ikarus/runtime/ikarus-numerics.c

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2006-11-23 19:48:14 -05:00
#include "ikarus.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <gmp.h>
#define most_positive_fixnum 0x1FFFFFFF
#define most_negative_fixnum 0x20000000
#define max_digits_per_limb 10
ikp
ikrt_isbignum(ikp x){
if(tagof(x) == vector_tag){
ikp fst = ref(x, -vector_tag);
if (bignum_tag == (bignum_mask & (int)fst)){
return true_object;
}
}
return false_object;
}
ikp
ikrt_positive_bn(ikp x){
ikp fst = ref(x, -vector_tag);
if((int)fst & bignum_sign_mask){
return false_object;
} else {
return true_object;
}
}
ikp
ikrt_fxfxplus(ikp x, ikp y, ikpcb* pcb){
int n1 = unfix(x);
int n2 = unfix(y);
int r = n1 + n2;
ikp q = fix(r);
if(r == unfix(q)){
return q;
}
else {
ikp bn = ik_alloc(pcb, align(disp_bignum_data + wordsize));
if(r > 0){
ref(bn, 0) = (ikp)(bignum_tag | (1 << bignum_length_shift));
ref(bn, disp_bignum_data) = (ikp)r;
}
else {
ref(bn, 0) =
(ikp)(bignum_tag |
(1 << bignum_length_shift) |
(1 << bignum_sign_shift));
ref(bn, disp_bignum_data) = (ikp)-r;
}
return bn+vector_tag;
}
}
ikp
ikrt_fxbnplus(ikp x, ikp y, ikpcb* pcb){
if(x == 0){ return y ; }
ikp fst = ref(y, -vector_tag);
int limb_count = ((unsigned int) fst) >> bignum_length_shift;
int intx = unfix(x);
if(intx > 0){
if((bignum_sign_mask & (int)fst) == 0){
/* positive fx + positive bn = even bigger positive */
ikp r = ik_alloc(pcb, align(disp_bignum_data+(limb_count+1)*wordsize));
int carry = mpn_add_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(y - vector_tag + disp_bignum_data),
limb_count,
intx);
if(carry){
ref(r, disp_bignum_data + limb_count*wordsize) = (ikp)1;
ref(r, 0) = (ikp)
(((limb_count + 1) << bignum_length_shift) |
(0 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
} else {
ref(r, 0) = (ikp)
((limb_count << bignum_length_shift) |
(0 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
}
}
else {
/* positive fx + negative bn = smaller negative bn */
ikp r = ik_alloc(pcb, align(disp_bignum_data+limb_count*wordsize));
int borrow = mpn_sub_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(y - vector_tag + disp_bignum_data),
limb_count,
intx);
if(borrow){
fprintf(stderr, "Error: BUG in borrow\n");
exit(-1);
}
int result_size =
(ref(r, disp_bignum_data + (limb_count-1)*wordsize))
? limb_count
: (limb_count - 1);
if(result_size == 0){
return 0;
}
if(result_size == 1){
unsigned int last =
(unsigned int) ref(r, disp_bignum_data + (result_size-1)*wordsize);
if(last <= most_negative_fixnum){
return fix(-(int)last);
}
}
ref(r, 0) = (ikp)
((result_size << bignum_length_shift) |
(1 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
}
}
else {
if((bignum_sign_mask & (int)fst) == 0){
/* negative fx + positive bn = smaller positive */
ikp r = ik_alloc(pcb, align(disp_bignum_data+limb_count*wordsize));
int borrow = mpn_sub_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(y - vector_tag + disp_bignum_data),
limb_count,
- intx);
if(borrow){
fprintf(stderr, "Error: BUG in borrow\n");
exit(-1);
}
int result_size =
(ref(r, disp_bignum_data + (limb_count-1)*wordsize) == 0)
? (limb_count - 1)
: limb_count;
if(result_size == 0){
return 0;
}
if(result_size == 1){
unsigned int last =
(unsigned int) ref(r, disp_bignum_data + (result_size-1)*wordsize);
if(last <= most_positive_fixnum){
return fix((int)last);
}
}
ref(r, 0) = (ikp)
((result_size << bignum_length_shift) |
(0 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
} else {
/* negative fx + negative bn = larger negative */
ikp r = ik_alloc(pcb, align(disp_bignum_data+(limb_count+1)*wordsize));
int carry = mpn_add_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(y - vector_tag + disp_bignum_data),
limb_count,
-intx);
if(carry){
ref(r, disp_bignum_data + limb_count*wordsize) = (ikp)1;
ref(r, 0) = (ikp)
(((limb_count + 1) << bignum_length_shift) |
(1 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
} else {
ref(r, 0) = (ikp)
((limb_count << bignum_length_shift) |
(1 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
}
}
}
}
ikp
ikrt_bnbnplus(ikp x, ikp y, ikpcb* pcb){
unsigned int xfst = (unsigned int)ref(x, -vector_tag);
unsigned int yfst = (unsigned int)ref(y, -vector_tag);
int xsign = xfst & bignum_sign_mask;
int ysign = yfst & bignum_sign_mask;
int xlimbs = xfst >> bignum_length_shift;
int ylimbs = yfst >> bignum_length_shift;
if(xsign == ysign){
int n1,n2;
ikp s1,s2;
if(xlimbs > ylimbs){
n1 = xlimbs; n2 = ylimbs; s1 = x; s2 = y;
} else {
n1 = ylimbs; n2 = xlimbs; s1 = y; s2 = x;
}
ikp res = ik_alloc(pcb, align(disp_bignum_data + (n1+1)*wordsize));
mp_limb_t carry = mpn_add((mp_limb_t*) (res+disp_bignum_data),
(mp_limb_t*) (s1-vector_tag+disp_bignum_data),
n1,
(mp_limb_t*) (s2-vector_tag+disp_bignum_data),
n2);
if(carry){
ref(res, disp_vector_data + xlimbs*wordsize) = (ikp)1;
ref(res, 0) = (ikp)
(((n1+1) << bignum_length_shift) |
xsign |
bignum_tag);
return res+vector_tag;
} else {
ref(res, 0) = (ikp)
((n1 << bignum_length_shift) |
xsign |
bignum_tag);
return res+vector_tag;
}
}
else {
ikp s1=x, s2=y;
int n1=xlimbs, n2=ylimbs;
int result_sign = xsign;
while((xlimbs == ylimbs) &&
(ref(x, -vector_tag+disp_bignum_data+(xlimbs-1)*wordsize) ==
ref(y, -vector_tag+disp_bignum_data+(xlimbs-1)*wordsize))){
xlimbs -= 1;
ylimbs -= 1;
if(xlimbs == 0){ return 0; }
}
/* |x| != |y| */
if(xlimbs <= ylimbs){
if(xlimbs == ylimbs){
if((ref(y, -vector_tag+disp_bignum_data+(xlimbs-1)*wordsize) >
ref(x, -vector_tag+disp_bignum_data+(xlimbs-1)*wordsize))){
s1 = y; n1 = ylimbs;
s2 = x; n2 = xlimbs;
result_sign = ysign;
}
} else {
s1 = y; n1 = ylimbs;
s2 = x; n2 = xlimbs;
result_sign = ysign;
}
}
/* |s1| > |s2| */
ikp res = ik_alloc(pcb, align(disp_bignum_data + n1 * wordsize));
int burrow = mpn_sub((mp_limb_t*) (res + disp_bignum_data),
(mp_limb_t*) (s1 - vector_tag + disp_bignum_data),
n1,
(mp_limb_t*) (s2 - vector_tag + disp_bignum_data),
n2);
if(burrow){
fprintf(stderr, "BUG: Burrow error in bnbn+\n");
exit(-1);
}
int len = n1;
while(ref(res, disp_bignum_data + (len-1)*wordsize) == 0){
len--;
if(len == 0){
return 0;
}
}
if(result_sign == 0){
/* positive result */
if(len == 1){
unsigned int fst_limb = (unsigned int) ref(res, disp_bignum_data);
if(fst_limb <= most_positive_fixnum){
return fix((int)fst_limb);
}
}
ref(res, 0) = (ikp)
((len << bignum_length_shift) |
result_sign |
bignum_tag);
return res+vector_tag;
} else {
/* negative result */
if(len == 1){
unsigned int fst_limb = (unsigned int) ref(res, disp_bignum_data);
if(fst_limb <= most_negative_fixnum){
return fix(-(int)fst_limb);
}
}
ref(res, 0) = (ikp)
((len << bignum_length_shift) |
result_sign |
bignum_tag);
return res+vector_tag;
}
}
}
ikp
ikrt_fxfxminus(ikp x, ikp y, ikpcb* pcb){
int n1 = unfix(x);
int n2 = unfix(y);
int r = n1 - n2;
if(r >= 0){
if(((unsigned int)r) <= most_positive_fixnum){
return fix(r);
} else {
ikp bn = ik_alloc(pcb, align(disp_bignum_data + wordsize));
ref(bn, 0) = (ikp) (bignum_tag | (1 << bignum_length_shift));
ref(bn, disp_bignum_data) = (ikp)r;
return bn+vector_tag;
}
} else {
if(((unsigned int)r) <= most_negative_fixnum){
return fix(r);
} else {
ikp bn = ik_alloc(pcb, align(disp_bignum_data + wordsize));
ref(bn, 0) = (ikp)
(bignum_tag |
(1 << bignum_sign_shift) |
(1 << bignum_length_shift));
ref(bn, disp_bignum_data) = (ikp)(-r);
return bn+vector_tag;
}
}
}
ikp
ikrt_bnnegate(ikp x, ikpcb* pcb){
ikp fst = ref(x, -vector_tag);
int limb_count = ((unsigned int) fst) >> bignum_length_shift;
if(limb_count == 1){
if((bignum_sign_mask & (int)fst) == 0){
/* positive bignum */
unsigned int limb = (unsigned int) ref(x, disp_bignum_data - vector_tag);
if(limb == (most_positive_fixnum + 1)){
return fix(-(int)limb);
}
}
}
ikp bn = ik_alloc(pcb, align(disp_bignum_data + limb_count * wordsize));
memcpy(bn+disp_bignum_data,
x-vector_tag+disp_bignum_data,
limb_count*wordsize);
ref(bn, 0) = (ikp)
(bignum_tag |
((1 << bignum_sign_shift) - (bignum_sign_mask & (int)fst)) |
(limb_count << bignum_length_shift));
return bn+vector_tag;
}
ikp
ikrt_fxbnminus(ikp x, ikp y, ikpcb* pcb){
if(x == 0){ return ikrt_bnnegate(y, pcb) ; }
ikp fst = ref(y, -vector_tag);
int limb_count = ((unsigned int) fst) >> bignum_length_shift;
int intx = unfix(x);
if(intx > 0){
if(bignum_sign_mask & (int)fst){
/* positive fx - negative bn = positive bn */
ikp r = ik_alloc(pcb, align(disp_bignum_data+(limb_count+1)*wordsize));
int carry = mpn_add_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(y - vector_tag + disp_bignum_data),
limb_count,
intx);
if(carry){
ref(r, disp_bignum_data + limb_count*wordsize) = (ikp)1;
ref(r, 0) = (ikp)
(((limb_count + 1) << bignum_length_shift) |
(0 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
} else {
ref(r, 0) = (ikp)
((limb_count << bignum_length_shift) |
(0 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
}
}
else {
/* positive fx - positive bn = smaller negative bn/fx */
ikp r = ik_alloc(pcb, align(disp_bignum_data+limb_count*wordsize));
int borrow = mpn_sub_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(y - vector_tag + disp_bignum_data),
limb_count,
intx);
if(borrow){
fprintf(stderr, "Error: BUG in borrow\n");
exit(-1);
}
int result_size =
(ref(r, disp_bignum_data + (limb_count-1)*wordsize))
? limb_count
: (limb_count - 1);
if(result_size == 0){
return 0;
}
if(result_size == 1){
unsigned int last =
(unsigned int) ref(r, disp_bignum_data + (result_size-1)*wordsize);
if(last <= most_negative_fixnum){
return fix(-(int)last);
}
}
ref(r, 0) = (ikp)
((result_size << bignum_length_shift) |
(1 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
}
}
else {
if(bignum_sign_mask & (int)fst){
/* negative fx - negative bn = smaller positive */
ikp r = ik_alloc(pcb, align(disp_bignum_data+limb_count*wordsize));
int borrow = mpn_sub_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(y - vector_tag + disp_bignum_data),
limb_count,
- intx);
if(borrow){
fprintf(stderr, "Error: BUG in borrow\n");
exit(-1);
}
int result_size =
(ref(r, disp_bignum_data + (limb_count-1)*wordsize) == 0)
? (limb_count - 1)
: limb_count;
if(result_size == 0){
return 0;
}
if(result_size == 1){
unsigned int last =
(unsigned int) ref(r, disp_bignum_data + (result_size-1)*wordsize);
if(last <= most_positive_fixnum){
return fix((int)last);
}
}
ref(r, 0) = (ikp)
((result_size << bignum_length_shift) |
(0 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
} else {
/* negative fx - positive bn = larger negative */
ikp r = ik_alloc(pcb, align(disp_bignum_data+(limb_count+1)*wordsize));
int carry = mpn_add_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(y - vector_tag + disp_bignum_data),
limb_count,
-intx);
if(carry){
ref(r, disp_bignum_data + limb_count*wordsize) = (ikp)1;
ref(r, 0) = (ikp)
(((limb_count + 1) << bignum_length_shift) |
(1 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
} else {
ref(r, 0) = (ikp)
((limb_count << bignum_length_shift) |
(1 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
}
}
}
}
ikp
ikrt_bnfxminus(ikp x, ikp y, ikpcb* pcb){
if(y == 0){ return x; }
ikp fst = ref(x, -vector_tag);
int limb_count = ((unsigned int) fst) >> bignum_length_shift;
int inty = unfix(y);
if(inty < 0){
if((bignum_sign_mask & (int)fst) == 0){
/* - negative fx + positive bn = positive bn */
ikp r = ik_alloc(pcb, align(disp_bignum_data+(limb_count+1)*wordsize));
int carry = mpn_add_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(x - vector_tag + disp_bignum_data),
limb_count,
-inty);
if(carry){
ref(r, disp_bignum_data + limb_count*wordsize) = (ikp)1;
ref(r, 0) = (ikp)
(((limb_count + 1) << bignum_length_shift) |
(0 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
} else {
ref(r, 0) = (ikp)
((limb_count << bignum_length_shift) |
(0 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
}
}
else {
/* - negative fx + negative bn = smaller negative bn/fx */
ikp r = ik_alloc(pcb, align(disp_bignum_data+limb_count*wordsize));
int borrow = mpn_sub_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(x - vector_tag + disp_bignum_data),
limb_count,
-inty);
if(borrow){
fprintf(stderr, "Error: BUG in borrow\n");
exit(-1);
}
int result_size =
(ref(r, disp_bignum_data + (limb_count-1)*wordsize))
? limb_count
: (limb_count - 1);
if(result_size == 0){
return 0;
}
if(result_size == 1){
unsigned int last =
(unsigned int) ref(r, disp_bignum_data + (result_size-1)*wordsize);
if(last <= most_negative_fixnum){
return fix(-(int)last);
}
}
ref(r, 0) = (ikp)
((result_size << bignum_length_shift) |
(1 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
}
}
else {
if((bignum_sign_mask & (int)fst) == 0){
/* - positive fx + positive bn = smaller positive */
ikp r = ik_alloc(pcb, align(disp_bignum_data+limb_count*wordsize));
int borrow = mpn_sub_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(x - vector_tag + disp_bignum_data),
limb_count,
inty);
if(borrow){
fprintf(stderr, "Error: BUG in borrow\n");
exit(-1);
}
int result_size =
(ref(r, disp_bignum_data + (limb_count-1)*wordsize) == 0)
? (limb_count - 1)
: limb_count;
if(result_size == 0){
return 0;
}
if(result_size == 1){
unsigned int last =
(unsigned int) ref(r, disp_bignum_data + (result_size-1)*wordsize);
if(last <= most_positive_fixnum){
return fix((int)last);
}
}
ref(r, 0) = (ikp)
((result_size << bignum_length_shift) |
(0 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
} else {
/* - positive fx + negative bn = larger negative */
ikp r = ik_alloc(pcb, align(disp_bignum_data+(limb_count+1)*wordsize));
int carry = mpn_add_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(x - vector_tag + disp_bignum_data),
limb_count,
inty);
if(carry){
ref(r, disp_bignum_data + limb_count*wordsize) = (ikp)1;
ref(r, 0) = (ikp)
(((limb_count + 1) << bignum_length_shift) |
(1 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
} else {
ref(r, 0) = (ikp)
((limb_count << bignum_length_shift) |
(1 << bignum_sign_shift) |
bignum_tag);
return r+vector_tag;
}
}
}
}
ikp
ikrt_bnbnminus(ikp x, ikp y, ikpcb* pcb){
if(x == y) { return 0; }
unsigned int xfst = (unsigned int)ref(x, -vector_tag);
unsigned int yfst = (unsigned int)ref(y, -vector_tag);
int xsign = xfst & bignum_sign_mask;
int ysign = yfst & bignum_sign_mask;
int xlimbs = xfst >> bignum_length_shift;
int ylimbs = yfst >> bignum_length_shift;
if(xsign != ysign){
int n1,n2;
ikp s1,s2;
if(xlimbs >= ylimbs){
n1 = xlimbs; n2 = ylimbs; s1 = x; s2 = y;
} else {
n1 = ylimbs; n2 = xlimbs; s1 = y; s2 = x;
}
ikp res = ik_alloc(pcb, align(disp_bignum_data + (n1+1)*wordsize));
mp_limb_t carry = mpn_add((mp_limb_t*) (res+disp_bignum_data),
(mp_limb_t*) (s1-vector_tag+disp_bignum_data),
n1,
(mp_limb_t*) (s2-vector_tag+disp_bignum_data),
n2);
if(carry){
ref(res, disp_vector_data + xlimbs*wordsize) = (ikp)1;
ref(res, 0) = (ikp)
(((n1+1) << bignum_length_shift) |
xsign |
bignum_tag);
return res+vector_tag;
} else {
ref(res, 0) = (ikp)
((n1 << bignum_length_shift) |
xsign |
bignum_tag);
return res+vector_tag;
}
}
else {
/* same sign */
if(xlimbs == ylimbs){
while((ref(x, -vector_tag+disp_bignum_data+(xlimbs-1)*wordsize) ==
ref(y, -vector_tag+disp_bignum_data+(xlimbs-1)*wordsize))){
xlimbs -= 1;
if(xlimbs == 0){ return 0; }
}
ylimbs = xlimbs;
}
ikp s1=x, s2=y;
int n1=xlimbs, n2=ylimbs;
int result_sign = xsign;
/* |x| != |y| */
if(xlimbs <= ylimbs){
if(xlimbs == ylimbs){
if((ref(y, -vector_tag+disp_bignum_data+(xlimbs-1)*wordsize) >
ref(x, -vector_tag+disp_bignum_data+(xlimbs-1)*wordsize))){
s1 = y; n1 = ylimbs;
s2 = x; n2 = xlimbs;
result_sign = (1 << bignum_length_shift) - ysign;
}
} else {
s1 = y; n1 = ylimbs;
s2 = x; n2 = xlimbs;
result_sign = (1 << bignum_length_shift) - ysign;
}
}
/* |s1| > |s2| */
ikp res = ik_alloc(pcb, align(disp_bignum_data + n1 * wordsize));
int burrow = mpn_sub((mp_limb_t*) (res + disp_bignum_data),
(mp_limb_t*) (s1 - vector_tag + disp_bignum_data),
n1,
(mp_limb_t*) (s2 - vector_tag + disp_bignum_data),
n2);
if(burrow){
fprintf(stderr, "BUG: Burrow error in bnbn-\n");
exit(-1);
}
int len = n1;
while(ref(res, disp_bignum_data + (len-1)*wordsize) == 0){
len--;
if(len == 0){
return 0;
}
}
if(result_sign == 0){
/* positive result */
if(len == 1){
unsigned int fst_limb = (unsigned int) ref(res, disp_bignum_data);
if(fst_limb <= most_positive_fixnum){
return fix((int)fst_limb);
}
}
ref(res, 0) = (ikp)
((len << bignum_length_shift) |
result_sign |
bignum_tag);
return res+vector_tag;
} else {
/* negative result */
if(len == 1){
unsigned int fst_limb = (unsigned int) ref(res, disp_bignum_data);
if(fst_limb <= most_negative_fixnum){
return fix(-(int)fst_limb);
}
}
ref(res, 0) = (ikp)
((len << bignum_length_shift) |
result_sign |
bignum_tag);
return res+vector_tag;
}
}
}
ikp
ikrt_fxfxmult(ikp x, ikp y, ikpcb* pcb){
int n1 = unfix(x);
int n2 = unfix(y);
mp_limb_t lo = 0;
mp_limb_t s1 = n1;
mp_limb_t s2 = n2;
int sign = 0;
if(n1 < 0){
s1 = -n1;
sign = 1 - sign;
}
if(n2 < 0){
s2 = -n2;
sign = 1 - sign;
}
mp_limb_t hi = mpn_mul_1(&lo, &s1, 1, s2);
if(hi == 0){
if(sign){
if(lo <= most_negative_fixnum){
return fix(-((int)lo));
}
} else {
if(lo <= most_positive_fixnum){
return fix((int)lo);
}
}
ikp r = ik_alloc(pcb, disp_bignum_data + wordsize);
ref(r, 0) = (ikp)
(bignum_tag |
(sign << bignum_sign_shift) |
(1 << bignum_length_shift));
ref(r, disp_bignum_data) = (ikp)lo;
return r+vector_tag;
} else {
ikp r = ik_alloc(pcb, align(disp_bignum_data + 2*wordsize));
ref(r, 0) = (ikp)
(bignum_tag |
(sign << bignum_sign_shift) |
(2 << bignum_length_shift));
ref(r, disp_bignum_data) = (ikp)lo;
ref(r, disp_bignum_data+wordsize) = (ikp)hi;
return r+vector_tag;
}
}
ikp
normalize_bignum(int limbs, int sign, ikp r){
while(ref(r, disp_bignum_data + (limbs-1)*wordsize) == 0){
limbs--;
if(limbs == 0){ return 0;}
}
if(limbs == 1){
unsigned int last = (unsigned int) ref(r, disp_bignum_data);
if(sign == 0){
if(last <= most_positive_fixnum){
return fix((int)last);
}
} else {
if(last <= most_negative_fixnum){
return fix(-((int)last));
}
}
}
ref(r, 0) = (ikp)
(bignum_tag |
sign |
(limbs << bignum_length_shift));
return r+vector_tag;
}
ikp
ikrt_fxbnmult(ikp x, ikp y, ikpcb* pcb){
int n2 = unfix(x);
if(n2 == 0) { return 0; }
mp_limb_t s2 = (n2>0) ? n2 : (- n2);
ikp fst = ref(y, -vector_tag);
int limb_count = ((unsigned int) fst) >> bignum_length_shift;
ikp r = ik_alloc(pcb, align(disp_bignum_data + (limb_count+1)*wordsize));
mp_limb_t hi = mpn_mul_1((mp_limb_t*)(r+disp_bignum_data),
(mp_limb_t*)(y-vector_tag+disp_bignum_data),
limb_count,
s2);
ref(r, disp_bignum_data + limb_count * wordsize) = (ikp)hi;
int sign =
((n2 > 0) ?
(bignum_sign_mask & (int)fst) :
((1 << bignum_sign_shift) - (bignum_sign_mask&(int)fst)));
return normalize_bignum(limb_count+1, sign, r);
}
ikp
ikrt_bnbnmult(ikp x, ikp y, ikpcb* pcb){
int f1 = (int)ref(x, -vector_tag);
int f2 = (int)ref(y, -vector_tag);
int n1 = ((unsigned int)f1) >> bignum_length_shift;
int n2 = ((unsigned int)f2) >> bignum_length_shift;
int nr = n1 + n2;
ikp bn = ik_alloc(pcb, align(disp_bignum_data + nr*wordsize));
mp_limb_t r;
if(n1 >= n2){
r = mpn_mul((mp_limb_t*)(bn+disp_bignum_data),
(mp_limb_t*)(x-vector_tag+disp_bignum_data),
n1,
(mp_limb_t*)(y-vector_tag+disp_bignum_data),
n2);
} else {
r = mpn_mul((mp_limb_t*)(bn+disp_bignum_data),
(mp_limb_t*)(y-vector_tag+disp_bignum_data),
n2,
(mp_limb_t*)(x-vector_tag+disp_bignum_data),
n1);
}
int sign =
((bignum_sign_mask & f1) ?
((1 << bignum_sign_shift) - (bignum_sign_mask & f2)) :
(bignum_sign_mask & f2));
return normalize_bignum(nr, sign, bn);
}
ikp
ikrt_bnbncomp(ikp bn1, ikp bn2){
ikp f1 = ref(bn1, -vector_tag);
ikp f2 = ref(bn2, -vector_tag);
if(bignum_sign_mask & (int)f1){
if(bignum_sign_mask & (int)f2){
/* both negative */
int n1 = ((unsigned int) f1) >> bignum_length_shift;
int n2 = ((unsigned int) f2) >> bignum_length_shift;
if(n1 < n2) {
return fix(1);
} else if(n1 > n2){
return fix(-1);
} else {
int i;
for(i=(n1-1); i>=0; i--){
unsigned int t1 =
(unsigned int) ref(bn1,disp_bignum_data-vector_tag+i*wordsize);
unsigned int t2 =
(unsigned int) ref(bn2,disp_bignum_data-vector_tag+i*wordsize);
if(t1 < t2){
return fix(1);
} else if(t1 > t2){
return fix(-1);
}
}
}
return 0;
} else {
/* n1 negative, n2 positive */
return fix(-1);
}
} else {
if(bignum_sign_mask & (int)f2){
/* n1 positive, n2 negative */
return fix(1);
} else {
/* both positive */
int n1 = ((unsigned int) f1) >> bignum_length_shift;
int n2 = ((unsigned int) f2) >> bignum_length_shift;
if(n1 < n2) {
return fix(-1);
} else if(n1 > n2){
return fix(1);
} else {
int i;
for(i=(n1-1); i>=0; i--){
unsigned int t1 =
(unsigned int) ref(bn1,disp_bignum_data-vector_tag+i*wordsize);
unsigned int t2 =
(unsigned int) ref(bn2,disp_bignum_data-vector_tag+i*wordsize);
if(t1 < t2){
return fix(-1);
} else if(t1 > t2){
return fix(1);
}
}
}
return 0;
}
}
}
ikp
ikrt_fxbnlogand(ikp x, ikp y, ikpcb* pcb){
int n1 = unfix(x);
ikp fst = ref(y, -vector_tag);
if(n1 >= 0){
if(bignum_sign_mask & (unsigned int) fst){
/* y is negative */
return fix(n1 & (1+~(int)ref(y, disp_vector_data-vector_tag)));
} else {
/* y is positive */
return fix(n1 & (int)ref(y, disp_vector_data-vector_tag));
}
} else {
if(n1 == -1){ return y; }
if(bignum_sign_mask & (unsigned int) fst){
/* y is negative */
int len = (((unsigned int) fst) >> bignum_length_shift);
unsigned int nn =
(1+~((1+~(int)ref(y, disp_bignum_data - vector_tag)) & n1));
if((len == 1) && (nn <= most_negative_fixnum)){
return fix(-nn);
}
ikp r = ik_alloc(pcb, align(disp_bignum_data + len * wordsize));
ref(r, 0) = fst;
ref(r, disp_bignum_data) = (ikp) nn;
int i;
for(i=1; i<len; i++){
ref(r, disp_bignum_data+i*wordsize) =
ref(y, disp_bignum_data-vector_tag+i*wordsize);
}
return r+vector_tag;
} else {
/* y is positive */
int len = (((unsigned int) fst) >> bignum_length_shift);
ikp r = ik_alloc(pcb, align(disp_bignum_data + len * wordsize));
ref(r, 0) = fst;
ref(r, disp_bignum_data) = (ikp)
(((int)ref(y, disp_bignum_data - vector_tag)) & n1);
int i;
for(i=1; i<len; i++){
ref(r, disp_bignum_data+i*wordsize) =
ref(y, disp_bignum_data-vector_tag+i*wordsize);
}
return r+vector_tag;
}
}
}
static inline int
count_leading_ffs(int n, unsigned int* x){
int idx;
for(idx=0; idx<n; idx++){
if(x[idx] != -1){
return idx;
}
}
return n;
}
ikp
ikrt_bnbnlogand(ikp x, ikp y, ikpcb* pcb){
ikp xfst = ref(x, -vector_tag);
ikp yfst = ref(y, -vector_tag);
int n1 = ((unsigned int) xfst) >> bignum_length_shift;
int n2 = ((unsigned int) yfst) >> bignum_length_shift;
if(bignum_sign_mask & (unsigned int) xfst){
if(bignum_sign_mask & (unsigned int) yfst){
fprintf(stderr, "not yet for bnbnlogand\n");
exit(-1);
} else {
return ikrt_bnbnlogand(y,x,pcb);
}
} else {
if(bignum_sign_mask & (unsigned int) yfst){
/* x positive, y negative */
/* the result is at most n1 words long */
unsigned int* s1 = ((unsigned int*)(x+disp_bignum_data-vector_tag));
unsigned int* s2 = ((unsigned int*)(y+disp_bignum_data-vector_tag));
if(n1 <= n2){
int i = n1-1;
while(i >= 0){
unsigned int t = s1[i] & (1+~s2[i]);
if(t != 0){
if((i == 0) && (t <= most_positive_fixnum)){
return fix(t);
}
ikp r = ik_alloc(pcb, align(disp_bignum_data+(i+1)*wordsize));
ref(r, 0) = (ikp) (bignum_tag | ((i+1) << bignum_length_shift));
unsigned int* s = (unsigned int*)(r+disp_bignum_data);
s[i] = t;
for(i--; i>=0; i--){
s[i] = s1[i] & (1+~s2[i]);
}
return r+vector_tag;
} else {
i--;
}
}
return 0;
} else {
fprintf(stderr, "not yet for bnbnlogand\n");
exit(-1);
}
} else {
/* both positive */
int n = (n1<n2)?n1:n2;
int i;
for(i=n-1; i>=0; i--){
int l1 =
(int) ref(x, disp_bignum_data-vector_tag+i*wordsize);
int l2 =
(int) ref(y, disp_bignum_data-vector_tag+i*wordsize);
int last = l1 & l2;
if(last){
if((i == 0) && (last < most_positive_fixnum)){
return fix(last);
}
ikp r = ik_alloc(pcb, align(disp_bignum_data+(i+1)*wordsize));
ref(r, 0) = (ikp) (bignum_tag | ((i+1)<<bignum_length_shift));
ref(r, disp_bignum_data + i*wordsize) = (ikp)last;
int j;
for(j=0; j<i; j++){
ref(r, disp_bignum_data + j*wordsize) = (ikp)
(((int)ref(x, disp_bignum_data-vector_tag+j*wordsize))
&
((int)ref(y, disp_bignum_data-vector_tag+j*wordsize)));
}
return r+vector_tag;
}
}
return 0;
}
}
}
ikp
ikrt_bntostring(ikp x, ikpcb* pcb){
/* FIXME: avoid calling malloc, instead, use the heap pointer itself
* as a buffer to hold the temporary data after ensuring that it has enough
* space */
ikp fst = ref(x, -vector_tag);
int limb_count = (((unsigned int)fst) >> bignum_length_shift);
if(limb_count <= 0){
fprintf(stderr, "BUG: nbtostring: invalid length %d\n", limb_count);
exit(-1);
}
int sign_bit = bignum_sign_mask & (int) fst;
int nbsize = limb_count * sizeof(mp_limb_t);
int strsize = limb_count * max_digits_per_limb;
int mem_req = nbsize + strsize + 1;
unsigned char* mem = malloc(mem_req);
if(! mem){
fprintf(stderr, "Error allocating space for bignum\n");
exit(-1);
}
memcpy(mem, x - vector_tag + disp_bignum_data, nbsize);
mp_size_t bytes =
mpn_get_str(mem+nbsize, /* output string */
10, /* base */
(mp_limb_t*) mem, /* limb */
limb_count /* number of limbs */
);
unsigned char* string_start = mem + nbsize;
while(*string_start == 0){
string_start++;
bytes--;
}
ikp str = ik_alloc(pcb, align(bytes + disp_string_data + (sign_bit?1:0)));
ref(str, 0) = fix(bytes + (sign_bit?1:0));
ikp dest = str + disp_string_data;
if(sign_bit){
*dest = '-';
dest++;
}
{
int i = 0;
while(i < bytes){
dest[i] = string_start[i] + '0';
i++;
}
dest[bytes] = 0;
}
free(mem);
return str + string_tag;
}