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Diffstat (limited to 'gas/flonum.h')
| -rw-r--r-- | gas/flonum.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/gas/flonum.h b/gas/flonum.h new file mode 100644 index 0000000..570bd3a --- /dev/null +++ b/gas/flonum.h @@ -0,0 +1,122 @@ +/* flonum.h - Floating point package + Copyright (C) 1987, 1990, 1991 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* $Id$ */ + +/***********************************************************************\ +* * +* 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! * +* * +\***********************************************************************/ +#if !defined(__STDC__) && !defined(const) +#define const /* empty */ +#endif + +#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. * +* * +\***********************************************************************/ + +#ifdef __STDC__ + +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); + +#else /* __STDC__ */ + +int atof_generic(); +void flonum_copy(); +void flonum_multip(); + +#endif /* __STDC__ */ + +/***********************************************************************\ +* * +* Declare error codes. * +* * +\***********************************************************************/ + +#define ERROR_EXPONENT_OVERFLOW (2) + +/* end: flonum.h */ |