| e_acos.c (22993) | e_acos.c (23579) |
|---|---|
| 1/* @(#)e_acos.c 5.1 93/09/24 */ 2/* 3 * ==================================================== 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5 * 6 * Developed at SunPro, a Sun Microsystems, Inc. business. 7 * Permission to use, copy, modify, and distribute this 8 * software is freely granted, provided that this notice 9 * is preserved. 10 * ==================================================== 11 */ 12 13#ifndef lint | 1/* @(#)e_acos.c 5.1 93/09/24 */ 2/* 3 * ==================================================== 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5 * 6 * Developed at SunPro, a Sun Microsystems, Inc. business. 7 * Permission to use, copy, modify, and distribute this 8 * software is freely granted, provided that this notice 9 * is preserved. 10 * ==================================================== 11 */ 12 13#ifndef lint |
| 14static char rcsid[] = "$Id$"; | 14static char rcsid[] = "$Id: e_acos.c,v 1.5 1997/02/22 15:09:54 peter Exp $"; |
| 15#endif 16 17/* __ieee754_acos(x) 18 * Method : 19 * acos(x) = pi/2 - asin(x) 20 * acos(-x) = pi/2 + asin(x) 21 * For |x|<=0.5 22 * acos(x) = pi/2 - (x + x*x^2*R(x^2)) (see asin.c) --- 7 unchanged lines hidden (view full) --- 30 * For x<-0.5 31 * acos(x) = pi - 2asin(sqrt((1-|x|)/2)) 32 * = pi - 0.5*(s+s*z*R(z)), where z=(1-|x|)/2,s=sqrt(z) 33 * 34 * Special cases: 35 * if x is NaN, return x itself; 36 * if |x|>1, return NaN with invalid signal. 37 * | 15#endif 16 17/* __ieee754_acos(x) 18 * Method : 19 * acos(x) = pi/2 - asin(x) 20 * acos(-x) = pi/2 + asin(x) 21 * For |x|<=0.5 22 * acos(x) = pi/2 - (x + x*x^2*R(x^2)) (see asin.c) --- 7 unchanged lines hidden (view full) --- 30 * For x<-0.5 31 * acos(x) = pi - 2asin(sqrt((1-|x|)/2)) 32 * = pi - 0.5*(s+s*z*R(z)), where z=(1-|x|)/2,s=sqrt(z) 33 * 34 * Special cases: 35 * if x is NaN, return x itself; 36 * if |x|>1, return NaN with invalid signal. 37 * |
| 38 * Function needed: sqrt | 38 * Function needed: __ieee754_sqrt |
| 39 */ 40 41#include "math.h" 42#include "math_private.h" 43 44#ifdef __STDC__ 45static const double 46#else --- 40 unchanged lines hidden (view full) --- 87 p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); 88 q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4))); 89 r = p/q; 90 return pio2_hi - (x - (pio2_lo-x*r)); 91 } else if (hx<0) { /* x < -0.5 */ 92 z = (one+x)*0.5; 93 p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); 94 q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4))); | 39 */ 40 41#include "math.h" 42#include "math_private.h" 43 44#ifdef __STDC__ 45static const double 46#else --- 40 unchanged lines hidden (view full) --- 87 p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); 88 q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4))); 89 r = p/q; 90 return pio2_hi - (x - (pio2_lo-x*r)); 91 } else if (hx<0) { /* x < -0.5 */ 92 z = (one+x)*0.5; 93 p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); 94 q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4))); |
| 95 s = sqrt(z); | 95 s = __ieee754_sqrt(z); |
| 96 r = p/q; 97 w = r*s-pio2_lo; 98 return pi - 2.0*(s+w); 99 } else { /* x > 0.5 */ 100 z = (one-x)*0.5; | 96 r = p/q; 97 w = r*s-pio2_lo; 98 return pi - 2.0*(s+w); 99 } else { /* x > 0.5 */ 100 z = (one-x)*0.5; |
| 101 s = sqrt(z); | 101 s = __ieee754_sqrt(z); |
| 102 df = s; 103 SET_LOW_WORD(df,0); 104 c = (z-df*df)/(s+df); 105 p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); 106 q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4))); 107 r = p/q; 108 w = r*s+c; 109 return 2.0*(df+w); 110 } 111} | 102 df = s; 103 SET_LOW_WORD(df,0); 104 c = (z-df*df)/(s+df); 105 p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5))))); 106 q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4))); 107 r = p/q; 108 w = r*s+c; 109 return 2.0*(df+w); 110 } 111} |