R600: Fix asserts related to constant initializers

This would assert if a constant address space was extern
and therefore didn't have an initializer. If the initializer
was undef, it would hit the unreachable unhandled initializer case.

An extern global should never really occur since we don't have
machine linking, but bugpoint likes to remove initializers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210967 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/R600/AMDGPUISelLowering.cpp b/lib/Target/R600/AMDGPUISelLowering.cpp
index 3ea789da5aa423a833cc3eac7ddfbdfeb53e7302..7867de23fd22f7ac503aaba99ef7d5d23eb01542 100644 (file)
--- a/lib/Target/R600/AMDGPUISelLowering.cpp
+++ b/lib/Target/R600/AMDGPUISelLowering.cpp
@@ -655,6 +655,14 @@ SDValue AMDGPUTargetLowering::LowerConstantInitializer(const Constant* Init,
     return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Chains);
   }
 
+  if (isa<UndefValue>(Init)) {
+    EVT VT = EVT::getEVT(InitTy);
+    PointerType *PtrTy = PointerType::get(InitTy, AMDGPUAS::PRIVATE_ADDRESS);
+    return DAG.getStore(Chain, DL, DAG.getUNDEF(VT), InitPtr,
+                        MachinePointerInfo(UndefValue::get(PtrTy)), false, false,
+                        TD->getPrefTypeAlignment(InitTy));
+  }
+
   Init->dump();
   llvm_unreachable("Unhandled constant initializer");
 }
@@ -694,11 +702,19 @@ SDValue AMDGPUTargetLowering::LowerGlobalAddress(AMDGPUMachineFunction* MFI,
     unsigned Size = TD->getTypeAllocSize(EltType);
     unsigned Alignment = TD->getPrefTypeAlignment(EltType);
 
+    MVT PrivPtrVT = getPointerTy(AMDGPUAS::PRIVATE_ADDRESS);
+    MVT ConstPtrVT = getPointerTy(AMDGPUAS::CONSTANT_ADDRESS);
+
+    int FI = FrameInfo->CreateStackObject(Size, Alignment, false);
+    SDValue InitPtr = DAG.getFrameIndex(FI, PrivPtrVT);
+
     const GlobalVariable *Var = cast<GlobalVariable>(GV);
+    if (!Var->hasInitializer()) {
+      // This has no use, but bugpoint will hit it.
+      return DAG.getZExtOrTrunc(InitPtr, SDLoc(Op), ConstPtrVT);
+    }
+
     const Constant *Init = Var->getInitializer();
-    int FI = FrameInfo->CreateStackObject(Size, Alignment, false);
-    SDValue InitPtr = DAG.getFrameIndex(FI,
-        getPointerTy(AMDGPUAS::PRIVATE_ADDRESS));
     SmallVector<SDNode*, 8> WorkList;
 
     for (SDNode::use_iterator I = DAG.getEntryNode()->use_begin(),
@@ -717,8 +733,7 @@ SDValue AMDGPUTargetLowering::LowerGlobalAddress(AMDGPUMachineFunction* MFI,
       }
       DAG.UpdateNodeOperands(*I, Ops);
     }
-    return DAG.getZExtOrTrunc(InitPtr, SDLoc(Op),
-        getPointerTy(AMDGPUAS::CONSTANT_ADDRESS));
+    return DAG.getZExtOrTrunc(InitPtr, SDLoc(Op), ConstPtrVT);
   }
   }
 }

diff --git a/test/CodeGen/R600/no-initializer-constant-addrspace.ll b/test/CodeGen/R600/no-initializer-constant-addrspace.ll
new file mode 100644 (file)
index 0000000..ab82e7e
--- /dev/null
+++ b/test/CodeGen/R600/no-initializer-constant-addrspace.ll
@@ -0,0 +1,20 @@
+; RUN: llc -march=r600 -mcpu=SI -o /dev/null %s
+; RUN: llc -march=r600 -mcpu=cypress -o /dev/null %s
+
+@extern_const_addrspace = external unnamed_addr addrspace(2) constant [5 x i32], align 4
+
+; FUNC-LABEL: @load_extern_const_init
+define void @load_extern_const_init(i32 addrspace(1)* %out) nounwind {
+  %val = load i32 addrspace(2)* getelementptr ([5 x i32] addrspace(2)* @extern_const_addrspace, i64 0, i64 3), align 4
+  store i32 %val, i32 addrspace(1)* %out, align 4
+  ret void
+}
+
+@undef_const_addrspace = unnamed_addr addrspace(2) constant [5 x i32] undef, align 4
+
+; FUNC-LABEL: @load_undef_const_init
+define void @load_undef_const_init(i32 addrspace(1)* %out) nounwind {
+  %val = load i32 addrspace(2)* getelementptr ([5 x i32] addrspace(2)* @undef_const_addrspace, i64 0, i64 3), align 4
+  store i32 %val, i32 addrspace(1)* %out, align 4
+  ret void
+}