[Bug target/108831] New: 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

            Bug ID: 108831
           Summary: QImode binary ops with one zero-extracted argument can
                    be optimized
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ubizjak at gmail dot com
  Target Milestone: ---

Following testcase:

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

unsigned char
test_add (unsigned char a, struct S b)
{
  a += b.val;

  return a;
}
--cut here--

should be compiled to something like:

        addb %dh, %al

but is currently compiled to:

        movzbl  %dh, %edx
        addl    %edx, %eax