ArraySubscript.swift

//===--- ArraySubscript.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
//
//===----------------------------------------------------------------------===//

// This test checks the performance of modifying an array element.
import TestsUtils

publicletbenchmarks=
BenchmarkInfo(
 name:"ArraySubscript",
 runFunction: run_ArraySubscript,
 tags:[.validation,.api,.Array],
 legacyFactor:4)

@inline(never)
publicfunc run_ArraySubscript(_ n:Int){
varlfsr=LFSR()

letnumArrays=50
letnumArrayElements=100

func bound(_ x:Int)->Int{returnmin(x, numArrayElements-1)}

for_in1...n {
vararrays=[[Int]](repeating:[], count: numArrays)
foriin0..<numArrays {
for_in0..<numArrayElements {
arrays[i].append(Int(truncatingIfNeeded: lfsr.next()))
}
}

 // Do a max up the diagonal.
foriin1..<numArrays {
arrays[i][bound(i)]=
max(arrays[i-1][bound(i-1)],arrays[i][bound(i)])
}
check(arrays[0][0]<=arrays[numArrays-1][bound(numArrays-1)])
}
}