use libc-internal malloc for pthread_atfork

[musl] / src / math / fmaf.c

diff --git a/src/math/fmaf.c b/src/math/fmaf.c
index aa57feb..7c65acf 100644 (file)
--- a/src/math/fmaf.c
+++ b/src/math/fmaf.c
@@ -50,7 +50,7 @@ float fmaf(float x, float y, float z)
        /* Common case: The double precision result is fine. */
        if ((u.i & 0x1fffffff) != 0x10000000 || /* not a halfway case */
                e == 0x7ff ||                   /* NaN */
-               result - xy == z ||                 /* exact */
+               (result - xy == z && result - z == xy) || /* exact */
                fegetround() != FE_TONEAREST)       /* not round-to-nearest */
        {
                /*
@@ -77,17 +77,16 @@ float fmaf(float x, float y, float z)
         * If result is inexact, and exactly halfway between two float values,
         * we need to adjust the low-order bit in the direction of the error.
         */
-#ifdef FE_TOWARDZERO
-       fesetround(FE_TOWARDZERO);
-#endif
-       volatile double vxy = xy;  /* XXX work around gcc CSE bug */
-       double adjusted_result = vxy + z;
-       fesetround(FE_TONEAREST);
-       if (result == adjusted_result) {
-               u.f = adjusted_result;
+       double err;
+       int neg = u.i >> 63;
+       if (neg == (z > xy))
+               err = xy - result + z;
+       else
+               err = z - result + xy;
+       if (neg == (err < 0))
                u.i++;
-               adjusted_result = u.f;
-       }
-       z = adjusted_result;
+       else
+               u.i--;
+       z = u.f;
        return z;
 }