/*
 * Copyright 2024 Peter McGoron
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <memory>
#include <limits>
#include <cstdint>
#include <iostream>
#include <verilated.h>
#include "Vxorshift.h"

Vxorshift *mod;

static void run_clock() {
	mod->clk = !mod->clk;
	mod->eval();

	mod->clk = !mod->clk;
	mod->eval();
}

static uint64_t xorshift_64() {
	static uint64_t state = 88172645463325252LL;
	state ^= state << 13;
	state ^= state >> 7;
	return state ^= state << 17;
}

int main(int argc, char **argv) {
	Verilated::commandArgs(argc, argv);
	mod = new Vxorshift;

	mod->clk = 0;
	mod->eval();

	for (int i = 0; i < 100000; i++) {
		uint64_t correct = xorshift_64();
		run_clock();
		if (correct != mod->data) {
			std::cout << i << " " << correct << "!=" << mod->data << std::endl;
		}
	}

	mod->final();

	delete mod;

	return 0;
}