[PATCH] D55768: [TargetLowering] Add DemandedElts mask to SimplifyDemandedBits (PR40000)

[Andrea Di Biagio via Phabricator via llvm-commits]

andreadb accepted this revision.
andreadb added a comment.
This revision is now accepted and ready to land.

LGTM. Thanks!



================
Comment at: test/CodeGen/X86/combine-sdiv.ll:3052-3057
 ; AVX1-NEXT:    vpsrlw $8, %xmm1, %xmm1
 ; AVX1-NEXT:    vpunpcklbw {{.*#+}} xmm2 = xmm0[0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7]
 ; AVX1-NEXT:    vpsraw $8, %xmm2, %xmm2
 ; AVX1-NEXT:    vpsllw $8, %xmm2, %xmm2
 ; AVX1-NEXT:    vpsrlw $8, %xmm2, %xmm2
 ; AVX1-NEXT:    vpackuswb %xmm1, %xmm2, %xmm1
----------------
Unrelated to your patch.

This could be simplified to:

```
    vpsrlw $8, %xmm1, %xmm1
    vpxor %xmm2, %xmm2, %xmm2
    vpunpcklbw %xmm2, %xmm0, %xmm2
    vpackuswb %xmm1, %xmm2, %xmm0
```


Repository:
  rL LLVM

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  https://reviews.llvm.org/D55768/new/

https://reviews.llvm.org/D55768