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From: Marco van de Voort <marcov@toad.stack.nl>
Newsgroups: comp.lang.pascal.borland
Subject: Re: longint and/or overflow bug?
Date: Wed, 31 Oct 2012 09:35:02 +0000 (UTC)
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Xref: csiph.com comp.lang.pascal.borland:132

On 2012-10-30, Jim Leonard <mobygamer@gmail.com> wrote:
>
> var
>   l:longint;
>   w1,w2:word;
>
> begin
>   w1:=val1; w2:=val2;
>   l:=w1 * w2; {Throws runtime 215 "arithmetic overflow" if $Q+}

typing:
longint :=word * word

Pascal rule is afaik that an expression is evaluated in (at least?) the
combined range of the operands.  Which is word.

So the above translates to

tempresult: word = word * word
longint:=convert(word,longint,tempresult);

Note that FPC/Delphi do the same with 64-bit results (in 32-bit mode).