| /* flonum.h - Floating point package |
| Copyright (C) 1987-2016 Free Software Foundation, Inc. |
| |
| This file is part of GAS, the GNU Assembler. |
| |
| GAS 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 3, or (at your option) |
| any later version. |
| |
| GAS 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 GAS; see the file COPYING. If not, write to the Free |
| Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA |
| 02110-1301, USA. */ |
| |
| /***********************************************************************\ |
| * * |
| * Arbitrary-precision floating point arithmetic. * |
| * * |
| * * |
| * Notation: a floating point number is expressed as * |
| * MANTISSA * (2 ** EXPONENT). * |
| * * |
| * If this offends more traditional mathematicians, then * |
| * please tell me your nomenclature for flonums! * |
| * * |
| \***********************************************************************/ |
| |
| #include "bignum.h" |
| |
| /***********************************************************************\ |
| * * |
| * Variable precision floating point numbers. * |
| * * |
| * Exponent is the place value of the low littlenum. E.g.: * |
| * If 0: low points to the units littlenum. * |
| * If 1: low points to the LITTLENUM_RADIX littlenum. * |
| * If -1: low points to the 1/LITTLENUM_RADIX littlenum. * |
| * * |
| \***********************************************************************/ |
| |
| /* JF: A sign value of 0 means we have been asked to assemble NaN |
| A sign value of 'P' means we've been asked to assemble +Inf |
| A sign value of 'N' means we've been asked to assemble -Inf |
| */ |
| struct FLONUM_STRUCT { |
| LITTLENUM_TYPE *low; /* low order littlenum of a bignum */ |
| LITTLENUM_TYPE *high; /* high order littlenum of a bignum */ |
| LITTLENUM_TYPE *leader; /* -> 1st non-zero littlenum */ |
| /* If flonum is 0.0, leader==low-1 */ |
| long exponent; /* base LITTLENUM_RADIX */ |
| char sign; /* '+' or '-' */ |
| }; |
| |
| typedef struct FLONUM_STRUCT FLONUM_TYPE; |
| |
| /***********************************************************************\ |
| * * |
| * Since we can (& do) meet with exponents like 10^5000, it * |
| * is silly to make a table of ~ 10,000 entries, one for each * |
| * power of 10. We keep a table where item [n] is a struct * |
| * FLONUM_FLOATING_POINT representing 10^(2^n). We then * |
| * multiply appropriate entries from this table to get any * |
| * particular power of 10. For the example of 10^5000, a table * |
| * of just 25 entries suffices: 10^(2^-12)...10^(2^+12). * |
| * * |
| \***********************************************************************/ |
| |
| extern const FLONUM_TYPE flonum_positive_powers_of_ten[]; |
| extern const FLONUM_TYPE flonum_negative_powers_of_ten[]; |
| extern const int table_size_of_flonum_powers_of_ten; |
| /* Flonum_XXX_powers_of_ten[] table has legal indices from 0 to |
| + this number inclusive. */ |
| |
| /***********************************************************************\ |
| * * |
| * Declare worker functions. * |
| * * |
| \***********************************************************************/ |
| |
| int atof_generic (char **address_of_string_pointer, |
| const char *string_of_decimal_marks, |
| const char *string_of_decimal_exponent_marks, |
| FLONUM_TYPE * address_of_generic_floating_point_number); |
| |
| void flonum_copy (FLONUM_TYPE * in, FLONUM_TYPE * out); |
| void flonum_multip (const FLONUM_TYPE * a, const FLONUM_TYPE * b, |
| FLONUM_TYPE * product); |
| |
| /***********************************************************************\ |
| * * |
| * Declare error codes. * |
| * * |
| \***********************************************************************/ |
| |
| #define ERROR_EXPONENT_OVERFLOW (2) |