mirror of
https://github.com/0intro/conterm
synced 2024-11-22 05:41:28 +03:00
70 lines
995 B
C
70 lines
995 B
C
#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 (vlong) 0;
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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 = (uvlong) 0;
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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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}
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