Re: [Qemu-devel] [PATCH 2/7] tcg: Optimize add2 + sub2

[Richard Henderson]

On 2012-10-01 10:46, Aurelien Jarno wrote:
> For the first add2 that seemed to have work correctly, this patch
> optimized 0.2% of them. I am not sure it worth it as is.

You're probably right.

> I think optimizing add2, and in general all *2 ops is a good idea, but
> we should be able to do more agressive optimization. Maybe, a bit like
> Blue was suggesting, add2 should always be followed by a nop, so we can
> do more optimizations?

Adding an extra nop sounds like a better idea than add2_part[12].  And
it's probably easier than adding mov2 opcodes -- one little assert inside
the optimizer and we're golden.


r~