Any way to work with bits?

[infratec]

You were right.

When I use

Code: Select all

MessageRequester("Time", Str(ElapsedMilliseconds() - StartTime))

and disable the debugger,
I got:

Long: 1531
Byte: 1750

But...
I had to increase the loop counter to 100000000.

Ok, it is faster. (2us)
But it needs 3 bytes more memory in the worst case

Bernd

[Kaeru Gaman]

well... s**t on three bytes.
in the end the allocation the OS makes for the process will happen in 512byte chunks or something like that, so it's less than unimportant.

[infratec]

Hi,

here is my final version:

Code: Select all

#MaxBits = 1024


Macro BitArraySize(Bits)
 ((Bits - 1) / 32 + 1)
EndMacro


Structure Test
 arry.l [BitArraySize(#MaxBits)]
EndStructure

Define myTest.Test

Dim NormalArray.l(BitArraySize(#MaxBits))


Debug "Arraysize: " + Str(ArraySize(NormalArray()))


Procedure InitBits(*A.l, Bits.i, Value.l) 
 If Value <> 0 : Value = $FFFFFFFF : EndIf
 FillMemory(*A, BitArraySize(Bits) * 4, Value, #PB_Long)         ; * 4 because we need the bytesize
EndProcedure


Procedure SetBit(*A.l, Index.i)
 *A + (Index >> 5)
  PokeL(*A, PeekL(*A) | (1 << (Index & $1F)))
EndProcedure


Procedure ClrBit(*A.l, Index.i)
 *A + (Index >> 5)
 PokeL(*A, PeekL(*A) &~ (1 << (Index & $1F)))
EndProcedure


Procedure TglBit(*A.l, Index.i)
 *A + (Index >> 5)
 PokeL(*A, PeekL(*A) ! (1 << (Index & $1F)))
EndProcedure


Procedure.i GetBit(*A.l, Index.l)
 *A + (Index >> 5)
 ProcedureReturn (PeekL(*A) & (1 << (Index & $1F))) >> (Index & $1F)
EndProcedure




InitBits(@myTest\arry, #MaxBits, #True)

SetBit(@myTest\arry, 4)
Debug GetBit(@myTest\arry, 4)

ClrBit(@myTest\arry, 4)
Debug GetBit(@myTest\arry, 4)

TglBit(@myTest\arry, 4)
Debug GetBit(@myTest\arry, 4)



InitBits(@NormalArray(), #MaxBits, #False)

SetBit(@NormalArray(), 144)
Debug GetBit(@NormalArray(), 144)

ClrBit(@NormalArray(), 144)
Debug GetBit(@NormalArray(), 144)

TglBit(@NormalArray(), 144)
Debug GetBit(@NormalArray(), 144)

Now it uses long for the speed.
And I had a fault with the parameter of the NormalArray:

The address of the first element is @NormalArray() and not @NormalArray

Bernd

[Seymour Clufley]

Thanks for this.

[idle]

If you want it quicker better to use macros, I just ripped this from my bloomfilter

Code: Select all

*mem = AllocateMemory(32767/8)

Macro setBit(mem,bit)
*tb.byte
*tb = mem+(bit>>3)
*tb\b | (1 << (bit % 8))  
EndMacro

Macro GetBit(mem,bit,x)
*tb.byte
mf = (bit % 8)
*tb = mem+(bit>>3)
x  = (*tb\b & (1 << mf)) >> mf
EndMacro

getbit(*mem,1000,x)
Debug x  ;"0" 

setbit(*mem,1000)

getbit(*mem,1000,x)
Debug x  ;"1"