Login | Register   
LinkedIn
Google+
Twitter
RSS Feed
Download our iPhone app
TODAY'S HEADLINES  |   ARTICLE ARCHIVE  |   FORUMS  |   TIP BANK
Browse DevX
Sign up for e-mail newsletters from DevX


Tip of the Day
Language: VB4,VB5,VB6,VBS
Expertise: Intermediate
Jun 26, 1999

RotateLeftI - Rotate an Integer to the left

' Rotate an Integer to the left the specified number of times
'
' NOTE: requires Power2()

Function RotateLeftI(ByVal value As Integer, ByVal times As Long) As Integer
    Dim i As Long, signBits As Integer
    
    ' no need to rotate more times than required
    times = times Mod 16
    ' return the number if it's a multiple of 16
    If times = 0 Then RotateLeftI = value: Exit Function
    
    For i = 1 To times
        ' remember the 2 most significant bits
        signBits = value And &HC000
        ' clear those bit and shift to the left by one position
        value = (value And &H3FFF) * 2
        ' if the number was negative, then add 1
        ' if bit 30 was set, then set the sign bit
        value = value Or ((signBits < 0) And 1) Or (CBool(signBits And &H4000) _
            And &H8000)
    Next
    RotateLeftI = value
End Function

Francesco Balena
 
Comment and Contribute

 

 

 

 

 


(Maximum characters: 1200). You have 1200 characters left.

 

 

Sitemap
Thanks for your registration, follow us on our social networks to keep up-to-date