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| author | Rich Felker <dalias@aerifal.cx> | 2012-03-16 23:58:49 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2012-03-16 23:58:49 -0400 |
| commit | 2e77dc13f8bc2053642fcb136996f5f36c88c775 (patch) | |
| tree | c0fc346570b01898381431c51cd7520a22c402fb /src/math/fma.c | |
| parent | 8c071f872b2844ca297275176047f8d23eec96a7 (diff) | |
| download | musl-2e77dc13f8bc2053642fcb136996f5f36c88c775.tar.gz musl-2e77dc13f8bc2053642fcb136996f5f36c88c775.tar.xz musl-2e77dc13f8bc2053642fcb136996f5f36c88c775.zip | |
make fma and lrint functions build without full fenv support
this is necessary to support archs where fenv is incomplete or unavailable (presently arm). fma, fmal, and the lrint family should work perfectly fine with this change; fmaf is slightly broken with respect to rounding as it depends on non-default rounding modes to do its work.
Diffstat (limited to 'src/math/fma.c')
| -rw-r--r-- | src/math/fma.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/src/math/fma.c b/src/math/fma.c index c53f3148..f44ecda7 100644 --- a/src/math/fma.c +++ b/src/math/fma.c @@ -199,27 +199,37 @@ double fma(double x, double y, double z) * modes other than FE_TONEAREST are painful. */ if (spread < -DBL_MANT_DIG) { +#ifdef FE_INEXACT feraiseexcept(FE_INEXACT); +#endif +#ifdef FE_UNDERFLOW if (!isnormal(z)) feraiseexcept(FE_UNDERFLOW); +#endif switch (oround) { - case FE_TONEAREST: + default: /* FE_TONEAREST */ return (z); +#ifdef FE_TOWARDZERO case FE_TOWARDZERO: if (x > 0.0 ^ y < 0.0 ^ z < 0.0) return (z); else return (nextafter(z, 0)); +#endif +#ifdef FE_DOWNWARD case FE_DOWNWARD: if (x > 0.0 ^ y < 0.0) return (z); else return (nextafter(z, -INFINITY)); - default: /* FE_UPWARD */ +#endif +#ifdef FE_UPWARD + case FE_UPWARD: if (x > 0.0 ^ y < 0.0) return (nextafter(z, INFINITY)); else return (z); +#endif } } if (spread <= DBL_MANT_DIG * 2) |