[LLVMdev] [RFC] AArch64: Should we disable GlobalMerge?

[Jim Grosbach]

> On Feb 27, 2015, at 2:15 PM, Ahmed Bougacha <ahmed.bougacha at gmail.com> wrote:
> 
> On Fri, Feb 27, 2015 at 2:01 PM, Renato Golin <renato.golin at linaro.org> wrote:
>> On 27 February 2015 at 21:26, Ahmed Bougacha <ahmed.bougacha at gmail.com> wrote:
>>> Which brings us to my fallback proposal:  what about disabling the
>>> pass on darwin only?
>> 
>> That's a decision for Jim/Evan. I'm ok if they are.
> 
> Jim, thoughts?

I would prefer Darwin not differ in this regard, but I don’t feel incredibly strongly about it. Just a general preference to keeping platform dependencies and differences to a minimum. Whatever y’all decide is fine with me.

> 
>> 
>>> As for other targets, as a first step, making the pass run under -O3
>>> rather than -O1 is hopefully agreeable to everyone?
>> 
>> Sounds reasonable.
> 
> Great!
> 
>> Even though it conflicts with LTO, that's what O3 means, as you said,
>> instability. People at O3 might want to fiddle with the passes
>> (on/off) to get the best performance for their own code/workload.
> 
> By the way, I'm not convinced LTO being either -O3 or -O0 is sensible.
> But that's a discussion for another day =)
> 
> -Ahmed
> 
>> cheers,
>> --renato