[PATCH] D127115: [RFC][DAGCombine] Make sure combined nodes are added back to the worklist in topological order.

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/test/CodeGen/X86/vector-shuffle-sse4a.ll:367
 ; AMD10H-NEXT:    shufps {{.*#+}} xmm0 = xmm0[0,2,2,3]
+; AMD10H-NEXT:    andps {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
 ; AMD10H-NEXT:    pshuflw {{.*#+}} xmm0 = xmm0[2,1,2,3,4,5,6,7]
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chfast wrote:
> I don't understand why this change happened and if it is for better.
It looks like the change in combine order has affected when canonicalizeShuffleWithBinOps was applied - I'm not very concerned about this change - we already had the domain crossing penalty.

More annoying is why does this pre-SSSE3 target not end up with the same codegen as the post-SSSE3 targets below?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D127115/new/

https://reviews.llvm.org/D127115