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From: sar@datcon.UUCP (Simon A Reap)
Newsgroups: comp.lang.c
Subject: Re: Is this a bug in Turbo C 2.0?
Message-ID: <60@datcon.UUCP>
Date: 8 Mar 90 16:50:11 GMT
References: <3210@pur-phy>
Reply-To: sar@datcon.co.uk (Simon A Reap)
Organization: Data Connection Limited, Enfield, Middlesex, UK
Lines: 17

In article <3210@pur-phy> murphy@newton.physics.purdue.edu.UUCP
(William J. Murphy) writes:
>long SUM;
>short data1, data2, data3, data4, data5;
>SUM = data1 + data2 + data3 + data4 + data5;
>Here is the problem, when the sum of data? < 32767 it sums correctly on both
>GNU C and TC.  Hwen the sum of data? > 32767, TC does the rollover and 
>becomes negative while GNU C carries the sum as a long and returns the
: 
>SUM = (long)data1 + (long)data2 + (long)data3 + (long)data4 + (long)data5;
>solved the problem.
Microsoft C 5.1 (under OS/2) does the same (wrong) thing.  BTW, you only need
to (long) cast one of the data? to get the right result.
-- 
Enjoy,
yerluvinunclesimon      Opinions are mine - my cat (1CC) has her own ideas
Reach me at sar@datcon.co.uk, or ...!mcvax!ukc!pyrltd!datcon!sar