[OPENMP5.0]Add support for device_type clause in declare target

construct.

OpenMP 5.0 introduced new clause for declare target directive, device_type clause, which may accept values host, nohost, and any. Host means
that the function must be emitted only for the host, nohost - only for
the device, and any - for both, device and the host.

llvm-svn: 369775

1 files changed, 15 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 3dc40a84868f..eedf70b8d50d 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2122,6 +2122,10 @@ void CodeGenModule::EmitDeferred() {
     if (!GV->isDeclaration())
       continue;
 
+    // If this is OpenMP, check if it is legal to emit this global normally.
+    if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
+      continue;
+
     // Otherwise, emit the definition and move on to the next one.
     EmitGlobalDefinition(D, GV);
 
@@ -2318,11 +2322,20 @@ bool CodeGenModule::MustBeEmitted(const ValueDecl *Global) {
 }
 
 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
-  if (const auto *FD = dyn_cast<FunctionDecl>(Global))
+  if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
     if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
       // Implicit template instantiations may change linkage if they are later
       // explicitly instantiated, so they should not be emitted eagerly.
       return false;
+    // In OpenMP 5.0 function may be marked as device_type(nohost) and we should
+    // not emit them eagerly unless we sure that the function must be emitted on
+    // the host.
+    if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd &&
+        !LangOpts.OpenMPIsDevice &&
+        !OMPDeclareTargetDeclAttr::getDeviceType(FD) &&
+        !FD->isUsed(/*CheckUsedAttr=*/false) && !FD->isReferenced())
+      return false;
+  }
   if (const auto *VD = dyn_cast<VarDecl>(Global))
     if (Context.getInlineVariableDefinitionKind(VD) ==
         ASTContext::InlineVariableDefinitionKind::WeakUnknown)
@@ -2445,8 +2458,7 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) {
   }
 
   if (LangOpts.OpenMP) {
-    // If this is OpenMP device, check if it is legal to emit this global
-    // normally.
+    // If this is OpenMP, check if it is legal to emit this global normally.
     if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
       return;
     if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {