Anastasia added inline comments.
================ Comment at: include/clang/Basic/TargetInfo.h:1041 + default: + return LangAS::Default; + } ---------------- bader wrote: > yaxunl wrote: > > bader wrote: > > > yaxunl wrote: > > > > I think the default (including even_t, clk_event_t, queue_t, > > > > reserved_id_t) should be global since these opaque OpenCL objects are > > > > pointers to some shared resources. These pointers may be an automatic > > > > variable themselves but the memory they point to should be global. > > > > Since these objects are dynamically allocated, assuming them in private > > > > address space implies runtime needs to maintain a private memory pool > > > > for each work item and allocate objects from there. Considering the > > > > huge number of work items in typical OpenCL applications, it would be > > > > very inefficient to implement these objects in private memory pool. On > > > > the other hand, a global memory pool seems much reasonable. > > > > > > > > Anastasia/Alexey, any comments on this? Thanks. > > > I remember we discussed this a couple of time in the past. > > > The address space for variables of these types is not clearly stated in > > > the spec, so I think the right way to treat it - it's implementation > > > defined. > > > On the other hand your reasoning on using global address space as default > > > AS makes sense in general - so can we put additional clarification to the > > > spec to align it with the proposed implementation? > > I think it is unnecessary to specify the implementation details in the > > OpenCL spec. > > > > It is also unnecessary for SPIR-V spec since the pointee address space of > > OpenCL opaque struct is not encoded in SPIR-V. > > > > We can use the commonly accepted address space definition in the TargetInfo > > base class. If a target chooses to use different address space for specific > > opaque objects, it can override it in its own virtual function. > > I think it is unnecessary to specify the implementation details in the > > OpenCL spec. > > Agree, but my point was about specifying the intention in the specification. > For instance, OpenCL spec says that image objects are located in global > memory. > It says nothing about objects like events, queues, etc., so I assumed that if > it says nothing an implementation is allowed to choose the memory region, but > it might be false assumption. We could create a bug to Khronos OpenCL C spec and discuss it on the next call just to make sure... but otherwise this change seems reasonable enough! https://reviews.llvm.org/D33989 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
