X-Git-Url: http://nsz.repo.hu/git/?p=musl;a=blobdiff_plain;f=src%2Fmath%2Ftan.c;h=9c724a45af51e09f9da9069ba7ab1073e8fee05c;hp=2e1f3c832b3253e8ada06413480d46478614fd3d;hb=1d5ba3bb5a3f55e10db05219638cfcd967d65417;hpb=22730d65608db06500cc6e0be4aaec03238f996b

diff --git a/src/math/tan.c b/src/math/tan.c
index 2e1f3c83..9c724a45 100644
--- a/src/math/tan.c
+++ b/src/math/tan.c
@@ -43,27 +43,28 @@
 
 double tan(double x)
 {
-	double y[2], z = 0.0;
-	int32_t n, ix;
+	double y[2];
+	uint32_t ix;
+	unsigned n;
 
-	/* High word of x. */
 	GET_HIGH_WORD(ix, x);
+	ix &= 0x7fffffff;
 
 	/* |x| ~< pi/4 */
-	ix &= 0x7fffffff;
 	if (ix <= 0x3fe921fb) {
-		if (ix < 0x3e400000) /* x < 2**-27 */
-			/* raise inexact if x != 0 */
-			if ((int)x == 0)
-				return x;
-		return __tan(x, z, 1);
+		if (ix < 0x3e400000) { /* |x| < 2**-27 */
+			/* raise inexact if x!=0 and underflow if subnormal */
+			FORCE_EVAL(ix < 0x00100000 ? x/0x1p120f : x+0x1p120f);
+			return x;
+		}
+		return __tan(x, 0.0, 0);
 	}
 
 	/* tan(Inf or NaN) is NaN */
 	if (ix >= 0x7ff00000)
 		return x - x;
 
-	/* argument reduction needed */
+	/* argument reduction */
 	n = __rem_pio2(x, y);
-	return __tan(y[0], y[1], 1 - ((n&1)<<1)); /* n even: 1, n odd: -1 */
+	return __tan(y[0], y[1], n&1);
 }