tate a long to the right
''''
Function LongLeftRotate(value As Long, bits As Long) As Long
Dim lngSign As Long
Dim lngI As Long
bits = bits Mod 32
If bits = 0 Then LongLeftRotate = value: Exit Function
For lngI = 1 To bits
lngSign = value And &HC0000000
value = (value And &H3FFFFFFF) * 2
value = value Or ((lngSign < 0) And 1) Or (CBool(lngSign And _
&H40000000) And &H80000000)
Next
LongLeftRotate = value
End Function
''''
'''' Function to add two unsigned numbers together as in C.
'''' Overflows are ignored!
''''
Private Function LongOverflowAdd(Val1 As Long, Val2 As Long) As Long
Dim lngHighWord As Long
Dim lngLowWord As Long
Dim lngOverflow As Long
lngLowWord = (Val1 And &HFFFF&) + (Val2 And &HFFFF&)
lngOverflow = lngLowWord \ 65536
lngHighWord = (((Val1 And &HFFFF0000) \ 65536) + ((Val2 And &HFFFF0000) \ 65536) + lngOverflow) And &HFFFF&
LongOverflowAdd = UnsignedToLong((lngHighWord * 65536#) + (lngLowWord And &HFFFF&))
End Function
''''
'''' Function to add two unsigned numbers together as in C.
'''' Overflows are ignored!
''''
Private Function LongOverflowAdd4(Val1 As Long, Val2 As Long, val3 As Long, val4 As Long) As Long
Dim lngHighWord As Long
Dim lngLowWord As Long
Dim lngOverflow As Long
lngLowWord = (Val1 And &HFFFF&) + (Val2 And &HFFFF&) + (val3 And &HFFFF&) + (val4 And &HFFFF&)
lngOverflow = lngLowWord \ 65536
lngHighWord = (((Val1 And &HFFFF0000) \ 65536) + _
((Val2 And &HFFFF0000) \ 65536) + _
((val3 And &HFFFF0000) \ 65536) + _
((val4 And &HFFFF0000) \ 65536) + _
lngOverflow) And &HFFFF&
LongOverflowAdd4 = UnsignedToLong((lngHighWord * 65536#) + (lngLowWord And &HFFFF&))
End Function
''''
'''' Convert an unsigned double into a long
''''
Private Function UnsignedToLong(value As Double) As Long
If value < 0 Or value >= OFFSET_4 Then Error 6 '''' Overflow
If value <= MAXINT_4 Then
UnsignedToLong = value
Else
UnsignedToLong = value - OFFSET_4
End If
End Function
''''
'''' Convert a long to an unsigned Double
''''
Private Function LongToUnsigned(value As Long) As Double
If value < 0 Then
LongToUnsigned = value + OFFSET_4
Else
LongToUnsigned = value
End If
End Function
上一页 [1] [2] [3] [4] | 
