Re: [Qemu-devel] [PATCH 9/x] ppc: Convert op_add, op_addi to TCG

[Andreas Färber]

Am 05.09.2008 um 16:18 schrieb Aurélien Jarno:

> > --- a/target-ppc/translate.c
> > +++ b/target-ppc/translate.c
> > @@ -827,10 +827,14 @@ __GEN_INT_ARITH1_O_64(name##o, opc1, opc2,  
> > opc3 |
> > 0x10, type)
> > #endif
> >
> > /* add    add.    addo    addo.    */
> > +static always_inline void gen_op_add (void)
> > +{
> > +    tcg_gen_add_tl(cpu_T[0], cpu_T[0], cpu_T[1]);
> > +}
>
> At some point, we will have to change this kind of function, otherwise
> it will be really difficult to get rid of T0, T1 and T2.

Right, same for subf. But for now, a function of this name is still  
required here for the add instruction due to the GEN_INT_ARITH2 (or  
similar) macro slightly below, which appears to set up these functions  
as handlers for the family of instruction opcodes iiuc. To change  
those macros, the whole family (or even more instructions) will need  
to be converted first.

For me, the use of global TCG variables should permit it to run on Mac  
OS X Leopard with GCC 4.0.1 at some point, so even if it doesn't allow  
optimizations right away, it has some mid-term benefits. For the other  
occurrences of gen_op_add I already inlined it for future  
optimizations but didn't spot opportunities to do that yet.

I will be mostly offline starting this weekend but would likely  
continue working on ppc. If anyone else plans to work on it, it would  
be nice to coordinate that in advance to avoid conflicting patches.

Andreas