Index: lib/Target/PowerPC/LLVMBuild.txt
===================================================================
--- lib/Target/PowerPC/LLVMBuild.txt
+++ lib/Target/PowerPC/LLVMBuild.txt
@@ -31,5 +31,5 @@
 type = Library
 name = PowerPCCodeGen
 parent = PowerPC
-required_libraries = Analysis AsmPrinter CodeGen Core MC PowerPCAsmPrinter PowerPCDesc PowerPCInfo Scalar SelectionDAG Support Target TransformUtils
+required_libraries = Analysis AsmPrinter CodeGen Core InstCombine MC PowerPCAsmPrinter PowerPCDesc PowerPCInfo Scalar SelectionDAG Support Target TransformUtils
 add_to_library_groups = PowerPC
Index: lib/Target/PowerPC/PPCTargetMachine.cpp
===================================================================
--- lib/Target/PowerPC/PPCTargetMachine.cpp
+++ lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -336,9 +336,14 @@
   if (!DisablePreIncPrep && getOptLevel() != CodeGenOpt::None)
     addPass(createPPCLoopPreIncPrepPass(getPPCTargetMachine()));
 
-  if (!DisableCTRLoops && getOptLevel() != CodeGenOpt::None)
+  if (!DisableCTRLoops && getOptLevel() != CodeGenOpt::None) {
     addPass(createPPCCTRLoops());
 
+    // Run instcombine to eliminate induction variables unused after
+    // rewritten by CTR loop optimization.
+    addPass(createInstructionCombiningPass(/* ExpensiveCombines = */false));
+  }
+
   return false;
 }