diff --git a/llvm/lib/Analysis/TargetLibraryInfo.cpp b/llvm/lib/Analysis/TargetLibraryInfo.cpp
index 0484f1dcfb243..e01fc6c10466e 100644
--- a/llvm/lib/Analysis/TargetLibraryInfo.cpp
+++ b/llvm/lib/Analysis/TargetLibraryInfo.cpp
@@ -1491,25 +1491,9 @@ bool TargetLibraryInfoImpl::isValidProtoForLibFunc(const FunctionType &FTy,
   }
 
   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());
+    return true;
 
   case LibFunc::NumLibFuncs:
   case LibFunc::NotLibFunc: