🚀 go-pugleaf

Andries Dippenaar (1:105/42) writes to All:

: >>>I need a DOS Modula-2 compiler that will pack subranges, for 
: >>>example, [0..255] would be stored in 1 BYTE.  The compiler 
: >>>that I ues store it as an INTEGER.

 >Most DOS compilers should -- for one I know that the TopSpeed
 >compilers pack all data types into the smallest possible memory.  
 >You may select to override it here and there if you wish.  I 
 >haven't got any experience with the Stony Brook compiler, but 
 >would expect nothing less of it. 

As it happens, I left my the relevant Stony Brook manual at work.  However, thanks to the wonders of OS/2, I can whip up a sample program right away.  

This program:


MODULE PackTest;

FROM InOut      IMPORT WriteCard, WriteString, WriteLn;
FROM SYSTEM     IMPORT BYTE;

TYPE
    SubRange                = [0..255];
    SubRangeArray           = ARRAY SubRange OF SubRange;

VAR
    Size                                : CARDINAL;

BEGIN
    Size := SIZE(SubRange);
    WriteString('The Size of the subrange [0..255] is ');
    WriteCard(Size, 2);
    WriteLn;

    Size := SIZE(SubRangeArray);
    WriteString('The size of an array [0..255] of that subrange is ');
    WriteCard(Size, 2);
    WriteLn;

    Size := SIZE(BYTE);
    WriteString('The Size of a byte is ');
    WriteCard(Size, 2);
    WriteLn
END PackTest.

When Compiled to an executable by SBM2 for OS/2 produces this output:

The Size of the subrange [0..255] is  2
The size of an array [0..255] of that subrange is 512
The Size of a byte is  1

I believe that I have selected all of the options properly.  So, it appears that SBM2 does NOT pack small subranges into bytes even if there are arrays of those subrange values.


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uucp: uunet!m2xenix!puddle!106!2000.25!Jon.Guthrie
Internet: Jon.Guthrie@p25.f2000.n106.z1.fidonet.org