[OpenMP] Update target codegen for NVPTX device.

This patch includes updates for codegen of the target region for the NVPTX
device. It moves initializers from the compiler to the runtime and updates
the worker loop to assume parallel work is retrieved from the runtime. A
subsequent patch will update the codegen to retrieve the parallel work using
calls to the runtime. It includes the removal of the inline attribute
for the worker loop and disabling debug info in it.

This allows codegen for a target directive and serial execution on the
NVPTX device.

Reviewers: ABataev
Differential Revision: https://reviews.llvm.org/D28125

llvm-svn: 290983

1 files changed, 24 insertions, 23 deletions

diff --git a/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.h b/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.h
index a33fb27579f..723f7f88828 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.h
+++ b/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.h
@@ -24,7 +24,7 @@ namespace clang {
 namespace CodeGen {
 
 class CGOpenMPRuntimeNVPTX : public CGOpenMPRuntime {
-public:
+private:
   struct EntryFunctionState {
     llvm::BasicBlock *ExitBB = nullptr;
   };
@@ -40,34 +40,21 @@ public:
     void createWorkerFunction(CodeGenModule &CGM);
   };
 
-  /// \brief Helper for target entry function. Guide the master and worker
-  /// threads to their respective locations.
-  void emitEntryHeader(CodeGenFunction &CGF, EntryFunctionState &EST,
-                       WorkerFunctionState &WST);
-
-  /// \brief Signal termination of OMP execution.
-  void emitEntryFooter(CodeGenFunction &CGF, EntryFunctionState &EST);
-
-private:
-  //
-  // Private state and methods.
-  //
-
-  // Master-worker control state.
-  // Number of requested OMP threads in parallel region.
-  llvm::GlobalVariable *ActiveWorkers;
-  // Outlined function for the workers to execute.
-  llvm::GlobalVariable *WorkID;
-
-  /// \brief Initialize master-worker control state.
-  void initializeEnvironment();
-
   /// \brief Emit the worker function for the current target region.
   void emitWorkerFunction(WorkerFunctionState &WST);
 
   /// \brief Helper for worker function. Emit body of worker loop.
   void emitWorkerLoop(CodeGenFunction &CGF, WorkerFunctionState &WST);
 
+  /// \brief Helper for generic target entry function. Guide the master and
+  /// worker threads to their respective locations.
+  void emitGenericEntryHeader(CodeGenFunction &CGF, EntryFunctionState &EST,
+                              WorkerFunctionState &WST);
+
+  /// \brief Signal termination of OMP execution for generic target entry
+  /// function.
+  void emitGenericEntryFooter(CodeGenFunction &CGF, EntryFunctionState &EST);
+
   /// \brief Returns specified OpenMP runtime function for the current OpenMP
   /// implementation.  Specialized for the NVPTX device.
   /// \param Function OpenMP runtime function.
@@ -83,6 +70,20 @@ private:
   void createOffloadEntry(llvm::Constant *ID, llvm::Constant *Addr,
                           uint64_t Size) override;
 
+  /// \brief Emit outlined function specialized for the Fork-Join
+  /// programming model for applicable target directives on the NVPTX device.
+  /// \param D Directive to emit.
+  /// \param ParentName Name of the function that encloses the target region.
+  /// \param OutlinedFn Outlined function value to be defined by this call.
+  /// \param OutlinedFnID Outlined function ID value to be defined by this call.
+  /// \param IsOffloadEntry True if the outlined function is an offload entry.
+  /// An outlined function may not be an entry if, e.g. the if clause always
+  /// evaluates to false.
+  void emitGenericKernel(const OMPExecutableDirective &D, StringRef ParentName,
+                         llvm::Function *&OutlinedFn,
+                         llvm::Constant *&OutlinedFnID, bool IsOffloadEntry,
+                         const RegionCodeGenTy &CodeGen);
+
   /// \brief Emit outlined function for 'target' directive on the NVPTX
   /// device.
   /// \param D Directive to emit.