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amiga-clib2/library/math_acos.c
Olaf Barthel 984c6729c1 - Updated the copyright information.
git-svn-id: file:///Users/olsen/Code/migration-svn-zu-git/logical-line-staging/clib2/trunk@14789 87f5fb63-7c3d-0410-a384-fd976d0f7a62
2005-01-02 09:07:21 +00:00

239 lines
6.4 KiB
C

/*
* $Id: math_acos.c,v 1.3 2005-01-02 09:07:07 obarthel Exp $
*
* :ts=4
*
* Portable ISO 'C' (1994) runtime library for the Amiga computer
* Copyright (c) 2002-2005 by Olaf Barthel <olsen@sourcery.han.de>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Neither the name of Olaf Barthel nor the names of contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
*
* PowerPC math library based in part on work by Sun Microsystems
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
*/
#ifndef _MATH_HEADERS_H
#include "math_headers.h"
#endif /* _MATH_HEADERS_H */
/****************************************************************************/
#if defined(FLOATING_POINT_SUPPORT)
/****************************************************************************/
#if defined(IEEE_FLOATING_POINT_SUPPORT)
/****************************************************************************/
#if defined(__GNUC__)
/****************************************************************************/
#if defined(SMALL_DATA)
#define A4(x) "a4@(" #x ":W)"
#elif defined(SMALL_DATA32)
#define A4(x) "a4@(" #x ":L)"
#else
#define A4(x) #x
#endif /* SMALL_DATA */
/****************************************************************************/
extern double __acos(double x);
/****************************************************************************/
asm("
.text
.even
.globl _MathIeeeDoubTransBase
.globl ___acos
___acos:
movel a6,sp@-
movel "A4(_MathIeeeDoubTransBase)",a6
moveml sp@(8),d0/d1
jsr a6@(-120:W)
movel sp@+,a6
rts
");
/****************************************************************************/
#else
/****************************************************************************/
INLINE static const double
__acos(double x)
{
double result;
result = IEEEDPAcos(x);
return(result);
}
/****************************************************************************/
#endif /* __GNUC__ */
/****************************************************************************/
#endif /* IEEE_FLOATING_POINT_SUPPORT */
/****************************************************************************/
#if defined(M68881_FLOATING_POINT_SUPPORT)
INLINE static const double
__acos(double x)
{
double result;
__asm ("facos%.x %1,%0"
: "=f" (result)
: "f" (x));
return(result);
}
#endif /* M68881_FLOATING_POINT_SUPPORT */
/****************************************************************************/
#if defined(PPC_FLOATING_POINT_SUPPORT)
static const double
one= 1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
pi = 3.14159265358979311600e+00, /* 0x400921FB, 0x54442D18 */
pio2_hi = 1.57079632679489655800e+00, /* 0x3FF921FB, 0x54442D18 */
pio2_lo = 6.12323399573676603587e-17, /* 0x3C91A626, 0x33145C07 */
pS0 = 1.66666666666666657415e-01, /* 0x3FC55555, 0x55555555 */
pS1 = -3.25565818622400915405e-01, /* 0xBFD4D612, 0x03EB6F7D */
pS2 = 2.01212532134862925881e-01, /* 0x3FC9C155, 0x0E884455 */
pS3 = -4.00555345006794114027e-02, /* 0xBFA48228, 0xB5688F3B */
pS4 = 7.91534994289814532176e-04, /* 0x3F49EFE0, 0x7501B288 */
pS5 = 3.47933107596021167570e-05, /* 0x3F023DE1, 0x0DFDF709 */
qS1 = -2.40339491173441421878e+00, /* 0xC0033A27, 0x1C8A2D4B */
qS2 = 2.02094576023350569471e+00, /* 0x40002AE5, 0x9C598AC8 */
qS3 = -6.88283971605453293030e-01, /* 0xBFE6066C, 0x1B8D0159 */
qS4 = 7.70381505559019352791e-02; /* 0x3FB3B8C5, 0xB12E9282 */
INLINE static const double
__acos(double x)
{
double z,p,q,r,w,s,c,df;
int hx,ix;
GET_HIGH_WORD(hx,x);
ix = hx&0x7fffffff;
if(ix>=0x3ff00000) /* |x| >= 1 */
{
unsigned int lx;
GET_LOW_WORD(lx,x);
if(((ix-0x3ff00000)|lx)==0) /* |x|==1 */
{
if(hx>0)
return 0.0; /* acos(1) = 0 */
else
return pi+2.0*pio2_lo; /* acos(-1)= pi */
}
return (x-x)/(x-x); /* acos(|x|>1) is NaN */
}
if(ix<0x3fe00000) /* |x| < 0.5 */
{
if(ix<=0x3c600000)
return pio2_hi+pio2_lo; /*if|x|<2**-57*/
z = x*x;
p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
r = p/q;
return pio2_hi - (x - (pio2_lo-x*r));
}
else if (hx<0) /* x < -0.5 */
{
z = (one+x)*0.5;
p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
s = sqrt(z);
r = p/q;
w = r*s-pio2_lo;
return pi - 2.0*(s+w);
}
else /* x > 0.5 */
{
z = (one-x)*0.5;
s = sqrt(z);
df = s;
SET_LOW_WORD(df,0);
c = (z-df*df)/(s+df);
p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
r = p/q;
w = r*s+c;
return 2.0*(df+w);
}
}
#endif /* PPC_FLOATING_POINT_SUPPORT */
/****************************************************************************/
double
acos(double x)
{
double result;
if(-1.0 <= x && x <= 1.0)
{
result = __acos(x);
}
else
{
result = 0;
errno = EDOM;
}
return(result);
}
/****************************************************************************/
#endif /* FLOATING_POINT_SUPPORT */