MasterJH5574 commented on a change in pull request #8716: URL: https://github.com/apache/tvm/pull/8716#discussion_r690494402
########## File path: src/tir/transforms/unify_thread_binding.cc ########## @@ -0,0 +1,143 @@ +/* + * 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 unify_thread_binding.cc + */ + +#include <tvm/arith/analyzer.h> +#include <tvm/tir/analysis.h> +#include <tvm/tir/stmt_functor.h> +#include <tvm/tir/transform.h> + +#include "ir_utils.h" + +namespace tvm { +namespace tir { + +/*! + * \brief A mutator which searches AttrStmts of thread bindings and changes the `node` field IterVar + * of the AttrStmts, so that for one kind of thread binding, all such thread bindings use the same + * IterVar + */ +class ThreadBindingUnifier : public StmtExprMutator { + public: + static Stmt Unify(const Stmt& stmt) { return ThreadBindingUnifier().VisitStmt(stmt); } + + private: + Stmt VisitStmt_(const AttrStmtNode* attr) final { + // If this AttrStmt is not thread binding attribute, return as usual. + if (attr->attr_key != attr::thread_extent && attr->attr_key != attr::virtual_thread) { + return StmtMutator::VisitStmt_(attr); + } + + // Step 1. Fetch the old IterVar and the thread tag. + IterVar old_iter_var = Downcast<IterVar>(attr->node); + IterVar new_iter_var{nullptr}; + const String& thread_tag = old_iter_var->thread_tag; + + // Step 2: Increase `thread_block_depth_` if the thread tag starts with "blockIdx". If the + // thread block depth is 0 before the increasement, it means we are entering a new kernel, and + // therefore we need to make `thread_tag2iter_var_map_` empty, as different kernels can have + // thread axes with different extents. + if (std::string(thread_tag).substr(0, 9) == "blockIdx.") { + if (!thread_block_depth_) { + thread_tag2iter_var_map_.clear(); + } + ++thread_block_depth_; + } + + // Step 3. See if an IterVar for this kind of thread binding was created before. If so, we use + // the created IterVar. Otherwise, we create a new IterVar for this thread binding and store the + // IterVar in mapping `thread_tag2iter_var_map_`. + Map<String, IterVar>::iterator it = thread_tag2iter_var_map_.find(thread_tag); + if (it != thread_tag2iter_var_map_.end()) { + new_iter_var = (*it).second; + arith::Analyzer ana; + CHECK(ana.CanProveEqual(old_iter_var->dom->extent, (*it).second->dom->extent)) Review comment: I create a temporary variable here because if I wrote ```c++ CHECK(arith::Analyzer().CanProveEqual(old_iter_var->dom->extent, (*it).second->dom->extent)) ``` , it throws `TVMError` instead of `ValueError`. The `TVMError` is as the following: ``` TVMError: Check failed: (arith: :Analyzer().CanProveEqual(old_iter_var->dom->extent, (*it).second->dom->extent)) is false: ValueError: All loops that are bound to `threadIdx.x` should have the same extent. However, there are two loops with extent 128 and 64, which are not equal ``` I guess the `arith: :Analyzer()` (note the non-consecutive colons) triggers the issue. @junrushao1994 See if you have any comments? Keep using a temporary variable, or throw `TVMError`, or fix the non-consecutive-colons issue? ########## File path: src/tir/transforms/unify_thread_binding.cc ########## @@ -0,0 +1,143 @@ +/* + * 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 unify_thread_binding.cc + */ + +#include <tvm/arith/analyzer.h> +#include <tvm/tir/analysis.h> +#include <tvm/tir/stmt_functor.h> +#include <tvm/tir/transform.h> + +#include "ir_utils.h" + +namespace tvm { +namespace tir { + +/*! + * \brief A mutator which searches AttrStmts of thread bindings and changes the `node` field IterVar + * of the AttrStmts, so that for one kind of thread binding, all such thread bindings use the same + * IterVar + */ +class ThreadBindingUnifier : public StmtExprMutator { + public: + static Stmt Unify(const Stmt& stmt) { return ThreadBindingUnifier().VisitStmt(stmt); } + + private: + Stmt VisitStmt_(const AttrStmtNode* attr) final { + // If this AttrStmt is not thread binding attribute, return as usual. + if (attr->attr_key != attr::thread_extent && attr->attr_key != attr::virtual_thread) { + return StmtMutator::VisitStmt_(attr); + } + + // Step 1. Fetch the old IterVar and the thread tag. + IterVar old_iter_var = Downcast<IterVar>(attr->node); + IterVar new_iter_var{nullptr}; + const String& thread_tag = old_iter_var->thread_tag; + + // Step 2: Increase `thread_block_depth_` if the thread tag starts with "blockIdx". If the + // thread block depth is 0 before the increasement, it means we are entering a new kernel, and + // therefore we need to make `thread_tag2iter_var_map_` empty, as different kernels can have + // thread axes with different extents. + if (std::string(thread_tag).substr(0, 9) == "blockIdx.") { + if (!thread_block_depth_) { + thread_tag2iter_var_map_.clear(); + } + ++thread_block_depth_; + } + + // Step 3. See if an IterVar for this kind of thread binding was created before. If so, we use + // the created IterVar. Otherwise, we create a new IterVar for this thread binding and store the + // IterVar in mapping `thread_tag2iter_var_map_`. + Map<String, IterVar>::iterator it = thread_tag2iter_var_map_.find(thread_tag); + if (it != thread_tag2iter_var_map_.end()) { + new_iter_var = (*it).second; + arith::Analyzer ana; + CHECK(ana.CanProveEqual(old_iter_var->dom->extent, (*it).second->dom->extent)) Review comment: > First, please have an analyzer in the class so that you don’t need to create a new one every time. Thanks! Will do it now. -- 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]
