[PATCH] D63318: [DAGCombine] Teach DAGCombine to fold the aext + select pattern

[Qing Shan Zhang via Phabricator via llvm-commits]

steven.zhang marked an inline comment as done.
steven.zhang added inline comments.


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Comment at: llvm/test/CodeGen/X86/cmov-promotion.ll:59
 ; CMOV-NEXT:    movl $255, %eax
-; CMOV-NEXT:    cmovnel %ecx, %eax
+; CMOV-NEXT:    cmovneq %rcx, %rax
 ; CMOV-NEXT:    retq
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craig.topper wrote:
> The zextisfree check isn't enough to fix this :( It's an i8->i64 zext which isn't free. I guess we'll have to handle this in the x86 backend.
Yes. The hook only check the type i32->i64. Do we need to pass the value instead of the type for the isZextFree to fix this issue ?


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