[OpenMP] Add fields for flags in the offload entry descriptor.

Summary:
This patch adds two fields to the offload entry descriptor. One field is meant to signal Ctors/Dtors and `link` global variables, and the other is reserved for runtime library use. 

 Currently, these fields are only filled with zeros in the current code generation, but that will change when `declare target` is added. 

The reason, we are adding these fields now is to make the code generation consistent with the runtime library proposal under review in https://reviews.llvm.org/D14031.

Reviewers: ABataev, hfinkel, carlo.bertolli, kkwli0, arpith-jacob, Hahnfeld

Subscribers: cfe-commits, caomhin, jholewinski

Differential Revision: https://reviews.llvm.org/D28298

llvm-svn: 291124

clang/lib/CodeGen/CGOpenMPRuntime.cpp

@@ -2701,14 +2701,16 @@ void CGOpenMPRuntime::OffloadEntriesInfoManagerTy::
                                              "only required for the device "
                                              "code generation.");
   OffloadEntriesTargetRegion[DeviceID][FileID][ParentName][LineNum] =
-      OffloadEntryInfoTargetRegion(Order, /*Addr=*/nullptr, /*ID=*/nullptr);
+      OffloadEntryInfoTargetRegion(Order, /*Addr=*/nullptr, /*ID=*/nullptr,
+                                   /*Flags=*/0);
   ++OffloadingEntriesNum;
 }
 
 void CGOpenMPRuntime::OffloadEntriesInfoManagerTy::
     registerTargetRegionEntryInfo(unsigned DeviceID, unsigned FileID,
                                   StringRef ParentName, unsigned LineNum,
-                                  llvm::Constant *Addr, llvm::Constant *ID) {
+                                  llvm::Constant *Addr, llvm::Constant *ID,
+                                  int32_t Flags) {
   // If we are emitting code for a target, the entry is already initialized,
   // only has to be registered.
   if (CGM.getLangOpts().OpenMPIsDevice) {
@@ -2719,9 +2721,10 @@ void CGOpenMPRuntime::OffloadEntriesInfoManagerTy::
     assert(Entry.isValid() && "Entry not initialized!");
     Entry.setAddress(Addr);
     Entry.setID(ID);
+    Entry.setFlags(Flags);
     return;
   } else {
-    OffloadEntryInfoTargetRegion Entry(OffloadingEntriesNum++, Addr, ID);
+    OffloadEntryInfoTargetRegion Entry(OffloadingEntriesNum++, Addr, ID, Flags);
     OffloadEntriesTargetRegion[DeviceID][FileID][ParentName][LineNum] = Entry;
   }
 }
@@ -2888,7 +2891,8 @@ CGOpenMPRuntime::createOffloadingBinaryDescriptorRegistration() {
 }
 
 void CGOpenMPRuntime::createOffloadEntry(llvm::Constant *ID,
-                                         llvm::Constant *Addr, uint64_t Size) {
+                                         llvm::Constant *Addr, uint64_t Size,
+                                         int32_t Flags) {
   StringRef Name = Addr->getName();
   auto *TgtOffloadEntryType = cast<llvm::StructType>(
       CGM.getTypes().ConvertTypeForMem(getTgtOffloadEntryQTy()));
@@ -2918,6 +2922,8 @@ void CGOpenMPRuntime::createOffloadEntry(llvm::Constant *ID,
   EntryInit.add(AddrPtr);
   EntryInit.add(StrPtr);
   EntryInit.addInt(CGM.SizeTy, Size);
+  EntryInit.addInt(CGM.Int32Ty, Flags);
+  EntryInit.addInt(CGM.Int32Ty, 0);
   llvm::GlobalVariable *Entry =
     EntryInit.finishAndCreateGlobal(".omp_offloading.entry",
                                     Align,
@@ -3090,6 +3096,8 @@ QualType CGOpenMPRuntime::getTgtOffloadEntryQTy() {
   //                          // (function or global)
   //   char      *name;       // Name of the function or global.
   //   size_t     size;       // Size of the entry info (0 if it a function).
+  //   int32_t    flags;      // Flags associated with the entry, e.g. 'link'.
+  //   int32_t    reserved;   // Reserved, to use by the runtime library.
   // };
   if (TgtOffloadEntryQTy.isNull()) {
     ASTContext &C = CGM.getContext();
@@ -3098,6 +3106,10 @@ QualType CGOpenMPRuntime::getTgtOffloadEntryQTy() {
     addFieldToRecordDecl(C, RD, C.VoidPtrTy);
     addFieldToRecordDecl(C, RD, C.getPointerType(C.CharTy));
     addFieldToRecordDecl(C, RD, C.getSizeType());
+    addFieldToRecordDecl(
+        C, RD, C.getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/true));
+    addFieldToRecordDecl(
+        C, RD, C.getIntTypeForBitwidth(/*DestWidth=*/32, /*Signed=*/true));
     RD->completeDefinition();
     TgtOffloadEntryQTy = C.getRecordType(RD);
   }
@@ -4852,7 +4864,8 @@ void CGOpenMPRuntime::emitTargetOutlinedFunctionHelper(
 
   // Register the information for the entry associated with this target region.
   OffloadEntriesInfoManager.registerTargetRegionEntryInfo(
-      DeviceID, FileID, ParentName, Line, OutlinedFn, OutlinedFnID);
+      DeviceID, FileID, ParentName, Line, OutlinedFn, OutlinedFnID,
+      /*Flags=*/0);
 }
 
 /// discard all CompoundStmts intervening between two constructs

clang/lib/CodeGen/CGOpenMPRuntime.h

@@ -110,9 +110,9 @@ class CGOpenMPRuntime {
   CodeGenModule &CGM;
 
   /// \brief Creates offloading entry for the provided entry ID \a ID,
-  /// address \a Addr and size \a Size.
+  /// address \a Addr, size \a Size, and flags \a Flags.
   virtual void createOffloadEntry(llvm::Constant *ID, llvm::Constant *Addr,
-                                  uint64_t Size);
+                                  uint64_t Size, int32_t Flags = 0);
 
   /// \brief Helper to emit outlined function for 'target' directive.
   /// \param D Directive to emit.
@@ -245,10 +245,10 @@ class CGOpenMPRuntime {
     unsigned OffloadingEntriesNum;
 
   public:
-    /// \brief Base class of the entries info.
+    /// Base class of the entries info.
     class OffloadEntryInfo {
     public:
-      /// \brief Kind of a given entry. Currently, only target regions are
+      /// Kind of a given entry. Currently, only target regions are
       /// supported.
       enum OffloadingEntryInfoKinds : unsigned {
         // Entry is a target region.
@@ -257,17 +257,24 @@ class CGOpenMPRuntime {
         OFFLOAD_ENTRY_INFO_INVALID = ~0u
       };
 
-      OffloadEntryInfo() : Order(~0u), Kind(OFFLOAD_ENTRY_INFO_INVALID) {}
-      explicit OffloadEntryInfo(OffloadingEntryInfoKinds Kind, unsigned Order)
-          : Order(Order), Kind(Kind) {}
+      OffloadEntryInfo()
+          : Flags(0), Order(~0u), Kind(OFFLOAD_ENTRY_INFO_INVALID) {}
+      explicit OffloadEntryInfo(OffloadingEntryInfoKinds Kind, unsigned Order,
+                                int32_t Flags)
+          : Flags(Flags), Order(Order), Kind(Kind) {}
 
       bool isValid() const { return Order != ~0u; }
       unsigned getOrder() const { return Order; }
       OffloadingEntryInfoKinds getKind() const { return Kind; }
+      int32_t getFlags() const { return Flags; }
+      void setFlags(int32_t NewFlags) { Flags = NewFlags; }
       static bool classof(const OffloadEntryInfo *Info) { return true; }
 
-    protected:
-      // \brief Order this entry was emitted.
+    private:
+      /// Flags associated with the device global.
+      int32_t Flags;
+
+      /// Order this entry was emitted.
       unsigned Order;
 
       OffloadingEntryInfoKinds Kind;
@@ -292,12 +299,13 @@ class CGOpenMPRuntime {
 
     public:
       OffloadEntryInfoTargetRegion()
-          : OffloadEntryInfo(OFFLOAD_ENTRY_INFO_TARGET_REGION, ~0u),
+          : OffloadEntryInfo(OFFLOAD_ENTRY_INFO_TARGET_REGION, ~0u,
+                             /*Flags=*/0),
             Addr(nullptr), ID(nullptr) {}
       explicit OffloadEntryInfoTargetRegion(unsigned Order,
                                             llvm::Constant *Addr,
-                                            llvm::Constant *ID)
-          : OffloadEntryInfo(OFFLOAD_ENTRY_INFO_TARGET_REGION, Order),
+                                            llvm::Constant *ID, int32_t Flags)
+          : OffloadEntryInfo(OFFLOAD_ENTRY_INFO_TARGET_REGION, Order, Flags),
             Addr(Addr), ID(ID) {}
 
       llvm::Constant *getAddress() const { return Addr; }
@@ -321,8 +329,8 @@ class CGOpenMPRuntime {
     /// \brief Register target region entry.
     void registerTargetRegionEntryInfo(unsigned DeviceID, unsigned FileID,
                                        StringRef ParentName, unsigned LineNum,
-                                       llvm::Constant *Addr,
-                                       llvm::Constant *ID);
+                                       llvm::Constant *Addr, llvm::Constant *ID,
+                                       int32_t Flags);
     /// \brief Return true if a target region entry with the provided
     /// information exists.
     bool hasTargetRegionEntryInfo(unsigned DeviceID, unsigned FileID,

clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp

@@ -306,7 +306,7 @@ CGOpenMPRuntimeNVPTX::createNVPTXRuntimeFunction(unsigned Function) {
 
 void CGOpenMPRuntimeNVPTX::createOffloadEntry(llvm::Constant *ID,
                                               llvm::Constant *Addr,
-                                              uint64_t Size) {
+                                              uint64_t Size, int32_t) {
   auto *F = dyn_cast<llvm::Function>(Addr);
   // TODO: Add support for global variables on the device after declare target
   // support.

clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.h

@@ -66,9 +66,9 @@ class CGOpenMPRuntimeNVPTX : public CGOpenMPRuntime {
   //
 
   /// \brief Creates offloading entry for the provided entry ID \a ID,
-  /// address \a Addr and size \a Size.
+  /// address \a Addr, size \a Size, and flags \a Flags.
   void createOffloadEntry(llvm::Constant *ID, llvm::Constant *Addr,
-                          uint64_t Size) override;
+                          uint64_t Size, int32_t Flags = 0) override;
 
   /// \brief Emit outlined function specialized for the Fork-Join
   /// programming model for applicable target directives on the NVPTX device.

clang/test/OpenMP/target_codegen.cpp

@@ -22,11 +22,11 @@
 
 // CHECK-DAG: [[TT:%.+]] = type { i64, i8 }
 // CHECK-DAG: [[S1:%.+]] = type { double }
-// CHECK-DAG: [[ENTTY:%.+]] = type { i8*, i8*, i[[SZ:32|64]] }
+// CHECK-DAG: [[ENTTY:%.+]] = type { i8*, i8*, i[[SZ:32|64]], i32, i32 }
 // CHECK-DAG: [[DEVTY:%.+]] = type { i8*, i8*, [[ENTTY]]*, [[ENTTY]]* }
 // CHECK-DAG: [[DSCTY:%.+]] = type { i32, [[DEVTY]]*, [[ENTTY]]*, [[ENTTY]]* }
 
-// TCHECK: [[ENTTY:%.+]] = type { i8*, i8*, i{{32|64}} }
+// TCHECK: [[ENTTY:%.+]] = type { i8*, i8*, i{{32|64}}, i32, i32 }
 
 // We have 8 target regions, but only 7 that actually will generate offloading
 // code, only 6 will have mapped arguments, and only 4 have all-constant map