diff options
Diffstat (limited to 'lib/msun/src')
| -rw-r--r-- | lib/msun/src/k_tanf.c | 28 |
1 files changed, 11 insertions, 17 deletions
diff --git a/lib/msun/src/k_tanf.c b/lib/msun/src/k_tanf.c index 8e19309..e7b816d 100644 --- a/lib/msun/src/k_tanf.c +++ b/lib/msun/src/k_tanf.c @@ -22,20 +22,14 @@ static const float one = 1.0000000000e+00, /* 0x3f800000 */ pio4 = 7.8539812565e-01, /* 0x3f490fda */ pio4lo= 3.7748947079e-08, /* 0x33222168 */ +/* Bounds for tan(x)/x - t(x): ~[-1.73e-09, 1.724e-09]. */ T[] = { - 3.3333334327e-01, /* 0x3eaaaaab */ - 1.3333334029e-01, /* 0x3e088889 */ - 5.3968254477e-02, /* 0x3d5d0dd1 */ - 2.1869488060e-02, /* 0x3cb327a4 */ - 8.8632395491e-03, /* 0x3c11371f */ - 3.5920790397e-03, /* 0x3b6b6916 */ - 1.4562094584e-03, /* 0x3abede48 */ - 5.8804126456e-04, /* 0x3a1a26c8 */ - 2.4646313977e-04, /* 0x398137b9 */ - 7.8179444245e-05, /* 0x38a3f445 */ - 7.1407252108e-05, /* 0x3895c07a */ - -1.8558637748e-05, /* 0xb79bae5f */ - 2.5907305826e-05, /* 0x37d95384 */ + 0xaaaaa3.0p-25, /* 0.33333310485 */ + 0x888b06.0p-26, /* 0.13334283238 */ + 0xdc84c8.0p-28, /* 0.053837567568 */ + 0xb9d8f1.0p-29, /* 0.022686453536 */ + 0xcfe632.0p-31, /* 0.0063445800915 */ + 0xeaf97e.0p-31, /* 0.0071708550677 */ }; float @@ -54,11 +48,11 @@ __kernel_tanf(float x, float y, int iy) z = x*x; w = z*z; /* Break x^5*(T[1]+x^2*T[2]+...) into - * x^5(T[1]+x^4*T[3]+...+x^20*T[11]) + - * x^5(x^2*(T[2]+x^4*T[4]+...+x^22*[T12])) + * x^5*(T[1]+x^4*T[3]+x^8*T[5]) + + * x^5*(x^2*(T[2]+x^4*T[4])) */ - r = T[1]+w*(T[3]+w*(T[5]+w*(T[7]+w*(T[9]+w*T[11])))); - v = z*(T[2]+w*(T[4]+w*(T[6]+w*(T[8]+w*(T[10]+w*T[12]))))); + r = T[1]+w*(T[3]+w*T[5]); + v = z*(T[2]+w*T[4]); s = z*x; r = y + z*(s*(r+v)+y); r += T[0]*s; |
