From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeffrey A Law <law@cygnus.com>
To: Oskar Enoksson <osken393@student.liu.se>
Cc: egcs@cygnus.com
Subject: Re: Optimization 
Date: Thu, 02 Apr 1998 08:21:00 -0000
Message-id: <6733.891434001@hurl.cygnus.com>
References: <Pine.SGI.3.96.980326123604.8153E-100000@purcell>
X-SW-Source: 1998-04/msg00049.html

--
Jeff Law (law@cygnus.com)
Cygnus Solutions		EGCS GNU Compiler System
http://www.cygnus.com		http://www.cygnus.com/egcs

  In message <Pine.SGI.3.96.980326123604.8153E-100000@purcell>you write:
  > 
  > Hi! I'm working with computational mathematics using c and c++.
  > 
  > Does g++/gcc have any optimization that brings out constant subexpressions
  > outside loops? Consider the following:
Yes, gcc performs loop invariant code motion.

I don't know why the loop invariants are not being hoisted out of
the loop for your example.  I haven't had the time to look at it.

jeff