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lxdream.org :: lxdream/src/xlat/disasm/floatformat.h
lxdream 0.9.1
released Jun 29
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filename src/xlat/disasm/floatformat.h
changeset 1265:7c6c5d26fd2e
author nkeynes
date Tue Mar 06 12:42:33 2012 +1000 (8 years ago)
permissions -rw-r--r--
last change Merge ARM disassembler from binutils 2.22
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     1 /* IEEE floating point support declarations, for GDB, the GNU Debugger.
     2    Copyright 1991, 1994, 1995, 1997, 2000, 2003, 2005, 2010
     3    Free Software Foundation, Inc.
     5 This file is part of GDB.
     7 This program is free software; you can redistribute it and/or modify
     8 it under the terms of the GNU General Public License as published by
     9 the Free Software Foundation; either version 2 of the License, or
    10 (at your option) any later version.
    12 This program is distributed in the hope that it will be useful,
    13 but WITHOUT ANY WARRANTY; without even the implied warranty of
    14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    15 GNU General Public License for more details.
    17 You should have received a copy of the GNU General Public License
    18 along with this program; if not, write to the Free Software
    19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */
    21 #if !defined (FLOATFORMAT_H)
    22 #define FLOATFORMAT_H 1
    24 #include "ansidecl.h"
    26 /* A floatformat consists of a sign bit, an exponent and a mantissa.  Once the
    27    bytes are concatenated according to the byteorder flag, then each of those
    28    fields is contiguous.  We number the bits with 0 being the most significant
    29    (i.e. BITS_BIG_ENDIAN type numbering), and specify which bits each field
    30    contains with the *_start and *_len fields.  */
    32 /* What is the order of the bytes?  */
    34 enum floatformat_byteorders {
    35   /* Standard little endian byte order.
    36      EX: 1.2345678e10 => 00 00 80 c5 e0 fe 06 42 */
    37   floatformat_little,
    39   /* Standard big endian byte order.
    40      EX: 1.2345678e10 => 42 06 fe e0 c5 80 00 00 */
    41   floatformat_big,
    43   /* Little endian byte order but big endian word order.
    44      EX: 1.2345678e10 => e0 fe 06 42 00 00 80 c5 */
    45   floatformat_littlebyte_bigword,
    47   /* VAX byte order.  Little endian byte order with 16-bit words.  The
    48      following example is an illustration of the byte order only; VAX
    49      doesn't have a fully IEEE compliant floating-point format.
    50      EX: 1.2345678e10 => 80 c5 00 00 06 42 e0 fe */
    51   floatformat_vax
    52 };
    54 enum floatformat_intbit { floatformat_intbit_yes, floatformat_intbit_no };
    56 struct floatformat
    57 {
    58   enum floatformat_byteorders byteorder;
    59   unsigned int totalsize;	/* Total size of number in bits */
    61   /* Sign bit is always one bit long.  1 means negative, 0 means positive.  */
    62   unsigned int sign_start;
    64   unsigned int exp_start;
    65   unsigned int exp_len;
    66   /* Bias added to a "true" exponent to form the biased exponent.  It
    67      is intentionally signed as, otherwize, -exp_bias can turn into a
    68      very large number (e.g., given the exp_bias of 0x3fff and a 64
    69      bit long, the equation (long)(1 - exp_bias) evaluates to
    70      4294950914) instead of -16382).  */
    71   int exp_bias;
    72   /* Exponent value which indicates NaN.  This is the actual value stored in
    73      the float, not adjusted by the exp_bias.  This usually consists of all
    74      one bits.  */
    75   unsigned int exp_nan;
    77   unsigned int man_start;
    78   unsigned int man_len;
    80   /* Is the integer bit explicit or implicit?  */
    81   enum floatformat_intbit intbit;
    83   /* Internal name for debugging. */
    84   const char *name;
    86   /* Validator method.  */
    87   int (*is_valid) (const struct floatformat *fmt, const void *from);
    89   /* Is the format actually the sum of two smaller floating point
    90      formats (IBM long double, as described in
    91      gcc/config/rs6000/darwin-ldouble-format)?  If so, this is the
    92      smaller format in question, and the fields sign_start through
    93      intbit describe the first half.  If not, this is NULL.  */
    94   const struct floatformat *split_half;
    95 };
    97 /* floatformats for IEEE single and double, big and little endian.  */
    99 extern const struct floatformat floatformat_ieee_half_big;
   100 extern const struct floatformat floatformat_ieee_half_little;
   101 extern const struct floatformat floatformat_ieee_single_big;
   102 extern const struct floatformat floatformat_ieee_single_little;
   103 extern const struct floatformat floatformat_ieee_double_big;
   104 extern const struct floatformat floatformat_ieee_double_little;
   106 /* floatformat for ARM IEEE double, little endian bytes and big endian words */
   108 extern const struct floatformat floatformat_ieee_double_littlebyte_bigword;
   110 /* floatformats for VAX.  */
   112 extern const struct floatformat floatformat_vax_f;
   113 extern const struct floatformat floatformat_vax_d;
   114 extern const struct floatformat floatformat_vax_g;
   116 /* floatformats for various extendeds.  */
   118 extern const struct floatformat floatformat_i387_ext;
   119 extern const struct floatformat floatformat_m68881_ext;
   120 extern const struct floatformat floatformat_i960_ext;
   121 extern const struct floatformat floatformat_m88110_ext;
   122 extern const struct floatformat floatformat_m88110_harris_ext;
   123 extern const struct floatformat floatformat_arm_ext_big;
   124 extern const struct floatformat floatformat_arm_ext_littlebyte_bigword;
   125 /* IA-64 Floating Point register spilt into memory.  */
   126 extern const struct floatformat floatformat_ia64_spill_big;
   127 extern const struct floatformat floatformat_ia64_spill_little;
   128 extern const struct floatformat floatformat_ia64_quad_big;
   129 extern const struct floatformat floatformat_ia64_quad_little;
   130 /* IBM long double (double+double).  */
   131 extern const struct floatformat floatformat_ibm_long_double;
   133 /* Convert from FMT to a double.
   134    FROM is the address of the extended float.
   135    Store the double in *TO.  */
   137 extern void
   138 floatformat_to_double (const struct floatformat *, const void *, double *);
   140 /* The converse: convert the double *FROM to FMT
   141    and store where TO points.  */
   143 extern void
   144 floatformat_from_double (const struct floatformat *, const double *, void *);
   146 /* Return non-zero iff the data at FROM is a valid number in format FMT.  */
   148 extern int
   149 floatformat_is_valid (const struct floatformat *fmt, const void *from);
   151 #endif	/* defined (FLOATFORMAT_H) */
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