X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Ffmal.c;h=87e30fcf65394f71b34027081feb9cab0f013ca4;hb=0636d5977aa796d78869ee310c6e69220b919eee;hp=3944c29298e108c861d1c0f6aee9a7fe6264ebdc;hpb=2e77dc13f8bc2053642fcb136996f5f36c88c775;p=musl

diff --git a/src/math/fmal.c b/src/math/fmal.c
index 3944c292..87e30fcf 100644
--- a/src/math/fmal.c
+++ b/src/math/fmal.c
@@ -115,7 +115,7 @@ static inline long double add_and_denormalize(long double a, long double b, int
 		if (bits_lost != 1 ^ (int)(u.bits.manl & 1))
 			sum.hi = nextafterl(sum.hi, INFINITY * sum.lo);
 	}
-	return (ldexp(sum.hi, scale));
+	return scalbnl(sum.hi, scale);
 }
 
 /*
@@ -162,6 +162,7 @@ static inline struct dd dd_mul(long double a, long double b)
  */
 long double fmal(long double x, long double y, long double z)
 {
+	#pragma STDC FENV_ACCESS ON
 	long double xs, ys, zs, adj;
 	struct dd xy, r;
 	int oround;
@@ -173,14 +174,14 @@ long double fmal(long double x, long double y, long double z)
 	 * return values here are crucial in handling special cases involving
 	 * infinities, NaNs, overflows, and signed zeroes correctly.
 	 */
-	if (x == 0.0 || y == 0.0)
-		return (x * y + z);
-	if (z == 0.0)
-		return (x * y);
 	if (!isfinite(x) || !isfinite(y))
 		return (x * y + z);
 	if (!isfinite(z))
 		return (z);
+	if (x == 0.0 || y == 0.0)
+		return (x * y + z);
+	if (z == 0.0)
+		return (x * y);
 
 	xs = frexpl(x, &ex);
 	ys = frexpl(y, &ey);
@@ -228,7 +229,7 @@ long double fmal(long double x, long double y, long double z)
 		}
 	}
 	if (spread <= LDBL_MANT_DIG * 2)
-		zs = ldexpl(zs, -spread);
+		zs = scalbnl(zs, -spread);
 	else
 		zs = copysignl(LDBL_MIN, zs);
 
@@ -254,23 +255,25 @@ long double fmal(long double x, long double y, long double z)
 		 */
 		fesetround(oround);
 		volatile long double vzs = zs; /* XXX gcc CSE bug workaround */
-		return (xy.hi + vzs + ldexpl(xy.lo, spread));
+		return xy.hi + vzs + scalbnl(xy.lo, spread);
 	}
 
 	if (oround != FE_TONEAREST) {
 		/*
 		 * There is no need to worry about double rounding in directed
 		 * rounding modes.
+		 * TODO: underflow is not raised correctly, example in downward rounding:
+		 * fmal(0x1.0000000001p-16000L, 0x1.0000000001p-400L, -0x1p-16440L)
 		 */
 		fesetround(oround);
 		adj = r.lo + xy.lo;
-		return (ldexpl(r.hi + adj, spread));
+		return scalbnl(r.hi + adj, spread);
 	}
 
 	adj = add_adjusted(r.lo, xy.lo);
 	if (spread + ilogbl(r.hi) > -16383)
-		return (ldexpl(r.hi + adj, spread));
+		return scalbnl(r.hi + adj, spread);
 	else
-		return (add_and_denormalize(r.hi, adj, spread));
+		return add_and_denormalize(r.hi, adj, spread);
 }
 #endif