------- Additional Comments From sabre at nondot dot org 2005-04-11 19:40
-------
This code from stl_bvector.h is the problem:
void _M_incr(ptrdiff_t __i) {
difference_type __n = __i + _M_offset;
_M_p += __n / _M_word_bit;
__n = __n % _M_word_bit;
if (__n < 0) {
_M_offset = (unsigned int) __n + _M_word_bit;
--_M_p;
} else
_M_offset = (unsigned int) __n;
}
Note that the division and mod is performed on a signed __n value. If it were
unsigned, the optimizer could trivially turn it into shift/and ops.
-Chris
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |sabre at nondot dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16611
