When folding a load into a return of SSE value, check the chain to
ensure the memory location has not been clobbered.

llvm-svn: 25861
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 1a60368..dce781d 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -1912,10 +1912,11 @@
         Ops.push_back(Op.getOperand(1));
         Copy = DAG.getNode(X86ISD::FP_SET_RESULT, Tys, Ops);
       } else {
-        SDOperand MemLoc, Chain;
+        SDOperand MemLoc;
+        SDOperand Chain = Op.getOperand(0);
         SDOperand Value = Op.getOperand(1);
 
-        if (Value.getOpcode() == ISD::LOAD) {
+        if (Value.getOpcode() == ISD::LOAD && Chain == Value.getOperand(0)) {
           Chain  = Value.getOperand(0);
           MemLoc = Value.getOperand(1);
         } else {