From mboxrd@z Thu Jan  1 00:00:00 1970
From: jbuck@synopsys.com
To: steffend@glitch.physics.colostate.edu (Dave Steffen)
Cc: egcs@cygnus.com
Subject: Re: EGCS vs GCC performance
Date: Wed, 14 Jan 1998 04:17:00 -0000
Message-id: <199801131736.JAA04529@atrus.synopsys.com>
References: <199801130145.RAA07615@cygnus.com>
X-SW-Source: 1998-01/msg00401.html

>    If anybody's interested, I just did a (very) informal performance
>    test between EGCS 1.0.1 and GCC 2.7.2. The test involved compiling
>    and executing some heavily-templated numerical code on a HP 715
>    running HP-UX 9.05.
...
>    The result, in a nutshell, is that EGCS outperforms GCC
>    significantly in both compile-time and run-time.

HP, if I understand correctly, is the platform that has benefited the
most from the Haifa scheduler.  The story isn't as great on some other
platforms; ix86/Pentium performance seems to have actually gotten worse
in some cases according to several reports.  But I'm sure this will be
addressed soon.

> I executed "time make" using GCC: 
> 
> g++ -ansi -frepo -O3 -I/usr/local/lib/TNT -I/usr/local/lib/C++  -c kubo.C
> 
>     (... etc etc)
> 
> real    5m40.990s
> user    4m54.180s
> sys     0m30.970s
> 
> 	A lot of time was used recompiling the source to get the
> 	templates right; this took seven iterations. (The -frepo flag
> 	is convenient, but it does take a while the first time.

This is why I dislike -frepo.  If you're willing to trade larger
object files (and possibly a larger executable if on your platform
the linker cannot eliminate duplicate functions) in exchange for
much faster compile/link time, just don't use -frepo.