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

[Alexey Bataev via cfe-commits]

ABataev added inline comments.

================
Comment at: lib/CodeGen/CGOpenMPRuntime.cpp:256-296
@@ -255,26 +255,43 @@
 /// \brief RAII for emitting code of OpenMP constructs.
 class InlinedOpenMPRegionRAII {
   CodeGenFunction &CGF;
+  /// \brief Saves the varaibles that were forced to be local in the current
+  /// inlined region.
+  SmallVector<const VarDecl *, 4> ForcedLocalVars;
 
 public:
-  /// \brief Constructs region for combined constructs.
+  /// \brief Constructs inlined region. Mostly used for combined constructs. If
+  /// a captured statement is provided it also ensures the captured variables
+  /// are all defined in the scope of the enclosing function. This is typical
+  /// used for regions that make local instances of global variables, e.g.
+  /// target regions.
   /// \param CodeGen Code generation sequence for combined directives. Includes
   /// a list of functions used for code generation of implicitly inlined
   /// regions.
   InlinedOpenMPRegionRAII(CodeGenFunction &CGF, const RegionCodeGenTy &CodeGen,
-                          OpenMPDirectiveKind Kind, bool HasCancel)
+                          OpenMPDirectiveKind Kind, bool HasCancel,
+                          const CapturedStmt *CS)
       : CGF(CGF) {
     // Start emission for the construct.
     CGF.CapturedStmtInfo = new CGOpenMPInlinedRegionInfo(
         CGF.CapturedStmtInfo, CodeGen, Kind, HasCancel);
+
+    // Ensures that all the captures are local in the current inlined region.
+    if (CS)
+      CGF.StartOpenMPInlinedCapturedRegion(*CS, ForcedLocalVars);
   }
 
   ~InlinedOpenMPRegionRAII() {
+    // Restore the local variable information if we have anything forced in this
+    // inlined region.
+    if (!ForcedLocalVars.empty())
+      CGF.CloseOpenMPInlinedCapturedRegion(ForcedLocalVars);
+
     // Restore original CapturedStmtInfo only if we're done with code emission.
     auto *OldCSI =
         cast<CGOpenMPInlinedRegionInfo>(CGF.CapturedStmtInfo)->getOldCSI();
     delete CGF.CapturedStmtInfo;
     CGF.CapturedStmtInfo = OldCSI;
   }
 };
 
----------------
Do not modify this one, add a new one like this:
```
static void EmptyCodeGen(CodeGenFunction &) {
  llvm_unreachable("No codegen for expressions");
}
/// \brief API for generation of expressions captured in OpenMP region in outer
/// scope.
class CGOpenMPOuterExprInfo : public CGOpenMPInlinedRegionInfo {
public:
  CGOpenMPOuterExprInfo(CodeGenFunction &CGF)
      : CGOpenMPInlinedRegionInfo(CGF.CapturedStmtInfo, CodeGen, OMPD_unknown,
                                  /*HasCancel=*/false),
        CGF(CGF) {}

  /// \brief Lookup the captured field decl for a variable.
  const FieldDecl *lookup(const VarDecl *VD) const override {
    if (auto *FD = CGOpenMPInlinedRegionInfo::lookup(VD))
      return FD;
    if (!VD->isLocalVarDeclOrParm() && Mapped.count(VD) == 0) {
      auto It =
          PrivateGlobals.insert(new CodeGenFunction::OMPPrivateScope(CGF));
      DeclRefExpr DRE(const_cast<VarDecl *>(VD),
                      /*RefersToEnclosingVariableOrCapture=*/false,
                      VD->getType().getNonReferenceType(), VK_LValue,
                      SourceLocation());
      It.first->addPrivate(
          VD, [&]() -> Address { return CGF.EmitLValue(&DRE).getAddress(); });
      (void)It.first->Privatize();
      Mapped.insert(VD);
    }
    return nullptr;
  }

  /// \brief Emit the captured statement body.
  void EmitBody(CodeGenFunction &CGF, const Stmt *S) override {
    llvm_unreachable("No body for expressions");
  }

  /// \brief Get a variable or parameter for storing global thread id
  /// inside OpenMP construct.
  const VarDecl *getThreadIDVariable() const override {
    llvm_unreachable("No thread id for expressions");
  }

  /// \brief Get the name of the capture helper.
  StringRef getHelperName() const override {
    llvm_unreachable("No helper name for expressions");
  }

  static bool classof(const CGCapturedStmtInfo *Info) {
    llvm_unreachable("No helper name for expressions");
  }

  virtual ~CGOpenMPOuterExprInfo() {
    for (auto *Scope : PrivateGlobals)
      delete Scope;
    PrivateGlobals.clear();
  }

private:
  CodeGenFunction &CGF;
  /// Private scopes for each captured global variables.
  llvm::SmallPtrSet<CodeGenFunction::OMPPrivateScope *, 4> PrivateGlobals;
  SmallSet<VarDecl *> Mapped;
};
```


http://reviews.llvm.org/D17019