[PATCH][combine][v2] Canonicalise (r + r) to (r << 1) to aid recognition

[Bernd Schmidt]

On 12/18/2015 03:29 PM, Kyrill Tkachov wrote:
> Bootstrapped and tested on arm, aarch64, x86_64.
> As before, there were no codegen differences for SPEC2006 on x86_64.
> aarch64 SPEC2006 sees the effects described above.

I think this is OK. There may be some question as to whether this is a 
bug fix, so please wait a few days for objections before committing. I'm 
assuming there's no place which tries to do the opposite transformation...


Bernd