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