ref: 855cf4326f5a07d7142c2d8918f5fa856d912b85
dir: /sys/src/ape/lib/ap/math/floor.c/
#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);
}