Files
swift-mirror/benchmark/single-source/MonteCarloPi.swift
Karoy Lorentey 758c52bc2a [benchmark] Don't create array instance in modules with solitary benchmarks
It just produces unnecessary code sign churn.
2021-09-16 18:54:14 -07:00

39 lines
1.1 KiB
Swift

//===--- MonteCarloPi.swift -----------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
import TestsUtils
public let benchmarks =
BenchmarkInfo(
name: "MonteCarloPi",
runFunction: run_MonteCarloPi,
tags: [.validation, .algorithm],
legacyFactor: 125)
public func run_MonteCarloPi(scale: Int) {
var rng = LFSR()
var pointsInside = 0
let r = 10000
let n = 4_000*scale
for _ in 1...n {
let x = Int(truncatingIfNeeded: rng.next()) % r
let y = Int(truncatingIfNeeded: rng.next()) % r
if x*x + y*y < r*r {
pointsInside += 1
}
}
let pi_estimate: Double = Double(pointsInside)*4.0/Double(n)
let pi = 3.1415
check(abs(pi_estimate - pi) < 0.2)
}