From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27436 invoked by alias); 20 Mar 2007 17:52:07 -0000 Received: (qmail 27414 invoked by uid 22791); 20 Mar 2007 17:52:06 -0000 X-Spam-Check-By: sourceware.org Received: from mailgw2a.lmco.com (HELO mailgw2a.lmco.com) (192.91.147.7) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 20 Mar 2007 17:51:59 +0000 Received: from emss03g01.ems.lmco.com (relay3.ems.lmco.com [141.240.4.144])by mailgw2a.lmco.com (LM-6) with ESMTP id l2KHpvid006373for ; Tue, 20 Mar 2007 13:51:57 -0400 (EDT) Received: from CONVERSION-DAEMON.lmco.com by lmco.com (PMDF V6.3-x3 #31239) id <0JF700101QXZP8@lmco.com> for gdb@sourceware.org; Tue, 20 Mar 2007 13:51:56 -0400 (EDT) Received: from EMSS01I00.us.lmco.com ([137.249.139.145]) by lmco.com (PMDF V6.3-x3 #31239) with ESMTP id <0JF7006P1QXV7V@lmco.com> for gdb@sourceware.org; Tue, 20 Mar 2007 13:51:37 -0400 (EDT) Received: from EMSS01M14.us.lmco.com ([137.249.139.149]) by EMSS01I00.us.lmco.com with Microsoft SMTPSVC(5.0.2195.6713); Tue, 20 Mar 2007 10:51:16 -0700 Date: Tue, 20 Mar 2007 17:52:00 -0000 From: "Wealand, Barry" Subject: Reconciling PowerPC simulator traces with performance monitor results To: gdb@sourceware.org Message-id: <8F507E88CEE37244AF6947A3E0E479DF123F88E5@emss01m14.us.lmco.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT Content-class: urn:content-classes:message Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2007-03/txt/msg00231.txt.bz2 Hello - I'm using the PowerPC simulator in GDB to collect instruction (-t semantics) and load-store (-t load-store) traces for a pretty-good-sized program (several hundred million trace lines). I then apply various filters to the traces to collect measurements of interest. All of this seems to work very well. Then I run the exact same code on a PowerPC 750FX processor, which I set up to collect performance monitor statistics. For example, I can collect "completed load and store instructions", and "number of instructions completed from the FPU". What puzzles me is that the results that I collect from the simulator for these two counts in particular are 10 to 15 percent lower than the results reported by the performance monitor. I'm guessing that this discrepancy might have something to do with the details of how the performance monitor works, but the descriptions above are typical of the level of detail provided in the 750 FX manual. I wonder if anyone else has grappled with this, or might have any suggestions. Thanks! Barry Wealand Lockheed Martin Space Systems Company