c reproducer

test.c

#include <stdio.h>
#include <math.h>

struct rect {
	double x, y, w, h;
};

__attribute__((noinline))
void test(struct rect *res, const struct rect *a, const struct rect *b)
{
	double x1 = pow(a->x, b->x);
	double y1 = pow(a->y, b->y);
	double x2 = pow(a->x + a->w, b->x + b->w);
	double y2 = pow(a->y + a->h, b->y + b->h);

	if (x2 > x1 && y2 > y1) {
		res->x = x1;
		res->y = y1;
		res->w = x2 - x1;
		res->h = y2 - y1;
	}
}

int main(void)
{
	struct rect a = { 0.0, 2.0, 2.0, 3.0 };
	struct rect b = { 0.0, 2.0, 2.0, 3.0 };
	struct rect res = { 0.0, 0.0, 0.0, 0.0 };

	test(&res, &a, &b);

	printf("x = %f, y = %f, w = %f, h = %f\n", res.x, res.y, res.w, res.h);

	return res.x != 1.0;
}