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#include "os.h"
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#include <mp.h>
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#include "dat.h"
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#define VLDIGITS (sizeof(vlong)/sizeof(mpdigit))
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/*
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 *  this code assumes that a vlong is an integral number of
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 *  mpdigits long.
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 */
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mpint*
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vtomp(vlong v, mpint *b)
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{
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	int s;
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	uvlong uv;
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	if(b == nil)
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		b = mpnew(VLDIGITS*sizeof(mpdigit));
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	else
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		mpbits(b, VLDIGITS*sizeof(mpdigit));
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	mpassign(mpzero, b);
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	if(v == 0)
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		return b;
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	if(v < 0){
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		b->sign = -1;
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		uv = -v;
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	} else
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		uv = v;
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	for(s = 0; s < VLDIGITS && uv != 0; s++){
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		b->p[s] = uv;
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		uv >>= sizeof(mpdigit)*8;
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	}
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	b->top = s;
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	return b;
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}
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vlong
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mptov(mpint *b)
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{
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	uvlong v;
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	int s;
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	if(b->top == 0)
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		return 0LL;
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	mpnorm(b);
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	if(b->top > VLDIGITS){
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		if(b->sign > 0)
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			return (vlong)MAXVLONG;
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		else
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			return (vlong)MINVLONG;
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	}
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	v = 0ULL;
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	for(s = 0; s < b->top; s++)
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		v |= b->p[s]<<(s*sizeof(mpdigit)*8);
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	if(b->sign > 0){
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		if(v > MAXVLONG)
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			v = MAXVLONG;
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	} else {
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		if(v > MINVLONG)
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			v = MINVLONG;
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		else
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			v = -(vlong)v;
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	}
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	return (vlong)v;
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}