lib/libm/hypotf.c


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#include <math.h>   // for hypotf, sqrtf, float_t
#include <stdint.h> // for uint32_t

float hypotf(float x, float y)
{
	union {
		float f;
		uint32_t i;
	} ux = { x }, uy = { y }, ut;
	float_t z;

	ux.i &= -1U >> 1;
	uy.i &= -1U >> 1;
	if (ux.i < uy.i) {
		ut = ux;
		ux = uy;
		uy = ut;
	}

	x = ux.f;
	y = uy.f;
	if (uy.i == 0xff << 23)
		return y;
	if (ux.i >= 0xff << 23 || uy.i == 0 || ux.i - uy.i >= 25 << 23)
		return x + y;

	z = 1;
	if (ux.i >= (0x7f + 60) << 23) {
		z = 0x1p90f;
		x *= 0x1p-90f;
		y *= 0x1p-90f;
	} else if (uy.i < (0x7f - 60) << 23) {
		z = 0x1p-90f;
		x *= 0x1p90f;
		y *= 0x1p90f;
	}
	return z * sqrtf((double)x * x + (double)y * y);
}