From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1DVyha-0005cC-E2 for qemu-devel@nongnu.org; Wed, 11 May 2005 17:25:12 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1DVyhR-0005Xp-60 for qemu-devel@nongnu.org; Wed, 11 May 2005 17:25:02 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1DVyhQ-0005W4-UZ for qemu-devel@nongnu.org; Wed, 11 May 2005 17:25:00 -0400 Received: from [62.210.158.45] (helo=quito.magic.fr) by monty-python.gnu.org with esmtp (Exim 4.34) id 1DVykG-0006pm-6i for qemu-devel@nongnu.org; Wed, 11 May 2005 17:27:56 -0400 Subject: Re: [Qemu-devel] Compile fixes for newer gcc From: "J. Mayer" In-Reply-To: <200505102210.59973.paul@codesourcery.com> References: <200505090249.52556.paul@codesourcery.com> <1115758043.29701.14.camel@rapid> <200505102210.59973.paul@codesourcery.com> Content-Type: text/plain Date: Wed, 11 May 2005 23:20:48 +0200 Message-Id: <1115846448.29701.53.camel@rapid> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: qemu-devel@nongnu.org On Tue, 2005-05-10 at 22:10 +0100, Paul Brook wrote: > On Tuesday 10 May 2005 21:47, J. Mayer wrote: > > On Mon, 2005-05-09 at 02:49 +0100, Paul Brook wrote: > > > The attached patch fixes some trivial build problems with newer gcc on > > > amd64. It adds FORCE_RET on load ops, > > > > Index: target-ppc/exec.h > > =================================================================== > > RCS file: /cvsroot/qemu/qemu/target-ppc/exec.h,v > > retrieving revision 1.10 > > diff -u -p -r1.10 exec.h > > --- target-ppc/exec.h 13 Mar 2005 17:01:22 -0000 1.10 > > +++ target-ppc/exec.h 9 May 2005 01:33:04 -0000 > > @@ -33,11 +33,7 @@ register uint32_t T2 asm(AREG3); > > #define FT1 (env->ft1) > > #define FT2 (env->ft2) > > > > -#if defined (DEBUG_OP) > > -#define RETURN() __asm__ __volatile__("nop"); > > -#else > > -#define RETURN() __asm__ __volatile__(""); > > -#endif > > +#define RETURN() FORCE_RET() > > > > Please don't change this. This is usefull and your so-called "fix" only > > makes debug harder. > > Same goes for all other patches: use RETURN macro everywhere in PowerPC > > emulation code. > > Ok. This slipped in from a following patch, so we can revisit it when I submit > those changes. A much better way to do this is to add the NOPs in dyngen. > Then you get nops after all ops, not just the ones that use RETURN() A better fix would be to improve qemu disasembly routines so it can clearly separate micro-ops when displaying generated code. Since I'm too lazy to do this, those days, a simple nop is all I need. I think patching dyngen for a debug-only feature is a really bad idea... > > > and introduces helper functions for floating > > > point negation (these require a literal constant load). > > > > /* fneg */ > > +void do_fneg (void); > > PPC_OP(fneg) > > { > > - FT0 = -FT0; > > + do_fneg(); > > RETURN(); > > } > > > > Where's the problem ? It compiles and run perfectly on my amd64. Calling > > a function for this is a nonsense. Don't apply this. > > As I said it's required to avoid a pc-relative constant literal load. > gcc4.0 compiles fneg to: Then use the softfloat helper, but never call a function for such a thing: replace it with FT0 = float64_chs(FT0); It uses a 8 bit constant with gcc3. gcc 4 should do the same, if it's not too buggy.... -- J. Mayer Never organized