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From: spellbinder@uwav1.u.washington.edu
Newsgroups: comp.sys.mac.programmer
Subject: <None>
Message-ID: <13955.268a81d4@uwav1.u.washington.edu>
Date: 29 Jun 90 05:16:52 GMT
Organization: University of Washington, Seattle WA
Lines: 38


Here is a compiler question for those programmers out in net-land.

I'm writing a Pascal procedure which performs some mathematical computations.
The procedure gets passed handles to the data, which look like this

   type ArrayRecord = record
                         arraySize : longint;
                         signal : array [ 0..1 ] of real;
                         end;
        ArrayRecordPtr = ^ArrayRecord;
        ArrayRecordHdl = ^ArrayRecordPtr;

The procedure knows how much data there is by getting the arraySize variable.

Now I'm writing this code in THINK Pascal version 2.03. It works fine when the
amount of memory dedicated to the signal array is less than 32K, but when it
gets bigger than this, then things start to mess up. So basically, for array
sizes less than 8K data points, everything's fine. My idea is that THINK Pascal
has a problem getting a value at an offset greater than 32K from the start
of the variable. I have verified my idea by changing signal to become
an array of double and an array of extended and each time the procedure
craps out when the data exceeds 32K. My feeling is that the compiler is not
generating the correct code to access values beyond 32K.

My questions are this:

   1) Is there another explanation for the problem?

   2) Are there any work arounds in THINK Pascal version 2.03?

   3) Will THINK Pascal 3.01 avoid the problem?

Thanks in advance.

Blair Zajac                    Zajac@phast.phys.washington.edu
Physics Dept.
University of Washington