r233208 - Fix addrspace when emitting constructors of static local variables

[Jingyue Wu]

Author: jingyue
Date: Wed Mar 25 15:06:28 2015
New Revision: 233208

URL: http://llvm.org/viewvc/llvm-project?rev=233208&view=rev
Log:
Fix addrspace when emitting constructors of static local variables

Summary:
Due to CUDA's implicit address space casting, the type of a static local
variable may be more specific (i.e. with address space qualifiers) than
the type expected by the constructor. Emit an addrspacecast in that
case.

Test Plan: Clang used to crash on the added test.

Reviewers: nlewycky, pcc, eliben, rsmith

Reviewed By: eliben, rsmith

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8575

Modified:
    cfe/trunk/lib/CodeGen/CGDeclCXX.cpp
    cfe/trunk/test/CodeGenCUDA/address-spaces.cu

Modified: cfe/trunk/lib/CodeGen/CGDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDeclCXX.cpp?rev=233208&r1=233207&r2=233208&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDeclCXX.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGDeclCXX.cpp Wed Mar 25 15:06:28 2015
@@ -139,6 +139,29 @@ void CodeGenFunction::EmitCXXGlobalVarDe
   const Expr *Init = D.getInit();
   QualType T = D.getType();
 
+  // The address space of a static local variable (DeclPtr) may be different
+  // from the address space of the "this" argument of the constructor. In that
+  // case, we need an addrspacecast before calling the constructor.
+  //
+  // struct StructWithCtor {
+  //   __device__ StructWithCtor() {...}
+  // };
+  // __device__ void foo() {
+  //   __shared__ StructWithCtor s;
+  //   ...
+  // }
+  //
+  // For example, in the above CUDA code, the static local variable s has a
+  // "shared" address space qualifier, but the constructor of StructWithCtor
+  // expects "this" in the "generic" address space.
+  unsigned ExpectedAddrSpace = getContext().getTargetAddressSpace(T);
+  unsigned ActualAddrSpace = DeclPtr->getType()->getPointerAddressSpace();
+  if (ActualAddrSpace != ExpectedAddrSpace) {
+    llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(T);
+    llvm::PointerType *PTy = llvm::PointerType::get(LTy, ExpectedAddrSpace);
+    DeclPtr = llvm::ConstantExpr::getAddrSpaceCast(DeclPtr, PTy);
+  }
+
   if (!T->isReferenceType()) {
     if (getLangOpts().OpenMP && D.hasAttr<OMPThreadPrivateDeclAttr>())
       (void)CGM.getOpenMPRuntime().emitThreadPrivateVarDefinition(

Modified: cfe/trunk/test/CodeGenCUDA/address-spaces.cu
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCUDA/address-spaces.cu?rev=233208&r1=233207&r2=233208&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCUDA/address-spaces.cu (original)
+++ cfe/trunk/test/CodeGenCUDA/address-spaces.cu Wed Mar 25 15:06:28 2015
@@ -100,3 +100,20 @@ __device__ float *func5() {
 }
 // CHECK: define float* @_Z5func5v()
 // CHECK: ret float* addrspacecast (float addrspace(3)* @b to float*)
+
+struct StructWithCtor {
+  __device__ StructWithCtor(): data(1) {}
+  __device__ StructWithCtor(const StructWithCtor &second): data(second.data) {}
+  __device__ int getData() { return data; }
+  int data;
+};
+
+__device__ int construct_shared_struct() {
+// CHECK-LABEL: define i32 @_Z23construct_shared_structv()
+  __shared__ StructWithCtor s;
+// CHECK: call void @_ZN14StructWithCtorC1Ev(%struct.StructWithCtor* addrspacecast (%struct.StructWithCtor addrspace(3)* @_ZZ23construct_shared_structvE1s to %struct.StructWithCtor*))
+  __shared__ StructWithCtor t(s);
+// CHECK: call void @_ZN14StructWithCtorC1ERKS_(%struct.StructWithCtor* addrspacecast (%struct.StructWithCtor addrspace(3)* @_ZZ23construct_shared_structvE1t to %struct.StructWithCtor*), %struct.StructWithCtor* dereferenceable(4) addrspacecast (%struct.StructWithCtor addrspace(3)* @_ZZ23construct_shared_structvE1s to %struct.StructWithCtor*))
+  return t.getData();
+// CHECK: call i32 @_ZN14StructWithCtor7getDataEv(%struct.StructWithCtor* addrspacecast (%struct.StructWithCtor addrspace(3)* @_ZZ23construct_shared_structvE1t to %struct.StructWithCtor*))
+}