From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Edelsohn <dje@watson.ibm.com>
To: jbuck@synopsys.com
Cc: egcs@cygnus.com
Subject: Re: EGCS vs GCC performance 
Date: Thu, 15 Jan 1998 16:06:00 -0000
Message-id: <9801141836.AA21716@rios1.watson.ibm.com>
References: <199801131736.JAA04529@atrus.synopsys.com>
X-SW-Source: 1998-01/msg00455.html

>>>>> jbuck  writes:

>> 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.
jbuck> ...
>> The result, in a nutshell, is that EGCS outperforms GCC
>> significantly in both compile-time and run-time.

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

	Neither GCC nor EGCS machine descriptions include any instruction
or function unit information for any x86 processor.  Without any
information, there is little that the Haifa scheduler can do.  I do not
know why Haifa makes it slightly worse than the old scheduler.  With info
for Pentiums and AMD and Cyrix, Haifa should show significant improvement.

David