1 /* flonum.h - Floating point package
3 Copyright (C) 1987, 1990, 1991, 1992 Free Software Foundation, Inc.
5 This file is part of GAS, the GNU Assembler.
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 2, or (at your option)
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.
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
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
25 /***********************************************************************\
27 * Arbitrary-precision floating point arithmetic. *
30 * Notation: a floating point number is expressed as *
31 * MANTISSA * (2 ** EXPONENT). *
33 * If this offends more traditional mathematicians, then *
34 * please tell me your nomenclature for flonums! *
36 \***********************************************************************/
37 #if (__STDC__ != 1) && !defined(const)
38 #define const /* empty */
43 /***********************************************************************\
45 * Variable precision floating point numbers. *
47 * Exponent is the place value of the low littlenum. E.g.: *
48 * If 0: low points to the units littlenum. *
49 * If 1: low points to the LITTLENUM_RADIX littlenum. *
50 * If -1: low points to the 1/LITTLENUM_RADIX littlenum. *
52 \***********************************************************************/
54 /* JF: A sign value of 0 means we have been asked to assemble NaN
55 A sign value of 'P' means we've been asked to assemble +Inf
56 A sign value of 'N' means we've been asked to assemble -Inf
60 LITTLENUM_TYPE *low; /* low order littlenum of a bignum */
61 LITTLENUM_TYPE *high; /* high order littlenum of a bignum */
62 LITTLENUM_TYPE *leader; /* -> 1st non-zero littlenum */
63 /* If flonum is 0.0, leader == low-1 */
64 long exponent; /* base LITTLENUM_RADIX */
65 char sign; /* '+' or '-' */
68 typedef struct FLONUM_STRUCT FLONUM_TYPE;
71 /***********************************************************************\
73 * Since we can (& do) meet with exponents like 10^5000, it *
74 * is silly to make a table of ~ 10,000 entries, one for each *
75 * power of 10. We keep a table where item [n] is a struct *
76 * FLONUM_FLOATING_POINT representing 10^(2^n). We then *
77 * multiply appropriate entries from this table to get any *
78 * particular power of 10. For the example of 10^5000, a table *
79 * of just 25 entries suffices: 10^(2^-12)...10^(2^+12). *
81 \***********************************************************************/
84 extern const FLONUM_TYPE flonum_positive_powers_of_ten[];
85 extern const FLONUM_TYPE flonum_negative_powers_of_ten[];
86 extern const int table_size_of_flonum_powers_of_ten;
87 /* Flonum_XXX_powers_of_ten[] table has */
88 /* legal indices from 0 to */
89 /* + this number inclusive. */
93 /***********************************************************************\
95 * Declare worker functions. *
97 \***********************************************************************/
101 int atof_generic(char **address_of_string_pointer,
102 const char *string_of_decimal_marks,
103 const char *string_of_decimal_exponent_marks,
104 FLONUM_TYPE *address_of_generic_floating_point_number);
106 void flonum_copy(FLONUM_TYPE *in, FLONUM_TYPE *out);
107 void flonum_multip(const FLONUM_TYPE *a, const FLONUM_TYPE *b, FLONUM_TYPE *product);
109 #else /* not __STDC__ */
113 void flonum_multip();
115 #endif /* not __STDC__ */
117 /***********************************************************************\
119 * Declare error codes. *
121 \***********************************************************************/
123 #define ERROR_EXPONENT_OVERFLOW (2)
125 /* end of flonum.h */