[PATCH] D64707: [x86] try harder to form LEA from ADD to avoid flag conflicts (PR40483)

[Sanjay Patel via Phabricator via llvm-commits]

spatel marked 4 inline comments as done.
spatel added inline comments.


================
Comment at: llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:2482
+      case X86ISD::AND:
+        return true;
+      default:
----------------
craig.topper wrote:
> Should we make sure the flag output has a user? ADC/SBB could definitely only have a live flag input. Not sure about the others.
Yes, that seems safer, although we do try to reduce back to regular opcodes if the flag wasn't needed. I don't see any test diffs with a draft of that change.


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  https://reviews.llvm.org/D64707/new/

https://reviews.llvm.org/D64707