diff --git a/include/tvm/ir/module.h b/include/tvm/ir/module.h
index fefb08f878ef..852c7d0d8a98 100644
--- a/include/tvm/ir/module.h
+++ b/include/tvm/ir/module.h
@@ -122,6 +122,7 @@ class IRModuleNode : public Object {
     v->Visit("global_var_map_", &global_var_map_);
     v->Visit("global_type_var_map_", &global_type_var_map_);
     v->Visit("source_map", &source_map);
+    v->Visit("attrs", &attrs);
   }
 
   TVM_DLL bool SEqualReduce(const IRModuleNode* other, SEqualReducer equal) const;
@@ -277,6 +278,12 @@ class IRModuleNode : public Object {
    */
   TVM_DLL void Update(const IRModule& other);
 
+  /*!
+   * \brief Create a shallow copy of this IRModule.
+   * \returns The shallow copy of the IRModule.
+   */
+  TVM_DLL IRModule ShallowCopy();
+
   /*!
    * \brief Import Relay code from the file at path.
    * \param path The path of the Relay code to import.
@@ -348,12 +355,14 @@ class IRModule : public ObjectRef {
    * \brief constructor
    * \param functions Functions in the module.
    * \param type_definitions Type definitions in the module.
-   * \param import_set Set of imported files in the module
+   * \param import_set Set of imported files in the module.
    * \param map The module source map.
+   * \param attrs The module attributes.
    */
   TVM_DLL explicit IRModule(Map<GlobalVar, BaseFunc> functions,
                             Map<GlobalTypeVar, TypeData> type_definitions = {},
-                            std::unordered_set<String> import_set = {}, parser::SourceMap map = {});
+                            std::unordered_set<String> import_set = {}, parser::SourceMap map = {},
+                            DictAttrs attrs = {});
 
   /*! \brief default constructor */
   IRModule() : IRModule(Map<GlobalVar, BaseFunc>({})) {}
@@ -415,6 +424,13 @@ class IRModule : public ObjectRef {
    */
   TVM_DLL static IRModule FromText(const String& text, const String& source_path);
 
+  /*!
+   * \brief Create a shallow copy of an IRModule.
+   * \param mod The module to copy.
+   * \return The copied module.
+   */
+  IRModule ShallowCopyIRModule(IRModule mod);
+
   /*! \brief Declare the container type. */
   using ContainerType = IRModuleNode;
 
diff --git a/src/ir/module.cc b/src/ir/module.cc
index d4129c84ccf5..15c441d61a23 100644
--- a/src/ir/module.cc
+++ b/src/ir/module.cc
@@ -43,7 +43,8 @@ namespace tvm {
 
 IRModule::IRModule(tvm::Map<GlobalVar, BaseFunc> functions,
                    tvm::Map<GlobalTypeVar, TypeData> type_definitions,
-                   std::unordered_set<String> import_set, parser::SourceMap source_map) {
+                   std::unordered_set<String> import_set, parser::SourceMap source_map,
+                   DictAttrs attrs) {
   auto n = make_object<IRModuleNode>();
   n->functions = std::move(functions);
   n->type_definitions = std::move(type_definitions);
@@ -52,6 +53,7 @@ IRModule::IRModule(tvm::Map<GlobalVar, BaseFunc> functions,
   n->constructor_tag_map_ = {};
   n->import_set_ = std::move(import_set);
   n->source_map = source_map;
+  n->attrs = std::move(attrs);
 
   for (const auto& kv : n->functions) {
     // set global var map
@@ -72,6 +74,7 @@ IRModule::IRModule(tvm::Map<GlobalVar, BaseFunc> functions,
 
 bool IRModuleNode::SEqualReduce(const IRModuleNode* other, SEqualReducer equal) const {
   if (functions.size() != other->functions.size()) return false;
+  if (!equal(this->attrs, other->attrs)) return false;
   for (const auto& kv : this->functions) {
     if (!other->ContainGlobalVar(kv.first->name_hint)) return false;
     if (!equal(kv.second, other->Lookup(kv.first->name_hint))) return false;
@@ -112,6 +115,7 @@ void IRModuleNode::SHashReduce(SHashReducer hash_reduce) const {
     temp.emplace_back(kv.first->name_hint, kv.second);
   }
   reduce_temp();
+  hash_reduce(this->attrs);
 }
 
 bool IRModuleNode::ContainGlobalVar(const String& name) const {
@@ -361,6 +365,11 @@ void IRModuleNode::Update(const IRModule& mod) {
   }
 }
 
+IRModule IRModuleNode::ShallowCopy() {
+  return IRModule(this->functions, this->type_definitions, this->Imports(), this->source_map,
+                  this->attrs);
+}
+
 std::pair<IRModule, GlobalVar> IRModule::FromExprInContext(
     const RelayExpr& expr, const tvm::Map<GlobalVar, BaseFunc>& global_funcs,
     const tvm::Map<GlobalTypeVar, TypeData>& type_definitions,
diff --git a/src/relay/backend/aot_executor_codegen.cc b/src/relay/backend/aot_executor_codegen.cc
index 0c094cb1fa2c..70779ac58abf 100644
--- a/src/relay/backend/aot_executor_codegen.cc
+++ b/src/relay/backend/aot_executor_codegen.cc
@@ -676,7 +676,7 @@ class AOTExecutorCodegen : public MixedModeVisitor {
 
     Optional<Array<tvm::runtime::Module>> external_modules =
         lowered_mod->GetAttr<Array<tvm::runtime::Module>>("external_mods");
-    ICHECK(external_modules) << "Attribute \"external_modules\" should be set at this point.";
+    ICHECK(external_modules) << "Attribute \"external_mods\" should be set at this point.";
 
     // This is the point where we separate the functions in the module by target
     ret.lowered_funcs = tec::GetPerTargetModules(lowered_mod);
diff --git a/src/relay/backend/graph_executor_codegen.cc b/src/relay/backend/graph_executor_codegen.cc
index b7b388431ca1..aca95db34c4e 100644
--- a/src/relay/backend/graph_executor_codegen.cc
+++ b/src/relay/backend/graph_executor_codegen.cc
@@ -241,26 +241,23 @@ class GraphExecutorCodegen : public backend::MemoizedExprTranslator<std::vector<
     ICHECK(main_func_info) << "The attribute \"main_func_info\" should be set at this point.";
     function_metadata_.Set(runtime::symbol::tvm_module_main, main_func_info.value());
 
-    // Get only the Relay functions out of the lowered module so we can run type inference on them
-    IRModule main_module = tec::GetMainModule(lowered_mod);
-    main_module = relay::transform::InferType()(main_module);
-    relay::Function main_func = Downcast<relay::Function>(main_module->Lookup("main"));
+    Function lowered_main_func = Downcast<Function>(lowered_mod->Lookup("main"));
 
     // Now that we have lowered all operators to TIR code, we can proceed with compilation.
     //
     // We need to unfortunately re-plan as the previous results have been invalidated by lowering
     // we will fix this in future refactors.
-    memory_plan_ = GraphPlanMemory(main_func);
+    memory_plan_ = GraphPlanMemory(lowered_main_func);
 
     // The graph planner also can not handle planning calls to global variables to we must remap
 
     // First we convert all the parameters into input nodes.
-    for (auto param : main_func->params) {
+    for (auto param : lowered_main_func->params) {
       auto node_ptr = GraphInputNode::make_node_ptr(param->name_hint(), GraphAttrs());
       var_map_[param.get()] = AddNode(node_ptr, param);
     }
 
-    heads_ = VisitExpr(main_func->body);
+    heads_ = VisitExpr(lowered_main_func->body);
     std::ostringstream os;
 
     dmlc::JSONWriter writer(&os);
@@ -277,7 +274,7 @@ class GraphExecutorCodegen : public backend::MemoizedExprTranslator<std::vector<
 
     Optional<Array<tvm::runtime::Module>> external_modules =
         lowered_mod->GetAttr<Array<tvm::runtime::Module>>("external_mods");
-    ICHECK(external_modules) << "Attribute \"external_modules\" should be set at this point.";
+    ICHECK(external_modules) << "Attribute \"external_mods\" should be set at this point.";
 
     // This is the point where we separate the functions in the module by target
     ret.lowered_funcs = tec::GetPerTargetModules(lowered_mod);
diff --git a/src/relay/backend/interpreter.cc b/src/relay/backend/interpreter.cc
index 82455bdf925c..df14b9e078b6 100644
--- a/src/relay/backend/interpreter.cc
+++ b/src/relay/backend/interpreter.cc
@@ -292,14 +292,8 @@ InterpreterState::InterpreterState(Expr current_expr, InterpreterState::Stack st
 class Interpreter : public ExprFunctor<ObjectRef(const Expr& n)>,
                     PatternFunctor<bool(const Pattern& p, const ObjectRef& v)> {
  public:
-  // TODO(mbs, electriclilies): Collapse mod and per_target_module once IRModule subsumes
-  // LoweredModule.
-  Interpreter(IRModule mod, Map<Target, IRModule> per_target_module, Device device, Target target)
-      : mod_(mod),
-        per_target_module_(per_target_module),
-        device_(device),
-        target_(target),
-        debug_op_(Op::Get("debug")) {}
+  Interpreter(IRModule unified_mod, Device device, Target target)
+      : unified_mod_(unified_mod), device_(device), target_(target), debug_op_(Op::Get("debug")) {}
 
   template <typename T>
   T WithFrame(const Frame& fr, const std::function<T()>& f) {
@@ -316,7 +310,7 @@ class Interpreter : public ExprFunctor<ObjectRef(const Expr& n)>,
   ObjectRef VisitExpr_(const VarNode* var_node) final { return Lookup(GetRef<Var>(var_node)); }
 
   ObjectRef VisitExpr_(const GlobalVarNode* op) final {
-    return Eval(mod_->Lookup(GetRef<GlobalVar>(op)));
+    return Eval(unified_mod_->Lookup(GetRef<GlobalVar>(op)));
   }
 
   ObjectRef VisitExpr_(const OpNode* id) override {
@@ -387,9 +381,9 @@ class Interpreter : public ExprFunctor<ObjectRef(const Expr& n)>,
 
     // Project out just the function(s) we need.
     IRModule lowered_projected_mod;
+    Map<Target, IRModule> per_target_module = tec::GetPerTargetModules(unified_mod_);
     std::unordered_map<Target, IRModule, backend::TargetStrHash, backend::TargetStrEqual>
-        per_target_module_std_map =
-            backend::TargetModuleMapToTargetStrModuleMap(per_target_module_);
+        per_target_module_std_map = backend::TargetModuleMapToTargetStrModuleMap(per_target_module);
     auto mod_itr = per_target_module_std_map.find(target);
     ICHECK(mod_itr != per_target_module_std_map.end())
         << "No target module for target '" << target->str() << "'";
@@ -876,13 +870,11 @@ class Interpreter : public ExprFunctor<ObjectRef(const Expr& n)>,
   }
 
  private:
-  // Main module. All expressions are eval'ed w.r.t. the definitions in this module. This module
-  // may contain calls to TIR functions bound in a per_target_module_ below.
-  IRModule mod_;
-  // Map from target key to lowered TIR functions derived from mod_.
-  // Note that primitives are implicitly executed on target_, while shape functions are implicitly
-  // executed on the default 'cpu' host. Thus this map has at most two entries.
-  Map<Target, IRModule> per_target_module_;
+  // Unified module. Functions are annotated with their target.
+  // All expressions are eval'ed w.r.t. the definitions in this module.
+  // This module contains functions that used to be in main_module and the per_target_module (TIR
+  // functions) in one module.
+  IRModule unified_mod_;
   // Cached packed functions for the primitives and shape functions, keyed by target and
   // global var name.
   std::unordered_map<std::pair<Target, std::string>, PackedFunc, PairHash> compiled_packed_funcs_;
@@ -902,7 +894,7 @@ class Interpreter : public ExprFunctor<ObjectRef(const Expr& n)>,
  * rewritten \p mod and target-specific modules containing bindings for all TIR primitive
  * functions needed by the rewritten module.
  */
-std::pair<IRModule, Map<Target, IRModule>> Prepare(IRModule mod, Device device, Target target) {
+IRModule Prepare(IRModule mod, Device device, Target target) {
   // Things to initialize to pass into tec::LowerTEPass
   // We only have one device-specific target.
   tec::TargetMap targets = {{device.device_type, target}};
@@ -930,8 +922,7 @@ std::pair<IRModule, Map<Target, IRModule>> Prepare(IRModule mod, Device device,
   With<transform::PassContext> ctx(pass_ctx);
   mod = seq(mod);
 
-  // Lower all primitive functions reachable from expr.
-  return {tec::GetMainModule(mod), tec::GetPerTargetModules(mod)};
+  return mod;
 }
 
 /*! \brief Check if an expression could be changed by \p Prepare.
@@ -1020,11 +1011,9 @@ TypedPackedFunc<ObjectRef(Array<Expr>)> EvalFunction(IRModule mod, Expr expr, De
     // and can just eval it directly.
     expr_to_eval = expr;
   }
-  std::pair<IRModule, Map<Target, IRModule>> main_and_lowered =
-      Prepare(mod_with_expr, device, target);
-  std::shared_ptr<Interpreter> intrp = std::make_shared<Interpreter>(
-      /*mod=*/main_and_lowered.first, /*per_target_module=*/main_and_lowered.second, device,
-      target);
+  IRModule lowered_mod = Prepare(mod_with_expr, device, target);
+
+  std::shared_ptr<Interpreter> intrp = std::make_shared<Interpreter>(lowered_mod, device, target);
 
   //
   // Step 2: Evaluate target function to a closure.
@@ -1063,12 +1052,11 @@ ObjectRef Eval(Expr expr, Map<GlobalTypeVar, TypeData> type_definitions,
                std::unordered_set<String> import_set, Device device, Target target) {
   std::pair<IRModule, GlobalVar> mod_and_global =
       IRModule::FromExprInContext(expr, /*global_funcs=*/{}, type_definitions, import_set);
-  std::pair<IRModule, Map<Target, IRModule>> main_and_lowered =
-      Prepare(mod_and_global.first, device, target);
-  Interpreter intrp(
-      /*mod=*/main_and_lowered.first, /*per_target_module=*/main_and_lowered.second, device,
-      target);
-  Expr expr_to_eval = main_and_lowered.first->GetGlobalVar(mod_and_global.second->name_hint);
+
+  IRModule mod = Prepare(mod_and_global.first, device, target);
+
+  Interpreter intrp(mod, device, target);
+  Expr expr_to_eval = mod->GetGlobalVar(mod_and_global.second->name_hint);
   if (expr.as<BaseFuncNode>() == nullptr) {
     // TODO(mbs): IRModule::FromExpr will implicitly close over the free vars of expr
     // unless it is a function, so we must reverse that in the expression to eval.
diff --git a/src/relay/backend/te_compiler.cc b/src/relay/backend/te_compiler.cc
index 4d7f50b4f3a0..0393fdfec70d 100644
--- a/src/relay/backend/te_compiler.cc
+++ b/src/relay/backend/te_compiler.cc
@@ -900,8 +900,9 @@ Map<Target, IRModule> GetPerTargetModules(IRModule mod) {
 
       // Put the function in per_target_modules
       if (!per_target_modules.count(target.value())) {
-        // Initialize the IRModule for this target and add the function
-        IRModule target_module;
+        // Initialize the IRModule for this target with the attributes from the input IRModule
+        IRModule target_module = IRModule({}, {}, {}, {}, mod->attrs);
+        // Add the function to the IRModule
         target_module->Add(var, func);
         per_target_modules[target.value()] = target_module;
       } else {
@@ -918,23 +919,6 @@ Map<Target, IRModule> GetPerTargetModules(IRModule mod) {
   return per_target_modules;
 }
 
-IRModule GetMainModule(IRModule mod) {
-  IRModule main_module;
-  // Copy the type defs
-  for (const auto& kv : mod->type_definitions) {
-    main_module->AddTypeDef(kv.first, kv.second);
-  }
-  // Copy all Relay functions (we don't include PrimFuncs)
-  for (auto kv : mod->functions) {
-    const GlobalVar& var = kv.first;
-    const BaseFunc& func = kv.second;
-    if (func->IsInstance<tvm::relay::FunctionNode>()) {
-      main_module->Add(var, func);
-    }
-  }
-  return main_module;
-}
-
 Pass LowerTEPass(TargetMap targets, DeviceMap device_context_map,
                  backend::StaticMemoryPlan memory_plan, const String& module_name,
                  std::function<void(Function)> process_fn) {
@@ -942,9 +926,8 @@ Pass LowerTEPass(TargetMap targets, DeviceMap device_context_map,
                                                                             PassContext ctx) {
     return LowerTE(module, targets, device_context_map, memory_plan, module_name, process_fn);
   };
-  // TODO(@electriclilies, mbs): Fold InferType() pass into LowerTEPass since it will always need to
-  // be called afterwards
-  return tvm::transform::CreateModulePass(pass_func, 1, "LowerTE", {});
+  return tvm::transform::Sequential(
+      {tvm::transform::CreateModulePass(pass_func, 0, "LowerTE", {}), InferType()});
 }
 }  // namespace tec
 }  // namespace relay
diff --git a/src/relay/backend/te_compiler.h b/src/relay/backend/te_compiler.h
index 082cd8c4491a..9d0eb1078ee0 100644
--- a/src/relay/backend/te_compiler.h
+++ b/src/relay/backend/te_compiler.h
@@ -165,13 +165,6 @@ Target GetTargetFromInteger(DLDeviceType dev_type, TargetMap targets);
  */
 Map<Target, IRModule> GetPerTargetModules(IRModule mod);
 
-/*!
- * \brief Utility to extract all the Relay functions from an IRModule, with no PrimFuncs.
- * \param mod The IRModule to extract the Relay functions from
- * \return An IRModule containing only the Relay functions that are in the input mod (no PrimFuncs)
- */
-IRModule GetMainModule(IRModule mod);
-
 /*! \brief Lower an IRModule's primitive functions to TIR.
  *
  * This is the "back half" of the Relay compiler which lowers "primitive functions"
diff --git a/src/relay/ir/transform.cc b/src/relay/ir/transform.cc
index 4a7974cae5ae..344d1cae7823 100644
--- a/src/relay/ir/transform.cc
+++ b/src/relay/ir/transform.cc
@@ -133,9 +133,7 @@ IRModule FunctionPassNode::operator()(IRModule mod, const PassContext& pass_ctx)
   DLOG(INFO) << "Executing function pass : " << pass_info->name
              << " with opt level: " << pass_info->opt_level;
 
-  // Execute the pass function and return a new module.
-  IRModule updated_mod =
-      IRModule(mod->functions, mod->type_definitions, mod->Imports(), mod->source_map);
+  IRModule updated_mod = mod->ShallowCopy();
 
   std::vector<std::pair<GlobalVar, Function> > updates;
   for (const auto& it : updated_mod->functions) {
diff --git a/src/relay/transforms/partition_graph.cc b/src/relay/transforms/partition_graph.cc
index b48fbe44bd11..f74cf983ccae 100644
--- a/src/relay/transforms/partition_graph.cc
+++ b/src/relay/transforms/partition_graph.cc
@@ -30,6 +30,7 @@
  */
 
 #include <tvm/ir/error.h>
+#include <tvm/ir/module.h>
 #include <tvm/relay/analysis.h>
 #include <tvm/relay/attrs/annotation.h>
 #include <tvm/relay/expr.h>
@@ -509,7 +510,9 @@ class NameMangleExtFuncs : public MixedModeMutator {
 
     // Walk the tree and mangle the functions. Then replace compiler functions
     // with mangled functions in the module
-    IRModule new_module = IRModule({}, module_->type_definitions, module_->Imports());
+    IRModule new_module = module_->ShallowCopy();
+    new_module->functions = {};
+
     for (const auto& pair : glob_funcs) {
       if (auto* fn = pair.second.as<FunctionNode>()) {
         auto func = GetRef<Function>(fn);
diff --git a/src/relay/transforms/to_basic_block_normal_form.cc b/src/relay/transforms/to_basic_block_normal_form.cc
index d03fc1488aea..8e952d60b8b7 100644
--- a/src/relay/transforms/to_basic_block_normal_form.cc
+++ b/src/relay/transforms/to_basic_block_normal_form.cc
@@ -52,7 +52,7 @@ IRModule ToBasicBlockNormalForm(const IRModule& mod) {
   DLOG(INFO) << "ToBBlock:" << std::endl << mod;
 
   // Create a new module by shallow copy.
-  auto mod_ = IRModule(mod->functions, mod->type_definitions, mod->Imports(), mod->source_map);
+  IRModule mod_ = mod->ShallowCopy();
 
   tvm::Map<GlobalVar, Function> updates;
   auto funcs = mod_->functions;
diff --git a/src/relay/transforms/type_infer.cc b/src/relay/transforms/type_infer.cc
index f29087dcc049..6c2371716b16 100644
--- a/src/relay/transforms/type_infer.cc
+++ b/src/relay/transforms/type_infer.cc
@@ -205,13 +205,17 @@ class TypeInferencer : private ExprFunctor<Type(const Expr&)>,
       this->EmitFatal(Diagnostic::Error(op->span) << "Cannot do type inference on global variables "
                                                   << "without a module");
     }
-
     if (mod_->ContainGlobalVar(var->name_hint)) {
-      relay::Function e = Downcast<Function>(mod_->Lookup(var));
-      return e->checked_type();
-    } else {
-      return op->checked_type_;
+      BaseFunc func = mod_->Lookup(var->name_hint);
+
+      if (func->IsInstance<FunctionNode>()) {
+        relay::Function relay_func = Downcast<Function>(func);
+        return relay_func->checked_type();
+      }
     }
+    // Return op->checked_type if the module doesn't contain the GlobalVar or the function is a
+    // PrimFunc (we don't typecheck PrimFuncs)
+    return op->checked_type_;
   }
 
   Type VisitExpr_(const ConstantNode* op) final { return op->tensor_type(); }
@@ -822,8 +826,7 @@ Pass InferType() {
       [=](IRModule mod, const PassContext& pass_ctx) {
         DLOG(INFO) << "tvm::relay::transform::InferType";
         // Execute the pass function and return a new module.
-        IRModule updated_mod =
-            IRModule(mod->functions, mod->type_definitions, mod->Imports(), mod->source_map);
+        IRModule updated_mod = mod->ShallowCopy();
 
         pass_ctx->diag_ctx = DiagnosticContext::Default(updated_mod);
 
diff --git a/tests/python/relay/test_backend_compile_engine.py b/tests/python/relay/test_backend_compile_engine.py
index b90bce548a5e..092cae01f568 100644
--- a/tests/python/relay/test_backend_compile_engine.py
+++ b/tests/python/relay/test_backend_compile_engine.py
@@ -194,6 +194,8 @@ def get_func(shape):
     engine.dump()
 
 
+# Note: Once compile engine is removed, we should keep this test so that
+# we make sure that opt_level=0 passes are being called correctly.
 def test_compile_placeholder_bypass():
     engine = relay.backend.compile_engine.get()
     x = relay.var("x", shape=(2, 3))