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Diffstat (limited to 'libm/fpmacros.c')
| -rw-r--r-- | libm/fpmacros.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/libm/fpmacros.c b/libm/fpmacros.c new file mode 100644 index 000000000..6c5abbe87 --- /dev/null +++ b/libm/fpmacros.c @@ -0,0 +1,239 @@ +/*********************************************************************** +** 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 "fp_private.h" + +#define SIGN_MASK 0x80000000 +#define NSIGN_MASK 0x7fffffff +#define FEXP_MASK 0x7f800000 +#define FFRAC_MASK 0x007fffff + +/*********************************************************************** + long 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 +***********************************************************************/ + +long int __fpclassifyf ( float x ) +{ + unsigned long int iexp; + + union { + unsigned long int 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 (long int) FP_INFINITE; + else if ((z.lval & 0x00400000) != 0) + return (long int) FP_QNAN; + else + return (long int) FP_SNAN; + } + + if (iexp != 0) /* normal float */ + return (long int) FP_NORMAL; + + if (x == 0.0) + return (long int) FP_ZERO; /* zero */ + else + return (long int) FP_SUBNORMAL; /* must be subnormal */ +} + + +/*********************************************************************** + 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 +***********************************************************************/ + +long int __fpclassify ( double arg ) +{ + register unsigned long 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 (long int) FP_INFINITE; + else + return ( x.hex.high & 0x00080000 ) ? FP_QNAN : FP_SNAN; + } + else if ( exponent != 0) + return (long int) FP_NORMAL; + else { + if ( arg == 0.0 ) + return (long int) FP_ZERO; + else + return (long int) FP_SUBNORMAL; + } +} + + +/*********************************************************************** + long 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 +***********************************************************************/ + +long int __isnormalf ( float x ) +{ + unsigned long int iexp; + union { + unsigned long int lval; + float fval; + } z; + + z.fval = x; + iexp = z.lval & FEXP_MASK; /* isolate float exponent */ + return ((iexp != FEXP_MASK) && (iexp != 0)); +} + + +long int __isnorma ( double x ) +{ + return ( __fpclassify ( x ) == FP_NORMAL ); +} + + +/*********************************************************************** + long 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 +***********************************************************************/ + +long int __isfinitef ( float x ) +{ + union { + unsigned long int lval; + float fval; + } z; + + z.fval = x; + return ((z.lval & FEXP_MASK) != FEXP_MASK); +} + +long int __isfinite ( double x ) +{ + return ( __fpclassify ( x ) >= FP_ZERO ); +} + + + +/*********************************************************************** + long 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 +***********************************************************************/ + +long int __isnanf ( float x ) +{ + union { + unsigned long int lval; + float fval; + } z; + + z.fval = x; + return (((z.lval&FEXP_MASK) == FEXP_MASK) && ((z.lval&FFRAC_MASK) != 0)); +} + +long int __isnan ( double x ) +{ + long int class = __fpclassify(x); + return ( ( class == FP_SNAN ) || ( class == FP_QNAN ) ); +} + + +/*********************************************************************** + long 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 +***********************************************************************/ + +long int __signbitf ( float x ) +{ + union { + unsigned long int lval; + float fval; + } z; + + z.fval = x; + return ((z.lval & SIGN_MASK) != 0); +} + + +/*********************************************************************** + Function sign of a double. + Implementation of sign bit for the PowerPC. + + Calls: none +***********************************************************************/ + +long int __signbit ( double arg ) +{ + union + { + dHexParts hex; + double dbl; + } x; + long int sign; + + x.dbl = arg; + sign = ( ( x.hex.high & dSgnMask ) == dSgnMask ) ? 1 : 0; + return sign; +} + + |