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//===--- BitCount.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 performance of Swift bit count.
// and mask operator.
// rdar://problem/22151678
import TestsUtils
public let benchmarks =
BenchmarkInfo(
name: "BitCount",
runFunction: run_BitCount,
tags: [.validation, .algorithm])
func countBitSet(_ num: Int) -> Int {
let bits = MemoryLayout<Int>.size * 8
var cnt: Int = 0
var mask: Int = 1
for _ in 0...bits {
if num & mask != 0 {
cnt += 1
}
mask <<= 1
}
return cnt
}
@inline(never)
public func run_BitCount(_ n: Int) {
var sum = 0
for _ in 1...1000*n {
// Check some results.
sum = sum &+ countBitSet(getInt(1))
&+ countBitSet(getInt(2))
&+ countBitSet(getInt(2457))
}
check(sum == 8 * 1000 * n)
}
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