[PATCH] D25485: [DAG] optimize negation of bool
Sanjay Patel via llvm-commits
llvm-commits at lists.llvm.org
Mon Oct 17 08:13:23 PDT 2016
spatel added inline comments.
Comment at: test/CodeGen/X86/negate-i1.ll:131
; X32-NEXT: movl %eax, %edx
+; X32-NEXT: sarl $31, %edx
; X32-NEXT: retl
> This SAR is redundant. Does DAGCombine know that SAR(all_ones/allzeros) is redundant?
It knows sometimes, but of course it missed this one. I'll work on that patch now.
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