Re: [Qemu-devel] [PATCH 25/26] target/s390x: implement TRANSLATE ONE/TWO TO ONE/TWO

[Aurelien Jarno]

On 2017-05-26 10:10, Richard Henderson wrote:
> On 05/25/2017 02:05 PM, Aurelien Jarno wrote:
> > +uint32_t HELPER(trXX)(CPUS390XState *env, uint32_t r1, uint32_t r2,
> > +                      uint32_t sizes)
> > +{
> > +    uintptr_t ra = GETPC();
> > +    int dsize = (sizes & 1) ? 1 : 2;
> > +    int ssize = (sizes & 2) ? 1 : 2;
> > +    uint16_t tst = env->regs[0] & ((1 << (8 * dsize)) - 1);
> 
> I think you should pass in tst as an argument.  That way you can pass in an
> out-of-band value when we implement ETF2 and test field M3 bit 3.

I don't mind passing r0 as an argument. That said if we want to pass tst
or bundle the M3 field, it means we need to use TCG instructions to do
so. I am not sure it brings a lot compare to doing so in the helper
side.

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
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