[clang] 8155ec1 - [HIP][NFC] Refactor managed var codegen (#85976)

[via cfe-commits]

Author: Yaxun (Sam) Liu
Date: 2024-03-22T12:30:02-04:00
New Revision: 8155ec13968b6457c61b8507f2ae8ba3ac3b748b

URL: https://github.com/llvm/llvm-project/commit/8155ec13968b6457c61b8507f2ae8ba3ac3b748b
DIFF: https://github.com/llvm/llvm-project/commit/8155ec13968b6457c61b8507f2ae8ba3ac3b748b.diff

LOG: [HIP][NFC] Refactor managed var codegen (#85976)

Refactor managed variable handling in codegen so that the transformation
is done separately from registration.

This will allow the new driver to register the managed var in the linker
wrapper.

Added: 
    

Modified: 
    clang/lib/CodeGen/CGCUDANV.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGCUDANV.cpp b/clang/lib/CodeGen/CGCUDANV.cpp
index d3f2573fd5e38a..b756318c46a900 100644
--- a/clang/lib/CodeGen/CGCUDANV.cpp
+++ b/clang/lib/CodeGen/CGCUDANV.cpp
@@ -605,20 +605,10 @@ llvm::Function *CGNVCUDARuntime::makeRegisterGlobalsFn() {
       uint64_t VarSize =
           CGM.getDataLayout().getTypeAllocSize(Var->getValueType());
       if (Info.Flags.isManaged()) {
-        auto *ManagedVar = new llvm::GlobalVariable(
-            CGM.getModule(), Var->getType(),
-            /*isConstant=*/false, Var->getLinkage(),
-            /*Init=*/Var->isDeclaration()
-                ? nullptr
-                : llvm::ConstantPointerNull::get(Var->getType()),
-            /*Name=*/"", /*InsertBefore=*/nullptr,
-            llvm::GlobalVariable::NotThreadLocal);
-        ManagedVar->setDSOLocal(Var->isDSOLocal());
-        ManagedVar->setVisibility(Var->getVisibility());
-        ManagedVar->setExternallyInitialized(true);
-        ManagedVar->takeName(Var);
-        Var->setName(Twine(ManagedVar->getName() + ".managed"));
-        replaceManagedVar(Var, ManagedVar);
+        assert(Var->getName().ends_with(".managed") &&
+               "HIP managed variables not transformed");
+        auto *ManagedVar = CGM.getModule().getNamedGlobal(
+            Var->getName().drop_back(StringRef(".managed").size()));
         llvm::Value *Args[] = {
             &GpuBinaryHandlePtr,
             ManagedVar,
@@ -1093,7 +1083,9 @@ void CGNVCUDARuntime::transformManagedVars() {
               : llvm::ConstantPointerNull::get(Var->getType()),
           /*Name=*/"", /*InsertBefore=*/nullptr,
           llvm::GlobalVariable::NotThreadLocal,
-          CGM.getContext().getTargetAddressSpace(LangAS::cuda_device));
+          CGM.getContext().getTargetAddressSpace(CGM.getLangOpts().CUDAIsDevice
+                                                     ? LangAS::cuda_device
+                                                     : LangAS::Default));
       ManagedVar->setDSOLocal(Var->isDSOLocal());
       ManagedVar->setVisibility(Var->getVisibility());
       ManagedVar->setExternallyInitialized(true);
@@ -1102,7 +1094,7 @@ void CGNVCUDARuntime::transformManagedVars() {
       Var->setName(Twine(ManagedVar->getName()) + ".managed");
       // Keep managed variables even if they are not used in device code since
       // they need to be allocated by the runtime.
-      if (!Var->isDeclaration()) {
+      if (CGM.getLangOpts().CUDAIsDevice && !Var->isDeclaration()) {
         assert(!ManagedVar->isDeclaration());
         CGM.addCompilerUsedGlobal(Var);
         CGM.addCompilerUsedGlobal(ManagedVar);
@@ -1160,9 +1152,8 @@ void CGNVCUDARuntime::createOffloadingEntries() {
 
 // Returns module constructor to be added.
 llvm::Function *CGNVCUDARuntime::finalizeModule() {
+  transformManagedVars();
   if (CGM.getLangOpts().CUDAIsDevice) {
-    transformManagedVars();
-
     // Mark ODR-used device variables as compiler used to prevent it from being
     // eliminated by optimization. This is necessary for device variables
     // ODR-used by host functions. Sema correctly marks them as ODR-used no