[PATCH] Implement ADRP CSE for global symbols

[Quentin Colombet]

Hi Jiangning,

> If I don't have other higher priority tasks, I will have a look. But it would be much better if your patch of fixing MOVAddr issue can be shared with me.

Sure! It is more a hack than a patch, but here it is :).
{F57887}

> Is there any possibility after this optimization the live range of base address is extended, and triggered spill/fill in hot loop by RA? If this is the case the rematerialization needs to be tuned, I think.

I thought about that and this is possible. Though the current implementation still uses the pseudo instructions so the rematerialization should kick in. That said, this is also possible that the rematerialization algorithm is not perfect.

> Actually I was hoping your patch can get it enabled at least for ARM64. :-)

For ARM64, yes, but for ARM64-apple-* no :). We need to address the regressions first before enabling it by default for our (apple) triple, but if you need it for other OS, I am fine with that, though I cannot test the performances for those.
We can land the patch with it disabled by default for all targets then enabled it for the targets (triple) we care along the way.

Thanks for checking the alignment thing.

Yes, I am happy with that :).

Thanks,
-Quentin

http://reviews.llvm.org/D3432