diff --git a/llvm/include/llvm-c/Transforms/Scalar.h b/llvm/include/llvm-c/Transforms/Scalar.h
--- a/llvm/include/llvm-c/Transforms/Scalar.h
+++ b/llvm/include/llvm-c/Transforms/Scalar.h
@@ -67,6 +67,9 @@
 /** See llvm::createInstructionCombiningPass function. */
 void LLVMAddInstructionCombiningPass(LLVMPassManagerRef PM);
 
+/** See llvm::createInstSimplifyLegacyPass function. */
+void LLVMAddInstructionSimplifyPass(LLVMPassManagerRef PM);
+
 /** See llvm::createJumpThreadingPass function. */
 void LLVMAddJumpThreadingPass(LLVMPassManagerRef PM);
 
diff --git a/llvm/lib/Transforms/Scalar/InstSimplifyPass.cpp b/llvm/lib/Transforms/Scalar/InstSimplifyPass.cpp
--- a/llvm/lib/Transforms/Scalar/InstSimplifyPass.cpp
+++ b/llvm/lib/Transforms/Scalar/InstSimplifyPass.cpp
@@ -17,12 +17,14 @@
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Type.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/Pass.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Utils.h"
 #include "llvm/Transforms/Utils/Local.h"
+
 using namespace llvm;
 
 #define DEBUG_TYPE "instsimplify"
@@ -129,6 +131,10 @@
   return new InstSimplifyLegacyPass();
 }
 
+void LLVMAddInstructionSimplifyPass(LLVMPassManagerRef PM) {
+  unwrap(PM)->add(createInstSimplifyLegacyPass());
+}
+
 PreservedAnalyses InstSimplifyPass::run(Function &F,
                                         FunctionAnalysisManager &AM) {
   auto &DT = AM.getResult<DominatorTreeAnalysis>(F);