math: sin cos cleanup

[musl] / src / math / sinl.c

diff --git a/src/math/sinl.c b/src/math/sinl.c
index 7e0b44f..6ca9998 100644 (file)
--- a/src/math/sinl.c
+++ b/src/math/sinl.c
@@ -37,33 +37,32 @@ long double sinl(long double x)
 long double sinl(long double x)
 {
        union IEEEl2bits z;
-       int e0, s;
+       unsigned n;
        long double y[2];
        long double hi, lo;
 
        z.e = x;
-       s = z.bits.sign;
        z.bits.sign = 0;
 
-       /* If x = +-0 or x is a subnormal number, then sin(x) = x */
-       if (z.bits.exp == 0)
-               return x;
-
        /* If x = NaN or Inf, then sin(x) = NaN. */
-       if (z.bits.exp == 32767)
+       if (z.bits.exp == 0x7fff)
                return (x - x) / (x - x);
 
-       /* Optimize the case where x is already within range. */
+       /* |x| < (double)pi/4 */
        if (z.e < M_PI_4) {
-               hi = __sinl(z.e, 0, 0);
-               return  s ? -hi : hi;
+               /* |x| < 0x1p-64 */
+               if (z.bits.exp < 0x3fff - 64) {
+                       /* raise inexact if x!=0 and underflow if subnormal */
+                       FORCE_EVAL(z.bits.exp == 0 ? x/0x1p120f : x+0x1p120f);
+                       return x;
+               }
+               return __sinl(x, 0.0, 0);
        }
 
-       e0 = __rem_pio2l(x, y);
+       n = __rem_pio2l(x, y);
        hi = y[0];
        lo = y[1];
-
-       switch (e0 & 3) {
+       switch (n & 3) {
        case 0:
                hi = __sinl(hi, lo, 1);
                break;
@@ -71,10 +70,10 @@ long double sinl(long double x)
                hi = __cosl(hi, lo);
                break;
        case 2:
-               hi = - __sinl(hi, lo, 1);
+               hi = -__sinl(hi, lo, 1);
                break;
        case 3:
-               hi = - __cosl(hi, lo);
+               hi = -__cosl(hi, lo);
                break;
        }
        return hi;