diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index 787c271..15340a3 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -24,11 +24,16 @@
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/ScoreboardHazardRecognizer.h"
 #include "llvm/CodeGen/PseudoSourceValue.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
+static cl::opt<bool> DisableHazardRecognizer(
+  "disable-sched-hazard", cl::Hidden, cl::init(false),
+  cl::desc("Disable hazard detection during preRA scheduling"));
+
 /// ReplaceTailWithBranchTo - Delete the instruction OldInst and everything
 /// after it, replacing it with an unconditional branch to NewDest.
 void
@@ -421,7 +426,13 @@
   return false;
 }
 
-// Default implementation of CreateTargetPreRAHazardRecognizer.
+// Provide a global flag for disabling the PreRA hazard recognizer that targets
+// may choose to honor.
+bool TargetInstrInfoImpl::usePreRAHazardRecognizer() const {
+  return !DisableHazardRecognizer;
+}
+
+// Default implementation of CreateTargetRAHazardRecognizer.
 ScheduleHazardRecognizer *TargetInstrInfoImpl::
 CreateTargetHazardRecognizer(const TargetMachine *TM,
                              const ScheduleDAG *DAG) const {