Low overhead assembler procedure in an SLL.

[Steve Hutchesson]

The example is an assembler procedure contained in a basic function in an SLL module. It is done this way for a reason, a single call to the enclosing basic function gets the address of the assembler procedure and returns it to the caller. At the caller end, the address is saved into a name which is used to call the assembler procedure. As PB does not directly support calling a bare assembler procedure, a set of macros are provided that make calling the procedure easy to use.

The example is a bit clunky in that setting up an array would not normally be the way it would be used, You would have some form of streaming set up where the data to append is being sourced at high speed.

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    #compile exe "FpSLL.exe"
    #compiler PBCC

    #include "asmcall.inc"
    #link "szappend.sll"

    GLOBAL szappend as DWORD                    ' name for the asm procedure in the SLL

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FUNCTION PBmain as LONG

    LOCAL buffer as STRINGZ * 1024
    LOCAL ptrbuf as DWORD                       ' output buffer pointer
    LOCAL text   as STRINGZ * 128
    LOCAL ptext  as DWORD                       ' pointer to input text buffer

    LOCAL cloc   as DWORD                       ' current location offset
    LOCAL acnt   as DWORD                       ' array loop counter

    szappend = pszappend                        ' attach the name to the SLL procedure address

    DIM tArr(10) as STRINGZ * 16                ' dimension a test array

    tArr(0) = "Text 1 "+$CRLF                   ' load the array
    tArr(1) = "Text 2 "+$CRLF
    tArr(2) = "Text 3 "+$CRLF
    tArr(3) = "Text 4 "+$CRLF
    tArr(4) = "Text 5 "+$CRLF
    tArr(5) = "Text 6 "+$CRLF
    tArr(6) = "Text 7 "+$CRLF
    tArr(7) = "Text 8 "+$CRLF
    tArr(8) = "Text 9 "+$CRLF
    tArr(9) = "Text 10 "+$CRLF

    cloc = 0                                    ' set location offset to zero
    ptrbuf = VarPtr(buffer)
    ptext  = VarPtr(text)                       ' only needs to be done once - reuse text buffer

    acnt = 0

    Do
      text = tArr(acnt)                         ' assign to single buffer
      asm3(szappend,ptrbuf,ptext,cloc)
      ! mov cloc, eax                           ' update the current location offset
      ! add acnt, 1
    Loop while acnt < 10

    StdOut buffer

    erase tArr()

    waitkey$

End FUNCTION

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