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Date: Wed, 9 Sep 1998 21:29:33 +0200
From: Marc Lehmann <pcg AT goof DOT com>
To: Steven Snyder <ssnyder AT indy DOT net>,
        pgcc mailing list <beastium-list AT Desk DOT nl>
Subject: Re: Is -fstrength-reduce unstable?
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In-Reply-To: <Pine.SUN.3.96.980909131604.9304A-100000@indy1>; from Steven Snyder on Wed, Sep 09, 1998 at 01:22:27PM -0500
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On Wed, Sep 09, 1998 at 01:22:27PM -0500, Steven Snyder wrote:
> I see a lot of software packages whose compilation uses the
> -fno-strength-reduce switch.  (I'm reminded of this because I'm building
> glibc right now and it uses that switch as well.)  
> 
> Is strength reduction known to be buggy?  And if so, why is it enabled by
> default?

Its not perfect, but its as safe as almost every other part of the compiler.
Back in linux-1.3, the kernel hit a bug with -fstrength-reduce, and all people
suddenly though "see how buggy gcc is", even when, in fact, they work fine.

But there is a reason why (some!) software packages use this switch, as it
sometimes (rare) decreases performance.

But normally you wouldn't want to disable strength reduction.

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      ---==---(_)__  __ ____  __       Marc Lehmann       +--
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    The choice of a GNU generation                        |
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