[PATCH] D57302: [DAGCombine] More diamond carry pattern optimization.

[Amaury SECHET via Phabricator via llvm-commits]

deadalnix added inline comments.


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Comment at: test/CodeGen/X86/subcarry.ll:107
+; CHECK-NEXT:    setb %dl
+; CHECK-NEXT:    movzbl %dl, %edx
 ; CHECK-NEXT:    notq %rcx
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RKSimon wrote:
> Whats your plan to deal with this regression?
It may seems counter intuitive, but this is regression is maybe the main motivation behind that patch. The code previously had 2 carries propagation, and now it has one. This new form is not as good independently, but can be optimized.

See D57317 and D59208 for instance.


Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D57302/new/

https://reviews.llvm.org/D57302