Bytes 'n bytes

[GwenelParticipant]

Here is one way to do SAR if anyone needs it. It could use optimisation if speed is an issue but it’s a start.

Monkey

Namespace myapp #Import "<std>" Using std.. ' Sar (Bit shifting right that saves the sign bit) Function Main() ' 100 Sar 2 Print Sar(100:UByte , 2:UByte) Print Sar(100:UShort , 2:UShort) Print Sar(100:UInt , 2:UInt) ' Print Sar(100:ULong , 2:ULong) End ' 8-bit SAR Function Sar:UByte(value:UByte,width:UByte) Local sign : UByte = value & $80 value = value Shr width If sign Then value |= (255 Shl (8 - width)) Return value End Function ' 16-bit SAR Function Sar:UShort(value:UShort,width:UShort) Local sign : UShort = value & $8000 value = value Shr width If sign Then value |= (65535 Shl (16 - width)) Return value End Function ' 32-bit SAR Function Sar:UInt(value:UInt,width:UInt) Local sign : UInt = value & $80000000 value = value Shr width If sign Then value |= ( 4294967295 Shl (32 - width)) Return value End Function ' 64-bit SAR (Gives error, Long seems to be the highest possible number in TED without String trick) Function Sar:ULong(value:ULong,width:ULong) Local sign : ULong = value & $8000000000000000 value = value Shr width If sign Then value |= ( 18446744073709551615 Shl (64 - width)) Return value End Function

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Namespace myapp #Import "<std>" Using std..   ' Sar (Bit shifting right that saves the sign bit)   Function Main()   ' 100 Sar 2 Print Sar(100:UByte , 2:UByte) Print Sar(100:UShort , 2:UShort) Print Sar(100:UInt , 2:UInt) ' Print Sar(100:ULong , 2:ULong)   End   ' 8-bit SAR Function Sar:UByte(value:UByte,width:UByte)   Local sign : UByte = value & $80 value = value Shr width If sign Then value |= (255 Shl (8 - width)) Return value   End Function   ' 16-bit SAR Function Sar:UShort(value:UShort,width:UShort)   Local sign : UShort = value & $8000 value = value Shr width If sign Then value |= (65535 Shl (16 - width)) Return value   End Function   ' 32-bit SAR Function Sar:UInt(value:UInt,width:UInt)   Local sign : UInt = value & $80000000 value = value Shr width If sign Then value |= ( 4294967295 Shl (32 - width)) Return value   End Function   ' 64-bit SAR (Gives error, Long seems to be the highest possible number in TED without String trick) Function Sar:ULong(value:ULong,width:ULong)   Local sign : ULong = value & $8000000000000000 value = value Shr width If sign Then value |= ( 18446744073709551615 Shl (64 - width)) Return value   End Function

[JesseParticipant]

Thats pretty good. Now all you need is “SAL”.

[GwenelParticipant]

Nope, SHL & SAL are identical. Lucky us huh?

[JesseParticipant]

That’s interesting. Never delved deep enough to notice that.

[GwenelParticipant]

Here’s a shorter variant.

Monkey

Namespace myapp #Import "<std>" Using std.. Function Main() ' Example of Sar test,2 ' This implementation uses cheaper instructions but needs a temporary ' bigger datatype so a 64-bit wont be happening as easily wo a 128-bit type ' Local test:UByte = UByte(StringToULong("11000001",2)) Print ULongToString(test,2) Local shifted:= Sar(test,2) ' Shifts 2 steps to the right, keeping the sign-bit (the leftmost bit) Print ULongToString(shifted,2) End Function Sar:UByte(value:UByte,s:UByte) ' 8-bit Local result:UShort = (value ~ 128) - 128 Return result Shr s End Function Sar:UShort(value:UShort,s:UShort) ' 16-bit Local result:UInt = (value ~ 32768) - 32768 Return result Shr s End Function Sar:UInt(value:UInt,s:UInt) ' 32-bit Local result:ULong = (value ~ 2147483648) - 2147483648 Return result Shr s End

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Namespace myapp #Import "<std>" Using std.. Function Main()   ' Example of Sar test,2 ' This implementation uses cheaper instructions but needs a temporary ' bigger datatype so a 64-bit wont be happening as easily wo a 128-bit type ' Local test:UByte = UByte(StringToULong("11000001",2)) Print ULongToString(test,2) Local shifted:= Sar(test,2) ' Shifts 2 steps to the right, keeping the sign-bit (the leftmost bit) Print ULongToString(shifted,2)   End Function Sar:UByte(value:UByte,s:UByte) ' 8-bit Local result:UShort = (value ~ 128) - 128 Return result Shr s End Function Sar:UShort(value:UShort,s:UShort) ' 16-bit Local result:UInt = (value ~ 32768) - 32768 Return result Shr s End Function Sar:UInt(value:UInt,s:UInt) ' 32-bit Local result:ULong = (value ~ 2147483648) - 2147483648 Return result Shr s End

[Mark SiblyKeymaster]

Shr is signed if operands are signed, eg: -64 Shr 1 does a signed shift right (ie: -32)  while print UInt(-64) shr 1 does an unsigned shift right.

[GwenelParticipant]

Hahaha my god, okay.  That’s clever. +1 for that

[GwenelParticipant]

You should really document Monkey2 better, these things are gold.

[Author]

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