void* is represented as pointer to empty struct {}.
Thus we need to check whether the struct is empty before trying to index into
it. This fixes PR3381.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62918 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index dd55d65..aed0867 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11170,6 +11170,8 @@
     
     while (1) {
       if (const StructType *STy = dyn_cast<StructType>(SrcPTy)) {
+        if (!STy->getNumElements()) /* Void is represented as {} */
+          break;
         NewGEPIndices.push_back(Zero);
         SrcPTy = STy->getElementType(0);
       } else if (const ArrayType *ATy = dyn_cast<ArrayType>(SrcPTy)) {