Merge branch 'vendor/GCC44'
[dragonfly.git] / contrib / binutils-2.21 / gas / flonum.h
1 /* flonum.h - Floating point package
2    Copyright 1987, 1990, 1991, 1992, 1994, 1996, 2000, 2003, 2005, 2007
3    Free Software Foundation, Inc.
4
5    This file is part of GAS, the GNU Assembler.
6
7    GAS 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 3, or (at your option)
10    any later version.
11
12    GAS 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.
16
17    You should have received a copy of the GNU General Public License
18    along with GAS; see the file COPYING.  If not, write to the Free
19    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
20    02110-1301, USA.  */
21
22 /***********************************************************************\
23  *                                                                      *
24  *      Arbitrary-precision floating point arithmetic.                  *
25  *                                                                      *
26  *                                                                      *
27  *      Notation: a floating point number is expressed as               *
28  *      MANTISSA * (2 ** EXPONENT).                                     *
29  *                                                                      *
30  *      If this offends more traditional mathematicians, then           *
31  *      please tell me your nomenclature for flonums!                   *
32  *                                                                      *
33  \***********************************************************************/
34
35 #include "bignum.h"
36
37 /***********************************************************************\
38  *                                                                      *
39  *      Variable precision floating point numbers.                      *
40  *                                                                      *
41  *      Exponent is the place value of the low littlenum. E.g.:         *
42  *      If  0:  low points to the units             littlenum.          *
43  *      If  1:  low points to the LITTLENUM_RADIX   littlenum.          *
44  *      If -1:  low points to the 1/LITTLENUM_RADIX littlenum.          *
45  *                                                                      *
46  \***********************************************************************/
47
48 /* JF:  A sign value of 0 means we have been asked to assemble NaN
49    A sign value of 'P' means we've been asked to assemble +Inf
50    A sign value of 'N' means we've been asked to assemble -Inf
51    */
52 struct FLONUM_STRUCT {
53   LITTLENUM_TYPE *low;          /* low order littlenum of a bignum */
54   LITTLENUM_TYPE *high;         /* high order littlenum of a bignum */
55   LITTLENUM_TYPE *leader;       /* -> 1st non-zero littlenum */
56   /* If flonum is 0.0, leader==low-1 */
57   long exponent;                /* base LITTLENUM_RADIX */
58   char sign;                    /* '+' or '-' */
59 };
60
61 typedef struct FLONUM_STRUCT FLONUM_TYPE;
62
63 /***********************************************************************\
64  *                                                                      *
65  *      Since we can (& do) meet with exponents like 10^5000, it        *
66  *      is silly to make a table of ~ 10,000 entries, one for each      *
67  *      power of 10. We keep a table where item [n] is a struct         *
68  *      FLONUM_FLOATING_POINT representing 10^(2^n). We then            *
69  *      multiply appropriate entries from this table to get any         *
70  *      particular power of 10. For the example of 10^5000, a table     *
71  *      of just 25 entries suffices: 10^(2^-12)...10^(2^+12).           *
72  *                                                                      *
73  \***********************************************************************/
74
75 extern const FLONUM_TYPE flonum_positive_powers_of_ten[];
76 extern const FLONUM_TYPE flonum_negative_powers_of_ten[];
77 extern const int table_size_of_flonum_powers_of_ten;
78 /* Flonum_XXX_powers_of_ten[] table has legal indices from 0 to
79    + this number inclusive.  */
80
81 /***********************************************************************\
82  *                                                                      *
83  *      Declare worker functions.                                       *
84  *                                                                      *
85  \***********************************************************************/
86
87 int atof_generic (char **address_of_string_pointer,
88                   const char *string_of_decimal_marks,
89                   const char *string_of_decimal_exponent_marks,
90                   FLONUM_TYPE * address_of_generic_floating_point_number);
91
92 void flonum_copy (FLONUM_TYPE * in, FLONUM_TYPE * out);
93 void flonum_multip (const FLONUM_TYPE * a, const FLONUM_TYPE * b,
94                     FLONUM_TYPE * product);
95
96 /***********************************************************************\
97  *                                                                      *
98  *      Declare error codes.                                            *
99  *                                                                      *
100  \***********************************************************************/
101
102 #define ERROR_EXPONENT_OVERFLOW (2)