X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Fatanf.c;h=ac8bfd0665f08547e444939c540dd6eafe461fd0;hb=9448b0513e2eec020fbca9c10412b83df5027a16;hp=73cebb5e92fc07810b17569b078ba3a96aedece0;hpb=93a50a26cd0f9efc59cc83daae7b2d916b327ab1;p=musl

diff --git a/src/math/atanf.c b/src/math/atanf.c
index 73cebb5e..ac8bfd06 100644
--- a/src/math/atanf.c
+++ b/src/math/atanf.c
@@ -38,30 +38,26 @@ static const float aT[] = {
   6.1687607318e-02,
 };
 
-static const float
-one = 1.0,
-huge = 1.0e30;
-
 float atanf(float x)
 {
-	float w,s1,s2,z;
-	int32_t ix,hx,id;
+	float_t w,s1,s2,z;
+	uint32_t ix,sign;
+	int id;
 
-	GET_FLOAT_WORD(hx, x);
-	ix = hx & 0x7fffffff;
+	GET_FLOAT_WORD(ix, x);
+	sign = ix>>31;
+	ix &= 0x7fffffff;
 	if (ix >= 0x4c800000) {  /* if |x| >= 2**26 */
-		if (ix > 0x7f800000)  /* NaN */
-			return x+x;
-		if (hx > 0)
-			return  atanhi[3] + *(volatile float *)&atanlo[3];
-		else
-			return -atanhi[3] - *(volatile float *)&atanlo[3];
+		if (isnan(x))
+			return x;
+		z = atanhi[3] + 0x1p-120f;
+		return sign ? -z : z;
 	}
 	if (ix < 0x3ee00000) {   /* |x| < 0.4375 */
 		if (ix < 0x39800000) {  /* |x| < 2**-12 */
-			/* raise inexact */
-			if(huge+x>one)
-				return x;
+			/* raise inexact if x!=0 */
+			FORCE_EVAL(x + 0x1p120f);
+			return x;
 		}
 		id = -1;
 	} else {
@@ -69,15 +65,15 @@ float atanf(float x)
 		if (ix < 0x3f980000) {  /* |x| < 1.1875 */
 			if (ix < 0x3f300000) {  /*  7/16 <= |x| < 11/16 */
 				id = 0;
-				x = (2.0f*x - one)/(2.0f + x);
+				x = (2.0f*x - 1.0f)/(2.0f + x);
 			} else {                /* 11/16 <= |x| < 19/16 */
 				id = 1;
-				x = (x - one)/(x + one);
+				x = (x - 1.0f)/(x + 1.0f);
 			}
 		} else {
 			if (ix < 0x401c0000) {  /* |x| < 2.4375 */
 				id = 2;
-				x = (x - 1.5f)/(one + 1.5f*x);
+				x = (x - 1.5f)/(1.0f + 1.5f*x);
 			} else {                /* 2.4375 <= |x| < 2**26 */
 				id = 3;
 				x = -1.0f/x;
@@ -93,5 +89,5 @@ float atanf(float x)
 	if (id < 0)
 		return x - x*(s1+s2);
 	z = atanhi[id] - ((x*(s1+s2) - atanlo[id]) - x);
-	return hx < 0 ? -z : z;
+	return sign ? -z : z;
 }