Re: [Qemu-ppc] [PATCH 2/2] target-*/cpu.h: remove cs_base for other targets

[Peter Maydell]

On 24 April 2013 08:15, li guang <address@hidden> wrote:
> 在 2013-04-24三的 08:05 +0100，Peter Maydell写道：
>> On 24 April 2013 02:48, liguang <address@hidden> wrote:
>> > Signed-off-by: liguang <address@hidden>
>>
>> I'm afraid this is definitely wrong. It has a less than
>> helpful name, but cs_base is actually just "another 32/64 bits
>> of state that the target can use to distinguish translation
>> blocks", and some non-x86 targets do use it. For instance:
>
> only sparc use it as a tmp buffer for pc.

And x86 uses it. And tomorrow anybody could submit a patch
to another target which makes use of it, if they find they
need to do something and there's not enough room left in
'flags'. It's a generic mechanism which happens to be used
by two targets today.

>> > --- a/target-sparc/cpu.h
>> > +++ b/target-sparc/cpu.h
>> > @@ -715,7 +715,7 @@ trap_state* cpu_tsptr(CPUSPARCState* env);
>> >  #define TB_FLAG_AM_ENABLED (1 << 5)
>> >
>> >  static inline void cpu_get_tb_cpu_state(CPUSPARCState *env, target_ulong 
>> > *pc,
>> > -                                        target_ulong *cs_base, int *flags)
>> > +                                        int *flags)
>> >  {
>> >      *pc = env->pc;
>> >      *cs_base = env->npc;
>>
>> ...surely this doesn't even compile after your changes?
>>
>
> seems no problem for me.

You clearly have a problem with your compile and test
process then, because it is clear from the patch that
you've removed the cs_base argument from this function
but the function still has a use of 'cs_base' in it.

-- PMM