Commit Graph

5 Commits

Author SHA1 Message Date
Craig Topper 1fae3ae6f0 [X86] Remove SSE/AVX patterns for AND/XOR/OR/ANDN that checked for the inputs being bitcasted from floating point types.
There's really no reason to do this we should just let isel pick the integer version and let the execution dependency fixing pass take care of moving to FP if necessary.

It's not very reliable to look for bitcasts at the edges of patterns. If for some reason one input was bitcasted and the other wasn't, or if one was a v4f32 bitcast and one was a v2f64 bitcast, we would have fallen back to the integer pattern anyway.

llvm-svn: 311138
2017-08-17 23:20:57 +00:00
Simon Pilgrim 8971b2904e [X86][SSE] Attempt to combine 64-bit and 32-bit shuffles to unary shuffles before bit shifts
We are combining shuffles to bit shifts before unary permutes, which means we can't fold loads plus the destination register is destructive

llvm-svn: 306978
2017-07-02 14:16:25 +00:00
Simon Pilgrim df39b03f29 [X86][SSE] Improve combineLogicBlendIntoPBLENDV to use general masks.
Currently combineLogicBlendIntoPBLENDV can only match ASHR to detect sign splatting of a bit mask, this patch generalises this to use computeNumSignBits instead.

This is a first step in several things we can do to improve PBLENDV support:

 * Better matching of X86ISD::ANDNP patterns.
 * Handle floating point cases.
 * Better vector and bitcast support in computeNumSignBits.
 * Recognise that PBLENDV only uses the sign bit of the mask, we should be able strip away sign splats (ASHR, PCMPGT isNeg tests etc.).

Differential Revision: https://reviews.llvm.org/D32953

llvm-svn: 302424
2017-05-08 14:16:39 +00:00
Sanjay Patel ad13826aea [DAGCombiner] shrink/widen a vselect to match its condition operand size (PR14657)
We discussed shrinking/widening of selects in IR in D26556, and I'll try to get back to that
patch eventually. But I'm hoping that this transform is less iffy in the DAG where we can check
legality of the select that we want to produce.

A few things to note:

1. We can't wait until after legalization and do this generically because (at least in the x86
   tests from PR14657), we'll have PACKSS and bitcasts in the pattern.
2. This might benefit more of the SSE codegen if we lifted the legal-or-custom requirement, but
   that requires a closer look to make sure we don't end up worse.
3. There's a 'vblendv' opportunity that we're missing that results in andn/and/or in some cases. 
   That should be fixed next.
4. I'm assuming that AVX1 offers the worst of all worlds wrt uneven ISA support with multiple 
   legal vector sizes, but if there are other targets like that, we should add more tests.
5. There's a codegen miracle in the multi-BB tests from PR14657 (the gcc auto-vectorization tests):
   despite IR that is terrible for the target, this patch allows us to generate the optimal loop
   code because something post-ISEL is hoisting the splat extends above the vector loops.

Differential Revision: https://reviews.llvm.org/D32620

llvm-svn: 301781
2017-04-30 22:44:51 +00:00
Sanjay Patel c3e00fcadd [x86] add minimal tests for potential size-changing vsel transforms; NFC
llvm-svn: 301554
2017-04-27 16:10:20 +00:00