Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!dptechno!dave
From: dave@dptechno.UUCP (Dave Lee)
Newsgroups: comp.sys.hp
Subject: Re: C Compiler Optimizer
Keywords: Optimizer C Complier
Message-ID: <570@dptechno.UUCP>
Date: 28 Aug 90 18:08:27 GMT
References: <59169@bbn.BBN.COM>
Reply-To: dave@dptechno.UUCP (Dave Lee)
Organization: D.P. Technology Corp. Camarillo California
Lines: 29

In article <59169@bbn.BBN.COM> ahill@bbn.com (Alan R. Hill) writes:
>
>	We have experienced problems of varying symptoms while using
>the optimizer switch of the HP-UX 7.0 C compiler.  Rather than 
>extensively analyzing these problems we have opted to compile without
>optimizing.  Has anyone else noticed bad behavior with the optimizer?
>

Alas, I also have had problems. A perfectly fine  program just stopped
working with -O .  Minor inspection showed no ***obvious*** flaws
in the code.  I didnt investigate enough to be able to pinpoint the
problem so it "could" be a program error, but in this case I 
really doubt it.   

It is exactly this type of hard to find infrequent optimization bugs that
make ANY optimization useless.   I am just too afraid of this type of
bug that we CANT afford to chance it.  Much Much Much better a slower
program than a broken one.  (Upps, sorry sir, didn't mean to crash
your $10000 part because of an optimization bug, try it again. 
What you say another $10000 part thrashed, well it's not MY fault ... )

Too bad really, because on the whole, the optimizer does a good job.
Someone please let me know when ALL optimization bugs are fixed 
(or atleast documented with all forms of source code that cause the problem).


-- 
Dave Lee
uunet!dptechno!dave