mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-11 19:49:32 +00:00
104 lines
2.1 KiB
C
104 lines
2.1 KiB
C
|
/* wf_exp.c -- float version of w_exp.c.
|
||
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* ====================================================
|
||
|
|
* 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.
|
||
|
|
* ====================================================
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* wrapper expf(x)
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "fdlibm.h"
|
||
|
|
#include <errno.h>
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
static const float
|
||
|
|
#else
|
||
|
|
static float
|
||
|
|
#endif
|
||
|
|
o_threshold= 8.8721679688e+01, /* 0x42b17180 */
|
||
|
|
u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
float expf(float x) /* wrapper expf */
|
||
|
|
#else
|
||
|
|
float expf(x) /* wrapper expf */
|
||
|
|
float x;
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
#ifdef _IEEE_LIBM
|
||
|
|
return __ieee754_expf(x);
|
||
|
|
#else
|
||
|
|
float z;
|
||
|
|
struct exception exc;
|
||
|
|
z = __ieee754_expf(x);
|
||
|
|
if(_LIB_VERSION == _IEEE_) return z;
|
||
|
|
if(finitef(x)) {
|
||
|
|
if(x>o_threshold) {
|
||
|
|
/* expf(finite) overflow */
|
||
|
|
#ifndef HUGE_VAL
|
||
|
|
#define HUGE_VAL inf
|
||
|
|
double inf = 0.0;
|
||
|
|
|
||
|
|
SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */
|
||
|
|
#endif
|
||
|
|
exc.type = OVERFLOW;
|
||
|
|
exc.name = "expf";
|
||
|
|
exc.err = 0;
|
||
|
|
exc.arg1 = exc.arg2 = (double)x;
|
||
|
|
if (_LIB_VERSION == _SVID_)
|
||
|
|
exc.retval = HUGE;
|
||
|
|
else
|
||
|
|
exc.retval = HUGE_VAL;
|
||
|
|
if (_LIB_VERSION == _POSIX_)
|
||
|
|
errno = ERANGE;
|
||
|
|
else if (!matherr(&exc)) {
|
||
|
|
errno = ERANGE;
|
||
|
|
}
|
||
|
|
if (exc.err != 0)
|
||
|
|
errno = exc.err;
|
||
|
|
return exc.retval;
|
||
|
|
} else if(x<u_threshold) {
|
||
|
|
/* expf(finite) underflow */
|
||
|
|
exc.type = UNDERFLOW;
|
||
|
|
exc.name = "expf";
|
||
|
|
exc.err = 0;
|
||
|
|
exc.arg1 = exc.arg2 = (double)x;
|
||
|
|
exc.retval = 0.0;
|
||
|
|
if (_LIB_VERSION == _POSIX_)
|
||
|
|
errno = ERANGE;
|
||
|
|
else if (!matherr(&exc)) {
|
||
|
|
errno = ERANGE;
|
||
|
|
}
|
||
|
|
if (exc.err != 0)
|
||
|
|
errno = exc.err;
|
||
|
|
return exc.retval;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return z;
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
|
||
|
|
#ifdef _DOUBLE_IS_32BITS
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
double exp(double x)
|
||
|
|
#else
|
||
|
|
double exp(x)
|
||
|
|
double x;
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
return (double) expf((float) x);
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|