1 /* ------------------------------------------------------------------ */ 2 /* Decimal Context module header */ 3 /* ------------------------------------------------------------------ */ 4 /* Copyright (c) IBM Corporation, 2000-2010. All rights reserved. */ 5 /* */ 6 /* This software is made available under the terms of the */ 7 /* ICU License -- ICU 1.8.1 and later. */ 8 /* */ 9 /* The description and User's Guide ("The decNumber C Library") for */ 10 /* this software is called decNumber.pdf. This document is */ 11 /* available, together with arithmetic and format specifications, */ 12 /* testcases, and Web links, on the General Decimal Arithmetic page. */ 13 /* */ 14 /* Please send comments, suggestions, and corrections to the author: */ 15 /* mfc@uk.ibm.com */ 16 /* Mike Cowlishaw, IBM Fellow */ 17 /* IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK */ 18 /* ------------------------------------------------------------------ */ 19 20 /* Modified version, for use from within ICU. 21 * Renamed public functions, to avoid an unwanted export of the 22 * standard names from the ICU library. 23 * 24 * Use ICU's uprv_malloc() and uprv_free() 25 * 26 * Revert comment syntax to plain C 27 * 28 * Remove a few compiler warnings. 29 */ 30 #include "unicode/utypes.h" 31 32 /* */ 33 /* Context variables must always have valid values: */ 34 /* */ 35 /* status -- [any bits may be cleared, but not set, by user] */ 36 /* round -- must be one of the enumerated rounding modes */ 37 /* */ 38 /* The following variables are implied for fixed size formats (i.e., */ 39 /* they are ignored) but should still be set correctly in case used */ 40 /* with decNumber functions: */ 41 /* */ 42 /* clamp -- must be either 0 or 1 */ 43 /* digits -- must be in the range 1 through 999999999 */ 44 /* emax -- must be in the range 0 through 999999999 */ 45 /* emin -- must be in the range 0 through -999999999 */ 46 /* extended -- must be either 0 or 1 [present only if DECSUBSET] */ 47 /* traps -- only defined bits may be set */ 48 /* */ 49 /* ------------------------------------------------------------------ */ 50 51 #if !defined(DECCONTEXT) 52 #define DECCONTEXT 53 #define DECCNAME "decContext" /* Short name */ 54 #define DECCFULLNAME "Decimal Context Descriptor" /* Verbose name */ 55 #define DECCAUTHOR "Mike Cowlishaw" /* Who to blame */ 56 57 #if !defined(int32_t) 58 /* #include <stdint.h> */ /* C99 standard integers */ 59 #endif 60 #include <stdio.h> /* for printf, etc. */ 61 #include <signal.h> /* for traps */ 62 63 /* Extended flags setting -- set this to 0 to use only IEEE flags */ 64 #if !defined(DECEXTFLAG) 65 #define DECEXTFLAG 1 /* 1=enable extended flags */ 66 #endif 67 68 /* Conditional code flag -- set this to 0 for best performance */ 69 #if !defined(DECSUBSET) 70 #define DECSUBSET 0 /* 1=enable subset arithmetic */ 71 #endif 72 73 /* Context for operations, with associated constants */ 74 enum rounding { 75 DEC_ROUND_CEILING, /* round towards +infinity */ 76 DEC_ROUND_UP, /* round away from 0 */ 77 DEC_ROUND_HALF_UP, /* 0.5 rounds up */ 78 DEC_ROUND_HALF_EVEN, /* 0.5 rounds to nearest even */ 79 DEC_ROUND_HALF_DOWN, /* 0.5 rounds down */ 80 DEC_ROUND_DOWN, /* round towards 0 (truncate) */ 81 DEC_ROUND_FLOOR, /* round towards -infinity */ 82 DEC_ROUND_05UP, /* round for reround */ 83 DEC_ROUND_MAX /* enum must be less than this */ 84 }; 85 #define DEC_ROUND_DEFAULT DEC_ROUND_HALF_EVEN; 86 87 typedef struct { 88 int32_t digits; /* working precision */ 89 int32_t emax; /* maximum positive exponent */ 90 int32_t emin; /* minimum negative exponent */ 91 enum rounding round; /* rounding mode */ 92 uint32_t traps; /* trap-enabler flags */ 93 uint32_t status; /* status flags */ 94 uint8_t clamp; /* flag: apply IEEE exponent clamp */ 95 #if DECSUBSET 96 uint8_t extended; /* flag: special-values allowed */ 97 #endif 98 } decContext; 99 100 /* Maxima and Minima for context settings */ 101 #define DEC_MAX_DIGITS 999999999 102 #define DEC_MIN_DIGITS 1 103 #define DEC_MAX_EMAX 999999999 104 #define DEC_MIN_EMAX 0 105 #define DEC_MAX_EMIN 0 106 #define DEC_MIN_EMIN -999999999 107 #define DEC_MAX_MATH 999999 /* max emax, etc., for math funcs. */ 108 109 /* Classifications for decimal numbers, aligned with 754 (note that */ 110 /* 'normal' and 'subnormal' are meaningful only with a decContext */ 111 /* or a fixed size format). */ 112 enum decClass { 113 DEC_CLASS_SNAN, 114 DEC_CLASS_QNAN, 115 DEC_CLASS_NEG_INF, 116 DEC_CLASS_NEG_NORMAL, 117 DEC_CLASS_NEG_SUBNORMAL, 118 DEC_CLASS_NEG_ZERO, 119 DEC_CLASS_POS_ZERO, 120 DEC_CLASS_POS_SUBNORMAL, 121 DEC_CLASS_POS_NORMAL, 122 DEC_CLASS_POS_INF 123 }; 124 /* Strings for the decClasses */ 125 #define DEC_ClassString_SN "sNaN" 126 #define DEC_ClassString_QN "NaN" 127 #define DEC_ClassString_NI "-Infinity" 128 #define DEC_ClassString_NN "-Normal" 129 #define DEC_ClassString_NS "-Subnormal" 130 #define DEC_ClassString_NZ "-Zero" 131 #define DEC_ClassString_PZ "+Zero" 132 #define DEC_ClassString_PS "+Subnormal" 133 #define DEC_ClassString_PN "+Normal" 134 #define DEC_ClassString_PI "+Infinity" 135 #define DEC_ClassString_UN "Invalid" 136 137 /* Trap-enabler and Status flags (exceptional conditions), and */ 138 /* their names. The top byte is reserved for internal use */ 139 #if DECEXTFLAG 140 /* Extended flags */ 141 #define DEC_Conversion_syntax 0x00000001 142 #define DEC_Division_by_zero 0x00000002 143 #define DEC_Division_impossible 0x00000004 144 #define DEC_Division_undefined 0x00000008 145 #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails] */ 146 #define DEC_Inexact 0x00000020 147 #define DEC_Invalid_context 0x00000040 148 #define DEC_Invalid_operation 0x00000080 149 #if DECSUBSET 150 #define DEC_Lost_digits 0x00000100 151 #endif 152 #define DEC_Overflow 0x00000200 153 #define DEC_Clamped 0x00000400 154 #define DEC_Rounded 0x00000800 155 #define DEC_Subnormal 0x00001000 156 #define DEC_Underflow 0x00002000 157 #else 158 /* IEEE flags only */ 159 #define DEC_Conversion_syntax 0x00000010 160 #define DEC_Division_by_zero 0x00000002 161 #define DEC_Division_impossible 0x00000010 162 #define DEC_Division_undefined 0x00000010 163 #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails] */ 164 #define DEC_Inexact 0x00000001 165 #define DEC_Invalid_context 0x00000010 166 #define DEC_Invalid_operation 0x00000010 167 #if DECSUBSET 168 #define DEC_Lost_digits 0x00000000 169 #endif 170 #define DEC_Overflow 0x00000008 171 #define DEC_Clamped 0x00000000 172 #define DEC_Rounded 0x00000000 173 #define DEC_Subnormal 0x00000000 174 #define DEC_Underflow 0x00000004 175 #endif 176 177 /* IEEE 754 groupings for the flags */ 178 /* [DEC_Clamped, DEC_Lost_digits, DEC_Rounded, and DEC_Subnormal */ 179 /* are not in IEEE 754] */ 180 #define DEC_IEEE_754_Division_by_zero (DEC_Division_by_zero) 181 #if DECSUBSET 182 #define DEC_IEEE_754_Inexact (DEC_Inexact | DEC_Lost_digits) 183 #else 184 #define DEC_IEEE_754_Inexact (DEC_Inexact) 185 #endif 186 #define DEC_IEEE_754_Invalid_operation (DEC_Conversion_syntax | \ 187 DEC_Division_impossible | \ 188 DEC_Division_undefined | \ 189 DEC_Insufficient_storage | \ 190 DEC_Invalid_context | \ 191 DEC_Invalid_operation) 192 #define DEC_IEEE_754_Overflow (DEC_Overflow) 193 #define DEC_IEEE_754_Underflow (DEC_Underflow) 194 195 /* flags which are normally errors (result is qNaN, infinite, or 0) */ 196 #define DEC_Errors (DEC_IEEE_754_Division_by_zero | \ 197 DEC_IEEE_754_Invalid_operation | \ 198 DEC_IEEE_754_Overflow | DEC_IEEE_754_Underflow) 199 /* flags which cause a result to become qNaN */ 200 #define DEC_NaNs DEC_IEEE_754_Invalid_operation 201 202 /* flags which are normally for information only (finite results) */ 203 #if DECSUBSET 204 #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact \ 205 | DEC_Lost_digits) 206 #else 207 #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact) 208 #endif 209 210 /* IEEE 854 names (for compatibility with older decNumber versions) */ 211 #define DEC_IEEE_854_Division_by_zero DEC_IEEE_754_Division_by_zero 212 #define DEC_IEEE_854_Inexact DEC_IEEE_754_Inexact 213 #define DEC_IEEE_854_Invalid_operation DEC_IEEE_754_Invalid_operation 214 #define DEC_IEEE_854_Overflow DEC_IEEE_754_Overflow 215 #define DEC_IEEE_854_Underflow DEC_IEEE_754_Underflow 216 217 /* Name strings for the exceptional conditions */ 218 #define DEC_Condition_CS "Conversion syntax" 219 #define DEC_Condition_DZ "Division by zero" 220 #define DEC_Condition_DI "Division impossible" 221 #define DEC_Condition_DU "Division undefined" 222 #define DEC_Condition_IE "Inexact" 223 #define DEC_Condition_IS "Insufficient storage" 224 #define DEC_Condition_IC "Invalid context" 225 #define DEC_Condition_IO "Invalid operation" 226 #if DECSUBSET 227 #define DEC_Condition_LD "Lost digits" 228 #endif 229 #define DEC_Condition_OV "Overflow" 230 #define DEC_Condition_PA "Clamped" 231 #define DEC_Condition_RO "Rounded" 232 #define DEC_Condition_SU "Subnormal" 233 #define DEC_Condition_UN "Underflow" 234 #define DEC_Condition_ZE "No status" 235 #define DEC_Condition_MU "Multiple status" 236 #define DEC_Condition_Length 21 /* length of the longest string, */ 237 /* including terminator */ 238 239 /* Initialization descriptors, used by decContextDefault */ 240 #define DEC_INIT_BASE 0 241 #define DEC_INIT_DECIMAL32 32 242 #define DEC_INIT_DECIMAL64 64 243 #define DEC_INIT_DECIMAL128 128 244 /* Synonyms */ 245 #define DEC_INIT_DECSINGLE DEC_INIT_DECIMAL32 246 #define DEC_INIT_DECDOUBLE DEC_INIT_DECIMAL64 247 #define DEC_INIT_DECQUAD DEC_INIT_DECIMAL128 248 249 /* decContext routines */ 250 U_INTERNAL decContext * U_EXPORT2 uprv_decContextClearStatus(decContext *, uint32_t); 251 U_INTERNAL decContext * U_EXPORT2 uprv_decContextDefault(decContext *, int32_t); 252 U_INTERNAL enum rounding U_EXPORT2 uprv_decContextGetRounding(decContext *); 253 U_INTERNAL uint32_t U_EXPORT2 uprv_decContextGetStatus(decContext *); 254 U_INTERNAL decContext * U_EXPORT2 uprv_decContextRestoreStatus(decContext *, uint32_t, uint32_t); 255 U_INTERNAL uint32_t U_EXPORT2 uprv_decContextSaveStatus(decContext *, uint32_t); 256 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetRounding(decContext *, enum rounding); 257 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetStatus(decContext *, uint32_t); 258 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetStatusFromString(decContext *, const char *); 259 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetStatusFromStringQuiet(decContext *, const char *); 260 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetStatusQuiet(decContext *, uint32_t); 261 U_INTERNAL const char * U_EXPORT2 uprv_decContextStatusToString(const decContext *); 262 U_INTERNAL int32_t U_EXPORT2 uprv_decContextTestEndian(uint8_t); 263 U_INTERNAL uint32_t U_EXPORT2 uprv_decContextTestSavedStatus(uint32_t, uint32_t); 264 U_INTERNAL uint32_t U_EXPORT2 uprv_decContextTestStatus(decContext *, uint32_t); 265 U_INTERNAL decContext * U_EXPORT2 uprv_decContextZeroStatus(decContext *); 266 267 #endif 268