https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84431
--- Comment #6 from Ruslan Nikolaev <nruslan_devel at yahoo dot com> --- (In reply to Uroš Bizjak from comment #5) > (In reply to Ruslan Nikolaev from comment #4) > > Thanks! I was wondering if the patch also fixes the same thing for x86-64 > > (i.e., -m64); in which case we would have something like this: > > > > __uint128_t func(__uint128_t a, unsigned shift) > > { > > return a << (shift & 63); > > } > > Yes, the patch also handles __int128. Great! Also, another interesting case (with the same idea for -m64 and __uint128_t) would be this: gcc -m32 -Wall -O2 -S test.c unsigned func(unsigned long long a, unsigned shift) { return (unsigned) (a >> (shift & 31)); } In this case, clang generates just a single 'shrd' instruction.