Which Is Faster: Assignment or Comparison

[eyeRmonkey]

Which of these is faster?
1)

If a_long_set_of_conditions Then a_variable = False

2)

a_variable = Not a_long_set_of_conditions

[MartinLiss]

According to a test I just ran (see the GetTickCount link in my signature) this

a_variable = Not (a And b And c)

takes about twice as long as

If a Or b Or c Then a_variable = False

[eyeRmonkey]

Thanks Marty.

I need to learn how to setup my own benchmarks. Not that its hard or anything, I just have no experience in it and always talk myself out of it. I suppose the link in your sig is a good place to start.

[MartinLiss]

...I suppose the link in your sig is a good place to start.

Yup.

[eyeRmonkey]

Hmmm. Here is the code I used:

Option Explicit
 
Private Declare Function GetTickCount Lib "kernel32" () As Long
 
Private Sub Command1_Click()
    Dim i           As Long
    Dim startTime   As Long
    Dim stopTime    As Long
    Dim timesToLoop As Long
    
    Dim time1       As Long
    Dim time2       As Long
    
    Dim glToGo     As Long
    Dim bContinueLoop   As Boolean
    
    Dim mcrdLastFound1  As Long
    Dim mcrdLastFound2  As Long
    
    Dim crd1            As Long
    Dim crd2            As Long
    
    mcrdLastFound1 = 9
    mcrdLastFound2 = 3
    
    crd1 = 1
    crd2 = 6
    
    bContinueLoop = True
    
    glToGo = 1
    
    timesToLoop = 20000000
    
    Me.MousePointer = vbArrowHourglass
    
    startTime = GetTickCount
        For i = 1 To timesToLoop
            bContinueLoop = Not (glToGo = 0 Or (mcrdLastFound1 = crd1 And mcrdLastFound2 = crd2))
        Next i
    stopTime = GetTickCount
    time1 = stopTime - startTime
    
    startTime = GetTickCount
        For i = 1 To timesToLoop
            If glToGo = 0 Or (mcrdLastFound1 = crd1 And mcrdLastFound2 = crd2) Then bContinueLoop = False
        Next i
    stopTime = GetTickCount
    time2 = stopTime - startTime
    
    Me.MousePointer = vbArrow
    
    Text1.Text = Text1.Text & time1 & vbCrLf
    Text2.Text = Text2.Text & time2 & vbCrLf
End Sub

I got these results:
First Way:
3359
3437
3359
3422

Second Way:
3094
3094
3172
3109


But if I set glToGo = 0 then I get these results:
First Way:
3203
3343
3125
3125

Second Way:
4047
3860
3875
3891


It must have something to do with the Or's