From a6dd3f93cd43d6fa3d6d8f930ed7f7d293251728 Mon Sep 17 00:00:00 2001
From: Richard Thier <magosit@outlook.hu>
Date: Thu, 3 Apr 2025 15:29:28 +0200
Subject: [PATCH] added C++ measurements

---
 perf.cpp | 34 +++++++++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/perf.cpp b/perf.cpp
index 1df5117..03ed5d1 100644
--- a/perf.cpp
+++ b/perf.cpp
@@ -2,6 +2,7 @@
 #include <cstdlib>
 #include <chrono>
 #include <cassert>
+#include <random>
 #include "fastrand.h"
 
 #define N 10000000
@@ -22,6 +23,10 @@ int main() {
 	srand((unsigned int)time(NULL));
 	rand_state rs = init_rand();
 	rand_ilp_state rs_ilp = init_rand_ilp();
+	// C++ engines
+	std::linear_congruential_engine<uint32_t, 1664525u, 1013904223u, 0> lce;
+	std::mt19937 mte;
+	std::minstd_rand lce_def;
 
 	// Generate FROM,TO as random, because otherwise compiler optimizes out IDIV of the '%' operator!
 	uint32_t FROM = (uint32_t) rand();
@@ -45,6 +50,27 @@ int main() {
 
 	auto t2 = std::chrono::high_resolution_clock::now();
 
+	// C++ LCG
+	for (int i = 0; i < N; ++i) {
+		res[i] += lce_def();
+	}
+
+	auto t21 = std::chrono::high_resolution_clock::now();
+
+	// C++ LCG - my parameters
+	for (int i = 0; i < N; ++i) {
+		res[i] += lce();
+	}
+
+	auto t211 = std::chrono::high_resolution_clock::now();
+
+	// C++ MT
+	for (int i = 0; i < N; ++i) {
+		res[i] += mte();
+	}
+
+	auto t22 = std::chrono::high_resolution_clock::now();
+
 	// lcg
 	for (int i = 0; i < N; ++i) {
 		res[i] += lcg(&rs);
@@ -65,11 +91,17 @@ int main() {
 
 	auto arc4_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(t1 - t0);
 	auto rand_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(t2 - t1);
-	auto lcg_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(t3 - t2);
+	auto lce_def_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(t21 - t2);
+	auto lce_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(t211 - t21);
+	auto mt_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(t22 - t21);
+	auto lcg_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(t3 - t22);
 	auto lcg4_elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(t31 - t3);
 
 	printf("Time (arc4): %.3f ms.\n", arc4_elapsed.count() * 1e-6);
 	printf("Time (rand): %.3f ms.\n", rand_elapsed.count() * 1e-6);
+	printf("Time (C++ lcg): %.3f ms.\n", lce_def_elapsed.count() * 1e-6);
+	printf("Time (C++ lcg my parameters): %.3f ms.\n", lce_elapsed.count() * 1e-6);
+	printf("Time (C++ mersenne twister 32bit): %.3f ms.\n", mt_elapsed.count() * 1e-6);
 	printf("Time (lcg): %.3f ms.\n", lcg_elapsed.count() * 1e-6);
 	printf("Time (lcg4): %.3f ms.\n", lcg4_elapsed.count() * 1e-6);