File indexing completed on 2023-12-10 12:54:09

 /*
     SPDX-FileCopyrightText: 2016-2017 Milian Wolff <mail@milianw.de>
 
     SPDX-License-Identifier: LGPL-2.1-or-later
 */
 
 #include <iostream>
 #include <malloc.h>
 #include <unistd.h>
 
 #include <benchutil.h>
 
 using namespace std;
 
 int main()
 {
     const auto log2_max = 17;
     const auto max_steps = log2_max * 2 + 1;
     size_t cost[max_steps];
     int sizes[max_steps];
 
     const auto baseline = mallinfo2().uordblks;
 
     for (int i = 1; i < max_steps; ++i) {
         int size = 1 << i / 2;
         if (i % 2) {
             size += size / 2;
         }
         sizes[i] = size;
         auto ptr = malloc(size);
         escape(ptr); // prevent the compiler from optimizing the malloc away
         cost[i] = mallinfo2().uordblks;
         free(ptr);
     }
 
     cout << "requested\t|\tactual\t|\toverhead\n";
     for (int i = 1; i < max_steps; ++i) {
         const auto actual = (cost[i] - baseline);
         cout << sizes[i] << "\t\t|\t" << actual << "\t|\t" << (actual - sizes[i]) << '\n';
     }
     return 0;
 }