0,0 → 1,94 |
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/* @(#)w_scalb.c 5.1 93/09/24 */ |
/* |
* ==================================================== |
* 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 scalb(double x, double fn) is provide for |
* passing various standard test suite. One |
* should use scalbn() instead. |
*/ |
|
#include "fdlibm.h" |
#include <errno.h> |
|
#ifndef _DOUBLE_IS_32BITS |
|
#ifdef __STDC__ |
#ifdef _SCALB_INT |
double scalb(double x, int fn) /* wrapper scalb */ |
#else |
double scalb(double x, double fn) /* wrapper scalb */ |
#endif |
#else |
double scalb(x,fn) /* wrapper scalb */ |
#ifdef _SCALB_INT |
double x; int fn; |
#else |
double x,fn; |
#endif |
#endif |
{ |
#ifdef _IEEE_LIBM |
return __ieee754_scalb(x,fn); |
#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_scalb(x,fn); |
if(_LIB_VERSION == _IEEE_) return z; |
if(!(finite(z)||isnan(z))&&finite(x)) { |
/* scalb overflow; SVID also returns +-HUGE_VAL */ |
exc.type = OVERFLOW; |
exc.name = "scalb"; |
exc.err = 0; |
exc.arg1 = x; |
exc.arg2 = fn; |
exc.retval = x > 0.0 ? HUGE_VAL : -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&&z!=x) { |
/* scalb underflow */ |
exc.type = UNDERFLOW; |
exc.name = "scalb"; |
exc.err = 0; |
exc.arg1 = x; |
exc.arg2 = fn; |
exc.retval = copysign(0.0,x); |
if (_LIB_VERSION == _POSIX_) |
errno = ERANGE; |
else if (!matherr(&exc)) { |
errno = ERANGE; |
} |
if (exc.err != 0) |
errno = exc.err; |
return exc.retval; |
} |
#ifndef _SCALB_INT |
if(!finite(fn)) errno = ERANGE; |
#endif |
return z; |
#endif |
} |
|
#endif /* defined(_DOUBLE_IS_32BITS) */ |