diff --git a/include/llvm/Analysis/TargetLibraryInfo.def b/include/llvm/Analysis/TargetLibraryInfo.def
index a461ed813b9b..579d23004d17 100644
--- a/include/llvm/Analysis/TargetLibraryInfo.def
+++ b/include/llvm/Analysis/TargetLibraryInfo.def
@@ -316,6 +316,16 @@ TLI_DEFINE_STRING_INTERNAL("__powf_finite")
 /// long double __powl_finite(long double x, long double y);
 TLI_DEFINE_ENUM_INTERNAL(powl_finite)
 TLI_DEFINE_STRING_INTERNAL("__powl_finite")
+
+TLI_DEFINE_ENUM_INTERNAL(rust_alloc)
+TLI_DEFINE_STRING_INTERNAL("__rust_alloc")
+
+TLI_DEFINE_ENUM_INTERNAL(rust_dealloc)
+TLI_DEFINE_STRING_INTERNAL("__rust_dealloc")
+
+TLI_DEFINE_ENUM_INTERNAL(rust_realloc)
+TLI_DEFINE_STRING_INTERNAL("__rust_realloc")
+
 /// double __sincospi_stret(double x);
 TLI_DEFINE_ENUM_INTERNAL(sincospi_stret)
 TLI_DEFINE_STRING_INTERNAL("__sincospi_stret")
diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp
index 24fedfed772c..2ed5ef0200a1 100644
--- a/lib/Analysis/MemoryBuiltins.cpp
+++ b/lib/Analysis/MemoryBuiltins.cpp
@@ -93,7 +93,10 @@ static const std::pair<LibFunc, AllocFnsTy> AllocationFnData[] = {
   {LibFunc_realloc,             {ReallocLike, 2, 1,  -1}},
   {LibFunc_reallocf,            {ReallocLike, 2, 1,  -1}},
   {LibFunc_strdup,              {StrDupLike,  1, -1, -1}},
-  {LibFunc_strndup,             {StrDupLike,  2, 1,  -1}}
+  {LibFunc_strndup,             {StrDupLike,  2, 1,  -1}},
+
+  {LibFunc_rust_alloc,         {MallocLike,  3, 0,  -1}},
+  {LibFunc_rust_realloc,       {ReallocLike,  6, 3,  -1}},
   // TODO: Handle "int posix_memalign(void **, size_t, size_t)"
 };
 
@@ -386,6 +389,8 @@ const CallInst *llvm::isFreeCall(const Value *I, const TargetLibraryInfo *TLI) {
            TLIFn == LibFunc_msvc_delete_array_ptr32_nothrow || // delete[](void*, nothrow)
            TLIFn == LibFunc_msvc_delete_array_ptr64_nothrow)   // delete[](void*, nothrow)
     ExpectedNumParams = 2;
+  else if (TLIFn == LibFunc_rust_dealloc)
+    ExpectedNumParams = 3;
   else
     return nullptr;
 
diff --git a/lib/Analysis/TargetLibraryInfo.cpp b/lib/Analysis/TargetLibraryInfo.cpp
index d18246ac5941..d217ed788e21 100644
--- a/lib/Analysis/TargetLibraryInfo.cpp
+++ b/lib/Analysis/TargetLibraryInfo.cpp
@@ -1289,6 +1289,28 @@ bool TargetLibraryInfoImpl::isValidProtoForLibFunc(const FunctionType &FTy,
     else
       return false;
   }
+
+  case LibFunc_rust_alloc:
+    return (NumParams == 3 && FTy.getReturnType()->isPointerTy() &&
+            FTy.getParamType(0)->isIntegerTy() &&
+            FTy.getParamType(1)->isIntegerTy() &&
+            FTy.getParamType(2)->isPointerTy());
+
+  case LibFunc_rust_dealloc:
+    return (NumParams == 3 && FTy.getReturnType()->isVoidTy() &&
+            FTy.getParamType(0)->isPointerTy() &&
+            FTy.getParamType(1)->isIntegerTy() &&
+            FTy.getParamType(2)->isIntegerTy());
+
+  case LibFunc_rust_realloc:
+    return (NumParams == 6 && FTy.getReturnType()->isPointerTy() &&
+            FTy.getParamType(0)->isPointerTy() &&
+            FTy.getParamType(1)->isIntegerTy() &&
+            FTy.getParamType(2)->isIntegerTy() &&
+            FTy.getParamType(3)->isIntegerTy() &&
+            FTy.getParamType(4)->isIntegerTy() &&
+            FTy.getParamType(5)->isPointerTy());
+
   case LibFunc::NumLibFuncs:
     break;
   }