From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29948 invoked by alias); 14 Nov 2011 15:49:13 -0000 Received: (qmail 29901 invoked by uid 22791); 14 Nov 2011 15:49:10 -0000 X-SWARE-Spam-Status: No, hits=-7.6 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 14 Nov 2011 15:48:57 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id pAEFmpeD015255 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 14 Nov 2011 10:48:51 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id pAEFmo7m021705; Mon, 14 Nov 2011 10:48:50 -0500 Received: from barimba (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id pAEFmmgY011682; Mon, 14 Nov 2011 10:48:48 -0500 From: Tom Tromey To: Werner Almesberger Cc: gdb-patches@sourceware.org, Jon Beniston Subject: Re: [PATCH] 32 bit-ism in lm32-tdep.c (and some sloppy macros) References: <20111111233808.GA10815@ws> Date: Mon, 14 Nov 2011 15:49:00 -0000 In-Reply-To: <20111111233808.GA10815@ws> (Werner Almesberger's message of "Fri, 11 Nov 2011 20:38:08 -0300") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.90 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2011-11/txt/msg00352.txt.bz2 >>>>> "Werner" == Werner Almesberger writes: Werner> The reason for this is that stack frames weren't unwound correctly. Werner> The bug is in the LM32_IMM16 macro, which tries to do sign expansion Werner> by shifting the value to the left edge of a long, expecting it to Werner> be 32 bits. This trick produces incorrect results on 64 bit systems. Thanks for the patch. It needs a ChangeLog entry. Werner> The patch below delegates the work of figuring out such details to Werner> the compiler. I've also taken the liberty of protecting all the Werner> macro arguments, just in case. Werner> -#define LM32_IMM16(insn) ((((long)insn & 0xffff) << 16) >> 16) [...] Werner> +#define LM32_IMM16(insn) ((long) (int16_t) (insn)) I was a little surprised to find out we already use int16_t in gdb. Anyway, it seems that the macro would be more obvious as: #define LM32_IMM16(insn) ((long) ((insn) & 0xffff)) WDYT? Tom