[PATCH] D145866: [DAG] visitAND - fold (and (any_ext V), c) -> (zero_ext (and (trunc V), c)) if profitable.

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


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Comment at: llvm/test/CodeGen/X86/switch-phi-const.ll:95
+; CHECK-NEXT:    movzbl %dil, %eax
+; CHECK-NEXT:    leal -1(%rax), %ecx
 ; CHECK-NEXT:    cmpl $54, %ecx
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pengfei wrote:
> This doesn't look efficient than `decl %ecx`.
I agree but we always fold mov+dec to lea: https://simd.godbolt.org/z/vvzfe14oc


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