slyubomirsky commented on code in PR #16184: URL: https://github.com/apache/tvm/pull/16184#discussion_r1431911913
########## 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: Not sure it's entirely necessary, but you can reduce nesting with a construction like ```c++ if (!base_func.as<PrimFunc>()) { continue; } auto prim_func = Downcast<PrimFunc>(base_func); // ... ``` I'm a fan of reducing nesting when possible, but that's up to you. ########## src/tir/ir/specialize.cc: ########## @@ -140,16 +141,54 @@ class PrimFuncSpecializer : public StmtExprMutator { } } + Stmt VisitStmt_(const DeclBufferNode* op) final { + // Visit the buffer before delegating to StmtExprMutator, so the + // buffer's replacement will be defined before the point of use. + Var old_buffer_var = op->buffer->data; + Buffer new_buf = MutateAllocBuffer(op->buffer); + + auto node = Downcast<DeclBuffer>(StmtExprMutator::VisitStmt_(op)); + + if (!new_buf.same_as(node->buffer)) { + node.CopyOnWrite()->buffer = new_buf; + } + + // If the buffer variable is begin remapped to an expression, we Review Comment: ```suggestion // If the buffer variable is being remapped to an expression, we ``` ########## 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 Review Comment: I assume "indirect callers" is aiming to get cases like mutual recursion? ########## src/tir/ir/specialize.cc: ########## @@ -115,18 +116,18 @@ class PrimFuncSpecializer : public StmtExprMutator { private: Stmt VisitStmt_(const BlockNode* op) final { // Step.0. Define buffer mappings which is allocated inside the block - Array<Buffer> alloc_buffers = op->alloc_buffers.Map( - std::bind(&PrimFuncSpecializer::MutateAllocBuffer, this, std::placeholders::_1)); + Array<Buffer> alloc_buffers = + op->alloc_buffers.Map([this](const auto& buf) { return MutateAllocBuffer(buf); }); Review Comment: Much cleaner this way :) ########## 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>()) { + auto prim_func = opt.value(); + + // Only inline private functions. Externally-exposed functions + // must be preserved so to avoid breaking callsites outside of + // the IRModule. + bool is_exposed = prim_func->GetAttr<String>(tvm::attr::kGlobalSymbol).defined(); + + // We do not currently implement any analysis for termination of + // a function. If a recursive function requires runtime checks + // in order to terminate, we would keep inlining until the + // recursive visits segfault. + bool is_recursive = recursive_functions.count(gvar); + + // We do not currently support inlining of functions that accept + // buffer arguments. + bool has_buffer_arguments = prim_func->buffer_map.size(); + + // We do not currently support inlining of schedulable TIR + // functions. To support this use case, repeated names in + // `tir::Block` nodes resulting from multiple calls to the same + // inlined function will need to be de-duplicated. + bool has_block_node = prim_func->body.as<BlockRealizeNode>(); + + if (!is_exposed && !is_recursive && !has_buffer_arguments && !has_block_node) { + output.Set(gvar, prim_func); + } + } + } + + return output; +} + +class PrimFuncInliner : StmtExprMutator { + public: + explicit PrimFuncInliner(Map<GlobalVar, PrimFunc> inlinable_funcs) + : inlinable_funcs_(inlinable_funcs) { + for (const auto& [gvar, callee] : inlinable_funcs_) { + removable_funcs_.insert(gvar); + } + } + + PrimFunc VisitFunc(PrimFunc func) { + current_target_ = func->GetAttr<Target>(tvm::attr::kTarget); + auto new_body = VisitStmt(func->body); + current_target_ = NullOpt; + + if (!new_body.same_as(func->body)) { + func.CopyOnWrite()->body = new_body; + } + + return func; + } + + PSet<GlobalVar> GetRemovableFunctions() const { return removable_funcs_; } + + private: + Stmt VisitStmt_(const EvaluateNode* eval) override { + if (auto call = eval->value.as<CallNode>()) { + if (auto gvar = call->op.as<GlobalVar>()) { + if (auto opt_callee = inlinable_funcs_.Get(gvar.value())) { Review Comment: This is perhaps a place where reducing nesting might improve readability. ########## 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>()) { + auto prim_func = opt.value(); + + // Only inline private functions. Externally-exposed functions + // must be preserved so to avoid breaking callsites outside of + // the IRModule. + bool is_exposed = prim_func->GetAttr<String>(tvm::attr::kGlobalSymbol).defined(); + + // We do not currently implement any analysis for termination of + // a function. If a recursive function requires runtime checks + // in order to terminate, we would keep inlining until the + // recursive visits segfault. + bool is_recursive = recursive_functions.count(gvar); + + // We do not currently support inlining of functions that accept + // buffer arguments. + bool has_buffer_arguments = prim_func->buffer_map.size(); + + // We do not currently support inlining of schedulable TIR + // functions. To support this use case, repeated names in + // `tir::Block` nodes resulting from multiple calls to the same + // inlined function will need to be de-duplicated. + bool has_block_node = prim_func->body.as<BlockRealizeNode>(); + + if (!is_exposed && !is_recursive && !has_buffer_arguments && !has_block_node) { + output.Set(gvar, prim_func); + } + } + } + + return output; +} + +class PrimFuncInliner : StmtExprMutator { + public: + explicit PrimFuncInliner(Map<GlobalVar, PrimFunc> inlinable_funcs) + : inlinable_funcs_(inlinable_funcs) { + for (const auto& [gvar, callee] : inlinable_funcs_) { + removable_funcs_.insert(gvar); + } + } + + PrimFunc VisitFunc(PrimFunc func) { + current_target_ = func->GetAttr<Target>(tvm::attr::kTarget); + auto new_body = VisitStmt(func->body); + current_target_ = NullOpt; + + if (!new_body.same_as(func->body)) { + func.CopyOnWrite()->body = new_body; + } + + return func; + } + + PSet<GlobalVar> GetRemovableFunctions() const { return removable_funcs_; } + + private: + Stmt VisitStmt_(const EvaluateNode* eval) override { Review Comment: You should probably mention the details from the PR description as for why `EvaluateNode` is the only case handled -- This is an automated message from the Apache Git Service. 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