math: sin cos cleanup

[musl] / src / math / sinf.c

diff --git a/src/math/sinf.c b/src/math/sinf.c
index dcca67a..64e39f5 100644 (file)
--- a/src/math/sinf.c
+++ b/src/math/sinf.c
@@ -26,35 +26,38 @@ s4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
 float sinf(float x)
 {
        double y;
-       int32_t n, hx, ix;
+       uint32_t ix;
+       int n, sign;
 
-       GET_FLOAT_WORD(hx, x);
-       ix = hx & 0x7fffffff;
+       GET_FLOAT_WORD(ix, x);
+       sign = ix >> 31;
+       ix &= 0x7fffffff;
 
        if (ix <= 0x3f490fda) {  /* |x| ~<= pi/4 */
-               if (ix < 0x39800000)  /* |x| < 2**-12 */
-                       /* raise inexact if x != 0 */
-                       if((int)x == 0)
-                               return x;
+               if (ix < 0x39800000) {  /* |x| < 2**-12 */
+                       /* raise inexact if x!=0 and underflow if subnormal */
+                       FORCE_EVAL(ix < 0x00800000 ? x/0x1p120f : x+0x1p120f);
+                       return x;
+               }
                return __sindf(x);
        }
        if (ix <= 0x407b53d1) {  /* |x| ~<= 5*pi/4 */
                if (ix <= 0x4016cbe3) {  /* |x| ~<= 3pi/4 */
-                       if (hx > 0)
-                               return __cosdf(x - s1pio2);
-                       else
+                       if (sign)
                                return -__cosdf(x + s1pio2);
+                       else
+                               return __cosdf(x - s1pio2);
                }
-               return __sindf(hx > 0 ? s2pio2 - x : -s2pio2 - x);
+               return __sindf(sign ? -(x + s2pio2) : -(x - s2pio2));
        }
        if (ix <= 0x40e231d5) {  /* |x| ~<= 9*pi/4 */
                if (ix <= 0x40afeddf) {  /* |x| ~<= 7*pi/4 */
-                       if (hx > 0)
-                               return -__cosdf(x - s3pio2);
-                       else
+                       if (sign)
                                return __cosdf(x + s3pio2);
+                       else
+                               return -__cosdf(x - s3pio2);
                }
-               return __sindf(hx > 0 ? x - s4pio2 : x + s4pio2);
+               return __sindf(sign ? x + s4pio2 : x - s4pio2);
        }
 
        /* sin(Inf or NaN) is NaN */