[Compiling Error][LiveIntervals.cpp] error: invalid use of incomplete type ‘const class llvm::TargetInstrInfo’

[hlyix]

When I invoke function in TII like:
bool test = TII->isTriviallyReMaterializable(*MI); (An example, no significance)

diff --git a/llvm/lib/CodeGen/LiveIntervals.cpp b/llvm/lib/CodeGen/LiveIntervals.cpp
index 68fff9bc221d..fd53728b54fa 100644
--- a/llvm/lib/CodeGen/LiveIntervals.cpp
+++ b/llvm/lib/CodeGen/LiveIntervals.cpp
@@ -517,6 +517,7 @@ bool LiveIntervals::computeDeadValues(LiveInterval &LI,
       if ((I == LI.begin() || std::prev(I)->end < Def) && !VNI->isPHIDef()) {
         MachineInstr *MI = getInstructionFromIndex(Def);
         MI->setRegisterDefReadUndef(VReg);
+        bool test = TII->isTriviallyReMaterializable(*MI);
       }
     }

it results in compiling error below:

Solution:
include
#include "llvm/CodeGen/TargetInstrInfo.h"
in
llvm/include/llvm/CodeGen/LiveIntervals.h