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26 7u83 1 
#include "os.h"
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#include <mp.h>
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#include "dat.h"
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/*
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	mplogic calculates b1|b2 subject to the
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	following flag bits (fl)
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	bit 0: subtract 1 from b1
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	bit 1: invert b1
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	bit 2: subtract 1 from b2
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	bit 3: invert b2
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	bit 4: add 1 to output
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	bit 5: invert output
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	it inverts appropriate bits automatically
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	depending on the signs of the inputs
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*/
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static void
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mplogic(mpint *b1, mpint *b2, mpint *sum, int fl)
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{
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	mpint *t;
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	mpdigit *dp1, *dp2, *dpo, d1, d2, d;
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	int c1, c2, co;
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	int i;
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	assert(((b1->flags | b2->flags | sum->flags) & MPtimesafe) == 0);
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	if(b1->sign < 0) fl ^= 0x03;
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	if(b2->sign < 0) fl ^= 0x0c;
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	sum->sign = (int)(((fl|fl>>2)^fl>>4)<<30)>>31|1;
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	if(sum->sign < 0) fl ^= 0x30;
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	if(b2->top > b1->top){
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		t = b1;
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		b1 = b2;
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		b2 = t;
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		fl = fl >> 2 & 0x03 | fl << 2 & 0x0c | fl & 0x30;
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	}
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	mpbits(sum, b1->top*Dbits+1);
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	dp1 = b1->p;
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	dp2 = b2->p;
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	dpo = sum->p;
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	c1 = fl & 1;
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	c2 = fl >> 2 & 1;
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	co = fl >> 4 & 1;
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	for(i = 0; i < b1->top; i++){
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		d1 = dp1[i] - c1;
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		if(i < b2->top)
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			d2 = dp2[i] - c2;
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		else
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			d2 = 0;
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		if(d1 != (mpdigit)-1) c1 = 0;
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		if(d2 != (mpdigit)-1) c2 = 0;
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		if((fl & 2) != 0) d1 ^= -1;
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		if((fl & 8) != 0) d2 ^= -1;
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		d = d1 | d2;
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		if((fl & 32) != 0) d ^= -1;
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		d += co;
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		if(d != 0) co = 0;
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		dpo[i] = d;
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	}
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	sum->top = i;
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	if(co)
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		dpo[sum->top++] = co;
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	mpnorm(sum);
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}
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void
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mpor(mpint *b1, mpint *b2, mpint *sum)
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{
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	mplogic(b1, b2, sum, 0);
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}
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void
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mpand(mpint *b1, mpint *b2, mpint *sum)
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{
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	mplogic(b1, b2, sum, 0x2a);
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}
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void
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mpbic(mpint *b1, mpint *b2, mpint *sum)
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{
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	mplogic(b1, b2, sum, 0x22);
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}
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void
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mpnot(mpint *b, mpint *r)
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{
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	mpadd(b, mpone, r);
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	if(r->top != 0)
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		r->sign ^= -2;
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}
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void
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mpxor(mpint *b1, mpint *b2, mpint *sum)
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{
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	mpint *t;
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	mpdigit *dp1, *dp2, *dpo, d1, d2, d;
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	int c1, c2, co;
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	int i, fl;
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	assert(((b1->flags | b2->flags | sum->flags) & MPtimesafe) == 0);
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	if(b2->top > b1->top){
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		t = b1;
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		b1 = b2;
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		b2 = t;
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	}
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	fl = (b1->sign & 10) ^ (b2->sign & 12);
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	sum->sign = (int)(fl << 28) >> 31 | 1;
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	mpbits(sum, b1->top*Dbits+1);
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	dp1 = b1->p;
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	dp2 = b2->p;
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	dpo = sum->p;
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	c1 = fl >> 1 & 1;
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	c2 = fl >> 2 & 1;
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	co = fl >> 3 & 1;
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	for(i = 0; i < b1->top; i++){
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		d1 = dp1[i] - c1;
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		if(i < b2->top)
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			d2 = dp2[i] - c2;
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		else
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			d2 = 0;
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		if(d1 != (mpdigit)-1) c1 = 0;
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		if(d2 != (mpdigit)-1) c2 = 0;
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		d = d1 ^ d2;
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		d += co;
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		if(d != 0) co = 0;
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		dpo[i] = d;
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	}
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	sum->top = i;
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	if(co)
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		dpo[sum->top++] = co;
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	mpnorm(sum);
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}
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void
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mptrunc(mpint *b, int n, mpint *r)
138 
{
139 
	int d, m, i, c;
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141 
	assert(((b->flags | r->flags) & MPtimesafe) == 0);
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	mpbits(r, n);
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	r->top = DIGITS(n);
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	d = n / Dbits;
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	m = n % Dbits;
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	if(b->sign == -1){
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		c = 1;
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		for(i = 0; i < r->top; i++){
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			if(i < b->top)
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				r->p[i] = ~(b->p[i] - c);
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			else
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				r->p[i] = -1;
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			if(r->p[i] != 0)
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				c = 0;
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		}
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		if(m != 0)
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			r->p[d] &= (1<<m) - 1;
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	}else if(b->sign == 1){
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		if(d >= b->top){
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			mpassign(b, r);
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			mpnorm(r);
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			return;
163 
		}
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		if(b != r)
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			for(i = 0; i < d; i++)
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				r->p[i] = b->p[i];
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		if(m != 0)
168 
			r->p[d] = b->p[d] & (1<<m)-1;
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	}
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	r->sign = 1;
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	mpnorm(r);
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}
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174 
void
175 
mpxtend(mpint *b, int n, mpint *r)
176 
{
177 
	int d, m, c, i;
178 
 
179 
	d = (n - 1) / Dbits;
180 
	m = (n - 1) % Dbits;
181 
	if(d >= b->top){
182 
		mpassign(b, r);
183 
		return;
184 
	}
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	mptrunc(b, n, r);
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	mpbits(r, n);
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	if((r->p[d] & 1<<m) == 0){
188 
		mpnorm(r);
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		return;
190 
	}
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	r->p[d] |= -(1<<m);
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	r->sign = -1;
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	c = 1;
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	for(i = 0; i < r->top; i++){
195 
		r->p[i] = ~(r->p[i] - c);
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		if(r->p[i] != 0)
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			c = 0;
198 
	}
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	mpnorm(r);
200 
}
201 
 
202 
void
203 
mpasr(mpint *b, int n, mpint *r)
204 
{
205 
	if(b->sign > 0 || n <= 0){
206 
		mpright(b, n, r);
207 
		return;
208 
	}
209 
	mpadd(b, mpone, r);
210 
	mpright(r, n, r);
211 
	mpsub(r, mpone, r);
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}