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[Bug math/13381] rounding problem wih sincosl


http://sourceware.org/bugzilla/show_bug.cgi?id=13381

Vincent LefÃvre <vincent-srcware at vinc17 dot net> changed:

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                 CC|                            |vincent-srcware at vinc17
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--- Comment #5 from Vincent LefÃvre <vincent-srcware at vinc17 dot net> 2011-11-09 00:48:59 UTC ---
The AMD Opteron doesn't have this "bug".

Now, there's a much more important problem than the rounding, on both Intel and
AMD processors: the fact that their implementation is broken due to the lack of
accurate range reduction. Try with X = 1.0e22 and compare the results obtained
with -O0 (hardware implementation) and -O3 (obtained with MPFR, I suppose, thus
correct).

In short, the hardware implementation must not be used. If the user wants a
fast implementation but incorrect results on large values, he can still use
compiler options like -ffast-math, with which the compiler would generate
hardware instructions directly.

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