math: tan cleanups

[musl] / src / math / __tanl.c

diff --git a/src/math/__tanl.c b/src/math/__tanl.c
index 50ba214..4b36e61 100644 (file)
--- a/src/math/__tanl.c
+++ b/src/math/__tanl.c
@@ -45,25 +45,21 @@ T29 =  0.0000078293456938132840,        /*  0x106b59141a6cb3.0p-69 */
 T31 = -0.0000032609076735050182,        /* -0x1b5abef3ba4b59.0p-71 */
 T33 =  0.0000023261313142559411;        /*  0x13835436c0c87f.0p-71 */
 
-long double __tanl(long double x, long double y, int iy) {
+long double __tanl(long double x, long double y, int odd) {
        long double z, r, v, w, s, a, t;
-       long double osign;
-       int i;
+       int big, sign;
 
-       iy = iy == 1 ? -1 : 1;        /* XXX recover original interface */
-       osign = copysignl(1.0, x);
-       if (fabsl(x) >= 0.67434) {
+       big = fabsl(x) >= 0.67434;
+       if (big) {
+               sign = 0;
                if (x < 0) {
+                       sign = 1;
                        x = -x;
                        y = -y;
                }
-               z = pio4 - x;
-               w = pio4lo - y;
-               x = z + w;
+               x = (pio4 - x) + (pio4lo - y);
                y = 0.0;
-               i = 1;
-       } else
-               i = 0;
+       }
        z = x * x;
        w = z * z;
        r = T5 + w * (T9 + w * (T13 + w * (T17 + w * (T21 +
@@ -71,14 +67,14 @@ long double __tanl(long double x, long double y, int iy) {
        v = z * (T7 + w * (T11 + w * (T15 + w * (T19 + w * (T23 +
             w * (T27 + w * T31))))));
        s = z * x;
-       r = y + z * (s * (r + v) + y);
-       r += T3 * s;
+       r = y + z * (s * (r + v) + y) + T3 * s;
        w = x + r;
-       if (i == 1) {
-               v = (long double)iy;
-               return osign * (v - 2.0 * (x - (w * w / (w + v) - r)));
+       if (big) {
+               s = 1 - 2*odd;
+               v = s - 2.0 * (x + (r - w * w / (w + s)));
+               return sign ? -v : v;
        }
-       if (iy == 1)
+       if (!odd)
                return w;
 
        /*