math: sin cos cleanup

[musl] / src / math / sin.c

diff --git a/src/math/sin.c b/src/math/sin.c
index 8e430f8..055e215 100644 (file)
--- a/src/math/sin.c
+++ b/src/math/sin.c
@@ -44,21 +44,22 @@
 
 double sin(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 < 0x3e500000) {  /* |x| < 2**-26 */
-                       /* raise inexact if x != 0 */
-                       if ((int)x == 0)
-                               return x;
+                       /* raise inexact if x != 0 and underflow if subnormal*/
+                       FORCE_EVAL(ix < 0x00100000 ? x/0x1p120f : x+0x1p120f);
+                       return x;
                }
-               return __sin(x, z, 0);
+               return __sin(x, 0.0, 0);
        }
 
        /* sin(Inf or NaN) is NaN */