add histogram program

c++/turing/histogram.cpp

@@ -0,0 +1,71 @@
+#include <iostream>
+#include <cstdlib>
+#include <chrono>
+
+#include "common.h"
+
+using namespace std;
+using namespace std::chrono;
+
+#define SEED (1337)
+
+int inputs[CASES];
+bool results[CASES];
+
+extern bool test(int input);
+
+bool isBinaryPalindrome(int input) {
+    int numberOfDigits = input == 0 ? 1 : static_cast<int>(floor(log2(input)) + 1);
+
+    for (int i = 0; i < numberOfDigits / 2; i++) {
+        if (((input & (1 << i)) ? 1 : 0) != ((input & (1 << (numberOfDigits - i - 1))) ? 1 : 0)) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+void resetTestData() {
+    srand(SEED);
+
+    for (int i = 0; i < CASES; i++) {
+        inputs[i] = rand() % (MAX_VALUE + 1);
+        results[i] = isBinaryPalindrome(inputs[i]);
+    }
+}
+
+#define HISTOGRAM_START (0)
+#define HISTOGRAM_END (15)
+#define HISTOGRAM_BUCKETS (100)
+
+int main() {
+    int histogram[HISTOGRAM_BUCKETS] = {0};
+
+    resetTestData();
+
+    for (int r = 0; r < REPEATS; r++) {
+        auto t1 = high_resolution_clock::now();
+        for (int i = 0; i < CASES; i++) {
+            bool result = test(inputs[i]);
+            if (result != results[i]) {
+                cout << i << ": " << inputs[i] << ", " << results[i] << " -> " << "FAIL" << endl;
+            }
+        }
+        auto t2 = high_resolution_clock::now();
+
+        duration<double, std::milli> ms = t2 - t1;
+        double tmp = ms.count();
+
+        int bucket = static_cast<int>(HISTOGRAM_BUCKETS * (tmp - HISTOGRAM_START) / HISTOGRAM_END);
+        if (bucket >= HISTOGRAM_BUCKETS) {
+            cout << "bucket out of range: " << bucket << " (" << tmp << " )" << endl;
+            bucket = HISTOGRAM_BUCKETS - 1;
+        }
+        histogram[bucket]++;
+    }
+
+    for (int i = 0; i < HISTOGRAM_BUCKETS; i++) {
+        cout << "( " << (static_cast<double>((HISTOGRAM_END - HISTOGRAM_START)) / HISTOGRAM_BUCKETS * i) << " , " << histogram[i] << " ) " << endl;
+    }
+}

c++/turing/runHistogram.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+run() {
+  test="$1"
+  optimization="$2"
+  repeats="$3"
+
+  clang++ -std=c++14 -DREPEATS="$repeats" -O"$optimization" "histogram.cpp" "$1.cpp"
+  echo "$test $optimization (n = $repeats): "
+  ./a.out
+}
+
+run "oop-without-virtual-methods" 3 200000