1 // © 2016 and later: Unicode, Inc. and others. 2 // License & terms of use: http://www.unicode.org/copyright.html 3 /* ------------------------------------------------------------------ */ 4 /* Decimal Context module header */ 5 /* ------------------------------------------------------------------ */ 6 /* Copyright (c) IBM Corporation, 2000-2011. All rights reserved. */ 7 /* */ 8 /* This software is made available under the terms of the */ 9 /* ICU License -- ICU 1.8.1 and later. */ 10 /* */ 11 /* The description and User's Guide ("The decNumber C Library") for */ 12 /* this software is called decNumber.pdf. This document is */ 13 /* available, together with arithmetic and format specifications, */ 14 /* testcases, and Web links, on the General Decimal Arithmetic page. */ 15 /* */ 16 /* Please send comments, suggestions, and corrections to the author: */ 17 /* mfc@uk.ibm.com */ 18 /* Mike Cowlishaw, IBM Fellow */ 19 /* IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK */ 20 /* ------------------------------------------------------------------ */ 21 22 /* Modified version, for use from within ICU. 23 * Renamed public functions, to avoid an unwanted export of the 24 * standard names from the ICU library. 25 * 26 * Use ICU's uprv_malloc() and uprv_free() 27 * 28 * Revert comment syntax to plain C 29 * 30 * Remove a few compiler warnings. 31 */ 32 #include "unicode/utypes.h" 33 #include "putilimp.h" 34 35 /* */ 36 /* Context variables must always have valid values: */ 37 /* */ 38 /* status -- [any bits may be cleared, but not set, by user] */ 39 /* round -- must be one of the enumerated rounding modes */ 40 /* */ 41 /* The following variables are implied for fixed size formats (i.e., */ 42 /* they are ignored) but should still be set correctly in case used */ 43 /* with decNumber functions: */ 44 /* */ 45 /* clamp -- must be either 0 or 1 */ 46 /* digits -- must be in the range 1 through 999999999 */ 47 /* emax -- must be in the range 0 through 999999999 */ 48 /* emin -- must be in the range 0 through -999999999 */ 49 /* extended -- must be either 0 or 1 [present only if DECSUBSET] */ 50 /* traps -- only defined bits may be set */ 51 /* */ 52 /* ------------------------------------------------------------------ */ 53 54 #if !defined(DECCONTEXT) 55 #define DECCONTEXT 56 #define DECCNAME "decContext" /* Short name */ 57 #define DECCFULLNAME "Decimal Context Descriptor" /* Verbose name */ 58 #define DECCAUTHOR "Mike Cowlishaw" /* Who to blame */ 59 60 #if !defined(int32_t) 61 /* #include <stdint.h> */ /* C99 standard integers */ 62 #endif 63 #include <stdio.h> /* for printf, etc. */ 64 #include <signal.h> /* for traps */ 65 66 /* Extended flags setting -- set this to 0 to use only IEEE flags */ 67 #if !defined(DECEXTFLAG) 68 #define DECEXTFLAG 1 /* 1=enable extended flags */ 69 #endif 70 71 /* Conditional code flag -- set this to 0 for best performance */ 72 #if !defined(DECSUBSET) 73 #define DECSUBSET 0 /* 1=enable subset arithmetic */ 74 #endif 75 76 /* Context for operations, with associated constants */ 77 enum rounding { 78 DEC_ROUND_CEILING, /* round towards +infinity */ 79 DEC_ROUND_UP, /* round away from 0 */ 80 DEC_ROUND_HALF_UP, /* 0.5 rounds up */ 81 DEC_ROUND_HALF_EVEN, /* 0.5 rounds to nearest even */ 82 DEC_ROUND_HALF_DOWN, /* 0.5 rounds down */ 83 DEC_ROUND_DOWN, /* round towards 0 (truncate) */ 84 DEC_ROUND_FLOOR, /* round towards -infinity */ 85 DEC_ROUND_05UP, /* round for reround */ 86 DEC_ROUND_MAX /* enum must be less than this */ 87 }; 88 #define DEC_ROUND_DEFAULT DEC_ROUND_HALF_EVEN; 89 90 typedef struct { 91 int32_t digits; /* working precision */ 92 int32_t emax; /* maximum positive exponent */ 93 int32_t emin; /* minimum negative exponent */ 94 enum rounding round; /* rounding mode */ 95 uint32_t traps; /* trap-enabler flags */ 96 uint32_t status; /* status flags */ 97 uint8_t clamp; /* flag: apply IEEE exponent clamp */ 98 #if DECSUBSET 99 uint8_t extended; /* flag: special-values allowed */ 100 #endif 101 } decContext; 102 103 /* Maxima and Minima for context settings */ 104 #define DEC_MAX_DIGITS 999999999 105 #define DEC_MIN_DIGITS 1 106 #define DEC_MAX_EMAX 999999999 107 #define DEC_MIN_EMAX 0 108 #define DEC_MAX_EMIN 0 109 #define DEC_MIN_EMIN -999999999 110 #define DEC_MAX_MATH 999999 /* max emax, etc., for math funcs. */ 111 112 /* Classifications for decimal numbers, aligned with 754 (note that */ 113 /* 'normal' and 'subnormal' are meaningful only with a decContext */ 114 /* or a fixed size format). */ 115 enum decClass { 116 DEC_CLASS_SNAN, 117 DEC_CLASS_QNAN, 118 DEC_CLASS_NEG_INF, 119 DEC_CLASS_NEG_NORMAL, 120 DEC_CLASS_NEG_SUBNORMAL, 121 DEC_CLASS_NEG_ZERO, 122 DEC_CLASS_POS_ZERO, 123 DEC_CLASS_POS_SUBNORMAL, 124 DEC_CLASS_POS_NORMAL, 125 DEC_CLASS_POS_INF 126 }; 127 /* Strings for the decClasses */ 128 #define DEC_ClassString_SN "sNaN" 129 #define DEC_ClassString_QN "NaN" 130 #define DEC_ClassString_NI "-Infinity" 131 #define DEC_ClassString_NN "-Normal" 132 #define DEC_ClassString_NS "-Subnormal" 133 #define DEC_ClassString_NZ "-Zero" 134 #define DEC_ClassString_PZ "+Zero" 135 #define DEC_ClassString_PS "+Subnormal" 136 #define DEC_ClassString_PN "+Normal" 137 #define DEC_ClassString_PI "+Infinity" 138 #define DEC_ClassString_UN "Invalid" 139 140 /* Trap-enabler and Status flags (exceptional conditions), and */ 141 /* their names. The top byte is reserved for internal use */ 142 #if DECEXTFLAG 143 /* Extended flags */ 144 #define DEC_Conversion_syntax 0x00000001 145 #define DEC_Division_by_zero 0x00000002 146 #define DEC_Division_impossible 0x00000004 147 #define DEC_Division_undefined 0x00000008 148 #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails] */ 149 #define DEC_Inexact 0x00000020 150 #define DEC_Invalid_context 0x00000040 151 #define DEC_Invalid_operation 0x00000080 152 #if DECSUBSET 153 #define DEC_Lost_digits 0x00000100 154 #endif 155 #define DEC_Overflow 0x00000200 156 #define DEC_Clamped 0x00000400 157 #define DEC_Rounded 0x00000800 158 #define DEC_Subnormal 0x00001000 159 #define DEC_Underflow 0x00002000 160 #else 161 /* IEEE flags only */ 162 #define DEC_Conversion_syntax 0x00000010 163 #define DEC_Division_by_zero 0x00000002 164 #define DEC_Division_impossible 0x00000010 165 #define DEC_Division_undefined 0x00000010 166 #define DEC_Insufficient_storage 0x00000010 /* [when malloc fails] */ 167 #define DEC_Inexact 0x00000001 168 #define DEC_Invalid_context 0x00000010 169 #define DEC_Invalid_operation 0x00000010 170 #if DECSUBSET 171 #define DEC_Lost_digits 0x00000000 172 #endif 173 #define DEC_Overflow 0x00000008 174 #define DEC_Clamped 0x00000000 175 #define DEC_Rounded 0x00000000 176 #define DEC_Subnormal 0x00000000 177 #define DEC_Underflow 0x00000004 178 #endif 179 180 /* IEEE 754 groupings for the flags */ 181 /* [DEC_Clamped, DEC_Lost_digits, DEC_Rounded, and DEC_Subnormal */ 182 /* are not in IEEE 754] */ 183 #define DEC_IEEE_754_Division_by_zero (DEC_Division_by_zero) 184 #if DECSUBSET 185 #define DEC_IEEE_754_Inexact (DEC_Inexact | DEC_Lost_digits) 186 #else 187 #define DEC_IEEE_754_Inexact (DEC_Inexact) 188 #endif 189 #define DEC_IEEE_754_Invalid_operation (DEC_Conversion_syntax | \ 190 DEC_Division_impossible | \ 191 DEC_Division_undefined | \ 192 DEC_Insufficient_storage | \ 193 DEC_Invalid_context | \ 194 DEC_Invalid_operation) 195 #define DEC_IEEE_754_Overflow (DEC_Overflow) 196 #define DEC_IEEE_754_Underflow (DEC_Underflow) 197 198 /* flags which are normally errors (result is qNaN, infinite, or 0) */ 199 #define DEC_Errors (DEC_IEEE_754_Division_by_zero | \ 200 DEC_IEEE_754_Invalid_operation | \ 201 DEC_IEEE_754_Overflow | DEC_IEEE_754_Underflow) 202 /* flags which cause a result to become qNaN */ 203 #define DEC_NaNs DEC_IEEE_754_Invalid_operation 204 205 /* flags which are normally for information only (finite results) */ 206 #if DECSUBSET 207 #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact \ 208 | DEC_Lost_digits) 209 #else 210 #define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact) 211 #endif 212 213 /* IEEE 854 names (for compatibility with older decNumber versions) */ 214 #define DEC_IEEE_854_Division_by_zero DEC_IEEE_754_Division_by_zero 215 #define DEC_IEEE_854_Inexact DEC_IEEE_754_Inexact 216 #define DEC_IEEE_854_Invalid_operation DEC_IEEE_754_Invalid_operation 217 #define DEC_IEEE_854_Overflow DEC_IEEE_754_Overflow 218 #define DEC_IEEE_854_Underflow DEC_IEEE_754_Underflow 219 220 /* Name strings for the exceptional conditions */ 221 #define DEC_Condition_CS "Conversion syntax" 222 #define DEC_Condition_DZ "Division by zero" 223 #define DEC_Condition_DI "Division impossible" 224 #define DEC_Condition_DU "Division undefined" 225 #define DEC_Condition_IE "Inexact" 226 #define DEC_Condition_IS "Insufficient storage" 227 #define DEC_Condition_IC "Invalid context" 228 #define DEC_Condition_IO "Invalid operation" 229 #if DECSUBSET 230 #define DEC_Condition_LD "Lost digits" 231 #endif 232 #define DEC_Condition_OV "Overflow" 233 #define DEC_Condition_PA "Clamped" 234 #define DEC_Condition_RO "Rounded" 235 #define DEC_Condition_SU "Subnormal" 236 #define DEC_Condition_UN "Underflow" 237 #define DEC_Condition_ZE "No status" 238 #define DEC_Condition_MU "Multiple status" 239 #define DEC_Condition_Length 21 /* length of the longest string, */ 240 /* including terminator */ 241 242 /* Initialization descriptors, used by decContextDefault */ 243 #define DEC_INIT_BASE 0 244 #define DEC_INIT_DECIMAL32 32 245 #define DEC_INIT_DECIMAL64 64 246 #define DEC_INIT_DECIMAL128 128 247 /* Synonyms */ 248 #define DEC_INIT_DECSINGLE DEC_INIT_DECIMAL32 249 #define DEC_INIT_DECDOUBLE DEC_INIT_DECIMAL64 250 #define DEC_INIT_DECQUAD DEC_INIT_DECIMAL128 251 252 /* decContext routines */ 253 U_INTERNAL decContext * U_EXPORT2 uprv_decContextClearStatus(decContext *, uint32_t); 254 U_INTERNAL decContext * U_EXPORT2 uprv_decContextDefault(decContext *, int32_t); 255 U_INTERNAL enum rounding U_EXPORT2 uprv_decContextGetRounding(decContext *); 256 U_INTERNAL uint32_t U_EXPORT2 uprv_decContextGetStatus(decContext *); 257 U_INTERNAL decContext * U_EXPORT2 uprv_decContextRestoreStatus(decContext *, uint32_t, uint32_t); 258 U_INTERNAL uint32_t U_EXPORT2 uprv_decContextSaveStatus(decContext *, uint32_t); 259 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetRounding(decContext *, enum rounding); 260 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetStatus(decContext *, uint32_t); 261 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetStatusFromString(decContext *, const char *); 262 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetStatusFromStringQuiet(decContext *, const char *); 263 U_INTERNAL decContext * U_EXPORT2 uprv_decContextSetStatusQuiet(decContext *, uint32_t); 264 U_INTERNAL const char * U_EXPORT2 uprv_decContextStatusToString(const decContext *); 265 U_INTERNAL int32_t U_EXPORT2 uprv_decContextTestEndian(uint8_t); 266 U_INTERNAL uint32_t U_EXPORT2 uprv_decContextTestSavedStatus(uint32_t, uint32_t); 267 U_INTERNAL uint32_t U_EXPORT2 uprv_decContextTestStatus(decContext *, uint32_t); 268 U_INTERNAL decContext * U_EXPORT2 uprv_decContextZeroStatus(decContext *); 269 270 #endif 271