Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!sun-barr!apple!keith
From: keith@Apple.COM (Keith Rollin)
Newsgroups: comp.sys.mac.programmer
Subject: Re: THINK C --> MPW C
Message-ID: <47607@apple.Apple.COM>
Date: 28 Dec 90 00:35:20 GMT
References: <1990Dec24.073137.16178@cs.uoregon.edu>
Organization: Apple Computer Inc., Cupertino, CA
Lines: 24

In article <1990Dec24.073137.16178@cs.uoregon.edu> mkelly@cs.uoregon.edu (Michael A. Kelly) writes:
>I've just finished porting a rather simple application from THINK C to
>MPW C.  After changing all the standard header names, the program compiled,
>but it didn't work quite right.  After much deliberation (and a bout with
>SADE), and finally a trip through the manuals, I discovered that MPW's 'int's
>are 4 bytes long (whereas THINK's are 2 bytes).  There was a small section
>of code that relied on the size of plain integers.  After changing those ints
>to shorts everything works fine.
>
>My question is: What other elusive differences do I have to look forward to
>when porting from THINK C to MPW C ?

I seem to recall that a shift right of a signed value is implementation
dependent, according to ANSI. You can either shift the sign bit and
fill it in with a zero or maintain the sign bit (this is the difference
between using ASR versus LSR). THINK implements it one way, and MPW
implements it another.

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"Argue for your Apple, and sure enough, it's yours" - Keith Rollin, Contusions