Re: [PATCH v2 12/22] target/loongarch: Add fixed point extra instruction translation

[Richard Henderson]

On 7/26/21 2:57 AM, Song Gao wrote:
> Hi, Richard.
>
> On 07/23/2021 01:12 PM, Richard Henderson wrote:
> > On 7/20/21 11:53 PM, Song Gao wrote:
> > > +target_ulong helper_cpucfg(CPULoongArchState *env, target_ulong rj)
> > > +{
> > > +    target_ulong r = 0;
> > > +
> > > +    switch (rj) {
> > > +    case 0:
> > > +        r = env->CSR_MCSR0 & 0xffffffff;
> > > +        break;
> > > +    case 1:
> > > +        r = (env->CSR_MCSR0 & 0xffffffff00000000) >> 32;
> > > +        break;
> >
> > Why do you represent all of these as high and low portions of a 64-bit internal 
> > value, when the manual describes them as 32-bit values?
> This method can reduce variables on env.

The number of variables may increase, but the memory consumed -- which is the metric that 
is more important -- is still the same.

Also, it is much less confusing to match the description in the manual.


r~