qemu-arm does not reject vrintz on non-v8 cpu

[Christophe Lyon]

Hello,

It seems that qemu-arm does not reject some v8-only instructions as it should, but executes them "correctly".

For instance, while compiling/running some of the GCC ARM instrinsics tests, we noticed that
vrintz should be rejected on cortex-a9 for instance, while it is executed as if the instruction was supported.

objdump says:
   1074c: f3fa05a0 vrintz.f32 d16, d16
and qemu -d in_asm says:
0x0001074c: f3fa05a0 vabal.u<illegal width 64> q8, d26, d16

The problem is still present in qemu-2.6.0

[Peter Maydell (pmaydell)]

Should be fixed by http://patchwork.ozlabs.org/patch/633105/

[Christophe Lyon (christophe-lyon)]

I confirm your patch does fix the problem.

You may still want to fix the disassembler such that it dumps the right instruction, but that would be a separate fix.

Thanks for your quick support.

[Peter Maydell (pmaydell)]

On 9 June 2016 at 20:14, Christophe Lyon <email address hidden> wrote:
> You may still want to fix the disassembler such that it dumps the right
> instruction, but that would be a separate fix.

Unfortunately the disassembler is the pre-GPLv3 binutils one,
so we can't just update it (and I'm not particularly inclined
to independently re-implement all the 32-bit instruction set
changes post that change).

thanks
-- PMM