diff --git a/llvm/include/llvm/Analysis/TargetLibraryInfo.def b/llvm/include/llvm/Analysis/TargetLibraryInfo.def
index defc95d0062a3..8b7023a1dfbaa 100644
--- a/llvm/include/llvm/Analysis/TargetLibraryInfo.def
+++ b/llvm/include/llvm/Analysis/TargetLibraryInfo.def
@@ -385,6 +385,16 @@ 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/llvm/lib/Analysis/MemoryBuiltins.cpp b/llvm/lib/Analysis/MemoryBuiltins.cpp
index 5dda96a2ca947..a42f54de9f2bc 100644
--- a/llvm/lib/Analysis/MemoryBuiltins.cpp
+++ b/llvm/lib/Analysis/MemoryBuiltins.cpp
@@ -109,7 +109,10 @@ static const std::pair<LibFunc, AllocFnsTy> AllocationFnData[] = {
   {LibFunc_vec_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,  2, 0,  -1}},
+  {LibFunc_rust_realloc,       {ReallocLike,  4, 3,  -1}},
   // TODO: Handle "int posix_memalign(void **, size_t, size_t)"
 };
 
@@ -462,7 +465,8 @@ bool llvm::isLibFreeFunction(const Function *F, const LibFunc TLIFn) {
            TLIFn == LibFunc_ZdlPvjSt11align_val_t || // delete(void*, unsigned long, align_val_t)
            TLIFn == LibFunc_ZdlPvmSt11align_val_t || // delete(void*, unsigned long, align_val_t)
            TLIFn == LibFunc_ZdaPvjSt11align_val_t || // delete[](void*, unsigned int, align_val_t)
-           TLIFn == LibFunc_ZdaPvmSt11align_val_t) // delete[](void*, unsigned long, align_val_t)
+           TLIFn == LibFunc_ZdaPvmSt11align_val_t || // delete[](void*, unsigned long, align_val_t)
+           TLIFn == LibFunc_rust_dealloc)
     ExpectedNumParams = 3;
   else
     return false;
diff --git a/llvm/lib/Analysis/TargetLibraryInfo.cpp b/llvm/lib/Analysis/TargetLibraryInfo.cpp
index a4de21a2541e5..7e90e8ca2948c 100644
--- a/llvm/lib/Analysis/TargetLibraryInfo.cpp
+++ b/llvm/lib/Analysis/TargetLibraryInfo.cpp
@@ -1513,6 +1513,28 @@ 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:
   case LibFunc::NotLibFunc:
     break;