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