https://gcc.gnu.org/bugzilla/show_bug.cgi?id=49611
--- Comment #16 from David <gccbugzilla at limegreensocks dot com> ---
I've tried it now and it seems to do good things. This code:
int main(int argc, char *argv[])
{
char x;
asm("setc" : "=@ccc"(x));
if (!x)
return 6;
else
return argc;
}
produces this output (-O3):
movl $6, %eax
/APP
# 6 "./r.cpp" 1
setc
# 0 "" 2
/NO_APP
cmovc %ebx, %eax
addq $32, %rsp
popq %rbx
ret
Although a minor variation (change "return argc" to "return 7") ends up doing
setc+cmpb, so it's not a perfect solution.
Still, if I were Richard, I'd be closing this bug. If someone has optimization
issues with his solution, that's a new bug.
