tree bab9d06d5fa091d6313ed4559ff89558fe202d6a
parent a8af9f679231a55b8a0f5707d8727679a98f4b06
author Bill Wendling <morbo@google.com> 1670972789 -0800
committer Tom Stellard <tstellar@redhat.com> 1673294940 -0800

[X86] Don't zero out %eax if both %al and %ah are used

The iterator over super and sub registers doesn't include both 8-bit
registers in its list. So if both registers are used and only one of
them is live on return, then we need to make sure that the other 8-bit
register is also marked as live and not zeroed out.

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D139679

(cherry picked from commit 14d4cddc5506fb0fd3c4ac556b4edd970aa151eb)