Comment by ndesaulniers

5 years ago

commit a468601e0ead ("[X86] Re-enable conditional tail calls and fix PR31257.")

https://reviews.llvm.org/D29856

added the comment.

If I remove the check for `OptForSize` and `PredTBB == MBB`, we can optimize OP's report, but seem to regress basic tests like llvm/test/CodeGen/X86/conditional-tailcall.ll, literally flipping the branches incorrectly IIUC.

Filed: https://bugs.llvm.org/show_bug.cgi?id=50130