Bug#727841: powl() inaccurate but only at runtime
>>>>> "Z" == Zefram <zefram@fysh.org> writes:
Z> On amd64, powl() is generating inaccurate results when called at runtime,
Z> but if a call to it gets constant-folded at compile time (by gcc 4.7)
Z> then the constant-folded result is much more accurate.
AIUI, gcc uses multi-precision arith for constant folding, so that it
can generate accurate results even when cross-compiling.
The difference you show is likely libm vs mpfr.
-JimC
--
James Cloos <cloos@jhcloos.com> OpenPGP: 1024D/ED7DAEA6
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