From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14840 invoked by alias); 24 Feb 2003 02:36:00 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 14825 invoked from network); 24 Feb 2003 02:36:00 -0000 Received: from unknown (HELO duracef.shout.net) (204.253.184.12) by 172.16.49.205 with SMTP; 24 Feb 2003 02:36:00 -0000 Received: (from mec@localhost) by duracef.shout.net (8.11.6/8.11.6) id h1O2Zws05373; Sun, 23 Feb 2003 20:35:58 -0600 Date: Mon, 24 Feb 2003 02:36:00 -0000 From: Michael Elizabeth Chastain Message-Id: <200302240235.h1O2Zws05373@duracef.shout.net> To: drow@mvista.com, gdb@sources.redhat.com Subject: 8-byte register values on a 32-bit machine X-SW-Source: 2003-02/txt/msg00505.txt.bz2 I saw a regression in gdb.base/store.exp this week: gdb.base/store.exp: new check struct 4 PASS -> FAIL This happens with gcc 2.95.3 -gdwarf-2. This happens because gcc 2.95.3 puts an 8-byte variable into a pair of 4-byte registers. (gcc 3.2.2 puts the variable into memory so the problem never arises -- but I bet it will come back for things like FORTRAN complex numbers, which are very natural for register pairs). It happened this particular week because the old dwarf-2 code had some code to handle multi-register variables, although the code doesn't appear to work for me. The new dwarf-2 code just completely spaces in the case of multi-register variables. We need to figure out what the right symbol table information is for multi-register variables. If gcc is emitting good symbol table information, gdb can do its job, and I can write a test case for it. But I suspect that gcc 2.95.3 tells us about just one register and that we can't win. But gdb can at least say "hmmm, you are trying to print 8 bytes from reg0, I can't do that", rather than print 4 bytes of correct information and 4 bytes of rat poison. I think that would be acceptable support for 2.95.3. I filed a PR and I'll attach some executables to it. Michael C