[PATCH] D17019: [OpenMP] Code generation for teams - kernel launching

[Samuel Antao via cfe-commits]

sfantao added a comment.

Hi Alexey,


================
Comment at: lib/CodeGen/CGOpenMPRuntime.cpp:3799-3806
@@ -3780,4 +3798,10 @@
   OffloadEntriesInfoManager.registerTargetRegionEntryInfo(
       DeviceID, FileID, ParentName, Line, OutlinedFn, OutlinedFnID);
 }
 
+/// \brief Emit the num_teams clause of an enclosed teams directive at the
+/// target region scope. If there is no teams directive associated with the
+/// target directive, or if there is no num_teams clause associated with the
+/// enclosed teams directive, return nullptr.
+static llvm::Value *
+emitNumTeamsClauseForTargetDirective(CodeGenFunction &CGF,
----------------
ABataev wrote:
> I don't understand why global var is not captured in target region. If it is not implemented yet, it must be implemented. If it is not captured, it must be captured in Sema. We should not introduce some function/other objects to find a workaround for 'not implemented' features.
Sorry, I was not clear in my comment. It is not that globals are not captured in target regions - they are, we already have Sema doing that. 

My point is that exactly because we capture globals in target regions the magic that `OMPCapturedExprDecl` introduces does not work for that specific case. So, if we have something like:

```
int Gbl;

foo() {
  #pragma omp target
  #pragma omp teams num_teams(Gbl)
  {}
}
```
when the DeclRefExpr for Gbl used in num_teams is emitted in the scope that encloses '#pragma omp target', it will crash because Gbl is not a local and is marked as refer to enclosing capture. 

If I got it right, a solution based on `OMPCapturedExprDecl` basically makes local declarations whose initializers are the expression we are interested in. In the cases that  `OMPCapturedExprDecl` is currently employed we don't have globals being captured and that is why it works fine.

It is likely I am missing something here. Let me know if you need me to provide more details.

Thanks!


http://reviews.llvm.org/D17019