diff options
| -rw-r--r-- | ChangeLog | 4 | ||||
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/s_fmal.c | 8 |
2 files changed, 11 insertions, 1 deletions
@@ -1,5 +1,9 @@ 2012-11-22 Joseph Myers <joseph@codesourcery.com> + [BZ #14645] + * sysdeps/ieee754/ldbl-128ibm/s_fmal.c (__fmal): Compute result as + x * y if x and y are nonzero and z is zero. + [BZ #14811] * sysdeps/ieee754/ldbl-128ibm/e_powl.c (__ieee754_powl): Saturate nonzero exponents with absolute value below 0x1p-117 to +/- diff --git a/sysdeps/ieee754/ldbl-128ibm/s_fmal.c b/sysdeps/ieee754/ldbl-128ibm/s_fmal.c index a868b8d514..6706eb20ed 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) 2011-2012 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 |