diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/s_fmal.c')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_fmal.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_fmal.c b/sysdeps/ieee754/ldbl-128ibm/s_fmal.c index a868b8d514..46dedf83fb 100644 --- a/sysdeps/ieee754/ldbl-128ibm/s_fmal.c +++ b/sysdeps/ieee754/ldbl-128ibm/s_fmal.c @@ -1,5 +1,5 @@ /* Compute x * y + z as ternary operation. - Copyright (C) 2011 Free Software Foundation, Inc. + Copyright (C) 2011-2014 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by David Flaherty <flaherty@linux.vnet.ibm.com>. @@ -29,6 +29,12 @@ __fmal (long double x, long double y, long double z) if ((finite ((double)x) && finite ((double)y)) && isinf ((double)z)) return (z); + /* If z is zero and x are y are nonzero, compute the result + as x * y to avoid the wrong sign of a zero result if x * y + underflows to 0. */ + if (z == 0 && x != 0 && y != 0) + return x * y; + return (x * y) + z; } #ifdef IS_IN_libm |