[Bug target/108831] QImode binary ops with one zero-extracted argument can be optimized

[ubizjak at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108831

--- Comment #2 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Uroš Bizjak from comment #1)
> The patch also handles constant memory operands on x86_64.

--cut here--
struct S
{
  unsigned char pad1;
  unsigned char val;
  unsigned short pad2;
};

unsigned char a;

void
test_and (struct S b)
{
  a &= b.val;
}
--cut here--

compiles to:

        andb    %ah, a(%rip)