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/***********************************************************************
** File: fpmacros.c
**
** Contains: C source code for implementations of floating-point
** functions which involve float format numbers, as
** defined in header <fp.h>. In particular, this file
** contains implementations of functions
** __fpclassify(d,f), __isnormal(d,f), __isfinite(d,f),
** __isnan(d,f), and __signbit(d,f). This file targets
** PowerPC platforms.
**
** Written by: Robert A. Murley, Ali Sazegari
**
** Copyright: c 2001 by Apple Computer, Inc., all rights reserved
**
** Change History (most recent first):
**
** 07 Jul 01 ram First created from fpfloatfunc.c, fp.c,
** classify.c and sign.c in MathLib v3 Mac OS9.
**
***********************************************************************/
#include <features.h>
#include <sys/types.h>
#include <math.h>
#include "fp_private.h"
#define SIGN_MASK 0x80000000
#define NSIGN_MASK 0x7fffffff
#define FEXP_MASK 0x7f800000
#define FFRAC_MASK 0x007fffff
/***********************************************************************
int __fpclassifyf(float x) returns the classification code of the
argument x, as defined in <fp.h>.
Exceptions: INVALID signaled if x is a signaling NaN; in this case,
the FP_QNAN code is returned.
Calls: none
***********************************************************************/
libm_hidden_proto(__fpclassifyf)
int __fpclassifyf ( float x )
{
unsigned int iexp;
union {
u_int32_t lval;
float fval;
} z;
z.fval = x;
iexp = z.lval & FEXP_MASK; /* isolate float exponent */
if (iexp == FEXP_MASK) { /* NaN or INF case */
if ((z.lval & 0x007fffff) == 0)
return FP_INFINITE;
return FP_NAN;
}
if (iexp != 0) /* normal float */
return FP_NORMAL;
if (x == 0.0)
return FP_ZERO; /* zero */
else
return FP_SUBNORMAL; /* must be subnormal */
}
libm_hidden_def(__fpclassifyf)
/***********************************************************************
Function __fpclassify,
Implementation of classify of a double number for the PowerPC.
Exceptions: INVALID signaled if x is a signaling NaN; in this case,
the FP_QNAN code is returned.
Calls: none
***********************************************************************/
libm_hidden_proto(__fpclassify)
int __fpclassify ( double arg )
{
register unsigned int exponent;
union
{
dHexParts hex;
double dbl;
} x;
x.dbl = arg;
exponent = x.hex.high & dExpMask;
if ( exponent == dExpMask )
{
if ( ( ( x.hex.high & dHighMan ) | x.hex.low ) == 0 )
return FP_INFINITE;
else
return FP_NAN;
}
else if ( exponent != 0)
return FP_NORMAL;
else {
if ( arg == 0.0 )
return FP_ZERO;
else
return FP_SUBNORMAL;
}
}
libm_hidden_def(__fpclassify)
/***********************************************************************
int __isnormalf(float x) returns nonzero if and only if x is a
normalized float number and zero otherwise.
Exceptions: INVALID is raised if x is a signaling NaN; in this case,
zero is returned.
Calls: none
***********************************************************************/
int __isnormalf ( float x );
int __isnormalf ( float x )
{
unsigned int iexp;
union {
u_int32_t lval;
float fval;
} z;
z.fval = x;
iexp = z.lval & FEXP_MASK; /* isolate float exponent */
return ((iexp != FEXP_MASK) && (iexp != 0));
}
int __isnormal ( double x );
int __isnormal ( double x )
{
return ( __fpclassify ( x ) == FP_NORMAL );
}
/***********************************************************************
int __isfinitef(float x) returns nonzero if and only if x is a
finite (normal, subnormal, or zero) float number and zero otherwise.
Exceptions: INVALID is raised if x is a signaling NaN; in this case,
zero is returned.
Calls: none
***********************************************************************/
int __finitef ( float x )
{
union {
u_int32_t lval;
float fval;
} z;
z.fval = x;
return ((z.lval & FEXP_MASK) != FEXP_MASK);
}
strong_alias(__finitef,finitef)
#if 0 /* use __finite in s_finite.c */
int __finite ( double x )
{
return ( __fpclassify ( x ) >= FP_ZERO );
}
strong_alias(__finite,finite)
#endif
/***********************************************************************
int __signbitf(float x) returns nonzero if and only if the sign
bit of x is set and zero otherwise.
Exceptions: INVALID is raised if x is a signaling NaN.
Calls: none
***********************************************************************/
libm_hidden_proto(__signbitf)
int __signbitf ( float x )
{
union {
u_int32_t lval;
float fval;
} z;
z.fval = x;
return ((z.lval & SIGN_MASK) != 0);
}
libm_hidden_def(__signbitf)
/***********************************************************************
Function sign of a double.
Implementation of sign bit for the PowerPC.
Calls: none
***********************************************************************/
libm_hidden_proto(__signbit)
int __signbit ( double arg )
{
union
{
dHexParts hex;
double dbl;
} x;
int sign;
x.dbl = arg;
sign = ( ( x.hex.high & dSgnMask ) == dSgnMask ) ? 1 : 0;
return sign;
}
libm_hidden_def(__signbit)
/***********************************************************************
* int __isinff(float x) returns -1 if value represents negative
* infinity, 1 if value represents positive infinity,
* and 0 otherwise.
*
* Calls: __signbit
* +***********************************************************************/
int __isinff ( float x )
{
int class = __fpclassifyf(x);
if ( class == FP_INFINITE ) {
return ( (__signbitf(x)) ? -1 : 1);
}
return 0;
}
strong_alias(__isinff,isinff)
int __isinf ( double x )
{
int class = __fpclassify(x);
if ( class == FP_INFINITE ) {
return ( (__signbit(x)) ? -1 : 1);
}
return 0;
}
strong_alias(__isinf,isinf)
#if 0
int __isinfl ( long double x )
{
int class = __fpclassify(x);
if ( class == FP_INFINITE ) {
return ( (__signbit(x)) ? -1 : 1);
}
return 0;
}
strong_alias(__isinfl,isinfl)
#endif
/***********************************************************************
int __isnanf(float x) returns nonzero if and only if x is a
NaN and zero otherwise.
Exceptions: INVALID is raised if x is a signaling NaN; in this case,
nonzero is returned.
Calls: none
***********************************************************************/
int __isnanf ( float x )
{
union {
u_int32_t lval;
float fval;
} z;
z.fval = x;
return (((z.lval&FEXP_MASK) == FEXP_MASK) && ((z.lval&FFRAC_MASK) != 0));
}
strong_alias(__isnanf,isnanf)
libm_hidden_proto(__isnan)
int __isnan ( double x )
{
int class = __fpclassify(x);
return ( class == FP_NAN );
}
libm_hidden_def(__isnan)
strong_alias(__isnan,isnan)
#if 0
int __isnanl ( long double x )
{
int class = __fpclassify(x);
return ( class == FP_NAN );
}
strong_alias(__isnanl,isnanl)
#endif
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