diff --git a/llvm/include/llvm/CodeGen/TargetInstrInfo.h b/llvm/include/llvm/CodeGen/TargetInstrInfo.h
--- a/llvm/include/llvm/CodeGen/TargetInstrInfo.h
+++ b/llvm/include/llvm/CodeGen/TargetInstrInfo.h
@@ -1095,6 +1095,9 @@
                       SmallVectorImpl<MachineInstr *> &DelInstrs,
                       DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const;
 
+  /// The limit on resource length extension we accept in MachineCombiner Pass.
+  virtual int16_t getExtendResourceLenLimit() const { return 0; }
+
   /// This is an architecture-specific helper function of reassociateOps.
   /// Set special operand attributes for new instructions after reassociation.
   virtual void setSpecialOperandAttr(MachineInstr &OldMI1, MachineInstr &OldMI2,
diff --git a/llvm/lib/CodeGen/MachineCombiner.cpp b/llvm/lib/CodeGen/MachineCombiner.cpp
--- a/llvm/lib/CodeGen/MachineCombiner.cpp
+++ b/llvm/lib/CodeGen/MachineCombiner.cpp
@@ -406,12 +406,14 @@
                     << ResLenBeforeCombine
                     << " and after: " << ResLenAfterCombine << "\n";);
   LLVM_DEBUG(
-      ResLenAfterCombine <= ResLenBeforeCombine
+      ResLenAfterCombine <=
+      ResLenBeforeCombine + TII->getExtendResourceLenLimit()
           ? dbgs() << "\t\t  As result it IMPROVES/PRESERVES Resource Length\n"
           : dbgs() << "\t\t  As result it DOES NOT improve/preserve Resource "
                       "Length\n");
 
-  return ResLenAfterCombine <= ResLenBeforeCombine;
+  return ResLenAfterCombine <=
+         ResLenBeforeCombine + TII->getExtendResourceLenLimit();
 }
 
 /// \returns true when new instruction sequence should be generated