[Bug target/118465] un-needed aligning the stack in some cases

[bonzini at gnu dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118465

Paolo Bonzini <bonzini at gnu dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bonzini at gnu dot org

--- Comment #1 from Paolo Bonzini <bonzini at gnu dot org> ---
Note %rbx is used, via %bh, to extract bits 8-15 of %r9:

movl    %r9d, %ebx
movzbl  %r9b, %edi
movzbl  %bh, %ebx
movl    %ebx, %r9d

This could be just

movzbl  %r9b, %edi
shrl $8, %r9
movzbl %r9b, %r9d

But if it's indeed due to stack alignment (didn't check), GCC is not wrong in
noticing it can use %ebx.