diff options
Diffstat (limited to 'lib/msun/src/k_sin.c')
-rw-r--r-- | lib/msun/src/k_sin.c | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/lib/msun/src/k_sin.c b/lib/msun/src/k_sin.c index f022901..394df927 100644 --- a/lib/msun/src/k_sin.c +++ b/lib/msun/src/k_sin.c @@ -5,37 +5,37 @@ * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this - * software is freely granted, provided that this notice + * software is freely granted, provided that this notice * is preserved. * ==================================================== */ #ifndef lint -static char rcsid[] = "$Id: k_sin.c,v 1.6 1994/08/18 23:06:14 jtc Exp $"; +static char rcsid[] = "$Id: k_sin.c,v 1.1.1.1 1994/08/19 09:39:45 jkh Exp $"; #endif /* __kernel_sin( x, y, iy) * kernel sin function on [-pi/4, pi/4], pi/4 ~ 0.7854 * Input x is assumed to be bounded by ~pi/4 in magnitude. * Input y is the tail of x. - * Input iy indicates whether y is 0. (if iy=0, y assume to be 0). + * Input iy indicates whether y is 0. (if iy=0, y assume to be 0). * * Algorithm - * 1. Since sin(-x) = -sin(x), we need only to consider positive x. + * 1. Since sin(-x) = -sin(x), we need only to consider positive x. * 2. if x < 2^-27 (hx<0x3e400000 0), return x with inexact if x!=0. * 3. sin(x) is approximated by a polynomial of degree 13 on * [0,pi/4] * 3 13 * sin(x) ~ x + S1*x + ... + S6*x * where - * + * * |sin(x) 2 4 6 8 10 12 | -58 * |----- - (1+S1*x +S2*x +S3*x +S4*x +S5*x +S6*x )| <= 2 - * | x | - * + * | x | + * * 4. sin(x+y) = sin(x) + sin'(x')*y * ~ sin(x) + (1-x*x/2)*y - * For better accuracy, let + * For better accuracy, let * 3 2 2 2 2 * r = x *(S2+x *(S3+x *(S4+x *(S5+x *S6)))) * then 3 2 @@ -46,9 +46,9 @@ static char rcsid[] = "$Id: k_sin.c,v 1.6 1994/08/18 23:06:14 jtc Exp $"; #include "math_private.h" #ifdef __STDC__ -static const double +static const double #else -static double +static double #endif half = 5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */ S1 = -1.66666666666666324348e-01, /* 0xBFC55555, 0x55555549 */ |