Minimum Functions for 3 Integers (or Variadic) in Swift

min.swift

import CoreFoundation

let TEST_ITTERATIONS = 100.0
let TEST_LOOPS = 100_000

func min3a(a: Int, b: Int, c: Int) -> Int {
    if a < b {
        if a < c {
            return a
        } else {
            return c
        }
    } else {
        if b < c {
            return b
        } else {
            return c
        }
    }
}

func min3a_generics<T: Comparable>(a: T, b: T, c: T) -> T {
    if a < b {
        if a < c {
            return a
        } else {
            return c
        }
    } else {
        if b < c {
            return b
        } else {
            return c
        }
    }
}

func min3a_variadic(possibleValues: Int...) -> Int {
    var minValue = Int.max
    for possibleValue in possibleValues {
        if possibleValue < minValue {
            minValue = possibleValue
        }
    }
    return minValue
}

func min3b(a: Int, b: Int, c: Int) -> Int {
    var result = a
    if b < result {
        result = b
    }
    if c < result {
        return c
    }
    return result
}

func testA() {
    var result = 0
    for i in 0..TEST_LOOPS {
        result = 0
        result += min3a(1, 2, 3)
        result += min3a(1, 3, 2)
        result += min3a(2, 1, 3)
        result += min3a(2, 3, 1)
        result += min3a(3, 1, 2)
        result += min3a(3, 2, 1)

        if (result != 6) {
            println("Bad min (method A, group 1, loop \(i)")
        }

        result = 0
        result = min3a(Int.max-2, Int.max-1, Int.max)
        result = min3a(Int.max-2, Int.max, Int.max-1)
        result = min3a(Int.max-1, Int.max-2, Int.max)
        result = min3a(Int.max-1, Int.max, Int.max-2)
        result = min3a(Int.max, Int.max-2, Int.max-1)
        result = min3a(Int.max, Int.max-1, Int.max-2)

        if (result != Int.max-2) {
            println("Bad min (method A, group 2, loop \(i)")
        }
    }
}

func testB() {
    var result = 0
    for i in 0..TEST_LOOPS {
        result = 0
        result += min3b(1, 2, 3)
        result += min3b(1, 3, 2)
        result += min3b(2, 1, 3)
        result += min3b(2, 3, 1)
        result += min3b(3, 1, 2)
        result += min3b(3, 2, 1)

        if (result != 6) {
            println("Bad min (method B, group 1, loop \(i)")
        }

        result = 0
        result = min3b(Int.max-2, Int.max-1, Int.max)
        result = min3b(Int.max-2, Int.max, Int.max-1)
        result = min3b(Int.max-1, Int.max-2, Int.max)
        result = min3b(Int.max-1, Int.max, Int.max-2)
        result = min3b(Int.max, Int.max-2, Int.max-1)
        result = min3b(Int.max, Int.max-1, Int.max-2)

        if (result != Int.max-2) {
            println("Bad min (method B, group 2, loop \(i)")
        }
    }
}

func testC() {
    var result = 0
    for i in 0..TEST_LOOPS {
        result = 0
        result += min(1, 2, 3)
        result += min(1, 3, 2)
        result += min(2, 1, 3)
        result += min(2, 3, 1)
        result += min(3, 1, 2)
        result += min(3, 2, 1)

        if (result != 6) {
            println("Bad min (method C, group 1, loop \(i)")
        }

        result = 0
        result = min(Int.max-2, Int.max-1, Int.max)
        result = min(Int.max-2, Int.max, Int.max-1)
        result = min(Int.max-1, Int.max-2, Int.max)
        result = min(Int.max-1, Int.max, Int.max-2)
        result = min(Int.max, Int.max-2, Int.max-1)
        result = min(Int.max, Int.max-1, Int.max-2)

        if (result != Int.max-2) {
            println("Bad min (method C, group 2, loop \(i)")
        }
    }
}

var totalTime = 0.0
for i in 0..TEST_ITTERATIONS {
    let timeStart = CFAbsoluteTimeGetCurrent()
    testA()
    let timeStop = CFAbsoluteTimeGetCurrent()
    let fullTime = timeStop - timeStart
    totalTime += fullTime
    println("Method A: \(fullTime) us ")
}
println("A Avg: \(totalTime / TEST_ITTERATIONS) us")

totalTime = 0.0
for i in 0..TEST_ITTERATIONS {
    let timeStart = CFAbsoluteTimeGetCurrent()
    testB()
    let timeStop = CFAbsoluteTimeGetCurrent()
    let fullTime = timeStop - timeStart
    totalTime += fullTime
    println("Method B: \(fullTime) us ")
}
println("B Avg: \(totalTime / TEST_ITTERATIONS) us")

totalTime = 0.0
for i in 0..TEST_ITTERATIONS {
    let timeStart = CFAbsoluteTimeGetCurrent()
    testC()
    let timeStop = CFAbsoluteTimeGetCurrent()
    let fullTime = timeStop - timeStart
    totalTime += fullTime
    println("Method C: \(fullTime) us ")
}
println("C Avg: \(totalTime / TEST_ITTERATIONS) us")