[Bug tree-optimization/90838] Detect table-based ctz implementation
ktkachov at gcc dot gnu.org
gcc-bugzilla@gcc.gnu.org
Wed Jun 12 08:14:00 GMT 2019
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90838
--- Comment #5 from ktkachov at gcc dot gnu.org ---
FWIW, there is another similar function in deepsjeng that computes a
side-effect:
int
myctz2 (unsigned long long * const b) {
unsigned long long lsb = (*b) & -(*b);
*b ^= lsb;
return table[(lsb * magic) >> 58];
}
so we'd need to make sure that our solution handles multiple uses of lsb
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