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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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