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From: jlg@cochiti.lanl.gov (Jim Giles)
Newsgroups: comp.lang.c
Subject: Re: When do you use "if ( a = b )"? (was Re: Funny mistake)
Message-ID: <18401@lanl.gov>
Date: 19 Mar 91 21:12:13 GMT
References: <8148@rsiatl.Dixie.Com> <15481@smoke.brl.mil> <775@camco.Celestial.COM> <65837@eerie.acsu.Buffalo.EDU> <1991Mar18.195351.11985@unlv.edu> <11109@dog.ee.lbl.gov>
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Reply-To: jlg@cochiti.lanl.gov (Jim Giles)
Organization: Los Alamos National Laboratory
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In article <11109@dog.ee.lbl.gov>, torek@elf.ee.lbl.gov (Chris Torek) writes:
|> [...]
|> Smaller source code, yes.  Smaller or faster object code---well, if
|> your compiler generates different code for
|> 
|> 	if (a = b)
|> 
|> than for
|> 
|> 	a = b;
|> 	if (a)
|> 
|> then your compiler is not worth what you paid for it.  [...]

Even if it was _free_!  The above 'optimization' was present
in Fortran compilers more than 30 years ago - and their _fastest_
machines were slow compared to today's micros (so the excuse that
doing the above analysis makes the compiler too slow or complex is
garbage).

J. Giles