Re: Bitwise OR on large memory regions

#include <algorithm>
#include <ctime>
#include <iostream>

struct Bitwise_or {
     template<typename T>
     T operator()(T t1, T t2) {
         return t1 | t2;
     }
};

int main() {
     int const n = 0x10000000; // Work with big arrays.

     char* a = new char[n];
     char* b = new char[n];
     char* c = new char[n];
     std::fill(a, a + n, 'A');
     std::fill(b, b + n, 'a' & ~'A');

     typedef long long T;
     T* p = reinterpret_cast<T*>(a - sizeof(T));
     T* q = reinterpret_cast<T*>(b - sizeof(T));
     T* r = reinterpret_cast<T*>(c - sizeof(T));

     t = std::time(0);
     std::transform(p, p + n / sizeof(T), q, r, Bitwise_or());
     std::cout << (std::time(0) - t) << '\n';

     delete[] a;
     delete[] b;
     delete[] c;
}