1169 lines
29 KiB
C
1169 lines
29 KiB
C
/*************************************************************************
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*
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* $Id: trionan.c,v 1.33 2005/05/29 11:57:25 breese Exp $
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*
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* Copyright (C) 2001 Bjorn Reese <breese@users.sourceforge.net>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
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* MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE AUTHORS AND
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* CONTRIBUTORS ACCEPT NO RESPONSIBILITY IN ANY CONCEIVABLE MANNER.
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*
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************************************************************************
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*
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* Functions to handle special quantities in floating-point numbers
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* (that is, NaNs and infinity). They provide the capability to detect
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* and fabricate special quantities.
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*
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* Although written to be as portable as possible, it can never be
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* guaranteed to work on all platforms, as not all hardware supports
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* special quantities.
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*
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* The approach used here (approximately) is to:
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*
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* 1. Use C99 functionality when available.
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* 2. Use IEEE 754 bit-patterns if possible.
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* 3. Use platform-specific techniques.
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*
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************************************************************************/
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/*************************************************************************
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* Include files
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*/
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#include "triodef.h"
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#include "trionan.h"
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#include <math.h>
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#include <string.h>
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#include <limits.h>
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#if !defined(TRIO_PLATFORM_SYMBIAN)
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#include <float.h>
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#endif
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#if defined(TRIO_PLATFORM_UNIX)
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#include <signal.h>
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#endif
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#if defined(TRIO_COMPILER_DECC)
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#include <fp_class.h>
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#endif
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#include <assert.h>
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#if defined(TRIO_DOCUMENTATION)
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#include "doc/doc_nan.h"
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#endif
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/** @addtogroup SpecialQuantities
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@{
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*/
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/*************************************************************************
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* Definitions
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*/
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#if !defined(TRIO_PUBLIC_NAN)
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#define TRIO_PUBLIC_NAN TRIO_PUBLIC
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#endif
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#if !defined(TRIO_PRIVATE_NAN)
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#define TRIO_PRIVATE_NAN TRIO_PRIVATE
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#endif
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#define TRIO_TRUE (1 == 1)
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#define TRIO_FALSE (0 == 1)
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/*
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* We must enable IEEE floating-point on Alpha
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*/
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#if defined(__alpha) && !defined(_IEEE_FP)
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#if defined(TRIO_COMPILER_DECC)
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#if defined(TRIO_PLATFORM_VMS)
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#error "Must be compiled with option /IEEE_MODE=UNDERFLOW_TO_ZERO/FLOAT=IEEE"
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#else
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#if !defined(_CFE)
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#error "Must be compiled with option -ieee"
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#endif
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#endif
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#else
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#if defined(TRIO_COMPILER_GCC)
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#error "Must be compiled with option -mieee"
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#endif
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#endif
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#endif /* __alpha && ! _IEEE_FP */
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/*
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* In ANSI/IEEE 754-1985 64-bits double format numbers have the
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* following properties (amoungst others)
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*
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* o FLT_RADIX == 2: binary encoding
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* o DBL_MAX_EXP == 1024: 11 bits exponent, where one bit is used
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* to indicate special numbers (e.g. NaN and Infinity), so the
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* maximum exponent is 10 bits wide (2^10 == 1024).
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* o DBL_MANT_DIG == 53: The mantissa is 52 bits wide, but because
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* numbers are normalized the initial binary 1 is represented
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* implicitly (the so-called "hidden bit"), which leaves us with
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* the ability to represent 53 bits wide mantissa.
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*/
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#if defined(__STDC_IEC_559__)
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#define TRIO_IEEE_754
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#else
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#if (FLT_RADIX - 0 == 2) && (DBL_MAX_EXP - 0 == 1024) && (DBL_MANT_DIG - 0 == 53)
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#define TRIO_IEEE_754
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#endif
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#endif
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/*
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* Determine which fpclassify_and_sign() function to use.
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*/
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#if defined(TRIO_FUNC_FPCLASSIFY_AND_SIGNBIT)
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#if defined(PREDEF_STANDARD_C99) && defined(fpclassify)
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#define TRIO_FUNC_C99_FPCLASSIFY_AND_SIGNBIT
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#else
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#if defined(TRIO_COMPILER_DECC)
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#define TRIO_FUNC_DECC_FPCLASSIFY_AND_SIGNBIT
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#else
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#if defined(TRIO_COMPILER_VISUALC) || defined(TRIO_COMPILER_BORLAND)
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#define TRIO_FUNC_MS_FPCLASSIFY_AND_SIGNBIT
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#else
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#if defined(TRIO_COMPILER_HP) && defined(FP_PLUS_NORM)
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#define TRIO_FUNC_HP_FPCLASSIFY_AND_SIGNBIT
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#else
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#if defined(TRIO_COMPILER_XLC) && defined(FP_PLUS_NORM)
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#define TRIO_FUNC_XLC_FPCLASSIFY_AND_SIGNBIT
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#else
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#define TRIO_FUNC_INTERNAL_FPCLASSIFY_AND_SIGNBIT
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#endif
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#endif
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#endif
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#endif
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#endif
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#endif
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/*
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* Determine how to generate negative zero.
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*/
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#if defined(TRIO_FUNC_NZERO)
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#if defined(TRIO_IEEE_754)
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#define TRIO_NZERO_IEEE_754
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#else
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#define TRIO_NZERO_FALLBACK
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#endif
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#endif
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/*
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* Determine how to generate positive infinity.
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*/
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#if defined(TRIO_FUNC_PINF)
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#if defined(INFINITY) && defined(__STDC_IEC_559__)
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#define TRIO_PINF_C99_MACRO
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#else
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#if defined(TRIO_IEEE_754)
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#define TRIO_PINF_IEEE_754
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#else
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#define TRIO_PINF_FALLBACK
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#endif
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#endif
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#endif
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/*
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* Determine how to generate NaN.
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*/
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#if defined(TRIO_FUNC_NAN)
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#if defined(PREDEF_STANDARD_C99) && !defined(TRIO_COMPILER_DECC)
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#define TRIO_NAN_C99_FUNCTION
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#else
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#if defined(NAN) && defined(__STDC_IEC_559__)
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#define TRIO_NAN_C99_MACRO
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#else
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#if defined(TRIO_IEEE_754)
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#define TRIO_NAN_IEEE_754
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#else
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#define TRIO_NAN_FALLBACK
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#endif
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#endif
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#endif
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#endif
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/*
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* Resolve internal dependencies.
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*/
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#if defined(TRIO_FUNC_INTERNAL_FPCLASSIFY_AND_SIGNBIT)
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#define TRIO_FUNC_INTERNAL_ISNAN
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#define TRIO_FUNC_INTERNAL_ISINF
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#if defined(TRIO_IEEE_754)
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#define TRIO_FUNC_INTERNAL_IS_SPECIAL_QUANTITY
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#define TRIO_FUNC_INTERNAL_IS_NEGATIVE
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#endif
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#endif
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#if defined(TRIO_NZERO_IEEE_754) || defined(TRIO_PINF_IEEE_754) || defined(TRIO_NAN_IEEE_754)
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#define TRIO_FUNC_INTERNAL_MAKE_DOUBLE
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#endif
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#if defined(TRIO_FUNC_INTERNAL_ISNAN)
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#if defined(PREDEF_STANDARD_XPG3)
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#define TRIO_INTERNAL_ISNAN_XPG3
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#else
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#if defined(TRIO_IEEE_754)
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#define TRIO_INTERNAL_ISNAN_IEEE_754
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#else
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#define TRIO_INTERNAL_ISNAN_FALLBACK
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#endif
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#endif
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#endif
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#if defined(TRIO_FUNC_INTERNAL_ISINF)
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#if defined(TRIO_IEEE_754)
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#define TRIO_INTERNAL_ISINF_IEEE_754
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#else
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#define TRIO_INTERNAL_ISINF_FALLBACK
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#endif
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#endif
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/*************************************************************************
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* Constants
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*/
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#if !defined(TRIO_EMBED_NAN)
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/* Unused but kept for reference */
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/* static TRIO_CONST char rcsid[] = "@(#)$Id: trionan.c,v 1.33 2005/05/29 11:57:25 breese Exp $"; */
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#endif
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#if defined(TRIO_FUNC_INTERNAL_MAKE_DOUBLE) || defined(TRIO_FUNC_INTERNAL_IS_SPECIAL_QUANTITY) || \
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defined(TRIO_FUNC_INTERNAL_IS_NEGATIVE)
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/*
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* Endian-agnostic indexing macro.
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*
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* The value of internalEndianMagic, when converted into a 64-bit
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* integer, becomes 0x0706050403020100 (we could have used a 64-bit
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* integer value instead of a double, but not all platforms supports
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* that type). The value is automatically encoded with the correct
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* endianess by the compiler, which means that we can support any
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* kind of endianess. The individual bytes are then used as an index
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* for the IEEE 754 bit-patterns and masks.
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*/
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#define TRIO_DOUBLE_INDEX(x) (((unsigned char*)&internalEndianMagic)[7 - (x)])
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static TRIO_CONST double internalEndianMagic = 7.949928895127363e-275;
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#endif
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#if defined(TRIO_FUNC_INTERNAL_IS_SPECIAL_QUANTITY)
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/* Mask for the exponent */
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static TRIO_CONST unsigned char ieee_754_exponent_mask[] = { 0x7F, 0xF0, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00 };
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/* Mask for the mantissa */
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static TRIO_CONST unsigned char ieee_754_mantissa_mask[] = { 0x00, 0x0F, 0xFF, 0xFF,
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0xFF, 0xFF, 0xFF, 0xFF };
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#endif
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#if defined(TRIO_FUNC_INTERNAL_IS_NEGATIVE)
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/* Mask for the sign bit */
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static TRIO_CONST unsigned char ieee_754_sign_mask[] = { 0x80, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00 };
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#endif
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#if defined(TRIO_NZERO_IEEE_754)
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/* Bit-pattern for negative zero */
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static TRIO_CONST unsigned char ieee_754_negzero_array[] = { 0x80, 0x00, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00 };
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#endif
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#if defined(TRIO_PINF_IEEE_754)
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/* Bit-pattern for infinity */
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static TRIO_CONST unsigned char ieee_754_infinity_array[] = { 0x7F, 0xF0, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00 };
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#endif
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#if defined(TRIO_NAN_IEEE_754)
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/* Bit-pattern for quiet NaN */
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static TRIO_CONST unsigned char ieee_754_qnan_array[] = { 0x7F, 0xF8, 0x00, 0x00,
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0x00, 0x00, 0x00, 0x00 };
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#endif
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/*************************************************************************
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* Internal functions
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*/
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/*
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* internal_make_double
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*/
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#if defined(TRIO_FUNC_INTERNAL_MAKE_DOUBLE)
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TRIO_PRIVATE_NAN double internal_make_double TRIO_ARGS1((values), TRIO_CONST unsigned char* values)
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{
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TRIO_VOLATILE double result;
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int i;
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for (i = 0; i < (int)sizeof(double); i++)
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{
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((TRIO_VOLATILE unsigned char*)&result)[TRIO_DOUBLE_INDEX(i)] = values[i];
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}
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return result;
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}
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#endif
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/*
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* internal_is_special_quantity
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*/
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#if defined(TRIO_FUNC_INTERNAL_IS_SPECIAL_QUANTITY)
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TRIO_PRIVATE_NAN int internal_is_special_quantity TRIO_ARGS2((number, has_mantissa), double number,
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int* has_mantissa)
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{
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unsigned int i;
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unsigned char current;
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int is_special_quantity = TRIO_TRUE;
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*has_mantissa = 0;
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for (i = 0; i < (unsigned int)sizeof(double); i++)
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{
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current = ((unsigned char*)&number)[TRIO_DOUBLE_INDEX(i)];
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is_special_quantity &= ((current & ieee_754_exponent_mask[i]) == ieee_754_exponent_mask[i]);
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*has_mantissa |= (current & ieee_754_mantissa_mask[i]);
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}
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return is_special_quantity;
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}
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#endif
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/*
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* internal_is_negative
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*/
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#if defined(TRIO_FUNC_INTERNAL_IS_NEGATIVE)
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TRIO_PRIVATE_NAN int internal_is_negative TRIO_ARGS1((number), double number)
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{
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unsigned int i;
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int is_negative = TRIO_FALSE;
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for (i = 0; i < (unsigned int)sizeof(double); i++)
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{
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is_negative |= (((unsigned char*)&number)[TRIO_DOUBLE_INDEX(i)] & ieee_754_sign_mask[i]);
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}
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return is_negative;
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}
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#endif
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#if defined(TRIO_FUNC_C99_FPCLASSIFY_AND_SIGNBIT)
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TRIO_PRIVATE_NAN TRIO_INLINE int c99_fpclassify_and_signbit TRIO_ARGS2((number, is_negative),
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double number,
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int* is_negative)
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{
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*is_negative = signbit(number);
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switch (fpclassify(number))
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{
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case FP_NAN:
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return TRIO_FP_NAN;
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case FP_INFINITE:
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return TRIO_FP_INFINITE;
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case FP_SUBNORMAL:
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return TRIO_FP_SUBNORMAL;
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case FP_ZERO:
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return TRIO_FP_ZERO;
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default:
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return TRIO_FP_NORMAL;
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}
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}
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#endif /* TRIO_FUNC_C99_FPCLASSIFY_AND_SIGNBIT */
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#if defined(TRIO_FUNC_DECC_FPCLASSIFY_AND_SIGNBIT)
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TRIO_PRIVATE_NAN TRIO_INLINE int decc_fpclassify_and_signbit TRIO_ARGS2((number, is_negative),
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double number,
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int* is_negative)
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{
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switch (fp_class(number))
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{
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case FP_QNAN:
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case FP_SNAN:
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*is_negative = TRIO_FALSE; /* NaN has no sign */
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return TRIO_FP_NAN;
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case FP_POS_INF:
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*is_negative = TRIO_FALSE;
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return TRIO_FP_INFINITE;
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case FP_NEG_INF:
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*is_negative = TRIO_TRUE;
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return TRIO_FP_INFINITE;
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case FP_POS_DENORM:
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*is_negative = TRIO_FALSE;
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return TRIO_FP_SUBNORMAL;
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case FP_NEG_DENORM:
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*is_negative = TRIO_TRUE;
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return TRIO_FP_SUBNORMAL;
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case FP_POS_ZERO:
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*is_negative = TRIO_FALSE;
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return TRIO_FP_ZERO;
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case FP_NEG_ZERO:
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*is_negative = TRIO_TRUE;
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return TRIO_FP_ZERO;
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case FP_POS_NORM:
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*is_negative = TRIO_FALSE;
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return TRIO_FP_NORMAL;
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case FP_NEG_NORM:
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*is_negative = TRIO_TRUE;
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return TRIO_FP_NORMAL;
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default:
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*is_negative = (number < 0.0);
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return TRIO_FP_NORMAL;
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}
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}
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#endif /* TRIO_FUNC_DECC_FPCLASSIFY_AND_SIGNBIT */
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#if defined(TRIO_FUNC_MS_FPCLASSIFY_AND_SIGNBIT)
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TRIO_PRIVATE_NAN int ms_fpclassify_and_signbit TRIO_ARGS2((number, is_negative), double number,
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int* is_negative)
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{
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int result;
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#if defined(TRIO_COMPILER_BORLAND)
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/*
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* The floating-point precision may be changed by the Borland _fpclass()
|
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* function, so we have to save and restore the floating-point control mask.
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*/
|
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unsigned int mask;
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/* Remember the old mask */
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mask = _control87(0, 0);
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#endif
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switch (_fpclass(number))
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{
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case _FPCLASS_QNAN:
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case _FPCLASS_SNAN:
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*is_negative = TRIO_FALSE; /* NaN has no sign */
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result = TRIO_FP_NAN;
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break;
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case _FPCLASS_PINF:
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*is_negative = TRIO_FALSE;
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result = TRIO_FP_INFINITE;
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break;
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case _FPCLASS_NINF:
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*is_negative = TRIO_TRUE;
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result = TRIO_FP_INFINITE;
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break;
|
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case _FPCLASS_PD:
|
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*is_negative = TRIO_FALSE;
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result = TRIO_FP_SUBNORMAL;
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break;
|
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case _FPCLASS_ND:
|
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*is_negative = TRIO_TRUE;
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result = TRIO_FP_SUBNORMAL;
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break;
|
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case _FPCLASS_PZ:
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*is_negative = TRIO_FALSE;
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result = TRIO_FP_ZERO;
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break;
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case _FPCLASS_NZ:
|
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*is_negative = TRIO_TRUE;
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result = TRIO_FP_ZERO;
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break;
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case _FPCLASS_PN:
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*is_negative = TRIO_FALSE;
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result = TRIO_FP_NORMAL;
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break;
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case _FPCLASS_NN:
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*is_negative = TRIO_TRUE;
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result = TRIO_FP_NORMAL;
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break;
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default:
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*is_negative = (number < 0.0);
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result = TRIO_FP_NORMAL;
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break;
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}
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#if defined(TRIO_COMPILER_BORLAND)
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/* Restore the old precision */
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(void)_control87(mask, MCW_PC);
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#endif
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return result;
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}
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#endif /* TRIO_FUNC_MS_FPCLASSIFY_AND_SIGNBIT */
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|
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#if defined(TRIO_FUNC_HP_FPCLASSIFY_AND_SIGNBIT)
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|
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TRIO_PRIVATE_NAN TRIO_INLINE int hp_fpclassify_and_signbit TRIO_ARGS2((number, is_negative),
|
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double number,
|
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int* is_negative)
|
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{
|
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/*
|
|
* HP-UX 9.x and 10.x have an fpclassify() function, that is different
|
|
* from the C99 fpclassify() macro supported on HP-UX 11.x.
|
|
*/
|
|
switch (fpclassify(number))
|
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{
|
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case FP_QNAN:
|
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case FP_SNAN:
|
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*is_negative = TRIO_FALSE; /* NaN has no sign */
|
|
return TRIO_FP_NAN;
|
|
case FP_PLUS_INF:
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_INFINITE;
|
|
case FP_MINUS_INF:
|
|
*is_negative = TRIO_TRUE;
|
|
return TRIO_FP_INFINITE;
|
|
case FP_PLUS_DENORM:
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_SUBNORMAL;
|
|
case FP_MINUS_DENORM:
|
|
*is_negative = TRIO_TRUE;
|
|
return TRIO_FP_SUBNORMAL;
|
|
case FP_PLUS_ZERO:
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_ZERO;
|
|
case FP_MINUS_ZERO:
|
|
*is_negative = TRIO_TRUE;
|
|
return TRIO_FP_ZERO;
|
|
case FP_PLUS_NORM:
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_NORMAL;
|
|
case FP_MINUS_NORM:
|
|
*is_negative = TRIO_TRUE;
|
|
return TRIO_FP_NORMAL;
|
|
default:
|
|
*is_negative = (number < 0.0);
|
|
return TRIO_FP_NORMAL;
|
|
}
|
|
}
|
|
|
|
#endif /* TRIO_FUNC_HP_FPCLASSIFY_AND_SIGNBIT */
|
|
|
|
#if defined(TRIO_FUNC_XLC_FPCLASSIFY_AND_SIGNBIT)
|
|
|
|
TRIO_PRIVATE_NAN TRIO_INLINE int xlc_fpclassify_and_signbit TRIO_ARGS2((number, is_negative),
|
|
double number,
|
|
int* is_negative)
|
|
{
|
|
/*
|
|
* AIX has class() for C, and _class() for C++
|
|
*/
|
|
#if defined(__cplusplus)
|
|
#define AIX_CLASS(n) _class(n)
|
|
#else
|
|
#define AIX_CLASS(n) class(n)
|
|
#endif
|
|
|
|
switch (AIX_CLASS(number))
|
|
{
|
|
case FP_QNAN:
|
|
case FP_SNAN:
|
|
*is_negative = TRIO_FALSE; /* NaN has no sign */
|
|
return TRIO_FP_NAN;
|
|
case FP_PLUS_INF:
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_INFINITE;
|
|
case FP_MINUS_INF:
|
|
*is_negative = TRIO_TRUE;
|
|
return TRIO_FP_INFINITE;
|
|
case FP_PLUS_DENORM:
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_SUBNORMAL;
|
|
case FP_MINUS_DENORM:
|
|
*is_negative = TRIO_TRUE;
|
|
return TRIO_FP_SUBNORMAL;
|
|
case FP_PLUS_ZERO:
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_ZERO;
|
|
case FP_MINUS_ZERO:
|
|
*is_negative = TRIO_TRUE;
|
|
return TRIO_FP_ZERO;
|
|
case FP_PLUS_NORM:
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_NORMAL;
|
|
case FP_MINUS_NORM:
|
|
*is_negative = TRIO_TRUE;
|
|
return TRIO_FP_NORMAL;
|
|
default:
|
|
*is_negative = (number < 0.0);
|
|
return TRIO_FP_NORMAL;
|
|
}
|
|
}
|
|
|
|
#endif /* TRIO_FUNC_XLC_FPCLASSIFY_AND_SIGNBIT */
|
|
|
|
#if defined(TRIO_FUNC_INTERNAL_ISNAN)
|
|
|
|
TRIO_PRIVATE_NAN TRIO_INLINE int internal_isnan TRIO_ARGS1((number), double number)
|
|
{
|
|
#if defined(TRIO_INTERNAL_ISNAN_XPG3) || defined(TRIO_PLATFORM_SYMBIAN)
|
|
/*
|
|
* XPG3 defines isnan() as a function.
|
|
*/
|
|
return isnan(number);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_INTERNAL_ISNAN_IEEE_754)
|
|
|
|
/*
|
|
* Examine IEEE 754 bit-pattern. A NaN must have a special exponent
|
|
* pattern, and a non-empty mantissa.
|
|
*/
|
|
int has_mantissa;
|
|
int is_special_quantity;
|
|
|
|
is_special_quantity = internal_is_special_quantity(number, &has_mantissa);
|
|
|
|
return (is_special_quantity && has_mantissa);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_INTERNAL_ISNAN_FALLBACK)
|
|
|
|
/*
|
|
* Fallback solution
|
|
*/
|
|
int status;
|
|
double integral, fraction;
|
|
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
void (*signal_handler)(int) = signal(SIGFPE, SIG_IGN);
|
|
#endif
|
|
|
|
status = (/*
|
|
* NaN is the only number which does not compare to itself
|
|
*/
|
|
((TRIO_VOLATILE double)number != (TRIO_VOLATILE double)number) ||
|
|
/*
|
|
* Fallback solution if NaN compares to NaN
|
|
*/
|
|
((number != 0.0) && (fraction = modf(number, &integral), integral == fraction)));
|
|
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
signal(SIGFPE, signal_handler);
|
|
#endif
|
|
|
|
return status;
|
|
|
|
#endif
|
|
}
|
|
|
|
#endif /* TRIO_FUNC_INTERNAL_ISNAN */
|
|
|
|
#if defined(TRIO_FUNC_INTERNAL_ISINF)
|
|
|
|
TRIO_PRIVATE_NAN TRIO_INLINE int internal_isinf TRIO_ARGS1((number), double number)
|
|
{
|
|
#if defined(TRIO_PLATFORM_SYMBIAN)
|
|
|
|
return isinf(number);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_INTERNAL_ISINF_IEEE_754)
|
|
/*
|
|
* Examine IEEE 754 bit-pattern. Infinity must have a special exponent
|
|
* pattern, and an empty mantissa.
|
|
*/
|
|
int has_mantissa;
|
|
int is_special_quantity;
|
|
|
|
is_special_quantity = internal_is_special_quantity(number, &has_mantissa);
|
|
|
|
return (is_special_quantity && !has_mantissa) ? ((number < 0.0) ? -1 : 1) : 0;
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_INTERNAL_ISINF_FALLBACK)
|
|
|
|
/*
|
|
* Fallback solution.
|
|
*/
|
|
int status;
|
|
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
void (*signal_handler)(int) = signal(SIGFPE, SIG_IGN);
|
|
#endif
|
|
|
|
double infinity = trio_pinf();
|
|
|
|
status = ((number == infinity) ? 1 : ((number == -infinity) ? -1 : 0));
|
|
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
signal(SIGFPE, signal_handler);
|
|
#endif
|
|
|
|
return status;
|
|
|
|
#endif
|
|
}
|
|
|
|
#endif /* TRIO_FUNC_INTERNAL_ISINF */
|
|
|
|
/*************************************************************************
|
|
* Public functions
|
|
*/
|
|
|
|
#if defined(TRIO_FUNC_FPCLASSIFY_AND_SIGNBIT)
|
|
|
|
TRIO_PUBLIC_NAN int trio_fpclassify_and_signbit TRIO_ARGS2((number, is_negative), double number,
|
|
int* is_negative)
|
|
{
|
|
/* The TRIO_FUNC_xxx_FPCLASSIFY_AND_SIGNBIT macros are mutually exclusive */
|
|
|
|
#if defined(TRIO_FUNC_C99_FPCLASSIFY_AND_SIGNBIT)
|
|
|
|
return c99_fpclassify_and_signbit(number, is_negative);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_FUNC_DECC_FPCLASSIFY_AND_SIGNBIT)
|
|
|
|
return decc_fpclassify_and_signbit(number, is_negative);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_FUNC_MS_FPCLASSIFY_AND_SIGNBIT)
|
|
|
|
return ms_fpclassify_and_signbit(number, is_negative);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_FUNC_HP_FPCLASSIFY_AND_SIGNBIT)
|
|
|
|
return hp_fpclassify_and_signbit(number, is_negative);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_FUNC_XLC_FPCLASSIFY_AND_SIGNBIT)
|
|
|
|
return xlc_fpclassify_and_signbit(number, is_negative);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_FUNC_INTERNAL_FPCLASSIFY_AND_SIGNBIT)
|
|
|
|
/*
|
|
* Fallback solution.
|
|
*/
|
|
int rc;
|
|
|
|
if (number == 0.0)
|
|
{
|
|
/*
|
|
* In IEEE 754 the sign of zero is ignored in comparisons, so we
|
|
* have to handle this as a special case by examining the sign bit
|
|
* directly.
|
|
*/
|
|
#if defined(TRIO_IEEE_754)
|
|
*is_negative = internal_is_negative(number);
|
|
#else
|
|
*is_negative = TRIO_FALSE; /* FIXME */
|
|
#endif
|
|
return TRIO_FP_ZERO;
|
|
}
|
|
if (internal_isnan(number))
|
|
{
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_NAN;
|
|
}
|
|
rc = internal_isinf(number);
|
|
if (rc != 0)
|
|
{
|
|
*is_negative = (rc == -1);
|
|
return TRIO_FP_INFINITE;
|
|
}
|
|
if ((number > 0.0) && (number < DBL_MIN))
|
|
{
|
|
*is_negative = TRIO_FALSE;
|
|
return TRIO_FP_SUBNORMAL;
|
|
}
|
|
if ((number < 0.0) && (number > -DBL_MIN))
|
|
{
|
|
*is_negative = TRIO_TRUE;
|
|
return TRIO_FP_SUBNORMAL;
|
|
}
|
|
*is_negative = (number < 0.0);
|
|
return TRIO_FP_NORMAL;
|
|
|
|
#endif
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
Check for NaN.
|
|
|
|
@param number An arbitrary floating-point number.
|
|
@return Boolean value indicating whether or not the number is a NaN.
|
|
*/
|
|
#if defined(TRIO_FUNC_ISNAN)
|
|
|
|
TRIO_PUBLIC_NAN int trio_isnan TRIO_ARGS1((number), double number)
|
|
{
|
|
int dummy;
|
|
|
|
return (trio_fpclassify_and_signbit(number, &dummy) == TRIO_FP_NAN);
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
Check for infinity.
|
|
|
|
@param number An arbitrary floating-point number.
|
|
@return 1 if positive infinity, -1 if negative infinity, 0 otherwise.
|
|
*/
|
|
#if defined(TRIO_FUNC_ISINF)
|
|
|
|
TRIO_PUBLIC_NAN int trio_isinf TRIO_ARGS1((number), double number)
|
|
{
|
|
int is_negative;
|
|
|
|
if (trio_fpclassify_and_signbit(number, &is_negative) == TRIO_FP_INFINITE)
|
|
{
|
|
return (is_negative) ? -1 : 1;
|
|
}
|
|
else
|
|
{
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
Check for finity.
|
|
|
|
@param number An arbitrary floating-point number.
|
|
@return Boolean value indicating whether or not the number is a finite.
|
|
*/
|
|
#if defined(TRIO_FUNC_ISFINITE)
|
|
|
|
TRIO_PUBLIC_NAN int trio_isfinite TRIO_ARGS1((number), double number)
|
|
{
|
|
int dummy;
|
|
|
|
switch (trio_fpclassify_and_signbit(number, &dummy))
|
|
{
|
|
case TRIO_FP_INFINITE:
|
|
case TRIO_FP_NAN:
|
|
return 0;
|
|
default:
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
Examine the sign of a number.
|
|
|
|
@param number An arbitrary floating-point number.
|
|
@return Boolean value indicating whether or not the number has the
|
|
sign bit set (i.e. is negative).
|
|
*/
|
|
#if defined(TRIO_FUNC_SIGNBIT)
|
|
|
|
TRIO_PUBLIC_NAN int trio_signbit TRIO_ARGS1((number), double number)
|
|
{
|
|
int is_negative;
|
|
|
|
(void)trio_fpclassify_and_signbit(number, &is_negative);
|
|
return is_negative;
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
Examine the class of a number.
|
|
|
|
@param number An arbitrary floating-point number.
|
|
@return Enumerable value indicating the class of @p number
|
|
*/
|
|
#if defined(TRIO_FUNC_FPCLASSIFY)
|
|
|
|
TRIO_PUBLIC_NAN int trio_fpclassify TRIO_ARGS1((number), double number)
|
|
{
|
|
int dummy;
|
|
|
|
return trio_fpclassify_and_signbit(number, &dummy);
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
Generate negative zero.
|
|
|
|
@return Floating-point representation of negative zero.
|
|
*/
|
|
#if defined(TRIO_FUNC_NZERO)
|
|
|
|
TRIO_PUBLIC_NAN double trio_nzero(TRIO_NOARGS)
|
|
{
|
|
#if defined(TRIO_NZERO_IEEE_754)
|
|
|
|
return internal_make_double(ieee_754_negzero_array);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_NZERO_FALLBACK)
|
|
|
|
TRIO_VOLATILE double zero = 0.0;
|
|
|
|
return -zero;
|
|
|
|
#endif
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
Generate positive infinity.
|
|
|
|
@return Floating-point representation of positive infinity.
|
|
*/
|
|
#if defined(TRIO_FUNC_PINF)
|
|
|
|
TRIO_PUBLIC_NAN double trio_pinf(TRIO_NOARGS)
|
|
{
|
|
/* Cache the result */
|
|
static double pinf_value = 0.0;
|
|
|
|
if (pinf_value == 0.0)
|
|
{
|
|
|
|
#if defined(TRIO_PINF_C99_MACRO)
|
|
|
|
pinf_value = (double)INFINITY;
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_PINF_IEEE_754)
|
|
|
|
pinf_value = internal_make_double(ieee_754_infinity_array);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_PINF_FALLBACK)
|
|
/*
|
|
* If HUGE_VAL is different from DBL_MAX, then HUGE_VAL is used
|
|
* as infinity. Otherwise we have to resort to an overflow
|
|
* operation to generate infinity.
|
|
*/
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
void (*signal_handler)(int) = signal(SIGFPE, SIG_IGN);
|
|
#endif
|
|
|
|
pinf_value = HUGE_VAL;
|
|
if (HUGE_VAL == DBL_MAX)
|
|
{
|
|
/* Force overflow */
|
|
pinf_value += HUGE_VAL;
|
|
}
|
|
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
signal(SIGFPE, signal_handler);
|
|
#endif
|
|
|
|
#endif
|
|
}
|
|
return pinf_value;
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
Generate negative infinity.
|
|
|
|
@return Floating-point value of negative infinity.
|
|
*/
|
|
#if defined(TRIO_FUNC_NINF)
|
|
|
|
TRIO_PUBLIC_NAN double trio_ninf(TRIO_NOARGS)
|
|
{
|
|
static double ninf_value = 0.0;
|
|
|
|
if (ninf_value == 0.0)
|
|
{
|
|
/*
|
|
* Negative infinity is calculated by negating positive infinity,
|
|
* which can be done because it is legal to do calculations on
|
|
* infinity (for example, 1 / infinity == 0).
|
|
*/
|
|
ninf_value = -trio_pinf();
|
|
}
|
|
return ninf_value;
|
|
}
|
|
|
|
#endif
|
|
|
|
/**
|
|
Generate NaN.
|
|
|
|
@return Floating-point representation of NaN.
|
|
*/
|
|
#if defined(TRIO_FUNC_NAN)
|
|
|
|
TRIO_PUBLIC_NAN double trio_nan(TRIO_NOARGS)
|
|
{
|
|
/* Cache the result */
|
|
static double nan_value = 0.0;
|
|
|
|
if (nan_value == 0.0)
|
|
{
|
|
|
|
#if defined(TRIO_NAN_C99_FUNCTION) || defined(TRIO_PLATFORM_SYMBIAN)
|
|
|
|
nan_value = nan("");
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_NAN_C99_MACRO)
|
|
|
|
nan_value = (double)NAN;
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_NAN_IEEE_754)
|
|
|
|
nan_value = internal_make_double(ieee_754_qnan_array);
|
|
|
|
#endif
|
|
|
|
#if defined(TRIO_NAN_FALLBACK)
|
|
/*
|
|
* There are several ways to generate NaN. The one used here is
|
|
* to divide infinity by infinity. I would have preferred to add
|
|
* negative infinity to positive infinity, but that yields wrong
|
|
* result (infinity) on FreeBSD.
|
|
*
|
|
* This may fail if the hardware does not support NaN, or if
|
|
* the Invalid Operation floating-point exception is unmasked.
|
|
*/
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
void (*signal_handler)(int) = signal(SIGFPE, SIG_IGN);
|
|
#endif
|
|
|
|
nan_value = trio_pinf() / trio_pinf();
|
|
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
signal(SIGFPE, signal_handler);
|
|
#endif
|
|
|
|
#endif
|
|
}
|
|
return nan_value;
|
|
}
|
|
|
|
#endif
|
|
|
|
/** @} SpecialQuantities */
|
|
|
|
/*************************************************************************
|
|
* For test purposes.
|
|
*
|
|
* Add the following compiler option to include this test code.
|
|
*
|
|
* Unix : -DSTANDALONE
|
|
* VMS : /DEFINE=(STANDALONE)
|
|
*/
|
|
#if defined(STANDALONE)
|
|
#include <stdio.h>
|
|
|
|
static TRIO_CONST char* getClassification TRIO_ARGS1((type), int type)
|
|
{
|
|
switch (type)
|
|
{
|
|
case TRIO_FP_INFINITE:
|
|
return "FP_INFINITE";
|
|
case TRIO_FP_NAN:
|
|
return "FP_NAN";
|
|
case TRIO_FP_NORMAL:
|
|
return "FP_NORMAL";
|
|
case TRIO_FP_SUBNORMAL:
|
|
return "FP_SUBNORMAL";
|
|
case TRIO_FP_ZERO:
|
|
return "FP_ZERO";
|
|
default:
|
|
return "FP_UNKNOWN";
|
|
}
|
|
}
|
|
|
|
static void print_class TRIO_ARGS2((prefix, number), TRIO_CONST char* prefix, double number)
|
|
{
|
|
printf("%-6s: %s %-15s %g\n", prefix, trio_signbit(number) ? "-" : "+",
|
|
getClassification(trio_fpclassify(number)), number);
|
|
}
|
|
|
|
int main(TRIO_NOARGS)
|
|
{
|
|
double my_nan;
|
|
double my_pinf;
|
|
double my_ninf;
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
void(*signal_handler) TRIO_PROTO((int));
|
|
#endif
|
|
|
|
my_nan = trio_nan();
|
|
my_pinf = trio_pinf();
|
|
my_ninf = trio_ninf();
|
|
|
|
print_class("Nan", my_nan);
|
|
print_class("PInf", my_pinf);
|
|
print_class("NInf", my_ninf);
|
|
print_class("PZero", 0.0);
|
|
print_class("NZero", -0.0);
|
|
print_class("PNorm", 1.0);
|
|
print_class("NNorm", -1.0);
|
|
print_class("PSub", 1.01e-307 - 1.00e-307);
|
|
print_class("NSub", 1.00e-307 - 1.01e-307);
|
|
|
|
printf("NaN : %4g 0x%02x%02x%02x%02x%02x%02x%02x%02x (%2d, %2d, %2d)\n", my_nan,
|
|
((unsigned char*)&my_nan)[0], ((unsigned char*)&my_nan)[1], ((unsigned char*)&my_nan)[2],
|
|
((unsigned char*)&my_nan)[3], ((unsigned char*)&my_nan)[4], ((unsigned char*)&my_nan)[5],
|
|
((unsigned char*)&my_nan)[6], ((unsigned char*)&my_nan)[7], trio_isnan(my_nan),
|
|
trio_isinf(my_nan), trio_isfinite(my_nan));
|
|
printf("PInf: %4g 0x%02x%02x%02x%02x%02x%02x%02x%02x (%2d, %2d, %2d)\n", my_pinf,
|
|
((unsigned char*)&my_pinf)[0], ((unsigned char*)&my_pinf)[1],
|
|
((unsigned char*)&my_pinf)[2], ((unsigned char*)&my_pinf)[3],
|
|
((unsigned char*)&my_pinf)[4], ((unsigned char*)&my_pinf)[5],
|
|
((unsigned char*)&my_pinf)[6], ((unsigned char*)&my_pinf)[7], trio_isnan(my_pinf),
|
|
trio_isinf(my_pinf), trio_isfinite(my_pinf));
|
|
printf("NInf: %4g 0x%02x%02x%02x%02x%02x%02x%02x%02x (%2d, %2d, %2d)\n", my_ninf,
|
|
((unsigned char*)&my_ninf)[0], ((unsigned char*)&my_ninf)[1],
|
|
((unsigned char*)&my_ninf)[2], ((unsigned char*)&my_ninf)[3],
|
|
((unsigned char*)&my_ninf)[4], ((unsigned char*)&my_ninf)[5],
|
|
((unsigned char*)&my_ninf)[6], ((unsigned char*)&my_ninf)[7], trio_isnan(my_ninf),
|
|
trio_isinf(my_ninf), trio_isfinite(my_ninf));
|
|
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
signal_handler = signal(SIGFPE, SIG_IGN);
|
|
#endif
|
|
|
|
my_pinf = DBL_MAX + DBL_MAX;
|
|
my_ninf = -my_pinf;
|
|
my_nan = my_pinf / my_pinf;
|
|
|
|
#if defined(TRIO_PLATFORM_UNIX)
|
|
signal(SIGFPE, signal_handler);
|
|
#endif
|
|
|
|
printf("NaN : %4g 0x%02x%02x%02x%02x%02x%02x%02x%02x (%2d, %2d, %2d)\n", my_nan,
|
|
((unsigned char*)&my_nan)[0], ((unsigned char*)&my_nan)[1], ((unsigned char*)&my_nan)[2],
|
|
((unsigned char*)&my_nan)[3], ((unsigned char*)&my_nan)[4], ((unsigned char*)&my_nan)[5],
|
|
((unsigned char*)&my_nan)[6], ((unsigned char*)&my_nan)[7], trio_isnan(my_nan),
|
|
trio_isinf(my_nan), trio_isfinite(my_nan));
|
|
printf("PInf: %4g 0x%02x%02x%02x%02x%02x%02x%02x%02x (%2d, %2d, %2d)\n", my_pinf,
|
|
((unsigned char*)&my_pinf)[0], ((unsigned char*)&my_pinf)[1],
|
|
((unsigned char*)&my_pinf)[2], ((unsigned char*)&my_pinf)[3],
|
|
((unsigned char*)&my_pinf)[4], ((unsigned char*)&my_pinf)[5],
|
|
((unsigned char*)&my_pinf)[6], ((unsigned char*)&my_pinf)[7], trio_isnan(my_pinf),
|
|
trio_isinf(my_pinf), trio_isfinite(my_pinf));
|
|
printf("NInf: %4g 0x%02x%02x%02x%02x%02x%02x%02x%02x (%2d, %2d, %2d)\n", my_ninf,
|
|
((unsigned char*)&my_ninf)[0], ((unsigned char*)&my_ninf)[1],
|
|
((unsigned char*)&my_ninf)[2], ((unsigned char*)&my_ninf)[3],
|
|
((unsigned char*)&my_ninf)[4], ((unsigned char*)&my_ninf)[5],
|
|
((unsigned char*)&my_ninf)[6], ((unsigned char*)&my_ninf)[7], trio_isnan(my_ninf),
|
|
trio_isinf(my_ninf), trio_isfinite(my_ninf));
|
|
|
|
return 0;
|
|
}
|
|
#endif
|