Re: [Qemu-devel] Re: SH4: Implement FD bit

[Aurelien Jarno]

On Tue, Dec 09, 2008 at 07:36:19PM +0300, Vladimir Prus wrote:
> Aurelien Jarno wrote:
> 
> >> 
> >> SH4 manual say that if a floating point instruction is executed while
> >> FD bit in the status register is 1, an exception should be raised. QEMU
> >> presently does not do that, so the kernel does not initialize FP state
> >> for any thread, nor does it save/restore FP state. The most apparent
> >> consequence is that while recent gcc/libc expect double-precision mode
> >> to be set by kernel, they run in single-precision mode, and all FP code
> >> produces wrong values.
> >> 
> >> This patch fixes this. It also fixes a couple of places where PC was
> >> not updated before handling an exception, although both those places
> >> deal with invalid instruction and don't lead to any user-visible bugs.
> >> 
> >> - Volodya
> > 
> > Thanks, applied.
> 
> Thanks, but it looks like one bit of the patch somehow did not
> make it into SVN. Specifically, this:
> 
> @@ -504,6 +523,13 @@ static void _decode_opc(DisasContext * ctx)
>               }
>         }
>  
> +    /* The 0xfffd instruction is underfined, so we don't want to
> +       raise fpu disable exception on it.  */
> +    if (((ctx->opcode & 0xf000) == 0xf000)
> +       && (ctx->opcode != 0xfffd))      
> +      {
> +       CHECK_FPU_ENABLED
> +      }
> 
> Is present in my post, and is not present in:
> 
>         http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5937
> 
> Maybe some merge issue?

Yes I haven't seen that one hunk of the patch has been rejected, so I
missed this part. I have just tried to merge it by hand, but it is not
possible to apply it. It looks like the patch was not done against the
current SVN.

Care to resend it against the current SVN?

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