[PATCH] D53181: SelectionDAG: Reuse bigger sized constants in memset expansion.

[JF Bastien via Phabricator via llvm-commits]

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

Nice! LGTM, assuming folks are OK with the llvm.org/pr38771 change.



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Comment at: test/CodeGen/X86/pr38771.ll:8
 ; CHECK-NEXT:    movl $0, (%rax)
+; CHECK-NEXT:    movq $0, (%rax)
 ; CHECK-NEXT:    retq
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MatzeB wrote:
> This code changes because ConstantHoisting touches the constants here, and the less aggressive behavior of trunc(OpaqueConstant)" somehow makes DAGCombiner realizes this whole expression being 0 now which it didn't do before. The testcase unfortunately doesn't have enough information to figure out how an equivalent tests would look like that wouldn't constant fold to zero. So this probably has to stay like this...
I expect @craig.topper can chime in on this one.


Repository:
  rL LLVM

https://reviews.llvm.org/D53181