Re: [Qemu-devel] [patch] make qemu work with GCC 4

["Blue Swirl" <blauwirbel@gmail.com>]

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On 8/29/07, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> Hi,
>
> On Wed, 29 Aug 2007, Michael Matz wrote:
>
> > On Wed, 29 Aug 2007, Johannes Schindelin wrote:
> >
> > > > Thanks for your effor Michael! Now, I only hope, one of the patches
> > > > that makes qemu gcc4 compliant are soon merged.
> > >
> > > Well, to throw a spanner in the works: this patch is the 4th patch along
> > > the lines that I came about.  None of them (AFAICT) was tested well
> > > enough to be included in CVS.  Indeed, the biggest problem seems to be
> > > to make a patch that not only works on the machine of the poster, but on
> > > other machines, too.
> >
> > Please?  qemu with that patch builds on four architectures, and tests
> > fine on two of them (including cross targets) and only because I haven't
> > run it on the other two architectures yet.
>
> Hey, I am not criticising you!  Instead, I am thankful enough that I went
> so far as to expose it with git.
>
> > It might or might not need more patches than just mine (as I started
> > from our package), but in that case they are independend of making qemu
> > work with gcc 4, which is the only thing my patch is concerned about.
>
> I already reported the non-compiling state of sparc-linux-user...  Any
> idea what I could do about it?

With the attached patch I can run Sparc32 and Sparc64 emulators on x86_64 host.

The performance feels slightly worse. Maybe the patch should be
conditional on GCC >= 4?

I think that the decision of using host registers vs. env fields
should be done in one file at top level.

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Index: qemu/target-sparc/op.c
===================================================================
--- qemu.orig/target-sparc/op.c	2007-08-29 17:57:21.000000000 +0000
+++ qemu/target-sparc/op.c	2007-08-29 17:58:00.000000000 +0000
@@ -520,8 +520,11 @@
 {
     target_ulong src1;
 
-    if ((T0 & 0x03) || (T1 & 0x03))
+    if ((T0 & 0x03) || (T1 & 0x03)) {
         raise_exception(TT_TOVF);
+        FORCE_RET();
+        return;
+    }
 
     src1 = T0;
     T0 += T1;