[PATCH] D57875: [LegalizeTypes] Expand FNEG to bitwise op for IEEE FP types

[Ana Pazos via Phabricator via llvm-commits]

apazos added a comment.

Without the patch, the fneg use in the given test case becomes a sub lib call in the targets I checked  when using soft abi (riscv, arm)

DAGCombiner::visitFNEG is transforming fneg(bitconvert(x)) to bitwise operation. So for other patterns, we end up with a lib call which is wasteful.

I also need someone to confirm whether for x86 and ppc FP types it is valid to use bitwise operation. The patch now excludes these formats.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D57875/new/

https://reviews.llvm.org/D57875