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