Date:	Thu, 6 May 1999 23:57:30 +0200
To:	PGCC Mailing List <pgcc AT delorie DOT com>
Cc:	egcs AT cygnus DOT com
Subject:	Re: When will PGCC be merged with EGCS?
Message-ID:	<19990506235730.F20732@cerebro.laendle>
Mail-Followup-To:	PGCC Mailing List <pgcc AT delorie DOT com>, egcs AT cygnus DOT com
References:	<199905062117 DOT QAA23167 AT indy1 DOT indy DOT net>
Mime-Version:	1.0
In-Reply-To:	<199905062117.QAA23167@indy1.indy.net>; from Steve Snyder on Thu, May 06, 1999 at 04:15:49PM -0400
X-Operating-System:	Linux version 2.2.7 (root AT cerebro) (gcc driver version pgcc-2.93.09 19990221 (gcc2 ss-980929 experimental) executing gcc version 2.7.2.3)
From:	Marc Lehmann <pcg AT goof DOT com>
Reply-To:	pgcc AT delorie DOT com
X-Mailing-List:	pgcc AT delorie DOT com
X-Unsubscribes-To:	listserv AT delorie DOT com

On Thu, May 06, 1999 at 04:15:49PM -0400, Steve Snyder wrote:
> Now that the unfortunate gcc/egcs fork has been resolved, I hope that
> integrating pgcc's Pentium/PPro/PII/PIII optimizations into egcs will soon
> take place.
> 
> Has any schedule (tentative, I know) been established to bring these 
> 80x86-specific optimizations into the standard egcs build?

Its happening all the time. If you compare egcs to, say, an old gcc
version you will see that many improvements have been incorporated into
egcs. pgcc also took many improvements from egcs (such as all the initial
pentiumpro/ii support when I didn't have such a chip).

Many of these features are not taken directly from pgcc, for a variety
of reasons. However, many new improvements were added after they proved
useful in pgcc. Many optimizations were re-implemented in egcs in a
superior and more general (i.e. not x86-specific) form.

There is no schedule for pgcc->gcc since it is a continuous
process. Another reason is that some thing in the architecture-independent
code of egcs are not optimal for the x86 architetcure, but you cannot
change them as this would badly affect other targets. In pgcc, this is
possible since its not used (yet) on non-x86 targets.

Some parts of pgcc are even inacceptable for inclusion into egcs:
some optimizations are known to generate wrong code under some
circumstances. For example there once was a problem with glibc (there
still are) and peep-spilling. Solving it would either mean to fix that
optimization (which is requires a different infrastructure) or to disable
it. In pgcc, I chose to enable it (after all its experimental), in egcs
you had to disable it.

--  
      -----==-                                             |
      ----==-- _                                           |
      ---==---(_)__  __ ____  __       Marc Lehmann      +--
      --==---/ / _ \/ // /\ \/ /       pcg AT goof DOT com      |e|
      -=====/_/_//_/\_,_/ /_/\_\       XX11-RIPE         --+
    The choice of a GNU generation                       |
                                                         |

- Raw text -