns v2i1/v4i1 for v2f32/v4f32 so default type legalization will end up changing the setcc result type back to vXi1 if it had been extended. The resulting extend gets messed up further by type legalization and is difficult to recombine back to (v4i32 (setcc (v4f32))) after legalization.

I went ahead and enabled this for SSE2 and later since its always the result we want and this helps type legalization get there in less steps.

llvm-svn: 324822
2018-02-10 19:12:58 +00:00
Craig Topper 28d3a73c81 [X86] Extend inputs with elements smaller than i32 to sint_to_fp/uint_to_fp before type legalization.
This prevents extends of masks being introduced during lowering where it become difficult to combine them out.

There are a few oddities in here.

We sometimes concatenate two k-registers produced by two compares, sign_extend the combined pair, then extract two halves. This worked better previously because the sign_extend wasn't created until after the fp_to_sint was split which led to a split sign_extend being created.

We probably also need to custom type legalize (v2i32 (sext v2i1)) via widening.

llvm-svn: 324820
2018-02-10 17:58:58 +00:00
Craig Topper 0fbdaa6d81 [X86] Remove some check-prefixes from avx512-cvt.ll to prepare for an upcoming patch.
The update script sometimes has trouble when there are check-prefixes representing every possible combination of feature flags. I have a patch where the update script was generating something that didn't pass lit.

This patch just removes some check-prefixes and expands out some of the checks to workaround this.

llvm-svn: 324819
2018-02-10 17:58:56 +00:00
Craig Topper b8d7b1620b [X86] Custom legalize (v2i1 (fp_to_uint/fp_to_sint v2f64)) without AVX512VL.
Strangely the code was already present, just the setOperationAction wasn't being called without VLX.

llvm-svn: 324806
2018-02-10 08:39:31 +00:00
Craig Topper c3aab4bbe1 [X86] Legalize zero extends from vXi1 to vXi16/vXi32/vXi64 using a sign extend and a shift.
This avoids a constant pool load to create 1.

The int->float are showing converts to mask and back. We probably need to widen inputs to sint_to_fp/uint_to_fp before type legalization.

llvm-svn: 324805
2018-02-10 08:06:52 +00:00
Craig Topper 94235556aa [X86] Modify a few tests to not use icmps that are provably false.
These used things like unsigned less than zero, which is always false because there is no unsigned number less than zero.

I plan to teach DAG combine to optimize these so need to stop using them.

llvm-svn: 324315
2018-02-06 06:44:05 +00:00
Puyan Lotfi 43e94b15ea Followup on Proposal to move MIR physical register namespace to '$' sigil.
Discussed here:

http://lists.llvm.org/pipermail/llvm-dev/2018-January/120320.html

In preparation for adding support for named vregs we are changing the sigil for
physical registers in MIR to '$' from '%'. This will prevent name clashes of
named physical register with named vregs.

llvm-svn: 323922
2018-01-31 22:04:26 +00:00
Craig Topper c58c2b5c9b [X86] Rewrite vXi1 element insertion by using a vXi1 scalar_to_vector and inserting into a vXi1 vector.
The existing code was already doing something very similar to subvector insertion so this allows us to remove the nearly duplicate code.

This patch is a little larger than it should be due to differences between the DQI handling between the two today.

llvm-svn: 323212
2018-01-23 15:56:36 +00:00
Craig Topper f090e8a89a [X86] Replace CVT2MASK ISD opcode with PCMPGTM compared to zero.
CVT2MASK is just checking the sign bit which can be represented with a comparison with zero.

llvm-svn: 321985
2018-01-08 06:53:54 +00:00
Craig Topper d58c165545 [X86] Make v2i1 and v4i1 legal types without VLX
Summary:
There are few oddities that occur due to v1i1, v8i1, v16i1 being legal without v2i1 and v4i1 being legal when we don't have VLX. Particularly during legalization of v2i32/v4i32/v2i64/v4i64 masked gather/scatter/load/store. We end up promoting the mask argument to these during type legalization and then have to widen the promoted type to v8iX/v16iX and truncate it to get the element size back down to v8i1/v16i1 to use a 512-bit operation. Since need to fill the upper bits of the mask we have to fill with 0s at the promoted type.

It would be better if we could just have the v2i1/v4i1 types as legal so they don't undergo any promotion. Then we can just widen with 0s directly in a k register. There are no real v4i1/v2i1 instructions anyway. Everything is done on a larger register anyway.

This also fixes an issue that we couldn't implement a masked vextractf32x4 from zmm to xmm properly.

We now have to support widening more compares to 512-bit to get a mask result out so new tablegen patterns got added.

I had to hack the legalizer for widening the operand of a setcc a bit so it didn't try create a setcc returning v4i32, extract from it, then try to promote it using a sign extend to v2i1. Now we create the setcc with v4i1 if the original setcc's result type is v2i1. Then extract that and don't sign extend it at all.

There's definitely room for improvement with some follow up patches.

Reviewers: RKSimon, zvi, guyblank

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41560

llvm-svn: 321967
2018-01-07 18:20:37 +00:00
Craig Topper e3b6bd337a [SelectionDAG] Teach WidenVecOp_Convert to widen the operation if a widened result type would still be legal.
llvm-svn: 321638
2018-01-02 07:30:53 +00:00
Craig Topper c8898b3640 [X86] Promote vXi1 fp_to_uint/fp_to_sint to vXi32 to avoid scalarization.
llvm-svn: 321632
2018-01-01 21:12:18 +00:00
Craig Topper bb8b79b0a0 [X86] Add test cases for vXi1 fptosi/fptoui.
Currently we do a lot of scalarization in these test cases.

llvm-svn: 321631
2018-01-01 21:12:10 +00:00
Craig Topper 2d1d9a11c1 [X86] Fix (v2f64 (s/uint_to_fp (v2i1))) to avoid scalarization without AVX512DQ.
Previously we extended v2i1 to v2f64 and then tried to use cvtuqq2pd/cvtqq2pd, but that only works with avx512dq. So we ended up scalarizing it. Now we widen to v4i1 first and extend to v4i32.

llvm-svn: 321420
2017-12-24 06:51:36 +00:00
Francis Visoiu Mistrih a8a83d150f [CodeGen] Use MachineOperand::print in the MIRPrinter for MO_Register.
Work towards the unification of MIR and debug output by refactoring the
interfaces.

For MachineOperand::print, keep a simple version that can be easily called
from `dump()`, and a more complex one which will be called from both the
MIRPrinter and MachineInstr::print.

Add extra checks inside MachineOperand for detached operands (operands
with getParent() == nullptr).

https://reviews.llvm.org/D40836

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+)<def> ([^ ]+)/kill: \1 def \2 \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: def ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: def \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/<def>//g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<kill>/killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use,kill>/implicit killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<def[ ]*,[ ]*dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def[ ]*,[ ]*dead>/implicit-def dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def>/implicit-def \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use>/implicit \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<internal>/internal \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<undef>/undef \1/g'

llvm-svn: 320022
2017-12-07 10:40:31 +00:00
Craig Topper a404ce955a [X86] Use vector widening to support sign extend from i1 when the dest type is not 512-bits and vlx is not enabled.
Previously we used a wider element type and truncated. But its more efficient to keep the element type and drop unused elements.

If BWI isn't supported and we have a i16 or i8 type, we'll extend it to be i32 and still use a truncate.

llvm-svn: 319740
2017-12-05 06:37:21 +00:00
Craig Topper 276c770e57 [X86] Use vector widening to support zero extend from i1 when the dest type is not 512-bits and vlx is not enabled.
Previously we used a wider element type and truncated. But its more efficient to keep the element type and drop unused elements.

If BWI isn't supported and we have a i16 or i8 type, we'll extend it to be i32 and still use a truncate.

llvm-svn: 319728
2017-12-05 01:45:46 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Craig Topper fbf7b3bf3e [X86] Promote fp_to_sint v16f32->v16i16/v16i8 to avoid scalarization.
llvm-svn: 319266
2017-11-29 00:32:09 +00:00
Craig Topper 8261c8c066 [X86] Add test cases for fptosi v16f32->v16i8/v16i16 to show scalarization.
llvm-svn: 319261
2017-11-29 00:02:22 +00:00
Craig Topper 88ffb5d4d5 [X86] Mark ISD::FP_TO_UINT v16i8/v16i16 as Promote under AVX512 instead of legal. Fix infinite loop in op legalization when promotion requires 2 steps.
Previously we had an isel pattern to add the truncate. Instead use Promote to add the truncate to the DAG before isel.

The Promote legalization code had to be updated to prevent an infinite loop if promotion took multiple steps because it wasn't remembering the previously tried value.

llvm-svn: 319259
2017-11-28 23:56:02 +00:00
Francis Visoiu Mistrih 9d7bb0cb40 [CodeGen] Print register names in lowercase in both MIR and debug output
As part of the unification of the debug format and the MIR format,
always print registers as lowercase.

* Only debug printing is affected. It now follows MIR.

Differential Revision: https://reviews.llvm.org/D40417

llvm-svn: 319187
2017-11-28 17:15:09 +00:00
Craig Topper beed653135 [X86] Make AVX512_512_SET0 XMM16-31 lower to 128-bit XOR when AVX512VL is enabled. Use 128-bit VLX instruction when VLX is enabled.
Unfortunately, this weakens our ability to do domain fixing when AVX512DQ is not enabled, but it is consistent with our 256-bit behavior.

Maybe we should add custom handling to domain fixing to allow EVEX integer XOR/AND/OR/ANDN to switch to VEX encoded fp instructions if the high registers aren't being used?

llvm-svn: 316978
2017-10-31 06:01:04 +00:00
Simon Pilgrim 96a0b9ef54 [SelectionDAG] Add VSELECT support to computeKnownBits
llvm-svn: 316944
2017-10-30 19:08:21 +00:00
Simon Pilgrim 1bc62f03a5 [SelectionDAG] Add VSELECT support to ComputeNumSignBits
llvm-svn: 316457
2017-10-24 16:38:38 +00:00
Gadi Haber 87337a2bb9 [X86][SKX][KNL] Updated regression tests to use -mattr instead of -mcpu flag.NFC.
NFC.
 Updated 8 regression tests to use -mattr instead of -mcpu flag as follows:
 -mcpu=knl --> -mattr=+avx512f
 -mcpu=skx --> -mattr=+avx512f,+avx512bw,+avx512vl,+avx512dq

The updates are as part of the preparation of a large commit to add all instruction scheduling for the SKX target.

Reviewers: delena, zvi, RKSimon
Differential Revision: https://reviews.llvm.org/D38222

Change-Id: I2381c9b5bb75ecacfca017243c22d054f6eddd14
llvm-svn: 314306
2017-09-27 14:44:15 +00:00
Craig Topper a6054328e8 [X86] Teach the execution domain fixing tables to use movlhps inplace of unpcklpd for the packed single domain.
MOVLHPS has a smaller encoding than UNPCKLPD in the legacy encodings. With VEX and EVEX encodings it doesn't matter.

llvm-svn: 313509
2017-09-18 04:40:58 +00:00
Zvi Rackover 255488a1e0 X86 Tests: More AVX512 conversions tests. NFC
Adding more tests for AVX512 fp<->int conversions that were missing.

llvm-svn: 312921
2017-09-11 15:54:38 +00:00
Zvi Rackover 25799d93f0 X86: Improve AVX512 fptoui lowering
Summary:
Add patterns for
  fptoui <16 x float> to <16 x i8>
  fptoui <16 x float> to <16 x i16>

Reviewers: igorb, delena, craig.topper

Reviewed By: craig.topper

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D37505

llvm-svn: 312704
2017-09-07 07:40:34 +00:00
Zvi Rackover 5ebe94a84d X86 Tests: Tidy up AVX512 conversion tests. NFC.
Rename functions to a consistent format to make it easier to track coverage.

llvm-svn: 312619
2017-09-06 05:33:04 +00:00
Zvi Rackover 2096893f34 X86 Tests: Adding missing AVX512 fptoui coverage tests. NFC.
Some of the cases show missing pattern i intend to fix shortly.

llvm-svn: 312560
2017-09-05 18:24:39 +00:00
Craig Topper 48a7917079 [AVX512] Use 256-bit extract instructions for extracting bits [255:128] from a 512-bit register
This enables the use of a smaller encoding by using a VEX instruction when possible.

Differential Revision: https://reviews.llvm.org/D37092

llvm-svn: 312100
2017-08-30 07:26:12 +00:00
Gadi Haber d76f7b824e [X86][Haswell] Updating HSW instruction scheduling information
This patch completely replaces the instruction scheduling information for the Haswell architecture target by modifying the file X86SchedHaswell.td located under the X86 Target.
We used the scheduling information retrieved from the Haswell architects in order to replace and modify the existing scheduling.
The patch continues the scheduling replacement effort started with the SNB target in r307529 and r310792.
Information includes latency, number of micro-Ops and used ports by each HSW instruction.

Please expect some performance fluctuations due to code alignment effects.

Reviewers: RKSimon, zvi, aymanmus, craig.topper, m_zuckerman, igorb, dim, chandlerc, aaboud

Differential Revision: https://reviews.llvm.org/D36663

llvm-svn: 311879
2017-08-28 10:04:16 +00:00
Craig Topper 3a622a14f9 [AVX512] Don't switch unmasked subvector insert/extract instructions when AVX512DQI is enabled.
There's no reason to switch instructions with and without DQI. It just creates extra isel patterns and test divergences.

There is however value in enabling the masked version of the instructions with DQI.

This required introducing some new multiclasses to enabling this splitting.

Differential Revision: https://reviews.llvm.org/D36661

llvm-svn: 311091
2017-08-17 15:40:25 +00:00
Dinar Temirbulatov a0beedef1c [X86] SET0 to use XMM registers where possible PR26018 PR32862
Differential Revision: https://reviews.llvm.org/D35965

llvm-svn: 309926
2017-08-03 08:50:18 +00:00
Craig Topper 410d252f5b [AVX-512] Add unmasked subvector inserts and extract to the execution domain tables.
llvm-svn: 309632
2017-07-31 22:07:29 +00:00
Dinar Temirbulatov aead31a36f [X86] SET0 to use XMM registers where possible PR26018 PR32862
Differential Revision: https://reviews.llvm.org/D35839

llvm-svn: 309298
2017-07-27 17:47:01 +00:00
Simon Pilgrim f9ea0959d9 [X86][AVX] Regenerate tests with constant broadcast comments
llvm-svn: 308110
2017-07-15 21:17:35 +00:00
Michael Zuckerman f66840020c Reverting commit 306414 on behalf of @gadi.haber
llvm-svn: 306532
2017-06-28 11:23:31 +00:00
Gadi Haber 13759a7ed6 Updated and extended the information about each instruction in HSW and SNB to include the following data:
•static latency
•number of uOps from which the instructions consists
•all ports used by the instruction

Reviewers: 
 RKSimon 
 zvi  
aymanmus  
m_zuckerman 

Differential Revision: https://reviews.llvm.org/D33897
 

llvm-svn: 306414
2017-06-27 15:05:13 +00:00
Sanjay Patel 6e8e7cc70e [x86] avoid flipping sign bits for vector icmp by using known bits
If we know that both operands of an unsigned integer vector comparison are non-negative, 
then it's safe to directly use a signed-compare-greater-than instruction (the only non-equality
integer vector compare predicate provided by SSE/AVX).

We're intentionally not changing the condition code to signed in order to preserve the
existing transforms that use min/max/psubus below here.

This should solve PR33276:
https://bugs.llvm.org/show_bug.cgi?id=33276

Differential Revision: https://reviews.llvm.org/D33862

llvm-svn: 304909
2017-06-07 13:46:34 +00:00
Sanjay Patel 56641ac497 [x86] fix over-specific triple; NFC
There's nothing darwin-specific in these tests, and using
that setting causes extra phantom diffs when the auto-generated 
check lines are regenerated today.

llvm-svn: 304614
2017-06-02 23:40:46 +00:00