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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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//
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//	divide two digits by one and return quotient
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//
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void
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mpdigdiv(mpdigit *dividend, mpdigit divisor, mpdigit *quotient)
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{
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	mpdigit hi, lo, q, x, y;
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	int i;
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	hi = dividend[1];
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	lo = dividend[0];
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	// return highest digit value if the result >= 2**32
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	if(hi >= divisor || divisor == 0){
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		divisor = 0;
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		*quotient = ~divisor;
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		return;
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	}
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	// very common case
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	if(~divisor == 0){
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		lo += hi;
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		if(lo < hi){
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			hi++;
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			lo++;
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		}
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		if(lo+1 == 0)
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			hi++;
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		*quotient = hi;
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		return;
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	}
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	// at this point we know that hi < divisor
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	// just shift and subtract till we're done
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	q = 0;
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	x = divisor;
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	for(i = Dbits-1; hi > 0 && i >= 0; i--){
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		x >>= 1;
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		if(x > hi)
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			continue;
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		y = divisor<<i;
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		if(x == hi && y > lo)
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			continue;
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		if(y > lo)
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			hi--;
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		lo -= y;
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		hi -= x;
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		q |= 1<<i;
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	}
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	q += lo/divisor;
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	*quotient = q;
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}