SDL/src/libm/s_isinff.c

#include "SDL_internal.h"
/*
 * Written by J.T. Conklin <jtc@netbsd.org>.
 * Public domain.
 */

/*
 * isinff(x) returns 1 if x is inf, -1 if x is -inf, else 0;
 * no branching!
 */

#include "math.h"
#include "math_private.h"

int __isinff (float x)
{
	int32_t ix,t;
	GET_FLOAT_WORD(ix,x);
	t = ix & 0x7fffffff;
	t ^= 0x7f800000;
	t |= -t;
	return ~(t >> 31) & (ix >> 30);
}
libm_hidden_def(__isinff)