https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103071
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
So a
_Bool EitherIsSubset (unsigned long v0, unsigned long v1)
{
return (v0 & v1) == v0 || (v0 & v1) == v1;
}
is compiled to
EitherIsSubset:
.LFB0:
.cfi_startproc
movq %rdi, %rdx
andq %rsi, %rdx
cmpq %rsi, %rdx
sete %al
cmpq %rdi, %rdx
sete %dl
orl %edx, %eax
ret
your super-opt asm doesn't call foo or bar.
On the GIMPLE level we eventually see
_1 = v0_3(D) & v1_4(D);
_8 = _1 == v1_4(D);
_9 = _1 == v0_3(D);
_10 = _8 | _9;
which I think is quite optimal. With the calls it becomes and if-conversion
problem on RTL (or an early RTL generation one).
