[llvm] r210967 - R600: Fix asserts related to constant initializers

[Matt Arsenault]

Author: arsenm
Date: Fri Jun 13 23:26:05 2014
New Revision: 210967

URL: http://llvm.org/viewvc/llvm-project?rev=210967&view=rev
Log:
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.

Added:
    llvm/trunk/test/CodeGen/R600/no-initializer-constant-addrspace.ll
Modified:
    llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp

Modified: llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp?rev=210967&r1=210966&r2=210967&view=diff
==============================================================================
--- llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/R600/AMDGPUISelLowering.cpp Fri Jun 13 23:26:05 2014
@@ -655,6 +655,14 @@ SDValue AMDGPUTargetLowering::LowerConst
     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::LowerGloba
     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::LowerGloba
       }
       DAG.UpdateNodeOperands(*I, Ops);
     }
-    return DAG.getZExtOrTrunc(InitPtr, SDLoc(Op),
-        getPointerTy(AMDGPUAS::CONSTANT_ADDRESS));
+    return DAG.getZExtOrTrunc(InitPtr, SDLoc(Op), ConstPtrVT);
   }
   }
 }

Added: llvm/trunk/test/CodeGen/R600/no-initializer-constant-addrspace.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/R600/no-initializer-constant-addrspace.ll?rev=210967&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/R600/no-initializer-constant-addrspace.ll (added)
+++ llvm/trunk/test/CodeGen/R600/no-initializer-constant-addrspace.ll Fri Jun 13 23:26:05 2014
@@ -0,0 +1,20 @@
+; RUN: llc -march=r600 -mcpu=SI -o /dev/null %s
+; RUN: llc -march=r600 -mcpu=cypress -o /dev/null %s
+
+ at 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
+}
+
+ at 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
+}