+++ /dev/null
-
-
-/* @(#)w_pow.c 5.2 93/10/01 */
-/*
- * ====================================================
- * 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.
- * ====================================================
- */
-
-/*
-FUNCTION
- <<pow>>, <<powf>>---x to the power y
-INDEX
- pow
-INDEX
- powf
-
-
-ANSI_SYNOPSIS
- #include <math.h>
- double pow(double <[x]>, double <[y]>);
- float pow(float <[x]>, float <[y]>);
-
-TRAD_SYNOPSIS
- #include <math.h>
- double pow(<[x]>, <[y]>);
- double <[x]>, <[y]>;
-
- float pow(<[x]>, <[y]>);
- float <[x]>, <[y]>;
-
-DESCRIPTION
- <<pow>> and <<powf>> calculate <[x]> raised to the exp1.0nt <[y]>.
- @tex
- (That is, $x^y$.)
- @end tex
-
-RETURNS
- On success, <<pow>> and <<powf>> return the value calculated.
-
- When the argument values would produce overflow, <<pow>>
- returns <<HUGE_VAL>> and set <<errno>> to <<ERANGE>>. If the
- argument <[x]> passed to <<pow>> or <<powf>> is a negative
- noninteger, and <[y]> is also not an integer, then <<errno>>
- is set to <<EDOM>>. If <[x]> and <[y]> are both 0, then
- <<pow>> and <<powf>> return <<1>>.
-
- You can modify error handling for these functions using <<matherr>>.
-
-PORTABILITY
- <<pow>> is ANSI C. <<powf>> is an extension. */
-
-/*
- * wrapper pow(x,y) return x**y
- */
-
-#include "fdlibm.h"
-#include <errno.h>
-
-#ifndef _DOUBLE_IS_32BITS
-
-#ifdef __STDC__
- double pow(double x, double y) /* wrapper pow */
-#else
- double pow(x,y) /* wrapper pow */
- double x,y;
-#endif
-{
-#ifdef _IEEE_LIBM
- return __ieee754_pow(x,y);
-#else
- double z;
-#ifndef HUGE_VAL
-#define HUGE_VAL inf
- double inf = 0.0;
-
- SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */
-#endif
- struct exception exc;
- z=__ieee754_pow(x,y);
- if(_LIB_VERSION == _IEEE_|| isnan(y)) return z;
- if(isnan(x)) {
- if(y==0.0) {
- /* pow(NaN,0.0) */
- /* error only if _LIB_VERSION == _SVID_ & _XOPEN_ */
- exc.type = DOMAIN;
- exc.name = "pow";
- exc.err = 0;
- exc.arg1 = x;
- exc.arg2 = 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 exc.retval;
- } else
- return z;
- }
- if(x==0.0){
- if(y==0.0) {
- /* pow(0.0,0.0) */
- /* error only if _LIB_VERSION == _SVID_ */
- exc.type = DOMAIN;
- exc.name = "pow";
- exc.err = 0;
- exc.arg1 = x;
- exc.arg2 = 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 exc.retval;
- }
- if(finite(y)&&y<0.0) {
- /* 0**neg */
- exc.type = DOMAIN;
- exc.name = "pow";
- exc.err = 0;
- exc.arg1 = x;
- exc.arg2 = 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 exc.retval;
- }
- return z;
- }
- if(!finite(z)) {
- if(finite(x)&&finite(y)) {
- if(isnan(z)) {
- /* neg**non-integral */
- exc.type = DOMAIN;
- exc.name = "pow";
- exc.err = 0;
- exc.arg1 = x;
- exc.arg2 = 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 exc.retval;
- } else {
- /* pow(x,y) overflow */
- exc.type = OVERFLOW;
- exc.name = "pow";
- exc.err = 0;
- exc.arg1 = x;
- exc.arg2 = 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 exc.retval;
- }
- }
- }
- if(z==0.0&&finite(x)&&finite(y)) {
- /* pow(x,y) underflow */
- exc.type = UNDERFLOW;
- exc.name = "pow";
- exc.err = 0;
- exc.arg1 = x;
- exc.arg2 = 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 exc.retval;
- }
- return z;
-#endif
-}
-
-#endif /* defined(_DOUBLE_IS_32BITS) */
-
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projects / msp430-gcc.git / blobdiff