https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48140
Albert Chan <albertmcchan at yahoo dot com> changed:
What |Removed |Added
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CC| |albertmcchan at yahoo dot com
--- Comment #4 from Albert Chan <albertmcchan at yahoo dot com> ---
I think fmod is accurate
Gcc cannot do exact fmod(1e9, 2*pi)
it can only do fmod(1e9, 0x1.921f54442d18p+2) = 0.57739546248310347
which is exactly what gcc returns
in fact, it is VERY accurate
If we do remainder calculation in steps:
quotient = floor(1e9 / (2 pi)) = 159154943
remainder = 1e9 - quotient * 0x1.921f54442d18p+2
= 0.57739543914794922
doing in steps under-counted 210,184,384 ULP
