Xref: news2.mv.net comp.os.msdos.djgpp:5012
From: Erik Max Francis <max AT alcyone DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: How to tell djgpp NOT to optimate a line of code
Date: Fri, 14 Jun 1996 23:15:03 -0700
Organization: Alcyone Systems
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To: djgpp AT delorie DOT com
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Lennart Steinke wrote:

> I wrote a ISR which hook into the timer interrupt and updates
> a global variable.
    ...
> ist there a possibilty to tell gcc not to touch the code
> (similar to the __volatile__ keyword)?

Yes.  It's called the volatile keyword.  :-)

Declare the global variable as being `volatile'.  Then the compiler won't
optimize the comparison away.

The `volatile' keyword is ANSI C, so you don't have to worry about it being
nonportable.

-- 
Erik Max Francis &tSftDotIotE && http://www.alcyone.com/max && max AT alcyone DOT com
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