diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_tanhl.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_tanhl.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/sysdeps/libm-ieee754/s_tanhl.c b/sysdeps/libm-ieee754/s_tanhl.c index f7ea3f4216..1e3dc3b613 100644 --- a/sysdeps/libm-ieee754/s_tanhl.c +++ b/sysdeps/libm-ieee754/s_tanhl.c @@ -68,12 +68,15 @@ static long double one=1.0, two=2.0, tiny = 1.0e-4900L; /* x is INF or NaN */ if(ix==0x7fff) { - if (se>=0x7fff) return one/x+one; /* tanhl(+-inf)=+-1 */ - else return one/x-one; /* tanhl(NaN) = NaN */ + /* for NaN it's not important which branch: tanhl(NaN) = NaN */ + if (se&0x8000) return one/x-one; /* tanhl(-inf)= -1; */ + else return one/x+one; /* tanhl(+inf)=+1 */ } /* |x| < 23 */ if (ix < 0x4003 || (ix == 0x4003 && j0 < 0xb8000000u)) {/* |x|<23 */ + if ((ix|j0|j1) == 0) + return x; /* x == +- 0 */ if (ix<0x3fc8) /* |x|<2**-55 */ return x*(one+x); /* tanh(small) = small */ if (ix>=0x3fff) { /* |x|>=1 */ |