https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85164
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The first above is on:
case MINUS:
/* If X is (minus C Y) where C's least set bit is larger than any bit
in the mask, then we may replace with (neg Y). */
if (poly_int_rtx_p (XEXP (x, 0), &const_op0)
&& (unsigned HOST_WIDE_INT) known_alignment (const_op0) > mask)
and
template<unsigned int N, typename Ca>
inline POLY_BINARY_COEFF (Ca, Ca)
known_alignment (const poly_int_pod<N, Ca> &a)
{
typedef POLY_BINARY_COEFF (Ca, Ca) C;
C r = a.coeffs[0];
for (unsigned int i = 1; i < N; ++i)
r |= a.coeffs[i];
return r & -r;
}
The poly_int* stuff makes this much harder to fix, it is unclear if there is
some way to get the unsigned type for the C type and use that as r & -(Cuns) r;
to avoid the UB, and there is no poly_uint_rtx_p or something to request
poly_uint64 from the rtx. Richard?
The second one is
return (!known_size_p (decl_size) || known_eq (decl_size, 0)
? maybe_ne (offset, 0)
: maybe_gt (offset + size, decl_size));
and again, both offset and size are poly_int64, not sure how can one
reinterpret cast that to poly_uint64 for the operation and then cast back to
poly_int64.
But in that case also if we shouldn't punt on the overflow somehow.
