Re: [PATCH] target/s390x: Fix CC set by CONVERT TO FIXED/LOGICAL

[Ulrich Weigand]

On Mon, Jun 28, 2021 at 10:49:52AM -0700, Richard Henderson wrote:
> On 6/28/21 9:32 AM, Ulrich Weigand wrote:
> >>Don't clear out env->fpu_status.float_exception_flags in
> >>handle_exceptions.  Wait until we're actually done with the data.
> >
> >I don't really know much about qemu internals, but this is really
> >confusing me, sorry.  Aren't env->fpu_status and env->cc_op two
> >elements of the same global state?  Why it is OK to use one of
> >these fields to pass information to the next helper, but not the
> >other?  I guess I must be missing something here ...
> 
> One of them has
> 
>     cc_op = tcg_global_mem_new_i32(cpu_env, offsetof(CPUS390XState, cc_op),
>                                    "cc_op");
> 
> which makes it a TCG Global, which may not be modified at will, and one of 
> them does not.

Got it, thanks!

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU/Linux compilers and toolchain
  Ulrich.Weigand@de.ibm.com