Lunderberg commented on code in PR #16184: URL: https://github.com/apache/tvm/pull/16184#discussion_r1432184337
########## src/tir/transforms/inline_private_functions.cc: ########## @@ -0,0 +1,273 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +/*! + * \file inline_private_functions.cc + * \brief Inline private functions to their callsite + */ +#include <tvm/runtime/registry.h> +#include <tvm/tir/analysis.h> +#include <tvm/tir/builtin.h> +#include <tvm/tir/op.h> +#include <tvm/tir/stmt.h> +#include <tvm/tir/stmt_functor.h> +#include <tvm/tir/transform.h> + +namespace tvm { +namespace tir { +namespace transform { + +namespace { + +template <typename T> +using PSet = std::unordered_set<T, ObjectPtrHash, ObjectPtrEqual>; + +template <typename T, typename U> +using PMap = std::unordered_map<T, U, ObjectPtrHash, ObjectPtrEqual>; + +PMap<GlobalVar, PSet<GlobalVar>> CollectCallMap(const IRModule& mod) { + struct Visitor : StmtExprVisitor { + GlobalVar current; + PMap<GlobalVar, PSet<GlobalVar>> caller_lookup; + + void VisitExpr_(const CallNode* op) { + if (auto gvar = op->op.as<GlobalVar>()) { + caller_lookup[gvar.value()].insert(current); + } + StmtExprVisitor::VisitExpr_(op); + } + } visitor; + + for (const auto& [gvar, base_func] : mod->functions) { + if (auto prim_func = base_func.as<PrimFuncNode>()) { + visitor.current = gvar; + visitor(prim_func->body); + } + } + + return visitor.caller_lookup; +} + +PSet<GlobalVar> CollectRecursiveFunctions(const IRModule& mod) { + // Collect all direct callers + auto call_map = CollectCallMap(mod); + + // Propagate to find all indirect callers + while (true) { + bool made_change = false; + for (const auto& [callee, callers] : call_map) { + for (const auto& caller : callers) { + if (auto it = call_map.find(caller); it != call_map.end()) { + PSet<GlobalVar>& indirect_callers = it->second; + + auto res = indirect_callers.insert(callee); + made_change = made_change || res.second; + } + } + } + if (!made_change) { + break; + } + } + + // Filter all GlobalVars that can be called by themselves, either + // directly or indirectly. + PSet<GlobalVar> recursive_funcs; + for (const auto& [caller, callees] : call_map) { + if (callees.count(caller)) { + recursive_funcs.insert(caller); + } + } + return recursive_funcs; +} + +Map<GlobalVar, PrimFunc> CollectInlinablePrimFuncs(const IRModule& mod) { + auto recursive_functions = CollectRecursiveFunctions(mod); + + Map<GlobalVar, PrimFunc> output; + for (const auto& [gvar, base_func] : mod->functions) { + if (auto opt = base_func.as<PrimFunc>()) { Review Comment: I try to avoid using `continue`, as the lack of nesting makes it harder to track when the flow control changes. If the nesting gets to be too much, I tend to switch to a subroutine with early return. The early return can mimic any flow control that `continue` could have, but the restricted context available in the subroutine keeps it manageable. Looking at this case again, I think it would be better to pull these out into an `bool IsInlinablePrimFunc(const PrimFunc& func, PSet<GlobalVar>& recursive_functions)` subroutine, and will update to do so. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
