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Diffstat (limited to 'gas/flonum.h')
| -rw-r--r-- | gas/flonum.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/gas/flonum.h b/gas/flonum.h new file mode 100644 index 0000000..6684f49 --- /dev/null +++ b/gas/flonum.h @@ -0,0 +1,110 @@ +/* flonum.h - Floating point package + + Copyright (C) 1987, 90, 91, 92, 94, 95, 1996 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 2, 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, 59 Temple Place - Suite 330, Boston, MA + 02111-1307, 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 PARAMS ((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 PARAMS ((FLONUM_TYPE * in, FLONUM_TYPE * out)); +void flonum_multip PARAMS ((const FLONUM_TYPE * a, const FLONUM_TYPE * b, + FLONUM_TYPE * product)); + +/***********************************************************************\ + * * + * Declare error codes. * + * * + \***********************************************************************/ + +#define ERROR_EXPONENT_OVERFLOW (2) + +/* end of flonum.h */ |