[PATCH] D17691: [X86][SSE] Improve vector ZERO_EXTEND by combining to ZERO_EXTEND_VECTOR_INREG

[Elena Demikhovsky via llvm-commits]

delena added inline comments.

================
Comment at: test/CodeGen/X86/avx512-ext.ll:116
@@ -115,2 +115,3 @@
 ; SKX-NEXT:    vpmovzxbw {{.*#+}} ymm0 = xmm0[0],zero,xmm0[1],zero,xmm0[2],zero,xmm0[3],zero,xmm0[4],zero,xmm0[5],zero,xmm0[6],zero,xmm0[7],zero,xmm0[8],zero,xmm0[9],zero,xmm0[10],zero,xmm0[11],zero,xmm0[12],zero,xmm0[13],zero,xmm0[14],zero,xmm0[15],zero
+; SKX-NEXT:    vmovdqu16 %ymm0, %ymm0 {%k1} {z}
 ; SKX-NEXT:    retq
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Hi Simon,

Why do we need an additional instruction here?
vpmovzxbw       %xmm0, %ymm0 {%k1} {z}        does the work


Repository:
  rL LLVM

http://reviews.llvm.org/D17691