shithub: femtolisp

ref: 5c4ffb3f45d3ebc1590c395a603bc60cf81de5a9
dir: /3rd/mp/mptoi.c/

#include "platform.h"

/*
 *  this code assumes that mpdigit is at least as
 *  big as an int.
 */

mpint*
itomp(int i, mpint *b)
{
	if(b == nil){
		b = mpnew(0);
	}
	b->sign = (i >> (sizeof(i)*8 - 1)) | 1;
	i *= b->sign;
	*b->p = i;
	b->top = 1;
	return mpnorm(b);
}

int
mptoi(mpint *b)
{
	mpdigit x;

	if(b->top == 0)
		return 0;
	x = *b->p;
	x = b->sign > 0 ? ((b->top > 1 || x > INT32_MAX) ? (int)INT32_MAX : (int)x)
	                : ((b->top > 1 || x > INT32_MAX) ? (int)INT32_MIN : -(int)x);
	return x;
}