Correctly lower memset / memcpy of undef. It should be a nop. PR6767.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100208 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index 19fefab..f816bdd 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -348,15 +348,19 @@
     virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const;
     
     /// getOptimalMemOpType - Returns the target specific optimal type for load
-    /// and store operations as a result of memset, memcpy, and memmove lowering.
-    /// If DstAlign is zero that means it's safe to destination alignment can
-    /// satisfy any constraint. Similarly if SrcAlign is zero it means there
-    /// isn't a need to check it against alignment requirement, probably because
-    /// the source does not need to be loaded. It returns EVT::Other if
-    /// SelectionDAG should be responsible for determining it.
-    virtual EVT getOptimalMemOpType(uint64_t Size,
-                                    unsigned DstAlign, unsigned SrcAlign,
-                                    bool SafeToUseFP, SelectionDAG &DAG) const;
+    /// and store operations as a result of memset, memcpy, and memmove
+    /// lowering. If DstAlign is zero that means it's safe to destination
+    /// alignment can satisfy any constraint. Similarly if SrcAlign is zero it
+    /// means there isn't a need to check it against alignment requirement,
+    /// probably because the source does not need to be loaded. If
+    /// 'NonScalarIntSafe' is true, that means it's safe to return a
+    /// non-scalar-integer type, e.g. empty string source, constant, or loaded
+    /// from memory. It returns EVT::Other if SelectionDAG should be responsible
+    /// for determining it.
+    virtual EVT
+    getOptimalMemOpType(uint64_t Size,
+                        unsigned DstAlign, unsigned SrcAlign,
+                        bool NonScalarIntSafe, SelectionDAG &DAG) const;
 
     /// getFunctionAlignment - Return the Log2 alignment of this function.
     virtual unsigned getFunctionAlignment(const Function *F) const;