1 files changed, 19 insertions, 3 deletions
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 7535528..4c7f516 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -28,6 +28,7 @@
 #include "CoverageMappingGen.h"
 #include "TargetInfo.h"
 #include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTLambda.h"
 #include "clang/AST/CharUnits.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclObjC.h"
@@ -3560,6 +3561,14 @@ ConstantAddress CodeGenModule::GetWeakRefReference(const ValueDecl *VD) {
   return ConstantAddress(Aliasee, DeclTy, Alignment);
 }
 
+template <typename AttrT> static bool hasImplicitAttr(const ValueDecl *D) {
+  if (!D)
+    return false;
+  if (auto *A = D->getAttr<AttrT>())
+    return A->isImplicit();
+  return D->isImplicit();
+}
+
 void CodeGenModule::EmitGlobal(GlobalDecl GD) {
   const auto *Global = cast<ValueDecl>(GD.getDecl());
 
@@ -3581,16 +3590,23 @@ void CodeGenModule::EmitGlobal(GlobalDecl GD) {
     return emitCPUDispatchDefinition(GD);
 
   // If this is CUDA, be selective about which declarations we emit.
+  // Non-constexpr non-lambda implicit host device functions are not emitted
+  // unless they are used on device side.
   if (LangOpts.CUDA) {
     if (LangOpts.CUDAIsDevice) {
-      if (!Global->hasAttr<CUDADeviceAttr>() &&
+      const auto *FD = dyn_cast<FunctionDecl>(Global);
+      if ((!Global->hasAttr<CUDADeviceAttr>() ||
+           (LangOpts.OffloadImplicitHostDeviceTemplates && FD &&
+            hasImplicitAttr<CUDAHostAttr>(FD) &&
+            hasImplicitAttr<CUDADeviceAttr>(FD) && !FD->isConstexpr() &&
+            !isLambdaCallOperator(FD) &&
+            !getContext().CUDAImplicitHostDeviceFunUsedByDevice.count(FD))) &&
           !Global->hasAttr<CUDAGlobalAttr>() &&
           !Global->hasAttr<CUDAConstantAttr>() &&
           !Global->hasAttr<CUDASharedAttr>() &&
           !Global->getType()->isCUDADeviceBuiltinSurfaceType() &&
           !Global->getType()->isCUDADeviceBuiltinTextureType() &&
-          !(LangOpts.HIPStdPar &&
-            isa<FunctionDecl>(Global) &&
+          !(LangOpts.HIPStdPar && isa<FunctionDecl>(Global) &&
             !Global->hasAttr<CUDAHostAttr>()))
         return;
     } else {