https://gcc.gnu.org/bugzilla/show_bug.cgi?id=15792
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to fail| |
--- Comment #12 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Gabriel Ravier from comment #11)
> Seems like the issue is present again, except it's test1 that gets the
> better asm now. Perhaps this should be re-opened ?
This bug was about 32bit x86 and the code looks good in GCC 9, 10, 11, and 12
and the trunk.
If you were testing on x86_64, you need to use __int128_t to see what the
original issue was about:
void gh();
void test(__int128_t x) {
long g = (long)x|((long)(x>>64));
if (g) gh();
}
void test1(__int128_t x) {
if (x) gh();
}
GCC 4.8+ produces:
test1:
.cfi_startproc
orq %rdi, %rsi
jne .L7
rep ret
For both. There was an extra mov in GCC 4.5.0-4.7.0 for test though. In GCC
4.4.0, test1 was two compare and jumps (ok). GCC 4.1.2 had the bad code
generation which was mentioned in comment #0.
