decContext.h revision 169696
1240116Smarcel/* Decimal Context module header for the decNumber C Library 2240116Smarcel Copyright (C) 2005, 2006 Free Software Foundation, Inc. 3240116Smarcel Contributed by IBM Corporation. Author Mike Cowlishaw. 4240116Smarcel 5240116Smarcel This file is part of GCC. 6240116Smarcel 7240116Smarcel GCC is free software; you can redistribute it and/or modify it under 8240116Smarcel the terms of the GNU General Public License as published by the Free 9240116Smarcel Software Foundation; either version 2, or (at your option) any later 10240116Smarcel version. 11240116Smarcel 12240116Smarcel In addition to the permissions in the GNU General Public License, 13240116Smarcel the Free Software Foundation gives you unlimited permission to link 14240116Smarcel the compiled version of this file into combinations with other 15240116Smarcel programs, and to distribute those combinations without any 16240116Smarcel restriction coming from the use of this file. (The General Public 17240116Smarcel License restrictions do apply in other respects; for example, they 18240116Smarcel cover modification of the file, and distribution when not linked 19240116Smarcel into a combine executable.) 20240116Smarcel 21240116Smarcel GCC is distributed in the hope that it will be useful, but WITHOUT ANY 22240116Smarcel WARRANTY; without even the implied warranty of MERCHANTABILITY or 23240116Smarcel FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 24240116Smarcel for more details. 25240116Smarcel 26240116Smarcel You should have received a copy of the GNU General Public License 27240116Smarcel along with GCC; see the file COPYING. If not, write to the Free 28240116Smarcel Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 29240116Smarcel 02110-1301, USA. */ 30240116Smarcel 31240116Smarcel/* ------------------------------------------------------------------ */ 32240116Smarcel/* */ 33240116Smarcel/* Context must always be set correctly: */ 34240116Smarcel/* */ 35240116Smarcel/* digits -- must be in the range 1 through 999999999 */ 36240116Smarcel/* emax -- must be in the range 0 through 999999999 */ 37240116Smarcel/* emin -- must be in the range 0 through -999999999 */ 38240116Smarcel/* round -- must be one of the enumerated rounding modes */ 39240116Smarcel/* traps -- only defined bits may be set */ 40240116Smarcel/* status -- [any bits may be cleared, but not set, by user] */ 41240116Smarcel/* clamp -- must be either 0 or 1 */ 42240116Smarcel/* extended -- must be either 0 or 1 [present only if DECSUBSET] */ 43240116Smarcel/* */ 44240116Smarcel/* ------------------------------------------------------------------ */ 45240116Smarcel 46240116Smarcel#if !defined(DECCONTEXT) 47240116Smarcel#define DECCONTEXT 48240116Smarcel#define DECCNAME "decContext" /* Short name */ 49240116Smarcel#define DECCFULLNAME "Decimal Context Descriptor" /* Verbose name */ 50240116Smarcel#define DECCAUTHOR "Mike Cowlishaw" /* Who to blame */ 51240116Smarcel 52240116Smarcel#include "gstdint.h" /* C99 standard integers */ 53240116Smarcel#include <signal.h> /* for traps */ 54240116Smarcel 55240116Smarcel 56240116Smarcel /* Conditional code flag -- set this to 0 for best performance */ 57240116Smarcel#define DECSUBSET 0 /* 1 to enable subset arithmetic */ 58240116Smarcel 59240116Smarcel /* Context for operations, with associated constants */ 60240116Smarcelenum rounding 61240116Smarcel{ 62240116Smarcel DEC_ROUND_CEILING, /* round towards +infinity */ 63240116Smarcel DEC_ROUND_UP, /* round away from 0 */ 64240116Smarcel DEC_ROUND_HALF_UP, /* 0.5 rounds up */ 65240116Smarcel DEC_ROUND_HALF_EVEN, /* 0.5 rounds to nearest even */ 66240116Smarcel DEC_ROUND_HALF_DOWN, /* 0.5 rounds down */ 67240116Smarcel DEC_ROUND_DOWN, /* round towards 0 (truncate) */ 68240116Smarcel DEC_ROUND_FLOOR, /* round towards -infinity */ 69240116Smarcel DEC_ROUND_MAX /* enum must be less than this */ 70240116Smarcel}; 71240116Smarcel 72240116Smarceltypedef struct 73240116Smarcel{ 74240116Smarcel int32_t digits; /* working precision */ 75240116Smarcel int32_t emax; /* maximum positive exponent */ 76240116Smarcel int32_t emin; /* minimum negative exponent */ 77240116Smarcel enum rounding round; /* rounding mode */ 78240116Smarcel uint32_t traps; /* trap-enabler flags */ 79240116Smarcel uint32_t status; /* status flags */ 80240116Smarcel uint8_t clamp; /* flag: apply IEEE exponent clamp */ 81240116Smarcel#if DECSUBSET 82240116Smarcel uint8_t extended; /* flag: special-values allowed */ 83240116Smarcel#endif 84240116Smarcel} decContext; 85240116Smarcel 86240116Smarcel /* Maxima and Minima */ 87240116Smarcel#define DEC_MAX_DIGITS 999999999 88240116Smarcel#define DEC_MIN_DIGITS 1 89240116Smarcel#define DEC_MAX_EMAX 999999999 90240116Smarcel#define DEC_MIN_EMAX 0 91240116Smarcel#define DEC_MAX_EMIN 0 92240116Smarcel#define DEC_MIN_EMIN -999999999 93240116Smarcel 94240116Smarcel /* Trap-enabler and Status flags (exceptional conditions), and their names */ 95240116Smarcel /* Top byte is reserved for internal use */ 96240116Smarcel#define DEC_Conversion_syntax 0x00000001 97240116Smarcel#define DEC_Division_by_zero 0x00000002 98240116Smarcel#define DEC_Division_impossible 0x00000004 99240116Smarcel#define DEC_Division_undefined 0x00000008 100240116Smarcel#define DEC_Insufficient_storage 0x00000010 /* [used if malloc fails] */ 101240116Smarcel#define DEC_Inexact 0x00000020 102240116Smarcel#define DEC_Invalid_context 0x00000040 103240116Smarcel#define DEC_Invalid_operation 0x00000080 104240116Smarcel#if DECSUBSET 105240116Smarcel#define DEC_Lost_digits 0x00000100 106240116Smarcel#endif 107240116Smarcel#define DEC_Overflow 0x00000200 108240116Smarcel#define DEC_Clamped 0x00000400 109240116Smarcel#define DEC_Rounded 0x00000800 110240116Smarcel#define DEC_Subnormal 0x00001000 111240116Smarcel#define DEC_Underflow 0x00002000 112240116Smarcel 113240116Smarcel /* IEEE 854 groupings for the flags */ 114240116Smarcel /* [DEC_Clamped, DEC_Lost_digits, DEC_Rounded, and DEC_Subnormal are */ 115240116Smarcel /* not in IEEE 854] */ 116240116Smarcel#define DEC_IEEE_854_Division_by_zero (DEC_Division_by_zero) 117240116Smarcel#if DECSUBSET 118240116Smarcel#define DEC_IEEE_854_Inexact (DEC_Inexact | DEC_Lost_digits) 119240116Smarcel#else 120#define DEC_IEEE_854_Inexact (DEC_Inexact) 121#endif 122#define DEC_IEEE_854_Invalid_operation (DEC_Conversion_syntax | \ 123 DEC_Division_impossible | \ 124 DEC_Division_undefined | \ 125 DEC_Insufficient_storage | \ 126 DEC_Invalid_context | \ 127 DEC_Invalid_operation) 128#define DEC_IEEE_854_Overflow (DEC_Overflow) 129#define DEC_IEEE_854_Underflow (DEC_Underflow) 130 131 /* flags which are normally errors (results are qNaN, infinite, or 0) */ 132#define DEC_Errors (DEC_IEEE_854_Division_by_zero | \ 133 DEC_IEEE_854_Invalid_operation | \ 134 DEC_IEEE_854_Overflow | DEC_IEEE_854_Underflow) 135 /* flags which cause a result to become qNaN */ 136#define DEC_NaNs DEC_IEEE_854_Invalid_operation 137 138 /* flags which are normally for information only (have finite results) */ 139#if DECSUBSET 140#define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact \ 141 | DEC_Lost_digits) 142#else 143#define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact) 144#endif 145 146 /* name strings for the exceptional conditions */ 147 148#define DEC_Condition_CS "Conversion syntax" 149#define DEC_Condition_DZ "Division by zero" 150#define DEC_Condition_DI "Division impossible" 151#define DEC_Condition_DU "Division undefined" 152#define DEC_Condition_IE "Inexact" 153#define DEC_Condition_IS "Insufficient storage" 154#define DEC_Condition_IC "Invalid context" 155#define DEC_Condition_IO "Invalid operation" 156#if DECSUBSET 157#define DEC_Condition_LD "Lost digits" 158#endif 159#define DEC_Condition_OV "Overflow" 160#define DEC_Condition_PA "Clamped" 161#define DEC_Condition_RO "Rounded" 162#define DEC_Condition_SU "Subnormal" 163#define DEC_Condition_UN "Underflow" 164#define DEC_Condition_ZE "No status" 165#define DEC_Condition_MU "Multiple status" 166#define DEC_Condition_Length 21 /* length of the longest string, */ 167 /* including terminator */ 168 169 /* Initialization descriptors, used by decContextDefault */ 170#define DEC_INIT_BASE 0 171#define DEC_INIT_DECIMAL32 32 172#define DEC_INIT_DECIMAL64 64 173#define DEC_INIT_DECIMAL128 128 174 175 /* decContext routines */ 176#ifdef IN_LIBGCC2 177#define decContextDefault __decContextDefault 178#define decContextSetStatus __decContextSetStatus 179#define decContextStatusToString __decContextStatusToString 180#define decContextSetStatusFromString __decContextSetStatusFromString 181#endif 182decContext *decContextDefault (decContext *, int32_t); 183decContext *decContextSetStatus (decContext *, uint32_t); 184const char *decContextStatusToString (const decContext *); 185decContext *decContextSetStatusFromString (decContext *, const char *); 186 187#endif 188