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/* wf_pow.c -- float version of w_pow.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 powf(x,y) return x**y
*/
#include "fdlibm.h"
#include <errno.h>
#ifdef __STDC__
float powf(float x, float y) /* wrapper powf */
#else
float powf(x,y) /* wrapper powf */
float x,y;
#endif
{
#ifdef _IEEE_LIBM
return __ieee754_powf(x,y);
#else
float z;
struct exception exc;
z=__ieee754_powf(x,y);
if(_LIB_VERSION == _IEEE_|| isnanf(y)) return z;
if(isnanf(x)) {
if(y==(float)0.0) {
/* powf(NaN,0.0) */
/* error only if _LIB_VERSION == _SVID_ & _XOPEN_ */
exc.type = DOMAIN;
exc.name = "powf";
exc.err = 0;
exc.arg1 = (double)x;
exc.arg2 = (double)y;
exc.retval = x;
if (_LIB_VERSION == _IEEE_ ||
_LIB_VERSION == _POSIX_) exc.retval = 1.0;
else if (!matherr(&exc)) {
errno = EDOM;
}
if (exc.err != 0)
errno = exc.err;
return (float)exc.retval;
} else
return z;
}
if(x==(float)0.0){
if(y==(float)0.0) {
/* powf(0.0,0.0) */
/* error only if _LIB_VERSION == _SVID_ */
exc.type = DOMAIN;
exc.name = "powf";
exc.err = 0;
exc.arg1 = (double)x;
exc.arg2 = (double)y;
exc.retval = 0.0;
if (_LIB_VERSION != _SVID_) exc.retval = 1.0;
else if (!matherr(&exc)) {
errno = EDOM;
}
if (exc.err != 0)
errno = exc.err;
return (float)exc.retval;
}
if(finitef(y)&&y<(float)0.0) {
/* 0**neg */
exc.type = DOMAIN;
exc.name = "powf";
exc.err = 0;
exc.arg1 = (double)x;
exc.arg2 = (double)y;
if (_LIB_VERSION == _SVID_)
exc.retval = 0.0;
else
exc.retval = -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
errno = EDOM;
}
if (exc.err != 0)
errno = exc.err;
return (float)exc.retval;
}
return z;
}
if(!finitef(z)) {
if(finitef(x)&&finitef(y)) {
if(isnanf(z)) {
/* neg**non-integral */
exc.type = DOMAIN;
exc.name = "powf";
exc.err = 0;
exc.arg1 = (double)x;
exc.arg2 = (double)y;
if (_LIB_VERSION == _SVID_)
exc.retval = 0.0;
else
exc.retval = 0.0/0.0; /* X/Open allow NaN */
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
errno = EDOM;
}
if (exc.err != 0)
errno = exc.err;
return (float)exc.retval;
} else {
/* powf(x,y) overflow */
exc.type = OVERFLOW;
exc.name = "powf";
exc.err = 0;
exc.arg1 = (double)x;
exc.arg2 = (double)y;
if (_LIB_VERSION == _SVID_) {
exc.retval = HUGE;
y *= 0.5;
if(x<0.0&&rint(y)!=y) exc.retval = -HUGE;
} else {
exc.retval = HUGE_VAL;
y *= 0.5;
if(x<0.0&&rint(y)!=y) exc.retval = -HUGE_VAL;
}
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
if (exc.err != 0)
errno = exc.err;
return (float)exc.retval;
}
}
}
if(z==(float)0.0&&finitef(x)&&finitef(y)) {
/* powf(x,y) underflow */
exc.type = UNDERFLOW;
exc.name = "powf";
exc.err = 0;
exc.arg1 = (double)x;
exc.arg2 = (double)y;
exc.retval = 0.0;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
if (exc.err != 0)
errno = exc.err;
return (float)exc.retval;
}
return z;
#endif
}
#ifdef _DOUBLE_IS_32BITS
#ifdef __STDC__
double pow(double x, double y)
#else
double pow(x,y)
double x,y;
#endif
{
return (double) powf((float) x, (float) y);
}
#endif /* defined(_DOUBLE_IS_32BITS) */
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