git: 9front

ref: 8f63d48a00251d74b67e7244c908e436cb540d2c
dir: /sys/src/ape/lib/ap/math/floor.c/

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#include <math.h>
/*
 * floor and ceil-- greatest integer <= arg
 * (resp least >=)
 */

double
floor(double d)
{
	double fract;

	if(d < 0) {
		fract = modf(-d, &d);
		if(fract != 0.0)
			d += 1;
		d = -d;
	} else
		modf(d, &d);
	return d;
}

double
ceil(double d)
{
	return -floor(-d);
}