[PATCH] D110865: X86InstrInfo: Optimize more combinations of SUB+CMP

[Pengfei Wang via Phabricator via llvm-commits]

pengfei added inline comments.


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Comment at: llvm/test/CodeGen/X86/optimize-compare.mir:189
+    ; 2nd CMP should be removed.
+    CMP32rr %1, %0, implicit-def $eflags
+    $bl = SETCCr 2, implicit $eflags
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Do we have such CMP + CMP cases in reality? I think optimization should merged them already. The only case I can think is eflags are clobbered, so that we have to def them again which can't be optimizated here either.


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  https://reviews.llvm.org/D110865/new/

https://reviews.llvm.org/D110865