Commit Graph

33 Commits

Author SHA1 Message Date
Craig Topper ff272ad4f3 [SelectionDAG] Teach getNode to simplify a couple easy cases of EXTRACT_SUBVECTOR
Summary:
This teaches getNode to simplify extracting from Undef. This is similar to what is done for EXTRACT_VECTOR_ELT. It also adds support for extracting from CONCAT_VECTOR when we can reuse one of the inputs to the concat. These seem like simple non-target specific optimizations.

For X86 we currently handle undef in extractSubvector, but not all EXTRACT_SUBVECTOR creations go through there.

Ultimately, my motivation here is to simplify extractSubvector and remove custom lowering for EXTRACT_SUBVECTOR since we don't do anything but handle undef and BUILD_VECTOR optimizations, but those should be DAG combines.

Reviewers: RKSimon, delena

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29000

llvm-svn: 292876
2017-01-24 02:36:59 +00:00
Craig Topper 96ab6fd2eb [AVX-512] Change another pattern that was using BLENDM to use masked moves. A future patch will conver it back to BLENDM if its beneficial to register allocation.
llvm-svn: 291419
2017-01-09 04:19:34 +00:00
Craig Topper 6393afce97 [AVX-512] Add patterns to use a zero masked VPTERNLOG instruction for vselects of all ones and all zeros.
Previously we emitted a VPTERNLOG and a separate masked move.

llvm-svn: 291415
2017-01-09 02:44:34 +00:00
Gadi Haber 19c4fc5e62 This is a large patch for X86 AVX-512 of an optimization for reducing code size by encoding EVEX AVX-512 instructions using the shorter VEX encoding when possible.
There are cases of AVX-512 instructions that have two possible encodings. This is the case with instructions that use vector registers with low indexes of 0 - 15 and do not use the zmm registers or the mask k registers.
The EVEX encoding prefix requires 4 bytes whereas the VEX prefix can take only up to 3 bytes. Consequently, using the VEX encoding for these instructions results in a code size reduction of ~2 bytes even though it is compiled with the AVX-512 features enabled.

Reviewers: Craig Topper, Zvi Rackoover, Elena Demikhovsky 
Differential Revision: https://reviews.llvm.org/D27901

llvm-svn: 290663
2016-12-28 10:12:48 +00:00
Simon Pilgrim 8f7c56125e [X86][AVX512] Add masked VPMOZX test case for PR26762
llvm-svn: 286763
2016-11-13 15:16:43 +00:00
Simon Pilgrim 778596bf59 [TargetLowering] Fix undef vector element issue with true/false result handling
Fixed an issue with vector usage of TargetLowering::isConstTrueVal / TargetLowering::isConstFalseVal boolean result matching.

The comment said we shouldn't handle constant splat vectors with undef elements. But the the actual code was returning false if the build vector contained no undef elements....

This patch now ignores the number of undefs (getConstantSplatNode will return null if the build vector is all undefs).

The change has also unearthed a couple of missed opportunities in AVX512 comparison code that will need to be addressed.

Differential Revision: https://reviews.llvm.org/D26031

llvm-svn: 286238
2016-11-08 15:07:01 +00:00
Craig Topper d9ca3d97ef [AVX-512] Simplify X86InstrInfo::copyPhysReg for 128/256-bit vectors with AVX512, but not VLX. We should use the VEX opcodes and trust the register allocator to not use the extended XMM/YMM register space.
Previously we were extending to copying the whole ZMM register. The register allocator shouldn't use XMM16-31 or YMM16-31 in this configuration as the instructions to spill them aren't available.

llvm-svn: 280648
2016-09-05 06:43:06 +00:00
Michael Kuperstein 2ee911e985 Revert r274613 because it breaks the test suite with AVX512
This reverts most of r274613 (AKA r274626) and its follow-ups (r276347, r277289),
due to miscompiles in the test suite. The FastISel change was left in, because
it apparently fixes an unrelated issue.

(Recommit of r279782 which was broken due to a bad merge.)

This fixes 4 out of the 5 test failures in PR29112.

llvm-svn: 279788
2016-08-25 22:48:11 +00:00
Michael Kuperstein 6e271f4ce8 Revert r279782 due to debug buildbot breakage.
llvm-svn: 279785
2016-08-25 22:14:45 +00:00
Michael Kuperstein a6ccc8d365 Revert r274613 because it breaks the test suite with AVX512
This reverts most of r274613 and its follow-ups (r276347, r277289), due to
miscompiles in the test suite. The FastISel change was left in, because it
apparently fixes an unrelated issue.

This fixes 4 out of the 5 test failures in PR29112.

llvm-svn: 279782
2016-08-25 21:55:41 +00:00
Igor Breger 8672408db0 [AVX512] Fix insertelement i1 lowering.
1. Use shuffle to insert element i1 into vector. The previous implementation was incorrect ( dest_bit OR src_bit , it doesn't clear the bit if src_bit=0 )
2. Improve shuffle i1 vector, use CVT2MASK if supported instead TRUNCATE.

Differential Revision: http://reviews.llvm.org/D23347

llvm-svn: 278623
2016-08-14 05:25:07 +00:00
Igor Breger a77b14d02c [AVX512] Fix extractelement i1 lowering.
The previous implementation (not custom) doesn't enforce zeroing off upper bits. The assumption is that i1 PRODUCER (truncate and extractelement) must zero all upper bits, so i1 CONSUMER instructions ( test, zext, save, etc) can be done without additional zeroing.
Make extractelement i1 lowering custom for all vector i1.

Differential Revision: http://reviews.llvm.org/D23246

llvm-svn: 278328
2016-08-11 12:13:46 +00:00
Elena Demikhovsky dca03bebd3 AVX-512: Changed lowering of BITCAST between i1 vectors and i8/i16/i32 integer values
Optimized lowering of BITCAST node. The BITCAST node can be replaced with COPY_TO_REG instead of KMOV.
It allows to suppress two opposite BITCAST operations and avoid redundant "movs".

Differential Revision: https://reviews.llvm.org/D23247

llvm-svn: 277958
2016-08-07 13:05:58 +00:00
Craig Topper 52e2e8381b [AVX512] Add ExeDomain to vector extend and truncate instructions.
llvm-svn: 276394
2016-07-22 05:46:44 +00:00
Craig Topper f4151bea72 [AVX512] Add initial support for the Execution Domain fixing pass to change some EVEX instructions.
llvm-svn: 276393
2016-07-22 05:00:52 +00:00
Sanjay Patel 610a2f6525 [x86][SSE/AVX] optimize pcmp results better (PR28484)
We know that pcmp produces all-ones/all-zeros bitmasks, so we can use that behavior to avoid unnecessary constant loading.

One could argue that load+and is actually a better solution for some CPUs (Intel big cores) because shifts don't have the
same throughput potential as load+and on those cores, but that should be handled as a CPU-specific later transformation if
it ever comes up. Removing the load is the more general x86 optimization. Note that the uneven usage of vpbroadcast in the
test cases is filed as PR28505:
https://llvm.org/bugs/show_bug.cgi?id=28505

Differential Revision: http://reviews.llvm.org/D22225

llvm-svn: 275276
2016-07-13 16:04:07 +00:00
Craig Topper 516e14cd8e [AVX512] Use vpternlog with an immediate of 0xff to create 512-bit all one vectors.
llvm-svn: 275045
2016-07-11 05:36:48 +00:00
Matthias Braun 152e7c8b12 VirtRegMap: Replace some identity copies with KILL instructions.
An identity COPY like this:
   %AL = COPY %AL, %EAX<imp-def>
has no semantic effect, but encodes liveness information: Further users
of %EAX only depend on this instruction even though it does not define
the full register.

Replace the COPY with a KILL instruction in those cases to maintain this
liveness information. (This reverts a small part of r238588 but this
time adds a comment explaining why a KILL instruction is useful).

llvm-svn: 274952
2016-07-09 00:19:07 +00:00
Elena Demikhovsky ad0a56f3da Re-commit of 274613.
The prev commit failed on compilation.
A minor change in one pattern in lib/Target/X86/X86InstrAVX512.td fixes the failure.

llvm-svn: 274626
2016-07-06 14:15:43 +00:00
Elena Demikhovsky 02ced295aa Reverted 274613 due to compilation failue.
llvm-svn: 274615
2016-07-06 09:11:49 +00:00
Elena Demikhovsky 5a4f2476fd AVX-512: Optimization for patterns with i1 scalar type
The patch removes redundant kmov instructions (not all, we still have a lot of work here) and redundant "and" instructions after "setcc".
I use "AssertZero" marker between X86ISD::SETCC node and "truncate" to eliminate extra "and $1" instruction.
I also changed zext, aext and trunc patterns in the .td file. It allows to remove extra "kmov" instruictions.

This patch fixes https://llvm.org/bugs/show_bug.cgi?id=28173.

Fast ISEL mode is not supported correctly for AVX-512. ICMP/FCMP scalar instruction should return result in k-reg. It will be fixed in one of the next patches. I redirected handling of "cmp" to the DAG builder mode. (The code looks worse in one specific test case, but without this fix the new patch fails).

Differential revision: http://reviews.llvm.org/D21956

llvm-svn: 274613
2016-07-06 09:01:20 +00:00
Simon Pilgrim 68f438a036 [X86][AVX512] Add support for PMOVZX masked shuffle comments
llvm-svn: 274461
2016-07-03 13:33:28 +00:00
Igor Breger a949100532 AVX512: icmp operation should be always lowered to CMPM (AVX-512) instruction on SKX.
implemented by delena

Differential Revision: http://reviews.llvm.org/D18054

llvm-svn: 263417
2016-03-14 10:26:39 +00:00
Elena Demikhovsky cd9967d160 AVX-512: Fixed a bug in i1 vector zero extending. (Skylake-avx512)
(failed on instruction selection phase)

Differential Revision: http://reviews.llvm.org/D17924

llvm-svn: 263111
2016-03-10 13:44:22 +00:00
Igor Breger c7ba5699c5 AVX512: Add vpmovzxbw/d/q ,vpmovzxw/d/q ,vpmovzxbdq lowering patterns that support 256bit inputs like AVX patterns ( that are disable in case HasVLX , see SS41I_pmovx_avx2_patterns).
Differential Revision: http://reviews.llvm.org/D17504

llvm-svn: 261724
2016-02-24 08:15:20 +00:00
Simon Pilgrim 0acc32a3b3 [X86][AVX512] Added support for VPMOVZX shuffle decoding.
llvm-svn: 260007
2016-02-06 19:51:21 +00:00
Igor Breger fca0a34398 AVX512: Fix truncate v32i8 to v32i1 lowering implementation.
Enable truncate 128/256bit packed byte/word with AVX512BW but without AVX512VL, use 512bit instructions.

Differential Revision: http://reviews.llvm.org/D16531

llvm-svn: 259044
2016-01-28 13:19:25 +00:00
Igor Breger 7a000f5bb2 AVX512: Masked move intrinsic implementation.
Implemented intrinsic for the follow instructions (reg move) : VMOVDQU8/16, VMOVDQA32/64, VMOVAPS/PD.

Differential Revision: http://reviews.llvm.org/D16316

llvm-svn: 258398
2016-01-21 14:18:11 +00:00
Igor Breger dd6522c653 AVX512 : Change v8i1 bitconvert GR8 pattern, remove unnecessary movzbl instruction.
code example , previous implementation.
    movzbl  %dil, %eax
    kmovw  %eax, %k0
  new code
    kmovw  %edi, %k0

Differential Revision: http://reviews.llvm.org/D16287

llvm-svn: 258045
2016-01-18 12:02:45 +00:00
Igor Breger 756c289dd8 AVX512: Change VPMOVB2M DAG lowering , use CVT2MASK node instead TRUNCATE.
Fix TRUNCATE lowering vector to vector i1, use LSB and not MSB.
Implement VPMOVB/W/D/Q2M intrinsic.

Differential Revision: http://reviews.llvm.org/D15675

llvm-svn: 256470
2015-12-27 13:56:16 +00:00
Igor Breger 074a64e72c AVX-512: Implemented encoding , DAG lowering and intrinsics for Integer Truncate with/without saturation
Added tests for DAG lowering ,encoding and intrinsic

Differential Revision: http://reviews.llvm.org/D11218

llvm-svn: 243122
2015-07-24 17:24:15 +00:00
Chandler Carruth fe414353db Revert r242990: "AVX-512: Implemented encoding , DAG lowering and ..."
This commit broke the build. Numerous build bots broken, and it was
blocking my progress so reverting.

It should be trivial to reproduce -- enable the BPF backend and it
should fail when running llvm-tblgen.

llvm-svn: 242992
2015-07-23 08:03:44 +00:00
Igor Breger da1b2ea955 AVX-512: Implemented encoding , DAG lowering and intrinsics for Integer Truncate with/without saturation
Added tests for DAG lowering ,encoding and intrinsic

Differential Revision: http://reviews.llvm.org/D11218

llvm-svn: 242990
2015-07-23 07:39:21 +00:00