diff options
Diffstat (limited to 'src/math/log1p.c')
| -rw-r--r-- | src/math/log1p.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/src/math/log1p.c b/src/math/log1p.c index 6c67249c..9bed63c2 100644 --- a/src/math/log1p.c +++ b/src/math/log1p.c @@ -104,9 +104,12 @@ double log1p(double x) return (x-x)/(x-x); /* log1p(x<-1)=NaN */ } if (ax < 0x3e200000) { /* |x| < 2**-29 */ - /* raise inexact */ - if (two54 + x > 0.0 && ax < 0x3c900000) /* |x| < 2**-54 */ + /* if 0x1p-1022 <= |x| < 0x1p-54, avoid raising underflow */ + if (ax < 0x3c900000 && ax >= 0x00100000) return x; +#if FLT_EVAL_METHOD != 0 + FORCE_EVAL((float)x); +#endif return x - x*x*0.5; } if (hx > 0 || hx <= (int32_t)0xbfd2bec4) { /* sqrt(2)/2- <= 1+x < sqrt(2)+ */ |