Date: Tue, 11 Jun 1996 11:43:15 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: "Mr A. Walker" <junaid AT aurora DOT cc DOT monash DOT edu DOT au>
Cc: djgpp AT delorie DOT com
Subject: Re: GCC fstrength-reduce bug
In-Reply-To: <4piu9t$4vp@harbinger.cc.monash.edu.au>
Message-Id: <Pine.SUN.3.91.960611113905.4911D-100000@is>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII


On 11 Jun 1996, Mr A. Walker wrote:

> 	I remember reading that the current GCC v2.7.2 is affliced
> with a bug that occurs when strength reduction optimisation is used.

That's why lib/specs in DJGPP disables that optimization.  You have to 
use -fstrength-reduce on the gcc command line to switch it on.

> Also is gcc v2.6.3 got this bug?

No.

> Can v2.6.3 be
> safely used instead of v2.7.2 with the current DJGPP V2 distribution?

For C programs, probably yes.  For C++ programs, it's likely that you 
can't, because the language has changed (as usual).

IMHO, this issue should only bother you if you see a significant effect 
of disabling that optimization.  If your program runs roughly with the 
same speed with and without strength-reduce, you can just leave that 
option off and use 2.7.2.