[PATCH] D56428: [SelectionDAGBuilder] Respect getBooleanContents in copies to VRegs

Tue Jan 8 11:28:55 PST 2019

tlively added a comment.

In D56428#1349304 <https://reviews.llvm.org/D56428#1349304>, @craig.topper wrote:

> Is the zext/cmp optimization in WebAssemblyFastISel::zeroExtendToI32 really valid? Do other targets do that? If that had instead emitted an And with i1 like X86 does. The any_extend wouldn't have been an issue.

The FastISel optimization is correct as long as the CmpInst is also lowered by FastISel. I will have to think more about whether that is a valid assumption.  But that FastISel logic does not actually affect the bug in question. See the continued discussion on the bug itself.

Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D56428/new/

https://reviews.llvm.org/D56428