math: use double_t for temporaries to avoid stores on i386

[musl] / src / math / atanf.c

diff --git a/src/math/atanf.c b/src/math/atanf.c
index 4e31b90..ac8bfd0 100644 (file)
--- a/src/math/atanf.c
+++ b/src/math/atanf.c
@@ -38,28 +38,26 @@ static const float aT[] = {
   6.1687607318e-02,
 };
 
-static const float 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>1.0f)
-                               return x;
+                       /* raise inexact if x!=0 */
+                       FORCE_EVAL(x + 0x1p120f);
+                       return x;
                }
                id = -1;
        } else {
@@ -91,5 +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;
 }