https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102134
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |sayle at gcc dot gnu.org
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This is triggering the:
else if (!wi::neg_p (r1val | r1mask, sgn))
{
/* Logical right shift, or zero sign bit. */
widest_int arg = r1val | r1mask;
int lzcount = wi::clz (arg);
lzcount -= wi::get_precision (arg) - width;
widest_int tmp = wi::mask <widest_int> (width, false);
tmp = wi::lrshift (tmp, lzcount);
tmp = wi::lrshift (tmp, wi::bit_and_not (r2val, r2mask));
*mask = wi::ext (tmp, width, sgn);
*val = 0;
}
sgn is UNSIGNED, so wi::neg_p is false even when r1val | r1mask is negative, so
wi::clz (arg) is 0, but wi::get_precision (arg) is 576 and width is 64, so
we end up with lzcount of -512 and I bet the code doesn't expect lzcount to be
negative.
