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Silly array benchmarks in diff languages
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| Ran on a 2015 MBP | |
| HOTSPOT | |
| public class Main { | |
| public static void main(String[] args) { | |
| int[] a = new int[500000000]; | |
| int[] b = new int[60000000]; | |
| for (int i = 0; i < a.length; i++) { | |
| a[i] = i; | |
| } | |
| for (int trial = 0; trial < 2; trial++) { | |
| long start = System.currentTimeMillis(); | |
| int j = 0; | |
| long sum = 0; | |
| for (int i = 0; i < a.length; i++) { | |
| sum += a[i]; | |
| if ((i+1) % 10 == 0) { | |
| b[j++] = (int) sum; | |
| sum = 0; | |
| } | |
| } | |
| long end = System.currentTimeMillis(); | |
| System.out.println("last sum is " + b[j-1] + "; took " + (end - start) + " ms"); | |
| } | |
| } | |
| } | |
| last sum is 705032649; took 1079 ms | |
| last sum is 705032649; took 1339 ms | |
| NODE | |
| function main() { | |
| //const a = []; | |
| //a.length = 5000000000; | |
| //a.fill(0); | |
| //const b = []; | |
| //b.length = 600000000; | |
| //b.fill(0); | |
| const a = new Uint32Array(500000000); | |
| const b = new Uint32Array(60000000); | |
| for (let i = 0; i < a.length; i++) { | |
| a[i] = i; | |
| } | |
| for (let i = 0; i < b.length; i++) { | |
| b[i] = i; | |
| } | |
| for (let trial = 0; trial < 2; trial++) { | |
| let sum = 0, j = 0; | |
| const start = +Date.now(); | |
| for (let i = 0; i < a.length; i++) { | |
| sum += a[i]; | |
| if ((i+1) % 10 == 0) { | |
| b[j++] = sum; | |
| sum = 0; | |
| } | |
| } | |
| const end = +Date.now(); | |
| console.log("last sum is " + b[j-1] + "; took " + (end - start) + " ms"); | |
| } | |
| } | |
| main(); | |
| last sum is 705032649; took 1654 ms | |
| last sum is 705032649; took 1557 ms | |
| CLANG++ | |
| #include <chrono> | |
| #include <iostream> | |
| int main() { | |
| const int ALEN = 500000000; | |
| const int BLEN = 60000000; | |
| int* a = new int[ALEN]; | |
| int *b = new int[60000000]; | |
| for (int i = 0; i < ALEN; i++) { | |
| a[i] = i; | |
| } | |
| for (int i = 0; i < BLEN; i++) { | |
| b[i] = i; | |
| } | |
| for (int trial = 0; trial < 2; trial++) { | |
| int sum = 0, j = 0; | |
| using namespace std::chrono; | |
| using namespace std; | |
| milliseconds start = duration_cast< milliseconds >( | |
| system_clock::now().time_since_epoch() | |
| ); | |
| for (int i = 0; i < ALEN; i++) { | |
| sum += a[i]; | |
| if ((i+1) % 10 == 0) { | |
| b[j++] = sum; | |
| sum = 0; | |
| } | |
| } | |
| milliseconds end = duration_cast< milliseconds >( | |
| system_clock::now().time_since_epoch() | |
| ); | |
| cout << "last sum is " << b[j-1] << "; took " << (end.count() - start.count()) << " ms" << endl; | |
| } | |
| } | |
| clang++ main.cc | |
| ./a.out | |
| last sum is 705032649; took 2380 ms | |
| last sum is 705032649; took 2313 ms | |
| clang++ -O3 main.cc | |
| ./a.out | |
| last sum is 705032649; took 717 ms | |
| last sum is 705032649; took 1016 ms |
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