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decContext.h
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decContext.h
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/* ------------------------------------------------------------------ */
/* Decimal Context module header */
/* ------------------------------------------------------------------ */
/* Copyright (c) IBM Corporation, 2000, 2010. All rights reserved. */
/* */
/* This software is made available under the terms of the */
/* ICU License -- ICU 1.8.1 and later. */
/* */
/* The description and User's Guide ("The decNumber C Library") for */
/* this software is called decNumber.pdf. This document is */
/* available, together with arithmetic and format specifications, */
/* testcases, and Web links, on the General Decimal Arithmetic page. */
/* */
/* Please send comments, suggestions, and corrections to the author: */
/* [email protected] */
/* Mike Cowlishaw, IBM Fellow */
/* IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK */
/* ------------------------------------------------------------------ */
/* */
/* Context variables must always have valid values: */
/* */
/* status -- [any bits may be cleared, but not set, by user] */
/* round -- must be one of the enumerated rounding modes */
/* */
/* The following variables are implied for fixed size formats (i.e., */
/* they are ignored) but should still be set correctly in case used */
/* with decNumber functions: */
/* */
/* clamp -- must be either 0 or 1 */
/* digits -- must be in the range 1 through 999999999 */
/* emax -- must be in the range 0 through 999999999 */
/* emin -- must be in the range 0 through -999999999 */
/* extended -- must be either 0 or 1 [present only if DECSUBSET] */
/* traps -- only defined bits may be set */
/* */
/* ------------------------------------------------------------------ */
#if !defined(DECCONTEXT)
#define DECCONTEXT
#define DECCNAME "decContext" /* Short name */
#define DECCFULLNAME "Decimal Context Descriptor" /* Verbose name */
#define DECCAUTHOR "Mike Cowlishaw" /* Who to blame */
#if !defined(int32_t)
#include <stdint.h> /* C99 standard integers */
#endif
#include <stdio.h> /* for printf, etc. */
#include <signal.h> /* for traps */
/* Extended flags setting -- set this to 0 to use only IEEE flags */
#if !defined(DECEXTFLAG)
#define DECEXTFLAG 1 /* 1=enable extended flags */
#endif
/* Conditional code flag -- set this to 0 for best performance */
#if !defined(DECSUBSET)
#define DECSUBSET 0 /* 1=enable subset arithmetic */
#endif
/* Context for operations, with associated constants */
enum rounding {
DEC_ROUND_CEILING, /* round towards +infinity */
DEC_ROUND_UP, /* round away from 0 */
DEC_ROUND_HALF_UP, /* 0.5 rounds up */
DEC_ROUND_HALF_EVEN, /* 0.5 rounds to nearest even */
DEC_ROUND_HALF_DOWN, /* 0.5 rounds down */
DEC_ROUND_DOWN, /* round towards 0 (truncate) */
DEC_ROUND_FLOOR, /* round towards -infinity */
DEC_ROUND_05UP, /* round for reround */
DEC_ROUND_MAX /* enum must be less than this */
};
#define DEC_ROUND_DEFAULT DEC_ROUND_HALF_EVEN;
typedef struct {
int32_t digits; /* working precision */
int32_t emax; /* maximum positive exponent */
int32_t emin; /* minimum negative exponent */
enum rounding round; /* rounding mode */
uint32_t traps; /* trap-enabler flags */
uint32_t status; /* status flags */
uint8_t clamp; /* flag: apply IEEE exponent clamp */
#if DECSUBSET
uint8_t extended; /* flag: special-values allowed */
#endif
} decContext;
/* Maxima and Minima for context settings */
#define DEC_MAX_DIGITS 999999999
#define DEC_MIN_DIGITS 1
#define DEC_MAX_EMAX 999999999
#define DEC_MIN_EMAX 0
#define DEC_MAX_EMIN 0
#define DEC_MIN_EMIN -999999999
#define DEC_MAX_MATH 999999 /* max emax, etc., for math funcs. */
/* Classifications for decimal numbers, aligned with 754 (note that */
/* 'normal' and 'subnormal' are meaningful only with a decContext */
/* or a fixed size format). */
enum decClass {
DEC_CLASS_SNAN,
DEC_CLASS_QNAN,
DEC_CLASS_NEG_INF,
DEC_CLASS_NEG_NORMAL,
DEC_CLASS_NEG_SUBNORMAL,
DEC_CLASS_NEG_ZERO,
DEC_CLASS_POS_ZERO,
DEC_CLASS_POS_SUBNORMAL,
DEC_CLASS_POS_NORMAL,
DEC_CLASS_POS_INF
};
/* Strings for the decClasses */
#define DEC_ClassString_SN "sNaN"
#define DEC_ClassString_QN "NaN"
#define DEC_ClassString_NI "-Infinity"
#define DEC_ClassString_NN "-Normal"
#define DEC_ClassString_NS "-Subnormal"
#define DEC_ClassString_NZ "-Zero"
#define DEC_ClassString_PZ "+Zero"
#define DEC_ClassString_PS "+Subnormal"
#define DEC_ClassString_PN "+Normal"
#define DEC_ClassString_PI "+Infinity"
#define DEC_ClassString_UN "Invalid"
/* Trap-enabler and Status flags (exceptional conditions), and */
/* their names. The top byte is reserved for internal use */
#if DECEXTFLAG
/* Extended flags */
#define DEC_Conversion_syntax 0x00000001
#define DEC_Division_by_zero 0x00000002
#define DEC_Division_impossible 0x00000004
#define DEC_Division_undefined 0x00000008
#define DEC_Insufficient_storage 0x00000010 /* [when malloc fails] */
#define DEC_Inexact 0x00000020
#define DEC_Invalid_context 0x00000040
#define DEC_Invalid_operation 0x00000080
#if DECSUBSET
#define DEC_Lost_digits 0x00000100
#endif
#define DEC_Overflow 0x00000200
#define DEC_Clamped 0x00000400
#define DEC_Rounded 0x00000800
#define DEC_Subnormal 0x00001000
#define DEC_Underflow 0x00002000
#else
/* IEEE flags only */
#define DEC_Conversion_syntax 0x00000010
#define DEC_Division_by_zero 0x00000002
#define DEC_Division_impossible 0x00000010
#define DEC_Division_undefined 0x00000010
#define DEC_Insufficient_storage 0x00000010 /* [when malloc fails] */
#define DEC_Inexact 0x00000001
#define DEC_Invalid_context 0x00000010
#define DEC_Invalid_operation 0x00000010
#if DECSUBSET
#define DEC_Lost_digits 0x00000000
#endif
#define DEC_Overflow 0x00000008
#define DEC_Clamped 0x00000000
#define DEC_Rounded 0x00000000
#define DEC_Subnormal 0x00000000
#define DEC_Underflow 0x00000004
#endif
/* IEEE 754 groupings for the flags */
/* [DEC_Clamped, DEC_Lost_digits, DEC_Rounded, and DEC_Subnormal */
/* are not in IEEE 754] */
#define DEC_IEEE_754_Division_by_zero (DEC_Division_by_zero)
#if DECSUBSET
#define DEC_IEEE_754_Inexact (DEC_Inexact | DEC_Lost_digits)
#else
#define DEC_IEEE_754_Inexact (DEC_Inexact)
#endif
#define DEC_IEEE_754_Invalid_operation (DEC_Conversion_syntax | \
DEC_Division_impossible | \
DEC_Division_undefined | \
DEC_Insufficient_storage | \
DEC_Invalid_context | \
DEC_Invalid_operation)
#define DEC_IEEE_754_Overflow (DEC_Overflow)
#define DEC_IEEE_754_Underflow (DEC_Underflow)
/* flags which are normally errors (result is qNaN, infinite, or 0) */
#define DEC_Errors (DEC_IEEE_754_Division_by_zero | \
DEC_IEEE_754_Invalid_operation | \
DEC_IEEE_754_Overflow | DEC_IEEE_754_Underflow)
/* flags which cause a result to become qNaN */
#define DEC_NaNs DEC_IEEE_754_Invalid_operation
/* flags which are normally for information only (finite results) */
#if DECSUBSET
#define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact \
| DEC_Lost_digits)
#else
#define DEC_Information (DEC_Clamped | DEC_Rounded | DEC_Inexact)
#endif
/* IEEE 854 names (for compatibility with older decNumber versions) */
#define DEC_IEEE_854_Division_by_zero DEC_IEEE_754_Division_by_zero
#define DEC_IEEE_854_Inexact DEC_IEEE_754_Inexact
#define DEC_IEEE_854_Invalid_operation DEC_IEEE_754_Invalid_operation
#define DEC_IEEE_854_Overflow DEC_IEEE_754_Overflow
#define DEC_IEEE_854_Underflow DEC_IEEE_754_Underflow
/* Name strings for the exceptional conditions */
#define DEC_Condition_CS "Conversion syntax"
#define DEC_Condition_DZ "Division by zero"
#define DEC_Condition_DI "Division impossible"
#define DEC_Condition_DU "Division undefined"
#define DEC_Condition_IE "Inexact"
#define DEC_Condition_IS "Insufficient storage"
#define DEC_Condition_IC "Invalid context"
#define DEC_Condition_IO "Invalid operation"
#if DECSUBSET
#define DEC_Condition_LD "Lost digits"
#endif
#define DEC_Condition_OV "Overflow"
#define DEC_Condition_PA "Clamped"
#define DEC_Condition_RO "Rounded"
#define DEC_Condition_SU "Subnormal"
#define DEC_Condition_UN "Underflow"
#define DEC_Condition_ZE "No status"
#define DEC_Condition_MU "Multiple status"
#define DEC_Condition_Length 21 /* length of the longest string, */
/* including terminator */
/* Initialization descriptors, used by decContextDefault */
#define DEC_INIT_BASE 0
#define DEC_INIT_DECIMAL32 32
#define DEC_INIT_DECIMAL64 64
#define DEC_INIT_DECIMAL128 128
/* Synonyms */
#define DEC_INIT_DECSINGLE DEC_INIT_DECIMAL32
#define DEC_INIT_DECDOUBLE DEC_INIT_DECIMAL64
#define DEC_INIT_DECQUAD DEC_INIT_DECIMAL128
/* decContext routines */
extern decContext * decContextClearStatus(decContext *, uint32_t);
extern decContext * decContextDefault(decContext *, int32_t);
extern enum rounding decContextGetRounding(decContext *);
extern uint32_t decContextGetStatus(decContext *);
extern decContext * decContextRestoreStatus(decContext *, uint32_t, uint32_t);
extern uint32_t decContextSaveStatus(decContext *, uint32_t);
extern decContext * decContextSetRounding(decContext *, enum rounding);
extern decContext * decContextSetStatus(decContext *, uint32_t);
extern decContext * decContextSetStatusFromString(decContext *, const char *);
extern decContext * decContextSetStatusFromStringQuiet(decContext *, const char *);
extern decContext * decContextSetStatusQuiet(decContext *, uint32_t);
extern const char * decContextStatusToString(const decContext *);
extern int32_t decContextTestEndian(uint8_t);
extern uint32_t decContextTestSavedStatus(uint32_t, uint32_t);
extern uint32_t decContextTestStatus(decContext *, uint32_t);
extern decContext * decContextZeroStatus(decContext *);
#endif