ecl/src/c/big.d

298 lines
6.3 KiB
C

/* -*- mode: c; c-basic-offset: 8 -*- */
/*
big.c -- Bignum routines.
*/
/*
Copyright (c) 1990, Giuseppe Attardi.
Copyright (c) 2001, Juan Jose Garcia Ripoll.
ECL is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
See file '../Copyright' for full details.
*/
#include <string.h>
#include <ecl/ecl.h>
#include <ecl/internal.h>
/*
* Using GMP multiple precision integers:
*
* typedef struct
* {
* long int alloc; // Number of limbs allocated and pointed
* // to by the D field.
* long int size; // abs(SIZE) is the number of limbs
* // the last field points to. If SIZE
* // is negative this is a negative number.
* unsigned long int *d; // Pointer to the limbs,
* // d[0] is the least significative.
* } MP_INT;
*
* typedef unsigned long int mp_limb_t;
*
*/
cl_object
big_register0_get(void)
{
cl_env.big_register[0]->big.big_size = 0;
return cl_env.big_register[0];
}
cl_object
big_register1_get(void)
{
cl_env.big_register[1]->big.big_size = 0;
return cl_env.big_register[1];
}
cl_object
big_register2_get(void)
{
cl_env.big_register[2]->big.big_size = 0;
return cl_env.big_register[2];
}
void
big_register_free(cl_object x)
{
/* FIXME! Is this thread safe? */
if (x == cl_env.big_register[0])
x->big.big_limbs = cl_env.big_register_limbs[0];
else if (x == cl_env.big_register[1])
x->big.big_limbs = cl_env.big_register_limbs[1];
else if (x == cl_env.big_register[2])
x->big.big_limbs = cl_env.big_register_limbs[2];
else
ecl_internal_error("big_register_free: unknown register");
x->big.big_size = 0;
x->big.big_dim = BIGNUM_REGISTER_SIZE;
}
cl_object
big_register_copy(cl_object old)
{
cl_object new_big = cl_alloc_object(t_bignum);
if (old->big.big_dim > BIGNUM_REGISTER_SIZE) {
/* The object already has suffered a mpz_realloc() so
we can use the pointer */
new_big->big = old->big;
big_register_free(old);
} else {
/* As the bignum points to the cl_env.big_register_limbs[] area
we must duplicate its contents. */
mpz_init_set(new_big->big.big_num,old->big.big_num);
}
return new_big;
}
cl_object
big_register_normalize(cl_object x)
{
int s = x->big.big_size;
mp_limb_t y;
if (s == 0)
return(MAKE_FIXNUM(0));
y = x->big.big_limbs[0];
if (s == 1) {
if (y <= MOST_POSITIVE_FIXNUM)
return(MAKE_FIXNUM(y));
} else if (s == -1) {
if (y <= -MOST_NEGATIVE_FIXNUM)
return(MAKE_FIXNUM(-y));
}
return big_register_copy(x);
}
/*
* Different from mpz_init since we initialize with NULL limbs
*/
static cl_object
big_alloc(int size)
{
volatile cl_object x = cl_alloc_object(t_bignum);
if (size <= 0)
ecl_internal_error("negative or zero size for bignum in big_alloc");
x->big.big_dim = size;
x->big.big_size = 0;
x->big.big_limbs = (mp_limb_t *)cl_alloc_atomic_align(size * sizeof(mp_limb_t), sizeof(mp_limb_t));
return(x);
}
cl_object
bignum1(cl_fixnum val)
{
volatile cl_object z = cl_alloc_object(t_bignum);
mpz_init_set_si(z->big.big_num, val);
return(z);
}
cl_object
bignum2(mp_limb_t hi, mp_limb_t lo)
{
cl_object z;
z = big_alloc(2);
z->big.big_size = 2;
z->big.big_limbs[0] = lo;
z->big.big_limbs[1] = hi;
return(z);
}
cl_object
big_copy(cl_object x)
{
volatile cl_object y = cl_alloc_object(t_bignum);
mpz_init_set(y->big.big_num, x->big.big_num);
return(y);
}
/*
big_zerop(x) tells whether bignum x is zero or not.
#define big_zerop(x) (mp_size(x->big.big_num) == 0)
*/
/*
big_sign(x) returns
something < 0 if x < 0
0 if x = 0
something > 0 if x > 0.
#define big_sign(x) (x->big.big_size)
*/
/*
big_compare(x, y) returns
-1 if x < y
0 if x = y
1 if x > y.
#define big_compare(x, y) mpz_cmp(x->big.big_num, y->big.big_num)
*/
/*
big_complement(x) destructively takes
the complement of bignum x.
#define big_complement(x) mpz_neg(x->big.big_num, x->big.num);
*/
/*
big_minus(x) returns the complement of bignum x.
*/
cl_object
big_minus(cl_object x)
{
volatile cl_object y = big_copy(x);
mpz_neg(y->big.big_num, y->big.big_num);
return y;
}
/*
big_add_ui(x, i) destructively adds non-negative int i
to bignum x.
I should be non-negative.
mpz_add_ui(x->big.big_num, x->big.big_num, i)
*/
/*
big_sub_ui(x, i) destructively subtracts non-negative int i
from bignum x.
I should be non-negative.
mpz_sub_ui(x->big.big_num, x->big.big_num, i)
*/
/*
big_mul_ui(x, i) destructively multiplies non-negative bignum x
by non-negative int i.
I should be non-negative.
X should be non-negative.
mpn_mul(&x->big.big_limbs, &x->big.big_limbs, x->big.big_size, &i, 1)
*/
/*
big_div_ui(x, i) destructively divides non-negative bignum x
by positive int i.
X will hold the remainder of the division.
div_int_big(i, x) returns the remainder of the division.
I should be positive.
X should be non-negative.
mp_limb_t q[x->big.big_size];
mpn_div(q, &x->big.big_limbs, &x->big.big_size, &i, 1), x
*/
/*
big_plus(x, y) returns the sum of bignum x and bignum y.
X and y may be any bignum.
*/
cl_object
big_plus(cl_object x, cl_object y)
{
volatile cl_object z = big_register0_get();
mpz_add(z->big.big_num, x->big.big_num, y->big.big_num);
return(big_register_copy(z));
}
cl_object
big_normalize(cl_object x)
{
int s = x->big.big_size;
mp_limb_t y;
if (s == 0)
return(MAKE_FIXNUM(0));
y = x->big.big_limbs[0];
if (s == 1 && y <= MOST_POSITIVE_FIXNUM)
return(MAKE_FIXNUM(y));
if (s == -1 && y <= -MOST_NEGATIVE_FIXNUM)
return(MAKE_FIXNUM(-y));
return(x);
}
static void *
mp_alloc(size_t size)
{
return cl_alloc_atomic_align(size, sizeof(mp_limb_t));
}
static void *
mp_realloc(void *ptr, size_t osize, size_t nsize)
{
void *p = cl_alloc_atomic_align(nsize, sizeof(mp_limb_t));
memcpy(p, ptr, osize);
return p;
}
static void
mp_free(void *ptr, size_t size)
{
char *x = ptr;
if (x < (char *)(cl_env.big_register_limbs) ||
x > (char *)(cl_env.big_register_limbs+2))
cl_dealloc(x);
}
void init_big_registers(void)
{
int i;
for (i = 0; i < 3; i++) {
cl_env.big_register[i] = cl_alloc_object(t_bignum);
big_register_free(cl_env.big_register[i]);
}
}
void
init_big(void)
{
init_big_registers();
mp_set_memory_functions(mp_alloc, mp_realloc, mp_free);
}