Back to index

lightning-sunbird  0.9+nobinonly
Functions | Variables
e_asin.c File Reference
#include "fdlibm.h"

Go to the source code of this file.

Functions

double __ieee754_asin (double x)

Variables

static double one = 1.00000000000000000000e+00
static double really_big = 1.000e+300
static double pio2_hi = 1.57079632679489655800e+00
static double pio2_lo = 6.12323399573676603587e-17
static double pio4_hi = 7.85398163397448278999e-01
static double pS0 = 1.66666666666666657415e-01
static double pS1 = -3.25565818622400915405e-01
static double pS2 = 2.01212532134862925881e-01
static double pS3 = -4.00555345006794114027e-02
static double pS4 = 7.91534994289814532176e-04
static double pS5 = 3.47933107596021167570e-05
static double qS1 = -2.40339491173441421878e+00
static double qS2 = 2.02094576023350569471e+00
static double qS3 = -6.88283971605453293030e-01
static double qS4 = 7.70381505559019352791e-02

Function Documentation

double __ieee754_asin ( double  x)

Definition at line 110 of file e_asin.c.

{
        fd_twoints u;
       double w,t,p,q,c,r,s;
       int hx,ix;
        u.d = x;
       hx = __HI(u);
        x = u.d;
       ix = hx&0x7fffffff;
       if(ix>= 0x3ff00000) {              /* |x|>= 1 */
           if(((ix-0x3ff00000)|__LO(u))==0)
                  /* asin(1)=+-pi/2 with inexact */
              return x*pio2_hi+x*pio2_lo; 
           return (x-x)/(x-x);            /* asin(|x|>1) is NaN */   
       } else if (ix<0x3fe00000) { /* |x|<0.5 */
           if(ix<0x3e400000) {            /* if |x| < 2**-27 */
              if(really_big+x>one) return x;/* return x with inexact if x!=0*/
           } else 
              t = x*x;
              p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5)))));
              q = one+t*(qS1+t*(qS2+t*(qS3+t*qS4)));
              w = p/q;
              return x+x*w;
       }
       /* 1> |x|>= 0.5 */
       w = one-fd_fabs(x);
       t = w*0.5;
       p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5)))));
       q = one+t*(qS1+t*(qS2+t*(qS3+t*qS4)));
       s = fd_sqrt(t);
       if(ix>=0x3FEF3333) {        /* if |x| > 0.975 */
           w = p/q;
           t = pio2_hi-(2.0*(s+s*w)-pio2_lo);
       } else {
           u.d  = s;
           __LO(u) = 0;
            w = u.d;
           c  = (t-w*w)/(s+w);
           r  = p/q;
           p  = 2.0*s*r-(pio2_lo-2.0*c);
           q  = pio4_hi-2.0*w;
           t  = pio4_hi-(p-q);
       }    
       if(hx>0) return t; else return -t;    
}

Here is the call graph for this function:

Here is the caller graph for this function:


Variable Documentation

double one = 1.00000000000000000000e+00 [static]

Definition at line 90 of file e_asin.c.

double pio2_hi = 1.57079632679489655800e+00 [static]

Definition at line 92 of file e_asin.c.

double pio2_lo = 6.12323399573676603587e-17 [static]

Definition at line 93 of file e_asin.c.

double pio4_hi = 7.85398163397448278999e-01 [static]

Definition at line 94 of file e_asin.c.

double pS0 = 1.66666666666666657415e-01 [static]

Definition at line 96 of file e_asin.c.

double pS1 = -3.25565818622400915405e-01 [static]

Definition at line 97 of file e_asin.c.

double pS2 = 2.01212532134862925881e-01 [static]

Definition at line 98 of file e_asin.c.

double pS3 = -4.00555345006794114027e-02 [static]

Definition at line 99 of file e_asin.c.

double pS4 = 7.91534994289814532176e-04 [static]

Definition at line 100 of file e_asin.c.

double pS5 = 3.47933107596021167570e-05 [static]

Definition at line 101 of file e_asin.c.

double qS1 = -2.40339491173441421878e+00 [static]

Definition at line 102 of file e_asin.c.

double qS2 = 2.02094576023350569471e+00 [static]

Definition at line 103 of file e_asin.c.

double qS3 = -6.88283971605453293030e-01 [static]

Definition at line 104 of file e_asin.c.

double qS4 = 7.70381505559019352791e-02 [static]

Definition at line 105 of file e_asin.c.

double really_big = 1.000e+300 [static]

Definition at line 91 of file e_asin.c.