[PATCH] D140811: [DAGCombiner][X86] `visitVECTOR_SHUFFLE()`: splats with a single non-undef element are not splats

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added inline comments.


================
Comment at: llvm/test/CodeGen/X86/vector-narrow-binop.ll:170
+; AVX1-NEXT:    vpermilpd {{.*#+}} xmm1 = xmm1[1,0]
+; AVX1-NEXT:    vaddpd %xmm0, %xmm1, %xmm0
 ; AVX1-NEXT:    retq
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lebedev.ri wrote:
> Failure to pull identical shuffle out of binop
X86's `narrowShuffle()` intentionally does this, we can't treat this as a general shuffle combining issue.
Do we have an inverse of `canonicalizeShuffleWithBinOps()`?


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  https://reviews.llvm.org/D140811/new/

https://reviews.llvm.org/D140811