451 lines
20 KiB
C
451 lines
20 KiB
C
/* Decimal context module for the decNumber C Library.
|
|
Copyright (C) 2005-2017 Free Software Foundation, Inc.
|
|
Contributed by IBM Corporation. Author Mike Cowlishaw.
|
|
|
|
This file is part of GCC.
|
|
|
|
GCC is free software; you can redistribute it and/or modify it under
|
|
the terms of the GNU General Public License as published by the Free
|
|
Software Foundation; either version 3, or (at your option) any later
|
|
version.
|
|
|
|
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
|
|
WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
for more details.
|
|
|
|
Under Section 7 of GPL version 3, you are granted additional
|
|
permissions described in the GCC Runtime Library Exception, version
|
|
3.1, as published by the Free Software Foundation.
|
|
|
|
You should have received a copy of the GNU General Public License and
|
|
a copy of the GCC Runtime Library Exception along with this program;
|
|
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Decimal Context module */
|
|
/* ------------------------------------------------------------------ */
|
|
/* This module comprises the routines for handling arithmetic */
|
|
/* context structures. */
|
|
/* ------------------------------------------------------------------ */
|
|
|
|
#include <string.h> /* for strcmp */
|
|
#ifdef DECCHECK
|
|
#include <stdio.h> /* for printf if DECCHECK */
|
|
#endif
|
|
#include "dconfig.h" /* for GCC definitions */
|
|
#include "decContext.h" /* context and base types */
|
|
#include "decNumberLocal.h" /* decNumber local types, etc. */
|
|
|
|
/* compile-time endian tester [assumes sizeof(Int)>1] */
|
|
static const Int mfcone=1; /* constant 1 */
|
|
static const Flag *mfctop=(const Flag *)&mfcone; /* -> top byte */
|
|
#define LITEND *mfctop /* named flag; 1=little-endian */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* round-for-reround digits */
|
|
/* ------------------------------------------------------------------ */
|
|
const uByte DECSTICKYTAB[10]={1,1,2,3,4,6,6,7,8,9}; /* used if sticky */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* Powers of ten (powers[n]==10**n, 0<=n<=9) */
|
|
/* ------------------------------------------------------------------ */
|
|
const uInt DECPOWERS[10]={1, 10, 100, 1000, 10000, 100000, 1000000,
|
|
10000000, 100000000, 1000000000};
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextClearStatus -- clear bits in current status */
|
|
/* */
|
|
/* context is the context structure to be queried */
|
|
/* mask indicates the bits to be cleared (the status bit that */
|
|
/* corresponds to each 1 bit in the mask is cleared) */
|
|
/* returns context */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
decContext *decContextClearStatus(decContext *context, uInt mask) {
|
|
context->status&=~mask;
|
|
return context;
|
|
} /* decContextClearStatus */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextDefault -- initialize a context structure */
|
|
/* */
|
|
/* context is the structure to be initialized */
|
|
/* kind selects the required set of default values, one of: */
|
|
/* DEC_INIT_BASE -- select ANSI X3-274 defaults */
|
|
/* DEC_INIT_DECIMAL32 -- select IEEE 754 defaults, 32-bit */
|
|
/* DEC_INIT_DECIMAL64 -- select IEEE 754 defaults, 64-bit */
|
|
/* DEC_INIT_DECIMAL128 -- select IEEE 754 defaults, 128-bit */
|
|
/* For any other value a valid context is returned, but with */
|
|
/* Invalid_operation set in the status field. */
|
|
/* returns a context structure with the appropriate initial values. */
|
|
/* ------------------------------------------------------------------ */
|
|
decContext * decContextDefault(decContext *context, Int kind) {
|
|
/* set defaults... */
|
|
context->digits=9; /* 9 digits */
|
|
context->emax=DEC_MAX_EMAX; /* 9-digit exponents */
|
|
context->emin=DEC_MIN_EMIN; /* .. balanced */
|
|
context->round=DEC_ROUND_HALF_UP; /* 0.5 rises */
|
|
context->traps=DEC_Errors; /* all but informational */
|
|
context->status=0; /* cleared */
|
|
context->clamp=0; /* no clamping */
|
|
#if DECSUBSET
|
|
context->extended=0; /* cleared */
|
|
#endif
|
|
switch (kind) {
|
|
case DEC_INIT_BASE:
|
|
/* [use defaults] */
|
|
break;
|
|
case DEC_INIT_DECIMAL32:
|
|
context->digits=7; /* digits */
|
|
context->emax=96; /* Emax */
|
|
context->emin=-95; /* Emin */
|
|
context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */
|
|
context->traps=0; /* no traps set */
|
|
context->clamp=1; /* clamp exponents */
|
|
#if DECSUBSET
|
|
context->extended=1; /* set */
|
|
#endif
|
|
break;
|
|
case DEC_INIT_DECIMAL64:
|
|
context->digits=16; /* digits */
|
|
context->emax=384; /* Emax */
|
|
context->emin=-383; /* Emin */
|
|
context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */
|
|
context->traps=0; /* no traps set */
|
|
context->clamp=1; /* clamp exponents */
|
|
#if DECSUBSET
|
|
context->extended=1; /* set */
|
|
#endif
|
|
break;
|
|
case DEC_INIT_DECIMAL128:
|
|
context->digits=34; /* digits */
|
|
context->emax=6144; /* Emax */
|
|
context->emin=-6143; /* Emin */
|
|
context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */
|
|
context->traps=0; /* no traps set */
|
|
context->clamp=1; /* clamp exponents */
|
|
#if DECSUBSET
|
|
context->extended=1; /* set */
|
|
#endif
|
|
break;
|
|
|
|
default: /* invalid Kind */
|
|
/* use defaults, and .. */
|
|
decContextSetStatus(context, DEC_Invalid_operation); /* trap */
|
|
}
|
|
|
|
return context;} /* decContextDefault */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextGetRounding -- return current rounding mode */
|
|
/* */
|
|
/* context is the context structure to be queried */
|
|
/* returns the rounding mode */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
enum rounding decContextGetRounding(decContext *context) {
|
|
return context->round;
|
|
} /* decContextGetRounding */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextGetStatus -- return current status */
|
|
/* */
|
|
/* context is the context structure to be queried */
|
|
/* returns status */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
uInt decContextGetStatus(decContext *context) {
|
|
return context->status;
|
|
} /* decContextGetStatus */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextRestoreStatus -- restore bits in current status */
|
|
/* */
|
|
/* context is the context structure to be updated */
|
|
/* newstatus is the source for the bits to be restored */
|
|
/* mask indicates the bits to be restored (the status bit that */
|
|
/* corresponds to each 1 bit in the mask is set to the value of */
|
|
/* the correspnding bit in newstatus) */
|
|
/* returns context */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
decContext *decContextRestoreStatus(decContext *context,
|
|
uInt newstatus, uInt mask) {
|
|
context->status&=~mask; /* clear the selected bits */
|
|
context->status|=(mask&newstatus); /* or in the new bits */
|
|
return context;
|
|
} /* decContextRestoreStatus */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextSaveStatus -- save bits in current status */
|
|
/* */
|
|
/* context is the context structure to be queried */
|
|
/* mask indicates the bits to be saved (the status bits that */
|
|
/* correspond to each 1 bit in the mask are saved) */
|
|
/* returns the AND of the mask and the current status */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
uInt decContextSaveStatus(decContext *context, uInt mask) {
|
|
return context->status&mask;
|
|
} /* decContextSaveStatus */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextSetRounding -- set current rounding mode */
|
|
/* */
|
|
/* context is the context structure to be updated */
|
|
/* newround is the value which will replace the current mode */
|
|
/* returns context */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
decContext *decContextSetRounding(decContext *context,
|
|
enum rounding newround) {
|
|
context->round=newround;
|
|
return context;
|
|
} /* decContextSetRounding */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextSetStatus -- set status and raise trap if appropriate */
|
|
/* */
|
|
/* context is the context structure to be updated */
|
|
/* status is the DEC_ exception code */
|
|
/* returns the context structure */
|
|
/* */
|
|
/* Control may never return from this routine, if there is a signal */
|
|
/* handler and it takes a long jump. */
|
|
/* ------------------------------------------------------------------ */
|
|
decContext * decContextSetStatus(decContext *context, uInt status) {
|
|
context->status|=status;
|
|
if (status & context->traps) raise(SIGFPE);
|
|
return context;} /* decContextSetStatus */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextSetStatusFromString -- set status from a string + trap */
|
|
/* */
|
|
/* context is the context structure to be updated */
|
|
/* string is a string exactly equal to one that might be returned */
|
|
/* by decContextStatusToString */
|
|
/* */
|
|
/* The status bit corresponding to the string is set, and a trap */
|
|
/* is raised if appropriate. */
|
|
/* */
|
|
/* returns the context structure, unless the string is equal to */
|
|
/* DEC_Condition_MU or is not recognized. In these cases NULL is */
|
|
/* returned. */
|
|
/* ------------------------------------------------------------------ */
|
|
decContext * decContextSetStatusFromString(decContext *context,
|
|
const char *string) {
|
|
if (strcmp(string, DEC_Condition_CS)==0)
|
|
return decContextSetStatus(context, DEC_Conversion_syntax);
|
|
if (strcmp(string, DEC_Condition_DZ)==0)
|
|
return decContextSetStatus(context, DEC_Division_by_zero);
|
|
if (strcmp(string, DEC_Condition_DI)==0)
|
|
return decContextSetStatus(context, DEC_Division_impossible);
|
|
if (strcmp(string, DEC_Condition_DU)==0)
|
|
return decContextSetStatus(context, DEC_Division_undefined);
|
|
if (strcmp(string, DEC_Condition_IE)==0)
|
|
return decContextSetStatus(context, DEC_Inexact);
|
|
if (strcmp(string, DEC_Condition_IS)==0)
|
|
return decContextSetStatus(context, DEC_Insufficient_storage);
|
|
if (strcmp(string, DEC_Condition_IC)==0)
|
|
return decContextSetStatus(context, DEC_Invalid_context);
|
|
if (strcmp(string, DEC_Condition_IO)==0)
|
|
return decContextSetStatus(context, DEC_Invalid_operation);
|
|
#if DECSUBSET
|
|
if (strcmp(string, DEC_Condition_LD)==0)
|
|
return decContextSetStatus(context, DEC_Lost_digits);
|
|
#endif
|
|
if (strcmp(string, DEC_Condition_OV)==0)
|
|
return decContextSetStatus(context, DEC_Overflow);
|
|
if (strcmp(string, DEC_Condition_PA)==0)
|
|
return decContextSetStatus(context, DEC_Clamped);
|
|
if (strcmp(string, DEC_Condition_RO)==0)
|
|
return decContextSetStatus(context, DEC_Rounded);
|
|
if (strcmp(string, DEC_Condition_SU)==0)
|
|
return decContextSetStatus(context, DEC_Subnormal);
|
|
if (strcmp(string, DEC_Condition_UN)==0)
|
|
return decContextSetStatus(context, DEC_Underflow);
|
|
if (strcmp(string, DEC_Condition_ZE)==0)
|
|
return context;
|
|
return NULL; /* Multiple status, or unknown */
|
|
} /* decContextSetStatusFromString */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextSetStatusFromStringQuiet -- set status from a string */
|
|
/* */
|
|
/* context is the context structure to be updated */
|
|
/* string is a string exactly equal to one that might be returned */
|
|
/* by decContextStatusToString */
|
|
/* */
|
|
/* The status bit corresponding to the string is set; no trap is */
|
|
/* raised. */
|
|
/* */
|
|
/* returns the context structure, unless the string is equal to */
|
|
/* DEC_Condition_MU or is not recognized. In these cases NULL is */
|
|
/* returned. */
|
|
/* ------------------------------------------------------------------ */
|
|
decContext * decContextSetStatusFromStringQuiet(decContext *context,
|
|
const char *string) {
|
|
if (strcmp(string, DEC_Condition_CS)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Conversion_syntax);
|
|
if (strcmp(string, DEC_Condition_DZ)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Division_by_zero);
|
|
if (strcmp(string, DEC_Condition_DI)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Division_impossible);
|
|
if (strcmp(string, DEC_Condition_DU)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Division_undefined);
|
|
if (strcmp(string, DEC_Condition_IE)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Inexact);
|
|
if (strcmp(string, DEC_Condition_IS)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Insufficient_storage);
|
|
if (strcmp(string, DEC_Condition_IC)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Invalid_context);
|
|
if (strcmp(string, DEC_Condition_IO)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Invalid_operation);
|
|
#if DECSUBSET
|
|
if (strcmp(string, DEC_Condition_LD)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Lost_digits);
|
|
#endif
|
|
if (strcmp(string, DEC_Condition_OV)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Overflow);
|
|
if (strcmp(string, DEC_Condition_PA)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Clamped);
|
|
if (strcmp(string, DEC_Condition_RO)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Rounded);
|
|
if (strcmp(string, DEC_Condition_SU)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Subnormal);
|
|
if (strcmp(string, DEC_Condition_UN)==0)
|
|
return decContextSetStatusQuiet(context, DEC_Underflow);
|
|
if (strcmp(string, DEC_Condition_ZE)==0)
|
|
return context;
|
|
return NULL; /* Multiple status, or unknown */
|
|
} /* decContextSetStatusFromStringQuiet */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextSetStatusQuiet -- set status without trap */
|
|
/* */
|
|
/* context is the context structure to be updated */
|
|
/* status is the DEC_ exception code */
|
|
/* returns the context structure */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
decContext * decContextSetStatusQuiet(decContext *context, uInt status) {
|
|
context->status|=status;
|
|
return context;} /* decContextSetStatusQuiet */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextStatusToString -- convert status flags to a string */
|
|
/* */
|
|
/* context is a context with valid status field */
|
|
/* */
|
|
/* returns a constant string describing the condition. If multiple */
|
|
/* (or no) flags are set, a generic constant message is returned. */
|
|
/* ------------------------------------------------------------------ */
|
|
const char *decContextStatusToString(const decContext *context) {
|
|
Int status=context->status;
|
|
|
|
/* test the five IEEE first, as some of the others are ambiguous when */
|
|
/* DECEXTFLAG=0 */
|
|
if (status==DEC_Invalid_operation ) return DEC_Condition_IO;
|
|
if (status==DEC_Division_by_zero ) return DEC_Condition_DZ;
|
|
if (status==DEC_Overflow ) return DEC_Condition_OV;
|
|
if (status==DEC_Underflow ) return DEC_Condition_UN;
|
|
if (status==DEC_Inexact ) return DEC_Condition_IE;
|
|
|
|
if (status==DEC_Division_impossible ) return DEC_Condition_DI;
|
|
if (status==DEC_Division_undefined ) return DEC_Condition_DU;
|
|
if (status==DEC_Rounded ) return DEC_Condition_RO;
|
|
if (status==DEC_Clamped ) return DEC_Condition_PA;
|
|
if (status==DEC_Subnormal ) return DEC_Condition_SU;
|
|
if (status==DEC_Conversion_syntax ) return DEC_Condition_CS;
|
|
if (status==DEC_Insufficient_storage ) return DEC_Condition_IS;
|
|
if (status==DEC_Invalid_context ) return DEC_Condition_IC;
|
|
#if DECSUBSET
|
|
if (status==DEC_Lost_digits ) return DEC_Condition_LD;
|
|
#endif
|
|
if (status==0 ) return DEC_Condition_ZE;
|
|
return DEC_Condition_MU; /* Multiple errors */
|
|
} /* decContextStatusToString */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextTestEndian -- test whether DECLITEND is set correctly */
|
|
/* */
|
|
/* quiet is 1 to suppress message; 0 otherwise */
|
|
/* returns 0 if DECLITEND is correct */
|
|
/* 1 if DECLITEND is incorrect and should be 1 */
|
|
/* -1 if DECLITEND is incorrect and should be 0 */
|
|
/* */
|
|
/* A message is displayed if the return value is not 0 and quiet==0. */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
Int decContextTestEndian(Flag quiet) {
|
|
Int res=0; /* optimist */
|
|
uInt dle=(uInt)DECLITEND; /* unsign */
|
|
if (dle>1) dle=1; /* ensure 0 or 1 */
|
|
|
|
if (LITEND!=DECLITEND) {
|
|
if (!quiet) {
|
|
#if DECCHECK
|
|
const char *adj;
|
|
if (LITEND) adj="little";
|
|
else adj="big";
|
|
printf("Warning: DECLITEND is set to %d, but this computer appears to be %s-endian\n",
|
|
DECLITEND, adj);
|
|
#endif
|
|
}
|
|
res=(Int)LITEND-dle;
|
|
}
|
|
return res;
|
|
} /* decContextTestEndian */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextTestSavedStatus -- test bits in saved status */
|
|
/* */
|
|
/* oldstatus is the status word to be tested */
|
|
/* mask indicates the bits to be tested (the oldstatus bits that */
|
|
/* correspond to each 1 bit in the mask are tested) */
|
|
/* returns 1 if any of the tested bits are 1, or 0 otherwise */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
uInt decContextTestSavedStatus(uInt oldstatus, uInt mask) {
|
|
return (oldstatus&mask)!=0;
|
|
} /* decContextTestSavedStatus */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextTestStatus -- test bits in current status */
|
|
/* */
|
|
/* context is the context structure to be updated */
|
|
/* mask indicates the bits to be tested (the status bits that */
|
|
/* correspond to each 1 bit in the mask are tested) */
|
|
/* returns 1 if any of the tested bits are 1, or 0 otherwise */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
uInt decContextTestStatus(decContext *context, uInt mask) {
|
|
return (context->status&mask)!=0;
|
|
} /* decContextTestStatus */
|
|
|
|
/* ------------------------------------------------------------------ */
|
|
/* decContextZeroStatus -- clear all status bits */
|
|
/* */
|
|
/* context is the context structure to be updated */
|
|
/* returns context */
|
|
/* */
|
|
/* No error is possible. */
|
|
/* ------------------------------------------------------------------ */
|
|
decContext *decContextZeroStatus(decContext *context) {
|
|
context->status=0;
|
|
return context;
|
|
} /* decContextZeroStatus */
|
|
|