Re: [PATCH 00/48] tcg: optimize redundant sign extensions

[Richard Henderson]

On 8/30/21 3:00 PM, Philippe Mathieu-Daudé wrote:
> Hi Richard,
>
> On 8/30/21 8:24 AM, Richard Henderson wrote:
> > Currently, we have support for optimizing redundant zero extensions,
> > which I think was done with x86 and aarch64 in mind, which zero-extend
> > all 32-bit operations into the 64-bit register.
> >
> > But targets like Alpha, MIPS, and RISC-V do sign-extensions instead.
> > The last 5 patches address this.
> >
> > But before that, split the quite massive tcg_optimize function.
>
> Looks promising after quick review. Do you have any comparison perf numbers?

No, not yet.  I expect there to be *lots* of redundant extensions with the patches for 
RV32 on RV64.  I think only MIPS n32 would compare, and I don't have a chroot for that, 
only n64.


r~