「プロセッサ命令の数をカウントする」という意味であれば、それを行う方法はありません。ただし、経過時間は非常に正確に測定できます。Windows API 関数QueryPerformanceCounterを使用して VBA で超正確なストップウォッチを作成する方法の詳細については、私の記事「VBA での正確なパフォーマンス タイマー」を参照してください。Stopwatch クラスの完全なコードは次のとおりです。
Option Explicit
Private Declare Function QueryPerformanceCounter Lib "kernel32" ( _
lpPerformanceCount As UINT64) As Long
Private Declare Function QueryPerformanceFrequency Lib "kernel32" ( _
lpFrequency As UINT64) As Long
Private pFrequency As Double
Private pStartTS As UINT64
Private pEndTS As UINT64
Private pElapsed As Double
Private pRunning As Boolean
Private Type UINT64
LowPart As Long
HighPart As Long
End Type
Private Const BSHIFT_32 = 4294967296# ' 2 ^ 32
Private Function U64Dbl(U64 As UINT64) As Double
Dim lDbl As Double, hDbl As Double
lDbl = U64.LowPart
hDbl = U64.HighPart
If lDbl < 0 Then lDbl = lDbl + BSHIFT_32
If hDbl < 0 Then hDbl = hDbl + BSHIFT_32
U64Dbl = lDbl + BSHIFT_32 * hDbl
End Function
Private Sub Class_Initialize()
Dim PerfFrequency As UINT64
QueryPerformanceFrequency PerfFrequency
pFrequency = U64Dbl(PerfFrequency)
End Sub
Public Property Get Elapsed() As Double
If pRunning Then
Dim pNow As UINT64
QueryPerformanceCounter pNow
Elapsed = pElapsed + (U64Dbl(pNow) - U64Dbl(pStartTS)) / pFrequency
Else
Elapsed = pElapsed
End If
End Property
Public Sub Start()
If Not pRunning Then
QueryPerformanceCounter pStartTS
pRunning = True
End If
End Sub
Public Sub Pause()
If pRunning Then
QueryPerformanceCounter pEndTS
pRunning = False
pElapsed = pElapsed + (U64Dbl(pEndTS) - U64Dbl(pStartTS)) / pFrequency
End If
End Sub
Public Sub Reset()
pElapsed = 0
pRunning = False
End Sub
Public Sub Restart()
pElapsed = 0
QueryPerformanceCounter pStartTS
pRunning = True
End Sub
Public Property Get Running() As Boolean
Running = pRunning
End Property
上記のコードを新しいクラス モジュールに貼り付け、モジュールに「Stopwatch」という名前を付けます。次に、コードの他の場所で、次のようなことができます。
Sub DoStuff
Dim sw As New Stopwatch
sw.Start
myResult = SomeFunction(A, B, C)
sw.Pause
Debug.Print "SomeFunction took " & Format(sw.Elapsed * 1000, "0.000000") & " milliseconds"
End Sub