diff options
| author | Ed Maste <emaste@FreeBSD.org> | 2024-03-19 14:31:39 +0000 |
|---|---|---|
| committer | Ed Maste <emaste@FreeBSD.org> | 2024-06-08 15:55:36 +0000 |
| commit | 888796ade2842486d3167067e8034254c38aadd3 (patch) | |
| tree | d235c9aa6238dac01c0b4bd7434cb782560e60b0 | |
| parent | 5ee5c40402c92a498ed8d6eeb6cf0b5c1680817b (diff) | |
| download | src-888796ade2842486d3167067e8034254c38aadd3.tar.gz src-888796ade2842486d3167067e8034254c38aadd3.zip | |
libm: fma: correct zero sign with small inputs
PR: 277783
Reported by: Victor Stinner
Submitted by: kargl
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D44433
| -rw-r--r-- | lib/msun/src/s_fma.c | 4 | ||||
| -rw-r--r-- | lib/msun/src/s_fmal.c | 4 |
2 files changed, 6 insertions, 2 deletions
diff --git a/lib/msun/src/s_fma.c b/lib/msun/src/s_fma.c index b8a342646d85..4d08b40cc71a 100644 --- a/lib/msun/src/s_fma.c +++ b/lib/msun/src/s_fma.c @@ -267,7 +267,9 @@ fma(double x, double y, double z) */ fesetround(oround); volatile double vzs = zs; /* XXX gcc CSE bug workaround */ - return (xy.hi + vzs + ldexp(xy.lo, spread)); + xs = ldexp(xy.lo, spread); + xy.hi += vzs; + return (xy.hi == 0 ? xs : xy.hi + xs); } if (oround != FE_TONEAREST) { diff --git a/lib/msun/src/s_fmal.c b/lib/msun/src/s_fmal.c index 3d333632127c..12f9c364670b 100644 --- a/lib/msun/src/s_fmal.c +++ b/lib/msun/src/s_fmal.c @@ -248,7 +248,9 @@ fmal(long double x, long double y, long double z) */ fesetround(oround); volatile long double vzs = zs; /* XXX gcc CSE bug workaround */ - return (xy.hi + vzs + ldexpl(xy.lo, spread)); + xs = ldexpl(xy.lo, spread); + xy.hi += vzs; + return (xy.hi == 0 ? xs : xy.hi + xs); } if (oround != FE_TONEAREST) { |