[PATCH] D31210: [AMDGPU] Add new address space mapping

[Konstantin Zhuravlyov via Phabricator via cfe-commits]

kzhuravl added a comment.

In https://reviews.llvm.org/D31210#706880, @rampitec wrote:

> I'm concerned about the default address space to be 64 bit. It would move alloca into generic address space effectively making private address to be 64 bit.
>  This may have very undesirable performance implications, like address arithmetic can become expensive 64 bit and only be truncated at load or store.
>  I realize you will use addrspacecast on an alloca's value, though I'm not sure that is sufficient to mitigate performance hit.
>  I believe such change shall not be made without a good performance comparison with the feature enabled, provided the very likely performance issues.


Did not we want to use this: http://lists.llvm.org/pipermail/llvm-dev/2017-March/111199.html and use non-0 for our allocas?


https://reviews.llvm.org/D31210