https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81906
Alexander Monakov <amonakov at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |amonakov at gcc dot gnu.org
--- Comment #12 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
[my comment collided with Joseph's, I'm pointing out that one additional
copysign is sufficient under -frounding-math)
I think this expansion works as intended for to-nearest and towards-zero
rounding modes, and swaps upwards and downwards rounding for negative operands.
Which implies that under -frounding-math the approach is fixable by swapping
signs of the 2**52 operands:
xa = fabs (operand1);
a2_52 = 2**52;
[if flag_rounding_math]
a2_52 = copysign (a2_52, operand1);
xa = xa + a2_52 - a2_52;
return copysign (xa, operand1);
