[PATCH] D59494: AMDGPU: Add support for cross address space synchronization scopes (clang)

[Brian Sumner via Phabricator via cfe-commits]

b-sumner added inline comments.


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Comment at: lib/CodeGen/TargetInfo.cpp:7976
+
+    Name = Twine(Twine(Name) + Twine("one-as")).str();
+  }
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rampitec wrote:
> b-sumner wrote:
> > kzhuravl wrote:
> > > rampitec wrote:
> > > > I think subgroup is in the single address space even if sequentially consistent.
> > > I have synced with @t-tye, and it seems like it might not be. @b-sumner, do you know what opencl spec states? Thanks.
> > As I understand the spec, memory order seq_cst must be consistent with both local- and global-happens-before, so I would say even subgroup is not in the single address space for OpenCL seq_cst.
> OK. Is it always one-as if not sequentially consistent? I thought we are about to change sequentially consistent case, and not everything else except it.
Right.  In OpenCL, only seq_cst can tie together address spaces.  But other languages without explicit address spaces will want them tied for other memory orders


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D59494/new/

https://reviews.llvm.org/D59494