Re: [Qemu-devel] [PATCH v3 42/43] tcg: introduce regions to split code_gen_buffer

[Emilio G. Cota]

On Thu, Jul 20, 2017 at 11:22:10 -1000, Richard Henderson wrote:
> >Perhaps we should then enlarge both the first and last regions so that we
> >fully use the buffer.
> 
> I really like the idea.  That's a lot of space recovered for 64k page hosts.
> 
> I do think we can make the computation clearer.  How about

(snip)
> 
> static inline void tcg_region_bounds(TCGContext *s, size_t curr_region,
>                                      void **pstart, void **pend)
> {
>   void *start, *end;
> 
>   /* ??? Maybe store "aligned" precomputed.  */
>   start = QEMU_ALIGN_PTR_UP(region.start, qemu_real_host_page_size);
>   /* ??? Maybe store "stride" precomputed.  */
>   start += curr_region * (region.size + qemu_real_host_page_size);
>   end = start + region.size;
> 
>   if (curr_region == 0) {
>     start = region.start;
>   }
>   if (curr_region == region.n - 1) {
>     end = region.end;
>   }
> 
>   *pstart = start;
>   *pend = end;
> }

That's a nice helper -- will do it this way.

For v4, should I send all patches again, or just the handful of patches
that are changing from v3?

                E.