🚀 go-pugleaf

Hi,

Vielen Dank. Klingt etwas laenglich, ich werde damit so schnell nicht
zurande kommen.

Gruss

>it seems I forgot to explain, what is exactly needed to port Coroutines
>to other Oberon implementations. If you successfully ported Coroutines,
>please send me your version, so that I can updated mine, and
>redistribute it.
>
>I'll explain what to do using the AXP example.
>	
>CONST
> (* AXP: *) MP=29; SP=30; negativeGrow=TRUE; align=16; TYPE
LONGINT=SYSTEM.SIGNED_64;
>
>The first constant (MP) is the register number used in REG() and
>SETREG() for accessing the Mark Pointer. The mark pointer is the
>register which is used for accessing local variables in procedures. The
>second constant (SP) is the register number used for the Stack Pointer.
>The third constant defines, whether a push on the stack will decrement
>(negativeGrow=TRUE) or increment (negativeGrow=FALSE) the stack pointer.
>The fourth constant defines the boundary to which a stack has to be
>aligend. This is the stack hast to start ion an address, such that this
>address modulo align is 0.
>
>The TYPE declaration is needed on AXP, as the return type of SYSTEM.ADR
>is not LONGINT as on most other systems. In Modula-2, SYSTEM.ADR would
>return the special type SYSTEM.ADDRESS, which is not existant in Oberon,
>thus I supposed, that every implementation would have SYSTEM.ADR return
>LONGINT.
>
>How does one find the correct values for those constants. The best
>solution would be to find them in some documentation. If none is
>available, one can do intelligent guesses using test programs and a
>disassembler, if one is supplied with the given Oberon implementation.
>
>In module CoTest which I included in my first distribution, you might
>have seen the procedure regTest and might have wondered what its scope
>ist. It contains a row of SETREG and REG statements with register
>numbers from 0 up to 255. I compiled this, to first see, which were
>accepted by the compiler and which were rejected, because of invalid
>register numbers. Then I commented out the invalid ones, and recompiled
>CoTest. Then I disassembled it and lookued up, where the register number
>in the assembler instruction was replaced by SP or MP.
>
>If you just see SP and no MP, then look at how the code for accessing a
>local variable looks like. If it uses the stack pointer as base, then
>your compiler uses the stack pointer also as mark pointer, and you
>should use the same constant for SP and MP.
>
>For finding the value for negativeGrowth, one would look at the
>procedure start and end, to see whether it somethinge like DEC SP...INC
>SP (negtiveGrowth=TRUE) or INC SP ... DEC SP (negativeGrow=FALSE).
>
>For the alignment, you simply have to know. I would guess that 4 times
>the processors word size is a good guess (32 bit = 4 byte => 16). If it
>is too large, then it takes off a bit too much from your stack, but it's
>just a few bytes, so it doesn't really matter.
>
>					claudio
>-- 
>claudio@dial.eunet.ch, Claudio Nieder, Kanalweg 1, CH-8610 Uster, Switzerland
>
>
>
Christian Hoffmann
Swiss Federal Institute for Forest, Snow and Landscape Research
CH-8903 Birmensdorf, Switzerland
phone: ++41-1-739 22 77    fax  : ++41-1-739 22 15   e-mail:  hoffmann@wsl.ch