base_conversion.h revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1988-1995, by Sun Microsystems, Inc.
* All rights reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <errno.h>
#include <floatingpoint.h>
#ifdef DEBUG
#include <stdio.h>
#include <assert.h>
#endif
/* Sun floating-point PRIVATE include file. */
/* PRIVATE MACROS */
#ifdef DEBUG
#define PRIVATE
#else
#define PRIVATE static
#endif
/* PRIVATE CONSTANTS */
#define SINGLE_BIAS 127
#define DOUBLE_BIAS 1023
#define EXTENDED_BIAS 16383
#define QUAD_BIAS 16383
* consider. */
* consider. */
* consider. */
* consider. */
/* PRIVATE TYPES */
typedef struct { /* Unpack floating-point internal format. *//* V
* alue is 0.s0s1..sn * 2**(1+exponent) */
int sign;
enum fp_class_type fpclass;
int exponent; /* Unbiased exponent. */
* and sticky. */
}
#ifdef i386
typedef struct { /* Most significant word formats. */
unsigned significand:23;
unsigned exponent:8;
unsigned sign:1;
}
typedef struct {
unsigned significand:20;
unsigned exponent:11;
unsigned sign:1;
}
typedef struct {
unsigned exponent:15;
unsigned sign:1;
unsigned unused:16;
}
typedef struct {
unsigned significand:16;
unsigned exponent:15;
unsigned sign:1;
}
typedef struct { /* Floating-point formats in detail. */
}
typedef struct {
unsigned significand2;
}
typedef struct {
unsigned significand2;
unsigned significand;
}
typedef struct {
unsigned significand4;
unsigned significand3;
unsigned significand2;
}
#else
typedef struct { /* Most significant word formats. */
unsigned sign:1;
unsigned exponent:8;
unsigned significand:23;
}
typedef struct {
unsigned sign:1;
unsigned exponent:11;
unsigned significand:20;
}
typedef struct {
unsigned sign:1;
unsigned exponent:15;
unsigned unused:16;
}
typedef struct {
unsigned sign:1;
unsigned exponent:15;
unsigned significand:16;
}
typedef struct { /* Floating-point formats in detail. */
}
typedef struct {
unsigned significand2;
}
typedef struct {
unsigned significand;
unsigned significand2;
}
typedef struct {
unsigned significand2;
unsigned significand3;
unsigned significand4;
}
#endif
typedef union { /* Floating-point formats equivalenced. */
single x;
}
typedef union {
double x;
}
typedef union {
extended x;
}
typedef union {
quadruple x;
}
/* PRIVATE GLOBAL VARIABLES */
* exceptions. */
enum fp_direction_type
_fp_current_direction; /* Current rounding direction. */
enum fp_precision_type
_fp_current_precision; /* Current rounding precision. */
/* PRIVATE FUNCTIONS */
extern void
_fp_normalize( /* pu */ );
/* unpacked *pu ; /* unpacked operand and result */
extern void
_fp_leftshift( /* pu, n */ );
/*
* unpacked *pu; unsigned n;
*/
extern void
_fp_set_exception( /* ex */ );
/* enum fp_exception_type ex ; /* exception to be set in curexcep */
/*
* Default size for _big_float - suitable for single and double precision.
*/
#define _BIG_FLOAT_DIGIT short unsigned /* big_float significand type */
* representable extended or quad. */
typedef struct { /* Variable-precision floating-point type
* used for intermediate results. */
unsigned short bsize; /* Maximum allowable logical length of
* significand. */
unsigned short blength;/* Logical length of significand. */
short int bexponent; /* Exponent to be attached to least
* significant word of significand.
* exponent >= 0 implies all integer,
* with decimal point to right of
* least significant word of
* significand, and is equivalent to
* number of omitted trailing zeros
* of significand. -length < exponent
* < 0 implies decimal point within
* significand. exponent = -length
* implies decimal point to left of
* most significand word. exponent <
* -length implies decimal point to
* left of most significant word with
* -length-exponent leading zeros. */
/*
* NOTE: bexponent represents a power of 2 or 10, even though big
* digits are powers of 2**16 or 10**4.
*/
/*
* Significand of digits in base 10**4 or 2**16. significand[0] is
* least significant, significand[length-1] is most significant.
*/
} _big_float;
#define BIG_FLOAT_TIMES_NOMEM (_big_float *)0
/* Internal functions defined in base conversion support routines. */
extern void _multiply_base_ten();
extern void _multiply_base_two_carry();
extern void _multiply_base_ten_by_two();
extern void _multiply_base_two();
extern void _multiply_base_two_by_two();
extern void _carry_propagate_two();
extern void _carry_propagate_ten();
extern void _multiply_base_two_vector();
extern void _multiply_base_ten_vector();
extern void _fourdigitsquick();
extern void _unpacked_to_big_float();
extern void _big_binary_to_big_decimal();
extern void _left_shift_base_ten();
extern void _left_shift_base_two();
extern void _right_shift_base_two();
extern void _free_big_float();
extern void _base_conversion_abort();
extern void _display_big_float();
extern void _integerstring_to_big_decimal();
extern void _fractionstring_to_big_decimal();
extern void _big_decimal_to_big_binary();
extern void _fp_rightshift();
extern void _fp_leftshift();
extern void _fp_normalize();
extern void _pack_single();
extern void _pack_double();
extern void _pack_extended();
extern void _pack_quadruple();
extern void _unpack_single();
extern void _unpack_double();
extern void _unpack_extended();
extern void _unpack_quadruple();
extern void _unpacked_to_decimal();
extern enum fp_class_type _class_single();
extern enum fp_class_type _class_double();
extern enum fp_class_type _class_extended();
extern enum fp_class_type _class_quadruple();
/*
Fundamental utilities that multiply or add two shorts into a unsigned long,
sometimes add an unsigned long carry,
compute quotient and remainder in underlying base, and return
quo<<16 | rem as a unsigned long.
*/
extern unsigned long _umac(); /* p = x * y + c ; return p */
/*
extern unsigned long _prodc_b65536(); /* p = x * y + c ; return p */
#define _prodc_b65536(x,y,c) (_umac((x),(y),(c)))
extern unsigned long _prodc_b10000(); /* p = x * y + c ; return (p/10000 <<
extern unsigned long _prod_b65536(); /* p = x * y ; return p */
extern unsigned long _prod_b10000(); /* p = x * y ; return (p/10000 << 16 | p%10000) */
extern unsigned long _prod_10000_b65536(); /* p = x * 10000 + c ; return
* p */
extern unsigned long _prod_65536_b10000(); /* p = x * 65536 + c ; return
* (p/10000 << 16 | p%10000) */
/*
extern unsigned long _rshift_b65536(); /* p = x << n + c<<16 ; return p */
/*
extern unsigned long _lshift_b65536(); /* p = x << n + c ; return p */
#define _lshift_b65536(x,n,c) ((((unsigned long) (x)) << (n)) + (c))
extern unsigned long _lshift_b10000(); /* p = x << n + c ; return (p/10000
* << 16 | p%10000) */
/*
extern unsigned long _carry_in_b65536(); /* p = x + c ; return p */
#define _carry_in_b65536(x,c) ((x) + (c))
extern unsigned long _carry_in_b10000(); /* p = x + c ; return
* (p/10000 << 16 | p%10000) */
/*
extern unsigned long _carry_out_b65536(); /* p = c ; return p */
#define _carry_out_b65536(c) (c)
extern unsigned long _carry_out_b10000(); /* p = c ; return (p/10000 <<
* 16 | p%10000) */
/*
* Header file for revised "fast" base conversion based upon table look-up
* methods.
*/
extern void
#ifdef notdef
/* function to multiply a big_float times a positive power of two or ten. */
* by the product x * mult **
* n. */
int mult; /* if mult is two, x is base 10**4; if mult
* is ten, x is base 2**16 */
int n;
int precision; /* Number of bits of precision
* ultimately required (mult=10) or
* number of digits of precision
* ultimately required (mult=2).
* Extra bits are allowed internally
* to permit correct rounding. */
* uneventful: *pbf holds the product ;
* BIG_FLOAT_TIMES_TOOBIG if n is
* bigger than the tables permit ;
* BIG_FLOAT_TIMES_NOMEM if
* pbf->blength was insufficient to hold the
* product, and malloc failed to produce a
* new block ; &newbf if
* pbf->blength was insufficient to hold the
* product, and a new _big_float was
* allocated by malloc. newbf holds the
* product. It's the caller's responsibility
* to free this space when no longer needed. */
#endif
);
/* Variables defined in _small_powers.c and _big_powers.c */
/* Used in base conversion. */
/*
* The run-time structure consists of two large tables of powers - either
* powers of 10**4 in base 2**16 or vice versa.
*
* Suppose it's powers of T in base B. Then
*
* _tiny_powers_T contains TTINY entries, T**0, T**1, ... T**TTINY-1 where
* T is 2 or 10, TTINY is 16 or 4 _small_powers_T contains TSMALL
* entries, T**0, T**1, ... T**TSMALL-1 where T is 2**TTINY or 10**TTINY
* _big_powers_T contains TBIG entries, T**0, T**1, ... T**TBIG-1
* where T is (2**TTINY)**TSMALL or (10**TTINY)**TSMALL
*
* so that any power of T from 0 to T**(TTINY*TSMALL*TBIG-1) can be represented
* as a product of just two table entries. Since the powers vary greatly in
* size, the tables are condensed to exclude leading and trailing zeros. The
* following tables
*
* _max_tiny_powers_T contains one entry, TTINY
* _start_tiny_powers_T contains TTINY entries
* _leading_zeros_tiny_powers_T contains TTINY entries
* _max_small_powers_T contains one entry, TSMALL
* _start_small_powers_T contains TSMALL entries
* _leading_zeros_small_powers_T contains TSMALL entries
* _max_big_powers_T contains one entry, TBIG
* _start_big_powers_T contains TBIG entries
* _leading_zeros_big_powers_T contains TBIG entries
*
* The powers are maintained with x[start] less significant than x[start+1], so
*
* The powers are maintained with x[start] less significant than x[start+1], so
* that the interpretation of a _small_powers_T entry is that
*
T**i = (B**leading_zeros[i]) * (x[start[i]] + x[start[i]+1] * B + ...
* x[start[i+1]-1] * B**(start[i+1]-start[i]) )
*
* where B = (2 or 10)**TTINY
*
* The powers are listed consecutively in the tables, with start index and
* leading zero information retained and printed out at the end.
*
*/
extern unsigned short _max_tiny_powers_ten;
extern unsigned short _tiny_powers_ten[];
extern unsigned short _start_tiny_powers_ten[];
extern unsigned short _leading_zeros_tiny_powers_ten[];
extern unsigned short _max_tiny_powers_two;
extern unsigned short _tiny_powers_two[];
extern unsigned short _start_tiny_powers_two[];
extern unsigned short _max_small_powers_ten;
extern unsigned short _small_powers_ten[];
extern unsigned short _start_small_powers_ten[];
extern unsigned short _leading_zeros_small_powers_ten[];
extern unsigned short _max_small_powers_two;
extern unsigned short _small_powers_two[];
extern unsigned short _start_small_powers_two[];
extern unsigned short _max_big_powers_ten;
extern unsigned short _big_powers_ten[];
extern unsigned short _start_big_powers_ten[];
extern unsigned short _leading_zeros_big_powers_ten[];
extern unsigned short _max_big_powers_two;
extern unsigned short _big_powers_two[];
extern unsigned short _start_big_powers_two[];