/* IEEE floating point support routines, for GDB, the GNU Debugger.
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/* IEEE floating point support routines, for GDB, the GNU Debugger.
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Copyright 1991, 1994, 1999, 2000, 2003, 2005, 2006
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Copyright 1991, 1994, 1999, 2000, 2003, 2005, 2006
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Free Software Foundation, Inc.
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Free Software Foundation, Inc.
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This file is part of GDB.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
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Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
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/* This is needed to pick up the NAN macro on some systems. */
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/* This is needed to pick up the NAN macro on some systems. */
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#define _GNU_SOURCE
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#define _GNU_SOURCE
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#ifdef HAVE_CONFIG_H
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#include "config.h"
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#endif
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#endif
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#include <math.h>
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#include <math.h>
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#ifdef HAVE_STRING_H
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#ifdef HAVE_STRING_H
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#include <string.h>
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#include <string.h>
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#endif
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#endif
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/* On some platforms, <float.h> provides DBL_QNAN. */
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/* On some platforms, <float.h> provides DBL_QNAN. */
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#ifdef STDC_HEADERS
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#ifdef STDC_HEADERS
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#include <float.h>
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#include <float.h>
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#endif
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#endif
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#include "ansidecl.h"
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#include "ansidecl.h"
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#include "libiberty.h"
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#include "libiberty.h"
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#include "floatformat.h"
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#include "floatformat.h"
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#ifndef INFINITY
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#ifndef INFINITY
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#ifdef HUGE_VAL
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#ifdef HUGE_VAL
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#define INFINITY HUGE_VAL
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#define INFINITY HUGE_VAL
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#else
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#else
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#define INFINITY (1.0 / 0.0)
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#define INFINITY (1.0 / 0.0)
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#endif
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#endif
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#endif
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#endif
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#ifndef NAN
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#ifndef NAN
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#ifdef DBL_QNAN
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#ifdef DBL_QNAN
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#define NAN DBL_QNAN
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#define NAN DBL_QNAN
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#else
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#else
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#define NAN (0.0 / 0.0)
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#define NAN (0.0 / 0.0)
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#endif
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#endif
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#endif
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#endif
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static unsigned long get_field (const unsigned char *,
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static unsigned long get_field (const unsigned char *,
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enum floatformat_byteorders,
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enum floatformat_byteorders,
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unsigned int,
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unsigned int,
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unsigned int,
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unsigned int,
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unsigned int);
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unsigned int);
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static int floatformat_always_valid (const struct floatformat *fmt,
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static int floatformat_always_valid (const struct floatformat *fmt,
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const void *from);
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const void *from);
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static int
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static int
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floatformat_always_valid (const struct floatformat *fmt ATTRIBUTE_UNUSED,
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floatformat_always_valid (const struct floatformat *fmt ATTRIBUTE_UNUSED,
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const void *from ATTRIBUTE_UNUSED)
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const void *from ATTRIBUTE_UNUSED)
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{
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{
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return 1;
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return 1;
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}
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}
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/* The odds that CHAR_BIT will be anything but 8 are low enough that I'm not
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/* The odds that CHAR_BIT will be anything but 8 are low enough that I'm not
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going to bother with trying to muck around with whether it is defined in
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going to bother with trying to muck around with whether it is defined in
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a system header, what we do if not, etc. */
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a system header, what we do if not, etc. */
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#define FLOATFORMAT_CHAR_BIT 8
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#define FLOATFORMAT_CHAR_BIT 8
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/* floatformats for IEEE single and double, big and little endian. */
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/* floatformats for IEEE single and double, big and little endian. */
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const struct floatformat floatformat_ieee_single_big =
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const struct floatformat floatformat_ieee_single_big =
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{
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{
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floatformat_big, 32, 0, 1, 8, 127, 255, 9, 23,
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floatformat_big, 32, 0, 1, 8, 127, 255, 9, 23,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_ieee_single_big",
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"floatformat_ieee_single_big",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_ieee_single_little =
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const struct floatformat floatformat_ieee_single_little =
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{
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{
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floatformat_little, 32, 0, 1, 8, 127, 255, 9, 23,
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floatformat_little, 32, 0, 1, 8, 127, 255, 9, 23,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_ieee_single_little",
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"floatformat_ieee_single_little",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_ieee_double_big =
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const struct floatformat floatformat_ieee_double_big =
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{
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{
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floatformat_big, 64, 0, 1, 11, 1023, 2047, 12, 52,
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floatformat_big, 64, 0, 1, 11, 1023, 2047, 12, 52,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_ieee_double_big",
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"floatformat_ieee_double_big",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_ieee_double_little =
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const struct floatformat floatformat_ieee_double_little =
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{
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{
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floatformat_little, 64, 0, 1, 11, 1023, 2047, 12, 52,
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floatformat_little, 64, 0, 1, 11, 1023, 2047, 12, 52,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_ieee_double_little",
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"floatformat_ieee_double_little",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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/* floatformat for IEEE double, little endian byte order, with big endian word
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/* floatformat for IEEE double, little endian byte order, with big endian word
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ordering, as on the ARM. */
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ordering, as on the ARM. */
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const struct floatformat floatformat_ieee_double_littlebyte_bigword =
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const struct floatformat floatformat_ieee_double_littlebyte_bigword =
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{
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{
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floatformat_littlebyte_bigword, 64, 0, 1, 11, 1023, 2047, 12, 52,
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floatformat_littlebyte_bigword, 64, 0, 1, 11, 1023, 2047, 12, 52,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_ieee_double_littlebyte_bigword",
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"floatformat_ieee_double_littlebyte_bigword",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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/* floatformat for VAX. Not quite IEEE, but close enough. */
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/* floatformat for VAX. Not quite IEEE, but close enough. */
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const struct floatformat floatformat_vax_f =
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const struct floatformat floatformat_vax_f =
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{
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{
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floatformat_vax, 32, 0, 1, 8, 129, 0, 9, 23,
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floatformat_vax, 32, 0, 1, 8, 129, 0, 9, 23,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_vax_f",
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"floatformat_vax_f",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_vax_d =
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const struct floatformat floatformat_vax_d =
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{
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{
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floatformat_vax, 64, 0, 1, 8, 129, 0, 9, 55,
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floatformat_vax, 64, 0, 1, 8, 129, 0, 9, 55,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_vax_d",
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"floatformat_vax_d",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_vax_g =
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const struct floatformat floatformat_vax_g =
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{
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{
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floatformat_vax, 64, 0, 1, 11, 1025, 0, 12, 52,
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floatformat_vax, 64, 0, 1, 11, 1025, 0, 12, 52,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_vax_g",
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"floatformat_vax_g",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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static int floatformat_i387_ext_is_valid (const struct floatformat *fmt,
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static int floatformat_i387_ext_is_valid (const struct floatformat *fmt,
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const void *from);
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const void *from);
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static int
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static int
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floatformat_i387_ext_is_valid (const struct floatformat *fmt, const void *from)
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floatformat_i387_ext_is_valid (const struct floatformat *fmt, const void *from)
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{
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{
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/* In the i387 double-extended format, if the exponent is all ones,
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/* In the i387 double-extended format, if the exponent is all ones,
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then the integer bit must be set. If the exponent is neither 0
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then the integer bit must be set. If the exponent is neither 0
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nor ~0, the intbit must also be set. Only if the exponent is
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nor ~0, the intbit must also be set. Only if the exponent is
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zero can it be zero, and then it must be zero. */
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zero can it be zero, and then it must be zero. */
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unsigned long exponent, int_bit;
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unsigned long exponent, int_bit;
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const unsigned char *ufrom = (const unsigned char *) from;
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const unsigned char *ufrom = (const unsigned char *) from;
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exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize,
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exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize,
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fmt->exp_start, fmt->exp_len);
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fmt->exp_start, fmt->exp_len);
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int_bit = get_field (ufrom, fmt->byteorder, fmt->totalsize,
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int_bit = get_field (ufrom, fmt->byteorder, fmt->totalsize,
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fmt->man_start, 1);
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fmt->man_start, 1);
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if ((exponent == 0) != (int_bit == 0))
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if ((exponent == 0) != (int_bit == 0))
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return 0;
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return 0;
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else
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else
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return 1;
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return 1;
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}
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}
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const struct floatformat floatformat_i387_ext =
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const struct floatformat floatformat_i387_ext =
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{
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{
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floatformat_little, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64,
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floatformat_little, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64,
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floatformat_intbit_yes,
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floatformat_intbit_yes,
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"floatformat_i387_ext",
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"floatformat_i387_ext",
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floatformat_i387_ext_is_valid
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floatformat_i387_ext_is_valid
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};
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};
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const struct floatformat floatformat_m68881_ext =
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const struct floatformat floatformat_m68881_ext =
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{
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{
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/* Note that the bits from 16 to 31 are unused. */
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/* Note that the bits from 16 to 31 are unused. */
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floatformat_big, 96, 0, 1, 15, 0x3fff, 0x7fff, 32, 64,
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floatformat_big, 96, 0, 1, 15, 0x3fff, 0x7fff, 32, 64,
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floatformat_intbit_yes,
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floatformat_intbit_yes,
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"floatformat_m68881_ext",
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"floatformat_m68881_ext",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_i960_ext =
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const struct floatformat floatformat_i960_ext =
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{
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{
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/* Note that the bits from 0 to 15 are unused. */
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/* Note that the bits from 0 to 15 are unused. */
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floatformat_little, 96, 16, 17, 15, 0x3fff, 0x7fff, 32, 64,
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floatformat_little, 96, 16, 17, 15, 0x3fff, 0x7fff, 32, 64,
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floatformat_intbit_yes,
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floatformat_intbit_yes,
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"floatformat_i960_ext",
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"floatformat_i960_ext",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_m88110_ext =
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const struct floatformat floatformat_m88110_ext =
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{
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{
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floatformat_big, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64,
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floatformat_big, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64,
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floatformat_intbit_yes,
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floatformat_intbit_yes,
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"floatformat_m88110_ext",
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"floatformat_m88110_ext",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_m88110_harris_ext =
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const struct floatformat floatformat_m88110_harris_ext =
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{
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{
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/* Harris uses raw format 128 bytes long, but the number is just an ieee
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/* Harris uses raw format 128 bytes long, but the number is just an ieee
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double, and the last 64 bits are wasted. */
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double, and the last 64 bits are wasted. */
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floatformat_big,128, 0, 1, 11, 0x3ff, 0x7ff, 12, 52,
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floatformat_big,128, 0, 1, 11, 0x3ff, 0x7ff, 12, 52,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_m88110_ext_harris",
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"floatformat_m88110_ext_harris",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_arm_ext_big =
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const struct floatformat floatformat_arm_ext_big =
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{
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{
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/* Bits 1 to 16 are unused. */
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/* Bits 1 to 16 are unused. */
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floatformat_big, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64,
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floatformat_big, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64,
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floatformat_intbit_yes,
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floatformat_intbit_yes,
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"floatformat_arm_ext_big",
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"floatformat_arm_ext_big",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_arm_ext_littlebyte_bigword =
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const struct floatformat floatformat_arm_ext_littlebyte_bigword =
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{
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{
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/* Bits 1 to 16 are unused. */
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/* Bits 1 to 16 are unused. */
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floatformat_littlebyte_bigword, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64,
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floatformat_littlebyte_bigword, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64,
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floatformat_intbit_yes,
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floatformat_intbit_yes,
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"floatformat_arm_ext_littlebyte_bigword",
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"floatformat_arm_ext_littlebyte_bigword",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_ia64_spill_big =
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const struct floatformat floatformat_ia64_spill_big =
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{
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{
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floatformat_big, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64,
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floatformat_big, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64,
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floatformat_intbit_yes,
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floatformat_intbit_yes,
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"floatformat_ia64_spill_big",
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"floatformat_ia64_spill_big",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_ia64_spill_little =
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const struct floatformat floatformat_ia64_spill_little =
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{
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{
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floatformat_little, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64,
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floatformat_little, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64,
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floatformat_intbit_yes,
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floatformat_intbit_yes,
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"floatformat_ia64_spill_little",
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"floatformat_ia64_spill_little",
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floatformat_always_valid
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floatformat_always_valid
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};
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};
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const struct floatformat floatformat_ia64_quad_big =
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const struct floatformat floatformat_ia64_quad_big =
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{
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{
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floatformat_big, 128, 0, 1, 15, 16383, 0x7fff, 16, 112,
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floatformat_big, 128, 0, 1, 15, 16383, 0x7fff, 16, 112,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_ia64_quad_big",
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"floatformat_ia64_quad_big",
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floatformat_always_valid
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floatformat_always_valid
|
};
|
};
|
const struct floatformat floatformat_ia64_quad_little =
|
const struct floatformat floatformat_ia64_quad_little =
|
{
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{
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floatformat_little, 128, 0, 1, 15, 16383, 0x7fff, 16, 112,
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floatformat_little, 128, 0, 1, 15, 16383, 0x7fff, 16, 112,
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floatformat_intbit_no,
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floatformat_intbit_no,
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"floatformat_ia64_quad_little",
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"floatformat_ia64_quad_little",
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floatformat_always_valid
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floatformat_always_valid
|
};
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};
|
|
|
/* Extract a field which starts at START and is LEN bits long. DATA and
|
/* Extract a field which starts at START and is LEN bits long. DATA and
|
TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */
|
TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */
|
static unsigned long
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static unsigned long
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get_field (const unsigned char *data, enum floatformat_byteorders order,
|
get_field (const unsigned char *data, enum floatformat_byteorders order,
|
unsigned int total_len, unsigned int start, unsigned int len)
|
unsigned int total_len, unsigned int start, unsigned int len)
|
{
|
{
|
unsigned long result;
|
unsigned long result;
|
unsigned int cur_byte;
|
unsigned int cur_byte;
|
int cur_bitshift;
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int cur_bitshift;
|
|
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/* Start at the least significant part of the field. */
|
/* Start at the least significant part of the field. */
|
cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT;
|
cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT;
|
if (order == floatformat_little)
|
if (order == floatformat_little)
|
cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1;
|
cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1;
|
cur_bitshift =
|
cur_bitshift =
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((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT;
|
((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT;
|
result = *(data + cur_byte) >> (-cur_bitshift);
|
result = *(data + cur_byte) >> (-cur_bitshift);
|
cur_bitshift += FLOATFORMAT_CHAR_BIT;
|
cur_bitshift += FLOATFORMAT_CHAR_BIT;
|
if (order == floatformat_little)
|
if (order == floatformat_little)
|
++cur_byte;
|
++cur_byte;
|
else
|
else
|
--cur_byte;
|
--cur_byte;
|
|
|
/* Move towards the most significant part of the field. */
|
/* Move towards the most significant part of the field. */
|
while ((unsigned int) cur_bitshift < len)
|
while ((unsigned int) cur_bitshift < len)
|
{
|
{
|
if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT)
|
if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT)
|
/* This is the last byte; zero out the bits which are not part of
|
/* This is the last byte; zero out the bits which are not part of
|
this field. */
|
this field. */
|
result |=
|
result |=
|
(*(data + cur_byte) & ((1 << (len - cur_bitshift)) - 1))
|
(*(data + cur_byte) & ((1 << (len - cur_bitshift)) - 1))
|
<< cur_bitshift;
|
<< cur_bitshift;
|
else
|
else
|
result |= *(data + cur_byte) << cur_bitshift;
|
result |= *(data + cur_byte) << cur_bitshift;
|
cur_bitshift += FLOATFORMAT_CHAR_BIT;
|
cur_bitshift += FLOATFORMAT_CHAR_BIT;
|
if (order == floatformat_little)
|
if (order == floatformat_little)
|
++cur_byte;
|
++cur_byte;
|
else
|
else
|
--cur_byte;
|
--cur_byte;
|
}
|
}
|
return result;
|
return result;
|
}
|
}
|
|
|
#ifndef min
|
#ifndef min
|
#define min(a, b) ((a) < (b) ? (a) : (b))
|
#define min(a, b) ((a) < (b) ? (a) : (b))
|
#endif
|
#endif
|
|
|
/* Convert from FMT to a double.
|
/* Convert from FMT to a double.
|
FROM is the address of the extended float.
|
FROM is the address of the extended float.
|
Store the double in *TO. */
|
Store the double in *TO. */
|
|
|
void
|
void
|
floatformat_to_double (const struct floatformat *fmt,
|
floatformat_to_double (const struct floatformat *fmt,
|
const void *from, double *to)
|
const void *from, double *to)
|
{
|
{
|
const unsigned char *ufrom = (const unsigned char *) from;
|
const unsigned char *ufrom = (const unsigned char *) from;
|
double dto;
|
double dto;
|
long exponent;
|
long exponent;
|
unsigned long mant;
|
unsigned long mant;
|
unsigned int mant_bits, mant_off;
|
unsigned int mant_bits, mant_off;
|
int mant_bits_left;
|
int mant_bits_left;
|
int special_exponent; /* It's a NaN, denorm or zero */
|
int special_exponent; /* It's a NaN, denorm or zero */
|
|
|
exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize,
|
exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize,
|
fmt->exp_start, fmt->exp_len);
|
fmt->exp_start, fmt->exp_len);
|
|
|
/* If the exponent indicates a NaN, we don't have information to
|
/* If the exponent indicates a NaN, we don't have information to
|
decide what to do. So we handle it like IEEE, except that we
|
decide what to do. So we handle it like IEEE, except that we
|
don't try to preserve the type of NaN. FIXME. */
|
don't try to preserve the type of NaN. FIXME. */
|
if ((unsigned long) exponent == fmt->exp_nan)
|
if ((unsigned long) exponent == fmt->exp_nan)
|
{
|
{
|
int nan;
|
int nan;
|
|
|
mant_off = fmt->man_start;
|
mant_off = fmt->man_start;
|
mant_bits_left = fmt->man_len;
|
mant_bits_left = fmt->man_len;
|
nan = 0;
|
nan = 0;
|
while (mant_bits_left > 0)
|
while (mant_bits_left > 0)
|
{
|
{
|
mant_bits = min (mant_bits_left, 32);
|
mant_bits = min (mant_bits_left, 32);
|
|
|
if (get_field (ufrom, fmt->byteorder, fmt->totalsize,
|
if (get_field (ufrom, fmt->byteorder, fmt->totalsize,
|
mant_off, mant_bits) != 0)
|
mant_off, mant_bits) != 0)
|
{
|
{
|
/* This is a NaN. */
|
/* This is a NaN. */
|
nan = 1;
|
nan = 1;
|
break;
|
break;
|
}
|
}
|
|
|
mant_off += mant_bits;
|
mant_off += mant_bits;
|
mant_bits_left -= mant_bits;
|
mant_bits_left -= mant_bits;
|
}
|
}
|
|
|
/* On certain systems (such as GNU/Linux), the use of the
|
/* On certain systems (such as GNU/Linux), the use of the
|
INFINITY macro below may generate a warning that can not be
|
INFINITY macro below may generate a warning that can not be
|
silenced due to a bug in GCC (PR preprocessor/11931). The
|
silenced due to a bug in GCC (PR preprocessor/11931). The
|
preprocessor fails to recognise the __extension__ keyword in
|
preprocessor fails to recognise the __extension__ keyword in
|
conjunction with the GNU/C99 extension for hexadecimal
|
conjunction with the GNU/C99 extension for hexadecimal
|
floating point constants and will issue a warning when
|
floating point constants and will issue a warning when
|
compiling with -pedantic. */
|
compiling with -pedantic. */
|
if (nan)
|
if (nan)
|
dto = NAN;
|
dto = NAN;
|
else
|
else
|
dto = INFINITY;
|
dto = INFINITY;
|
|
|
if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1))
|
if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1))
|
dto = -dto;
|
dto = -dto;
|
|
|
*to = dto;
|
*to = dto;
|
|
|
return;
|
return;
|
}
|
}
|
|
|
mant_bits_left = fmt->man_len;
|
mant_bits_left = fmt->man_len;
|
mant_off = fmt->man_start;
|
mant_off = fmt->man_start;
|
dto = 0.0;
|
dto = 0.0;
|
|
|
special_exponent = exponent == 0 || (unsigned long) exponent == fmt->exp_nan;
|
special_exponent = exponent == 0 || (unsigned long) exponent == fmt->exp_nan;
|
|
|
/* Don't bias zero's, denorms or NaNs. */
|
/* Don't bias zero's, denorms or NaNs. */
|
if (!special_exponent)
|
if (!special_exponent)
|
exponent -= fmt->exp_bias;
|
exponent -= fmt->exp_bias;
|
|
|
/* Build the result algebraically. Might go infinite, underflow, etc;
|
/* Build the result algebraically. Might go infinite, underflow, etc;
|
who cares. */
|
who cares. */
|
|
|
/* If this format uses a hidden bit, explicitly add it in now. Otherwise,
|
/* If this format uses a hidden bit, explicitly add it in now. Otherwise,
|
increment the exponent by one to account for the integer bit. */
|
increment the exponent by one to account for the integer bit. */
|
|
|
if (!special_exponent)
|
if (!special_exponent)
|
{
|
{
|
if (fmt->intbit == floatformat_intbit_no)
|
if (fmt->intbit == floatformat_intbit_no)
|
dto = ldexp (1.0, exponent);
|
dto = ldexp (1.0, exponent);
|
else
|
else
|
exponent++;
|
exponent++;
|
}
|
}
|
|
|
while (mant_bits_left > 0)
|
while (mant_bits_left > 0)
|
{
|
{
|
mant_bits = min (mant_bits_left, 32);
|
mant_bits = min (mant_bits_left, 32);
|
|
|
mant = get_field (ufrom, fmt->byteorder, fmt->totalsize,
|
mant = get_field (ufrom, fmt->byteorder, fmt->totalsize,
|
mant_off, mant_bits);
|
mant_off, mant_bits);
|
|
|
/* Handle denormalized numbers. FIXME: What should we do for
|
/* Handle denormalized numbers. FIXME: What should we do for
|
non-IEEE formats? */
|
non-IEEE formats? */
|
if (special_exponent && exponent == 0 && mant != 0)
|
if (special_exponent && exponent == 0 && mant != 0)
|
dto += ldexp ((double)mant,
|
dto += ldexp ((double)mant,
|
(- fmt->exp_bias
|
(- fmt->exp_bias
|
- mant_bits
|
- mant_bits
|
- (mant_off - fmt->man_start)
|
- (mant_off - fmt->man_start)
|
+ 1));
|
+ 1));
|
else
|
else
|
dto += ldexp ((double)mant, exponent - mant_bits);
|
dto += ldexp ((double)mant, exponent - mant_bits);
|
if (exponent != 0)
|
if (exponent != 0)
|
exponent -= mant_bits;
|
exponent -= mant_bits;
|
mant_off += mant_bits;
|
mant_off += mant_bits;
|
mant_bits_left -= mant_bits;
|
mant_bits_left -= mant_bits;
|
}
|
}
|
|
|
/* Negate it if negative. */
|
/* Negate it if negative. */
|
if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1))
|
if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1))
|
dto = -dto;
|
dto = -dto;
|
*to = dto;
|
*to = dto;
|
}
|
}
|
|
|
static void put_field (unsigned char *, enum floatformat_byteorders,
|
static void put_field (unsigned char *, enum floatformat_byteorders,
|
unsigned int,
|
unsigned int,
|
unsigned int,
|
unsigned int,
|
unsigned int,
|
unsigned int,
|
unsigned long);
|
unsigned long);
|
|
|
/* Set a field which starts at START and is LEN bits long. DATA and
|
/* Set a field which starts at START and is LEN bits long. DATA and
|
TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */
|
TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */
|
static void
|
static void
|
put_field (unsigned char *data, enum floatformat_byteorders order,
|
put_field (unsigned char *data, enum floatformat_byteorders order,
|
unsigned int total_len, unsigned int start, unsigned int len,
|
unsigned int total_len, unsigned int start, unsigned int len,
|
unsigned long stuff_to_put)
|
unsigned long stuff_to_put)
|
{
|
{
|
unsigned int cur_byte;
|
unsigned int cur_byte;
|
int cur_bitshift;
|
int cur_bitshift;
|
|
|
/* Start at the least significant part of the field. */
|
/* Start at the least significant part of the field. */
|
cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT;
|
cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT;
|
if (order == floatformat_little)
|
if (order == floatformat_little)
|
cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1;
|
cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1;
|
cur_bitshift =
|
cur_bitshift =
|
((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT;
|
((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT;
|
*(data + cur_byte) &=
|
*(data + cur_byte) &=
|
~(((1 << ((start + len) % FLOATFORMAT_CHAR_BIT)) - 1) << (-cur_bitshift));
|
~(((1 << ((start + len) % FLOATFORMAT_CHAR_BIT)) - 1) << (-cur_bitshift));
|
*(data + cur_byte) |=
|
*(data + cur_byte) |=
|
(stuff_to_put & ((1 << FLOATFORMAT_CHAR_BIT) - 1)) << (-cur_bitshift);
|
(stuff_to_put & ((1 << FLOATFORMAT_CHAR_BIT) - 1)) << (-cur_bitshift);
|
cur_bitshift += FLOATFORMAT_CHAR_BIT;
|
cur_bitshift += FLOATFORMAT_CHAR_BIT;
|
if (order == floatformat_little)
|
if (order == floatformat_little)
|
++cur_byte;
|
++cur_byte;
|
else
|
else
|
--cur_byte;
|
--cur_byte;
|
|
|
/* Move towards the most significant part of the field. */
|
/* Move towards the most significant part of the field. */
|
while ((unsigned int) cur_bitshift < len)
|
while ((unsigned int) cur_bitshift < len)
|
{
|
{
|
if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT)
|
if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT)
|
{
|
{
|
/* This is the last byte. */
|
/* This is the last byte. */
|
*(data + cur_byte) &=
|
*(data + cur_byte) &=
|
~((1 << (len - cur_bitshift)) - 1);
|
~((1 << (len - cur_bitshift)) - 1);
|
*(data + cur_byte) |= (stuff_to_put >> cur_bitshift);
|
*(data + cur_byte) |= (stuff_to_put >> cur_bitshift);
|
}
|
}
|
else
|
else
|
*(data + cur_byte) = ((stuff_to_put >> cur_bitshift)
|
*(data + cur_byte) = ((stuff_to_put >> cur_bitshift)
|
& ((1 << FLOATFORMAT_CHAR_BIT) - 1));
|
& ((1 << FLOATFORMAT_CHAR_BIT) - 1));
|
cur_bitshift += FLOATFORMAT_CHAR_BIT;
|
cur_bitshift += FLOATFORMAT_CHAR_BIT;
|
if (order == floatformat_little)
|
if (order == floatformat_little)
|
++cur_byte;
|
++cur_byte;
|
else
|
else
|
--cur_byte;
|
--cur_byte;
|
}
|
}
|
}
|
}
|
|
|
/* The converse: convert the double *FROM to an extended float
|
/* The converse: convert the double *FROM to an extended float
|
and store where TO points. Neither FROM nor TO have any alignment
|
and store where TO points. Neither FROM nor TO have any alignment
|
restrictions. */
|
restrictions. */
|
|
|
void
|
void
|
floatformat_from_double (const struct floatformat *fmt,
|
floatformat_from_double (const struct floatformat *fmt,
|
const double *from, void *to)
|
const double *from, void *to)
|
{
|
{
|
double dfrom;
|
double dfrom;
|
int exponent;
|
int exponent;
|
double mant;
|
double mant;
|
unsigned int mant_bits, mant_off;
|
unsigned int mant_bits, mant_off;
|
int mant_bits_left;
|
int mant_bits_left;
|
unsigned char *uto = (unsigned char *) to;
|
unsigned char *uto = (unsigned char *) to;
|
|
|
dfrom = *from;
|
dfrom = *from;
|
memset (uto, 0, fmt->totalsize / FLOATFORMAT_CHAR_BIT);
|
memset (uto, 0, fmt->totalsize / FLOATFORMAT_CHAR_BIT);
|
|
|
/* If negative, set the sign bit. */
|
/* If negative, set the sign bit. */
|
if (dfrom < 0)
|
if (dfrom < 0)
|
{
|
{
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1, 1);
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1, 1);
|
dfrom = -dfrom;
|
dfrom = -dfrom;
|
}
|
}
|
|
|
if (dfrom == 0)
|
if (dfrom == 0)
|
{
|
{
|
/* 0.0. */
|
/* 0.0. */
|
return;
|
return;
|
}
|
}
|
|
|
if (dfrom != dfrom)
|
if (dfrom != dfrom)
|
{
|
{
|
/* NaN. */
|
/* NaN. */
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
|
fmt->exp_len, fmt->exp_nan);
|
fmt->exp_len, fmt->exp_nan);
|
/* Be sure it's not infinity, but NaN value is irrelevant. */
|
/* Be sure it's not infinity, but NaN value is irrelevant. */
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->man_start,
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->man_start,
|
32, 1);
|
32, 1);
|
return;
|
return;
|
}
|
}
|
|
|
if (dfrom + dfrom == dfrom)
|
if (dfrom + dfrom == dfrom)
|
{
|
{
|
/* This can only happen for an infinite value (or zero, which we
|
/* This can only happen for an infinite value (or zero, which we
|
already handled above). */
|
already handled above). */
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
|
fmt->exp_len, fmt->exp_nan);
|
fmt->exp_len, fmt->exp_nan);
|
return;
|
return;
|
}
|
}
|
|
|
mant = frexp (dfrom, &exponent);
|
mant = frexp (dfrom, &exponent);
|
if (exponent + fmt->exp_bias - 1 > 0)
|
if (exponent + fmt->exp_bias - 1 > 0)
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
|
fmt->exp_len, exponent + fmt->exp_bias - 1);
|
fmt->exp_len, exponent + fmt->exp_bias - 1);
|
else
|
else
|
{
|
{
|
/* Handle a denormalized number. FIXME: What should we do for
|
/* Handle a denormalized number. FIXME: What should we do for
|
non-IEEE formats? */
|
non-IEEE formats? */
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
|
put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start,
|
fmt->exp_len, 0);
|
fmt->exp_len, 0);
|
mant = ldexp (mant, exponent + fmt->exp_bias - 1);
|
mant = ldexp (mant, exponent + fmt->exp_bias - 1);
|
}
|
}
|
|
|
mant_bits_left = fmt->man_len;
|
mant_bits_left = fmt->man_len;
|
mant_off = fmt->man_start;
|
mant_off = fmt->man_start;
|
while (mant_bits_left > 0)
|
while (mant_bits_left > 0)
|
{
|
{
|
unsigned long mant_long;
|
unsigned long mant_long;
|
mant_bits = mant_bits_left < 32 ? mant_bits_left : 32;
|
mant_bits = mant_bits_left < 32 ? mant_bits_left : 32;
|
|
|
mant *= 4294967296.0;
|
mant *= 4294967296.0;
|
mant_long = (unsigned long)mant;
|
mant_long = (unsigned long)mant;
|
mant -= mant_long;
|
mant -= mant_long;
|
|
|
/* If the integer bit is implicit, and we are not creating a
|
/* If the integer bit is implicit, and we are not creating a
|
denormalized number, then we need to discard it. */
|
denormalized number, then we need to discard it. */
|
if ((unsigned int) mant_bits_left == fmt->man_len
|
if ((unsigned int) mant_bits_left == fmt->man_len
|
&& fmt->intbit == floatformat_intbit_no
|
&& fmt->intbit == floatformat_intbit_no
|
&& exponent + fmt->exp_bias - 1 > 0)
|
&& exponent + fmt->exp_bias - 1 > 0)
|
{
|
{
|
mant_long &= 0x7fffffff;
|
mant_long &= 0x7fffffff;
|
mant_bits -= 1;
|
mant_bits -= 1;
|
}
|
}
|
else if (mant_bits < 32)
|
else if (mant_bits < 32)
|
{
|
{
|
/* The bits we want are in the most significant MANT_BITS bits of
|
/* The bits we want are in the most significant MANT_BITS bits of
|
mant_long. Move them to the least significant. */
|
mant_long. Move them to the least significant. */
|
mant_long >>= 32 - mant_bits;
|
mant_long >>= 32 - mant_bits;
|
}
|
}
|
|
|
put_field (uto, fmt->byteorder, fmt->totalsize,
|
put_field (uto, fmt->byteorder, fmt->totalsize,
|
mant_off, mant_bits, mant_long);
|
mant_off, mant_bits, mant_long);
|
mant_off += mant_bits;
|
mant_off += mant_bits;
|
mant_bits_left -= mant_bits;
|
mant_bits_left -= mant_bits;
|
}
|
}
|
}
|
}
|
|
|
/* Return non-zero iff the data at FROM is a valid number in format FMT. */
|
/* Return non-zero iff the data at FROM is a valid number in format FMT. */
|
|
|
int
|
int
|
floatformat_is_valid (const struct floatformat *fmt, const void *from)
|
floatformat_is_valid (const struct floatformat *fmt, const void *from)
|
{
|
{
|
return fmt->is_valid (fmt, from);
|
return fmt->is_valid (fmt, from);
|
}
|
}
|
|
|
|
|
#ifdef IEEE_DEBUG
|
#ifdef IEEE_DEBUG
|
|
|
#include <stdio.h>
|
#include <stdio.h>
|
|
|
/* This is to be run on a host which uses IEEE floating point. */
|
/* This is to be run on a host which uses IEEE floating point. */
|
|
|
void
|
void
|
ieee_test (double n)
|
ieee_test (double n)
|
{
|
{
|
double result;
|
double result;
|
|
|
floatformat_to_double (&floatformat_ieee_double_little, &n, &result);
|
floatformat_to_double (&floatformat_ieee_double_little, &n, &result);
|
if ((n != result && (! isnan (n) || ! isnan (result)))
|
if ((n != result && (! isnan (n) || ! isnan (result)))
|
|| (n < 0 && result >= 0)
|
|| (n < 0 && result >= 0)
|
|| (n >= 0 && result < 0))
|
|| (n >= 0 && result < 0))
|
printf ("Differ(to): %.20g -> %.20g\n", n, result);
|
printf ("Differ(to): %.20g -> %.20g\n", n, result);
|
|
|
floatformat_from_double (&floatformat_ieee_double_little, &n, &result);
|
floatformat_from_double (&floatformat_ieee_double_little, &n, &result);
|
if ((n != result && (! isnan (n) || ! isnan (result)))
|
if ((n != result && (! isnan (n) || ! isnan (result)))
|
|| (n < 0 && result >= 0)
|
|| (n < 0 && result >= 0)
|
|| (n >= 0 && result < 0))
|
|| (n >= 0 && result < 0))
|
printf ("Differ(from): %.20g -> %.20g\n", n, result);
|
printf ("Differ(from): %.20g -> %.20g\n", n, result);
|
|
|
#if 0
|
#if 0
|
{
|
{
|
char exten[16];
|
char exten[16];
|
|
|
floatformat_from_double (&floatformat_m68881_ext, &n, exten);
|
floatformat_from_double (&floatformat_m68881_ext, &n, exten);
|
floatformat_to_double (&floatformat_m68881_ext, exten, &result);
|
floatformat_to_double (&floatformat_m68881_ext, exten, &result);
|
if (n != result)
|
if (n != result)
|
printf ("Differ(to+from): %.20g -> %.20g\n", n, result);
|
printf ("Differ(to+from): %.20g -> %.20g\n", n, result);
|
}
|
}
|
#endif
|
#endif
|
|
|
#if IEEE_DEBUG > 1
|
#if IEEE_DEBUG > 1
|
/* This is to be run on a host which uses 68881 format. */
|
/* This is to be run on a host which uses 68881 format. */
|
{
|
{
|
long double ex = *(long double *)exten;
|
long double ex = *(long double *)exten;
|
if (ex != n)
|
if (ex != n)
|
printf ("Differ(from vs. extended): %.20g\n", n);
|
printf ("Differ(from vs. extended): %.20g\n", n);
|
}
|
}
|
#endif
|
#endif
|
}
|
}
|
|
|
int
|
int
|
main (void)
|
main (void)
|
{
|
{
|
ieee_test (0.0);
|
ieee_test (0.0);
|
ieee_test (0.5);
|
ieee_test (0.5);
|
ieee_test (256.0);
|
ieee_test (256.0);
|
ieee_test (0.12345);
|
ieee_test (0.12345);
|
ieee_test (234235.78907234);
|
ieee_test (234235.78907234);
|
ieee_test (-512.0);
|
ieee_test (-512.0);
|
ieee_test (-0.004321);
|
ieee_test (-0.004321);
|
ieee_test (1.2E-70);
|
ieee_test (1.2E-70);
|
ieee_test (1.2E-316);
|
ieee_test (1.2E-316);
|
ieee_test (4.9406564584124654E-324);
|
ieee_test (4.9406564584124654E-324);
|
ieee_test (- 4.9406564584124654E-324);
|
ieee_test (- 4.9406564584124654E-324);
|
ieee_test (- 0.0);
|
ieee_test (- 0.0);
|
ieee_test (- INFINITY);
|
ieee_test (- INFINITY);
|
ieee_test (- NAN);
|
ieee_test (- NAN);
|
ieee_test (INFINITY);
|
ieee_test (INFINITY);
|
ieee_test (NAN);
|
ieee_test (NAN);
|
return 0;
|
return 0;
|
}
|
}
|
#endif
|
#endif
|
|
|
