use scalbn or *2.0 instead of ldexp, fix fmal

[musl] / src / math / fma.c

diff --git a/src/math/fma.c b/src/math/fma.c
index 87d450c..5fb9540 100644 (file)
--- a/src/math/fma.c
+++ b/src/math/fma.c
@@ -247,7 +247,7 @@ static inline double add_and_denormalize(double a, double b, int scale)
                        INSERT_WORD64(sum.hi, hibits);
                }
        }
-       return (ldexp(sum.hi, scale));
+       return scalbn(sum.hi, scale);
 }
 
 /*
@@ -364,7 +364,7 @@ double fma(double x, double y, double z)
                }
        }
        if (spread <= DBL_MANT_DIG * 2)
-               zs = ldexp(zs, -spread);
+               zs = scalbn(zs, -spread);
        else
                zs = copysign(DBL_MIN, zs);
 
@@ -390,7 +390,7 @@ double fma(double x, double y, double z)
                 */
                fesetround(oround);
                volatile double vzs = zs; /* XXX gcc CSE bug workaround */
-               return (xy.hi + vzs + ldexp(xy.lo, spread));
+               return xy.hi + vzs + scalbn(xy.lo, spread);
        }
 
        if (oround != FE_TONEAREST) {
@@ -400,13 +400,13 @@ double fma(double x, double y, double z)
                 */
                fesetround(oround);
                adj = r.lo + xy.lo;
-               return (ldexp(r.hi + adj, spread));
+               return scalbn(r.hi + adj, spread);
        }
 
        adj = add_adjusted(r.lo, xy.lo);
        if (spread + ilogb(r.hi) > -1023)
-               return (ldexp(r.hi + adj, spread));
+               return scalbn(r.hi + adj, spread);
        else
-               return (add_and_denormalize(r.hi, adj, spread));
+               return add_and_denormalize(r.hi, adj, spread);
 }
 #endif