Re: [Qemu-devel] [PATCH v2 12/22] target-mips: add ALIGN, DALIGN, BITSWAP and DBITSWAP instructions

[Richard Henderson]

On 06/12/2014 01:35 AM, Leon Alrae wrote:
> Yes, it clutters the code a bit. However, by looking at the other
> instructions I got the impression that preferable approach is to avoid
> generating unnecessary code if we can. This seems to be sensible so I'm
> trying to stick to it. So in bitswap example I think there is no point
> in calling the helper if we know that the result will be 0.

On the other hand, for certain values of never that exclude conformance testing
software, one will never see r0 as input to bswap.  So it's still a useless
optimization.


r~