Bit Manipulation Functions (4)

ofer bester, 2007-12-25 (first published: 2007-11-01)

Execute / Usage example script:

declare @BitMap BIGINT
declare @bitNo TINYINT

set @BitMap = 0
set @bitNo = 55

print '- Bit # = '+CONVERT(VARCHAR,@bitNo)+ ', BitMap value = '+ CONVERT(VARCHAR,@BitMap)
print ' Check bit #'+CONVERT(VARCHAR,@bitNo)
+' - Is bit ON = '+ CONVERT(VARCHAR,dbo.fnBitIsOn(@BitMap, @bitNo))
+', Value ='+ CONVERT(VARCHAR,@BitMap)

set @BitMap = dbo.fnBitSetOn(@BitMap, @bitNo)
print ' Turn bit #'+CONVERT(VARCHAR,@bitNo) +' ON'+
+' - Is bit ON = '+ CONVERT(VARCHAR,dbo.fnBitIsOn(@BitMap, @bitNo))
+', Value ='+ CONVERT(VARCHAR,@BitMap)

set @BitMap = dbo.fnBitSetOff(@BitMap, @bitNo)
print ' Turn bit #'+ CONVERT(VARCHAR,@bitNo) +' OFF'
+' - Is bit ON = '+ CONVERT(VARCHAR,dbo.fnBitIsOn(@BitMap, @bitNo))
+', Value ='+ CONVERT(VARCHAR,@BitMap)

set @BitMap = dbo.fnBitToggle(@BitMap, @bitNo)
print ' Toggle bit #'+ CONVERT(VARCHAR,@bitNo)
+' - Is bit ON = '+ CONVERT(VARCHAR,dbo.fnBitIsOn(@BitMap, @bitNo))
+', Value ='+ CONVERT(VARCHAR,@BitMap)
set @BitMap = dbo.fnBitToggle(@BitMap, @bitNo)
print ' Toggle bit #'+ CONVERT(VARCHAR,@bitNo)
+' - Is bit ON = '+ CONVERT(VARCHAR,dbo.fnBitIsOn(@BitMap, @bitNo))
+', Value ='+ CONVERT(VARCHAR,@BitMap)

print ''
set @BitMap = -1

print '- Bit # = '+CONVERT(VARCHAR,@bitNo)+ ', BitMap value = '+ CONVERT(VARCHAR,@BitMap)
set @BitMap = dbo.fnBitSetOn(@BitMap, @bitNo)
print ' Turn bit #'+CONVERT(VARCHAR,@bitNo) +' ON'+
+' - Is bit ON = '+ CONVERT(VARCHAR,dbo.fnBitIsOn(@BitMap, @bitNo))
+', Value ='+ CONVERT(VARCHAR,@BitMap)

Result:

- Bit # = 55, BitMap value = 0
Check bit #55 - Is bit ON = 0, Value =0
Turn bit #55 ON - Is bit ON = 1, Value =36028797018963968
Turn bit #55 OFF - Is bit ON = 0, Value =0
Toggle bit #55 - Is bit ON = 1, Value =36028797018963968
Toggle bit #55 - Is bit ON = 0, Value =0

- Bit # = 55, BitMap value = -1
Turn bit #55 ON - Is bit ON = 1, Value =-1
Turn bit #55 OFF - Is bit ON = 0, Value =-36028797018963969
Toggle bit #55 - Is bit ON = 1, Value =-1
Toggle bit #55 - Is bit ON = 0, Value =-36028797018963969

----------------------------------------------------------------------------------- -- Check if bigint Bit is ON ----------------------------------------------------------------------------------- CREATE FUNCTION dbo.fnBitIsOn (@BitMap BIGINT, @BitNo TINYINT = 0) RETURNS TINYINT -- v1.0.0 2006.09.26, Ofer Bester AS BEGIN IF (@BitNo > 63) RETURN 0 IF (@BitNo = 63) BEGIN IF (@BitMap >= 0) RETURN 0 ELSE RETURN 1 END IF ( @BitMap & POWER( CAST(2 AS BIGINT), @BitNo ) ) <> 0 RETURN 1 RETURN 0 END GO ----------------------------------------------------------------------------------- -- Set bigint Bit OFF ----------------------------------------------------------------------------------- CREATE FUNCTION dbo.fnBitSetOff (@BitMap BIGINT, @BitNo TINYINT = 0) RETURNS BIGINT -- v1.0.0 2006.09.26, Ofer Bester AS BEGIN IF (@BitNo > 63) RETURN @BitMap IF (@BitNo = 63) RETURN @BitMap & 0x7FFFFFFFFFFFFFFF RETURN (@BitMap & ~POWER( CAST(2 AS BIGINT), @BitNo )) -- Set bit # @BitNo OFF END GO ----------------------------------------------------------------------------------- -- Set bigint Bit ON ----------------------------------------------------------------------------------- CREATE FUNCTION dbo.fnBitSetOn (@BitMap BIGINT, @BitNo TINYINT = 0) RETURNS BIGINT -- v1.0.0 2006.09.26, Ofer Bester AS BEGIN IF (@BitNo > 63) RETURN @BitMap IF (@BitNo = 63) RETURN @BitMap | 0x8000000000000000 RETURN (@BitMap | POWER( CAST(2 AS BIGINT), @BitNo )) -- Set bit # @BitNo ON END GO ----------------------------------------------------------------------------------- -- Toggle bigint Bit ON/OFF ----------------------------------------------------------------------------------- CREATE FUNCTION dbo.fnBitToggle (@BitMap BIGINT, @BitNo TINYINT = 0) RETURNS BIGINT -- v1.0.0 2006.09.26, Ofer Bester AS BEGIN IF ( dbo.fnBitIsOn(@BitMap, @BitNo) = 1 ) RETURN dbo.fnBitSetOff(@BitMap, @BitNo) RETURN dbo.fnBitSetOn(@BitMap, @BitNo) END

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