[OPENMP] Codegen for declare target with link clause.

If the link clause is used on the declare target directive, the object
should be linked on target or target data directives, not during the
codegen. Patch adds support for this clause.

llvm-svn: 328544

1 files changed, 121 insertions, 67 deletions

diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 6bbe639f908..891176b0097 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -893,6 +893,17 @@ static void EmitOMPAggregateInit(CodeGenFunction &CGF, Address DestAddr,
   CGF.EmitBlock(DoneBB, /*IsFinished=*/true);
 }
 
+static llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy>
+isDeclareTargetDeclaration(const ValueDecl *VD) {
+  for (const auto *D : VD->redecls()) {
+    if (!D->hasAttrs())
+      continue;
+    if (const auto *Attr = D->getAttr<OMPDeclareTargetDeclAttr>())
+      return Attr->getMapType();
+  }
+  return llvm::None;
+}
+
 LValue ReductionCodeGen::emitSharedLValue(CodeGenFunction &CGF, const Expr *E) {
   return CGF.EmitOMPSharedLValue(E);
 }
@@ -2326,6 +2337,28 @@ llvm::Constant *CGOpenMPRuntime::createDispatchNextFunction(unsigned IVSize,
   return CGM.CreateRuntimeFunction(FnTy, Name);
 }
 
+Address CGOpenMPRuntime::getAddrOfDeclareTargetLink(CodeGenFunction &CGF,
+                                                    const VarDecl *VD) {
+  llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
+      isDeclareTargetDeclaration(VD);
+  if (Res && *Res == OMPDeclareTargetDeclAttr::MT_Link) {
+    SmallString<64> PtrName;
+    {
+      llvm::raw_svector_ostream OS(PtrName);
+      OS << CGM.getMangledName(GlobalDecl(VD)) << "_decl_tgt_link_ptr";
+    }
+    llvm::Value *Ptr = CGM.getModule().getNamedValue(PtrName);
+    if (!Ptr) {
+      QualType PtrTy = CGM.getContext().getPointerType(VD->getType());
+      Ptr = getOrCreateInternalVariable(CGM.getTypes().ConvertTypeForMem(PtrTy),
+                                        PtrName);
+      CGF.CGM.addUsedGlobal(cast<llvm::GlobalValue>(Ptr));
+    }
+    return Address(Ptr, CGM.getContext().getDeclAlign(VD));
+  }
+  return Address::invalid();
+}
+
 llvm::Constant *
 CGOpenMPRuntime::getOrCreateThreadPrivateCache(const VarDecl *VD) {
   assert(!CGM.getLangOpts().OpenMPUseTLS ||
@@ -6320,6 +6353,50 @@ private:
     return ConstLength.getSExtValue() != 1;
   }
 
+  /// \brief Return the adjusted map modifiers if the declaration a capture
+  /// refers to appears in a first-private clause. This is expected to be used
+  /// only with directives that start with 'target'.
+  unsigned adjustMapModifiersForPrivateClauses(const CapturedStmt::Capture &Cap,
+                                               unsigned CurrentModifiers) {
+    assert(Cap.capturesVariable() && "Expected capture by reference only!");
+
+    // A first private variable captured by reference will use only the
+    // 'private ptr' and 'map to' flag. Return the right flags if the captured
+    // declaration is known as first-private in this handler.
+    if (FirstPrivateDecls.count(Cap.getCapturedVar()))
+      return MappableExprsHandler::OMP_MAP_PRIVATE |
+             MappableExprsHandler::OMP_MAP_TO;
+    // Reduction variable  will use only the 'private ptr' and 'map to_from'
+    // flag.
+    if (ReductionDecls.count(Cap.getCapturedVar())) {
+      return MappableExprsHandler::OMP_MAP_TO |
+             MappableExprsHandler::OMP_MAP_FROM;
+    }
+
+    // We didn't modify anything.
+    return CurrentModifiers;
+  }
+
+public:
+  MappableExprsHandler(const OMPExecutableDirective &Dir, CodeGenFunction &CGF)
+      : CurDir(Dir), CGF(CGF) {
+    // Extract firstprivate clause information.
+    for (const auto *C : Dir.getClausesOfKind<OMPFirstprivateClause>())
+      for (const auto *D : C->varlists())
+        FirstPrivateDecls.insert(
+            cast<VarDecl>(cast<DeclRefExpr>(D)->getDecl())->getCanonicalDecl());
+    for (const auto *C : Dir.getClausesOfKind<OMPReductionClause>()) {
+      for (const auto *D : C->varlists()) {
+        ReductionDecls.insert(
+            cast<VarDecl>(cast<DeclRefExpr>(D)->getDecl())->getCanonicalDecl());
+      }
+    }
+    // Extract device pointer clause information.
+    for (const auto *C : Dir.getClausesOfKind<OMPIsDevicePtrClause>())
+      for (auto L : C->component_lists())
+        DevPointersMap[L.first].push_back(L.second);
+  }
+
   /// \brief Generate the base pointers, section pointers, sizes and map type
   /// bits for the provided map type, map modifier, and expression components.
   /// \a IsFirstComponent should be set to true if the provided set of
@@ -6445,6 +6522,7 @@ private:
 
     // Track if the map information being generated is the first for a capture.
     bool IsCaptureFirstInfo = IsFirstComponentList;
+    bool IsLink = false; // Is this variable a "declare target link"?
 
     // Scan the components from the base to the complete expression.
     auto CI = Components.rbegin();
@@ -6464,6 +6542,20 @@ private:
       // The base is the reference to the variable.
       // BP = &Var.
       BP = CGF.EmitOMPSharedLValue(I->getAssociatedExpression()).getPointer();
+      if (const auto *VD =
+              dyn_cast_or_null<VarDecl>(I->getAssociatedDeclaration())) {
+        if (llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
+            isDeclareTargetDeclaration(VD)) {
+          assert(*Res == OMPDeclareTargetDeclAttr::MT_Link &&
+                 "Declare target link is expected.");
+          // Avoid warning in release build.
+          (void)*Res;
+          IsLink = true;
+          BP = CGF.CGM.getOpenMPRuntime()
+                   .getAddrOfDeclareTargetLink(CGF, VD)
+                   .getPointer();
+        }
+      }
 
       // If the variable is a pointer and is being dereferenced (i.e. is not
       // the last component), the base has to be the pointer itself, not its
@@ -6552,9 +6644,10 @@ private:
         // same expression except for the first one. We also need to signal
         // this map is the first one that relates with the current capture
         // (there is a set of entries for each capture).
-        Types.push_back(DefaultFlags | getMapTypeBits(MapType, MapTypeModifier,
-                                                      !IsExpressionFirstInfo,
-                                                      IsCaptureFirstInfo));
+        Types.push_back(DefaultFlags |
+                        getMapTypeBits(MapType, MapTypeModifier,
+                                       !IsExpressionFirstInfo || IsLink,
+                                       IsCaptureFirstInfo && !IsLink));
 
         // If we have a final array section, we are done with this expression.
         if (IsFinalArraySection)
@@ -6570,50 +6663,6 @@ private:
     }
   }
 
-  /// \brief Return the adjusted map modifiers if the declaration a capture
-  /// refers to appears in a first-private clause. This is expected to be used
-  /// only with directives that start with 'target'.
-  unsigned adjustMapModifiersForPrivateClauses(const CapturedStmt::Capture &Cap,
-                                               unsigned CurrentModifiers) {
-    assert(Cap.capturesVariable() && "Expected capture by reference only!");
-
-    // A first private variable captured by reference will use only the
-    // 'private ptr' and 'map to' flag. Return the right flags if the captured
-    // declaration is known as first-private in this handler.
-    if (FirstPrivateDecls.count(Cap.getCapturedVar()))
-      return MappableExprsHandler::OMP_MAP_PRIVATE |
-             MappableExprsHandler::OMP_MAP_TO;
-    // Reduction variable  will use only the 'private ptr' and 'map to_from'
-    // flag.
-    if (ReductionDecls.count(Cap.getCapturedVar())) {
-      return MappableExprsHandler::OMP_MAP_TO |
-             MappableExprsHandler::OMP_MAP_FROM;
-    }
-
-    // We didn't modify anything.
-    return CurrentModifiers;
-  }
-
-public:
-  MappableExprsHandler(const OMPExecutableDirective &Dir, CodeGenFunction &CGF)
-      : CurDir(Dir), CGF(CGF) {
-    // Extract firstprivate clause information.
-    for (const auto *C : Dir.getClausesOfKind<OMPFirstprivateClause>())
-      for (const auto *D : C->varlists())
-        FirstPrivateDecls.insert(
-            cast<VarDecl>(cast<DeclRefExpr>(D)->getDecl())->getCanonicalDecl());
-    for (const auto *C : Dir.getClausesOfKind<OMPReductionClause>()) {
-      for (const auto *D : C->varlists()) {
-        ReductionDecls.insert(
-            cast<VarDecl>(cast<DeclRefExpr>(D)->getDecl())->getCanonicalDecl());
-      }
-    }
-    // Extract device pointer clause information.
-    for (const auto *C : Dir.getClausesOfKind<OMPIsDevicePtrClause>())
-      for (auto L : C->component_lists())
-        DevPointersMap[L.first].push_back(L.second);
-  }
-
   /// \brief Generate all the base pointers, section pointers, sizes and map
   /// types for the extracted mappable expressions. Also, for each item that
   /// relates with a device pointer, a pair of the relevant declaration and
@@ -7254,6 +7303,25 @@ void CGOpenMPRuntime::emitTargetCall(CodeGenFunction &CGF,
       Sizes.append(CurSizes.begin(), CurSizes.end());
       MapTypes.append(CurMapTypes.begin(), CurMapTypes.end());
     }
+    // Map other list items in the map clause which are not captured variables
+    // but "declare target link" global variables.
+    for (const auto *C : D.getClausesOfKind<OMPMapClause>()) {
+      for (auto L : C->component_lists()) {
+        if (!L.first)
+          continue;
+        const auto *VD = dyn_cast<VarDecl>(L.first);
+        if (!VD)
+          continue;
+        llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
+            isDeclareTargetDeclaration(VD);
+        if (!Res || *Res != OMPDeclareTargetDeclAttr::MT_Link)
+          continue;
+        MEHandler.generateInfoForComponentList(
+            C->getMapType(), C->getMapTypeModifier(), L.second, BasePointers,
+            Pointers, Sizes, MapTypes, /*IsFirstComponentList=*/true,
+            C->isImplicit());
+      }
+    }
 
     TargetDataInfo Info;
     // Fill up the arrays and create the arguments.
@@ -7406,14 +7474,7 @@ bool CGOpenMPRuntime::emitTargetFunctions(GlobalDecl GD) {
   scanForTargetRegionsFunctions(FD.getBody(), CGM.getMangledName(GD));
 
   // Do not to emit function if it is not marked as declare target.
-  if (!GD.getDecl()->hasAttrs())
-    return true;
-
-  for (const auto *D = FD.getMostRecentDecl(); D; D = D->getPreviousDecl())
-    if (D->hasAttr<OMPDeclareTargetDeclAttr>())
-      return false;
-
-  return true;
+  return !isDeclareTargetDeclaration(&FD);
 }
 
 bool CGOpenMPRuntime::emitTargetGlobalVariable(GlobalDecl GD) {
@@ -7439,15 +7500,9 @@ bool CGOpenMPRuntime::emitTargetGlobalVariable(GlobalDecl GD) {
   }
 
   // Do not to emit variable if it is not marked as declare target.
-  if (!GD.getDecl()->hasAttrs())
-    return true;
-
-  for (const Decl *D = GD.getDecl()->getMostRecentDecl(); D;
-       D = D->getPreviousDecl())
-    if (D->hasAttr<OMPDeclareTargetDeclAttr>())
-      return false;
-
-  return true;
+  llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
+      isDeclareTargetDeclaration(cast<ValueDecl>(GD.getDecl()));
+  return !Res || *Res == OMPDeclareTargetDeclAttr::MT_Link;
 }
 
 bool CGOpenMPRuntime::emitTargetGlobal(GlobalDecl GD) {
@@ -7477,9 +7532,8 @@ bool CGOpenMPRuntime::markAsGlobalTarget(const FunctionDecl *D) {
     return true;
   // Do not to emit function if it is marked as declare target as it was already
   // emitted.
-  for (const auto *FD = D->getMostRecentDecl(); FD; FD = FD->getPreviousDecl())
-    if (FD->hasAttr<OMPDeclareTargetDeclAttr>())
-      return true;
+  if (isDeclareTargetDeclaration(D))
+    return true;
 
   const FunctionDecl *FD = D->getCanonicalDecl();
   // Do not mark member functions except for static.