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

1 files changed, 20 insertions, 5 deletions

diff --git a/lib/Target/R600/AMDGPUISelLowering.cpp b/lib/Target/R600/AMDGPUISelLowering.cpp
index 3ea789da5a..7867de23fd 100644
--- 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);
   }
   }
 }