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authorJoseph Myers <joseph@codesourcery.com>2012-09-29 18:31:54 +0000
committerJoseph Myers <joseph@codesourcery.com>2012-09-29 18:31:54 +0000
commit8ec5b01346114da38e806ca1867da688d3a360e2 (patch)
tree8a55bd704c2a6ca8164202217e2048bb33a7dacb /sysdeps/ieee754/ldbl-128/s_fmal.c
parentb1fa802e1ad4104060fe93b4b3b078ba46be0933 (diff)
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Fix sign of exact zero return from fma (bug 14638).
Diffstat (limited to 'sysdeps/ieee754/ldbl-128/s_fmal.c')
-rw-r--r--sysdeps/ieee754/ldbl-128/s_fmal.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128/s_fmal.c b/sysdeps/ieee754/ldbl-128/s_fmal.c
index 963bbd7345..df68ade435 100644
--- a/sysdeps/ieee754/ldbl-128/s_fmal.c
+++ b/sysdeps/ieee754/ldbl-128/s_fmal.c
@@ -129,6 +129,11 @@ __fmal (long double x, long double y, long double z)
       y = v.d;
       z = w.d;
     }
+
+  /* Ensure correct sign of exact 0 + 0.  */
+  if (__builtin_expect ((x == 0 || y == 0) && z == 0, 0))
+    return x * y + z;
+
   /* Multiplication m1 + m2 = x * y using Dekker's algorithm.  */
 #define C ((1LL << (LDBL_MANT_DIG + 1) / 2) + 1)
   long double x1 = x * C;