Skip to content

Instantly share code, notes, and snippets.

@joaqo
Last active May 18, 2020 20:00
Show Gist options
  • Save joaqo/28685823f19cd0c4a0393cdf7b12e7a0 to your computer and use it in GitHub Desktop.
Save joaqo/28685823f19cd0c4a0393cdf7b12e7a0 to your computer and use it in GitHub Desktop.
Changing the two commented lines in the code to the version used in this scripts makes this run twice as fast and makes it reach equal to C speed.
// Test motivated by the following discussion: https://twitter.com/vojtamolda/status/1258516339402006528
// Compile script: swiftc -O equal_to_c_speed_test.swift
import Foundation
// var result = ContiguousArray<Int>(repeating: 0, count: 3001)
var result = [Int](repeating: 0, count: 3001)
for it in 0..<15 {
let start = Date()
result.withUnsafeMutableBufferPointer { buffer in
for i in 0..<3000 {
buffer[i] = it}}
// let sum = result.reduce(0, +)
let sum = result.reduce(0, &+)
let end = Date()
print(start.timeIntervalSince(end), sum)}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment