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/* IEEE floating point support declarations, for GDB, the GNU Debugger.
Copyright (C) 1991-2019 Free Software Foundation, Inc.
This file is part of GDB.
This program 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 of the License, or
(at your option) any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
#if !defined (FLOATFORMAT_H)
#define FLOATFORMAT_H 1
#include "ansidecl.h"
#ifdef __cplusplus
extern "C" {
#endif
/* A floatformat consists of a sign bit, an exponent and a mantissa. Once the
bytes are concatenated according to the byteorder flag, then each of those
fields is contiguous. We number the bits with 0 being the most significant
(i.e. BITS_BIG_ENDIAN type numbering), and specify which bits each field
contains with the *_start and *_len fields. */
/* What is the order of the bytes? */
enum floatformat_byteorders {
/* Standard little endian byte order.
EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */
floatformat_little,
/* Standard big endian byte order.
EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */
floatformat_big,
/* Little endian byte order but big endian word order.
EX: 1.2345678e10 => e0 fe 06 42 00 00 80 c5 */
floatformat_littlebyte_bigword,
/* VAX byte order. Little endian byte order with 16-bit words. The
following example is an illustration of the byte order only; VAX
doesn't have a fully IEEE compliant floating-point format.
EX: 1.2345678e10 => 80 c5 00 00 06 42 e0 fe */
floatformat_vax
};
enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no };
struct floatformat
{
enum floatformat_byteorders byteorder;
unsigned int totalsize; /* Total size of number in bits */
/* Sign bit is always one bit long. 1 means negative, 0 means positive. */
unsigned int sign_start;
unsigned int exp_start;
unsigned int exp_len;
/* Bias added to a "true" exponent to form the biased exponent. It
is intentionally signed as, otherwize, -exp_bias can turn into a
very large number (e.g., given the exp_bias of 0x3fff and a 64
bit long, the equation (long)(1 - exp_bias) evaluates to
4294950914) instead of -16382). */
int exp_bias;
/* Exponent value which indicates NaN. This is the actual value stored in
the float, not adjusted by the exp_bias. This usually consists of all
one bits. */
unsigned int exp_nan;
unsigned int man_start;
unsigned int man_len;
/* Is the integer bit explicit or implicit? */
enum floatformat_intbit intbit;
/* Internal name for debugging. */
const char *name;
/* Validator method. */
int (*is_valid) (const struct floatformat *fmt, const void *from);
/* Is the format actually the sum of two smaller floating point
formats (IBM long double, as described in
gcc/config/rs6000/darwin-ldouble-format)? If so, this is the
smaller format in question, and the fields sign_start through
intbit describe the first half. If not, this is NULL. */
const struct floatformat *split_half;
};
/* floatformats for IEEE single and double, big and little endian. */
extern const struct floatformat floatformat_ieee_half_big;
extern const struct floatformat floatformat_ieee_half_little;
extern const struct floatformat floatformat_ieee_single_big;
extern const struct floatformat floatformat_ieee_single_little;
extern const struct floatformat floatformat_ieee_double_big;
extern const struct floatformat floatformat_ieee_double_little;
/* floatformat for ARM IEEE double, little endian bytes and big endian words */
extern const struct floatformat floatformat_ieee_double_littlebyte_bigword;
/* floatformats for VAX. */
extern const struct floatformat floatformat_vax_f;
extern const struct floatformat floatformat_vax_d;
extern const struct floatformat floatformat_vax_g;
/* floatformats for various extendeds. */
extern const struct floatformat floatformat_i387_ext;
extern const struct floatformat floatformat_m68881_ext;
extern const struct floatformat floatformat_i960_ext;
extern const struct floatformat floatformat_m88110_ext;
extern const struct floatformat floatformat_m88110_harris_ext;
extern const struct floatformat floatformat_arm_ext_big;
extern const struct floatformat floatformat_arm_ext_littlebyte_bigword;
/* IA-64 Floating Point register spilt into memory. */
extern const struct floatformat floatformat_ia64_spill_big;
extern const struct floatformat floatformat_ia64_spill_little;
extern const struct floatformat floatformat_ia64_quad_big;
extern const struct floatformat floatformat_ia64_quad_little;
/* IBM long double (double+double). */
extern const struct floatformat floatformat_ibm_long_double_big;
extern const struct floatformat floatformat_ibm_long_double_little;
/* Convert from FMT to a double.
FROM is the address of the extended float.
Store the double in *TO. */
extern void
floatformat_to_double (const struct floatformat *, const void *, double *);
/* The converse: convert the double *FROM to FMT
and store where TO points. */
extern void
floatformat_from_double (const struct floatformat *, const double *, void *);
/* Return non-zero iff the data at FROM is a valid number in format FMT. */
extern int
floatformat_is_valid (const struct floatformat *fmt, const void *from);
#ifdef __cplusplus
}
#endif
#endif /* defined (FLOATFORMAT_H) */
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