[PATCH] D37446: [x86] eliminate unnecessary vector compare for AVX masked store

[Ayman Musa via Phabricator via llvm-commits]

aymanmus added inline comments.


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Comment at: lib/Target/X86/X86ISelLowering.cpp:33185
+    SDValue Mask = Mst->getMask();
+    if (Mask.getOpcode() == X86ISD::PCMPGT &&
+        ISD::isBuildVectorAllZeros(Mask.getOperand(0).getNode())) {
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Is there any canonical form of compare-with-all-zeros that can be guaranteed here? Or should the pattern with (pcmplt X, 0) be added also?


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Comment at: test/CodeGen/X86/masked_memop.ll:1158
 ; SKX-LABEL: trunc_mask:
 ; SKX:       ## BB#0:
 ; SKX-NEXT:    vpxor %xmm1, %xmm1, %xmm1
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I think the optimal code for SKX is:
vpmovd2m %xmm2, %k1
vmovups %xmm0, (%rdi) {%k1}



https://reviews.llvm.org/D37446