http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48738
--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-04-23
09:20:46 UTC ---
Integer exponent powers are computed using
TYPE
NAME (TYPE x, int m)
{
unsigned int n = m < 0 ? -m : m;
TYPE y = n % 2 ? x : 1;
while (n >>= 1)
{
x = x * x;
if (n % 2)
y = y * x;
}
return m < 0 ? 1/y : y;
}
or optimal power series expansion for constant exponents starting with
GCC 4.5.
ISTR the standard allows this. You should use a double exponent to
use the real power function, pow (2., -1024.)
