gcc/libdecnumber/decRound.c

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/* Temporary support for a libc-like fp environment for decimal float.
Copyright (C) 2005 Free Software Foundation, Inc.
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 2, 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.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA. */
#include "config.h"
#include "decContext.h"
#define FE_DEC_DOWNWARD 0
#define FE_DEC_TONEAREST 1
#define FE_DEC_TONEARESTFROMZERO 2
#define FE_DEC_TOWARDZERO 3
#define FE_DEC_UPWARD 4
#define FE_DEC_MAX 5
extern void __dfp_set_round (int);
extern int __dfp_get_round (void);
extern enum rounding __decGetRound (void);
/* FIXME: these should be in thread-local storage for runtime support. */
static enum rounding __dfp_rounding_mode = DEC_ROUND_HALF_EVEN;
/* Set the decNumber rounding mode from the FE_DEC_* value in MODE. */
void
__dfp_set_round (int mode)
{
switch (mode)
{
case FE_DEC_DOWNWARD:
__dfp_rounding_mode = DEC_ROUND_FLOOR; break;
case FE_DEC_TONEAREST:
__dfp_rounding_mode = DEC_ROUND_HALF_EVEN; break;
case FE_DEC_TONEARESTFROMZERO:
__dfp_rounding_mode = DEC_ROUND_HALF_UP; break;
case FE_DEC_TOWARDZERO:
__dfp_rounding_mode = DEC_ROUND_DOWN; break;
case FE_DEC_UPWARD:
__dfp_rounding_mode = DEC_ROUND_CEILING; break;
default:
/* We can't use assert in libgcc, so just return the default mode. */
__dfp_rounding_mode = DEC_ROUND_HALF_EVEN; break;
}
}
/* Return the decNumber rounding mode as an FE_DEC_* value. */
int
__dfp_get_round (void)
{
int mode;
switch (__dfp_rounding_mode)
{
case DEC_ROUND_FLOOR:
mode = FE_DEC_DOWNWARD; break;
case DEC_ROUND_HALF_EVEN:
mode = FE_DEC_TONEAREST; break;
case DEC_ROUND_HALF_UP:
mode = FE_DEC_TONEARESTFROMZERO; break;
case DEC_ROUND_DOWN:
mode = FE_DEC_TOWARDZERO; break;
case DEC_ROUND_CEILING:
mode = FE_DEC_UPWARD; break;
default:
/* We shouldn't get here, but can't use assert in libgcc. */
mode = -1;
}
return mode;
}
/* Return the decNumber version of the current rounding mode. */
enum rounding
__decGetRound (void)
{
return __dfp_rounding_mode;
}