1 files changed, 9 insertions, 1 deletions
diff --git a/lib/Target/X86/X86SelectionDAGInfo.cpp b/lib/Target/X86/X86SelectionDAGInfo.cpp
index 723e50c..f934fdd 100644
--- a/lib/Target/X86/X86SelectionDAGInfo.cpp
+++ b/lib/Target/X86/X86SelectionDAGInfo.cpp
@@ -13,8 +13,8 @@
 
 #define DEBUG_TYPE "x86-selectiondag-info"
 #include "X86TargetMachine.h"
-#include "llvm/DerivedTypes.h"
 #include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/IR/DerivedTypes.h"
 using namespace llvm;
 
 X86SelectionDAGInfo::X86SelectionDAGInfo(const X86TargetMachine &TM) :
@@ -202,6 +202,14 @@ X86SelectionDAGInfo::EmitTargetCodeForMemcpy(SelectionDAG &DAG, DebugLoc dl,
       SrcPtrInfo.getAddrSpace() >= 256)
     return SDValue();
 
+  // ESI might be used as a base pointer, in that case we can't simply overwrite
+  // the register.  Fall back to generic code.
+  const X86RegisterInfo *TRI =
+      static_cast<const X86RegisterInfo *>(DAG.getTarget().getRegisterInfo());
+  if (TRI->hasBasePointer(DAG.getMachineFunction()) &&
+      TRI->getBaseRegister() == X86::ESI)
+    return SDValue();
+
   MVT AVT;
   if (Align & 1)
     AVT = MVT::i8;