Lunderberg commented on code in PR #16098: URL: https://github.com/apache/tvm/pull/16098#discussion_r1391638848
########## src/relax/distributed/transform/legalize_redistribute.cc: ########## @@ -0,0 +1,123 @@ +/* + * 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 tvm/relax/distributed/transform/legalize_redistribute.cc + * \brief Pass for legalizing redistribute op to ccl op. + */ + +#include <tvm/relax/attrs/ccl.h> +#include <tvm/relax/attrs/distributed.h> +#include <tvm/relax/distributed/axis_group_graph.h> +#include <tvm/relax/distributed/transform.h> +#include <tvm/relax/expr_functor.h> +#include <tvm/tir/stmt_functor.h> + +#include "../../../tir/schedule/transform.h" +#include "../../op/ccl/ccl.h" +#include "../../op/distributed/distributed.h" + +namespace tvm { +namespace relax { +namespace distributed { + +class RedistributeLegalizer : public ExprMutator { + public: + static IRModule LegalizeRedistribute(IRModule mod) { + return RedistributeLegalizer(mod).Legalize(); + } + + private: + explicit RedistributeLegalizer(IRModule mod) : ExprMutator(mod) {} + + IRModule Legalize() { + auto mod = builder_->GetContextIRModule(); + for (const auto& [gv, base_func] : mod->functions) { + const auto* func_ = base_func.as<FunctionNode>(); + if (func_ == nullptr) { + continue; + } + Expr new_func_body = VisitExpr(func_->body); + auto new_func = make_object<FunctionNode>(*func_); + new_func->body = new_func_body; + builder_->UpdateFunction(gv, Function(new_func)); + } + return builder_->GetContextIRModule(); + } + using ExprMutator::VisitExpr_; + Expr VisitExpr_(const CallNode* op) final { + Call call = Downcast<Call>(ExprMutator::VisitExpr_(op)); + static Op redistribute_op = Op::Get("relax.dist.redistribute"); + if (call->op.same_as(redistribute_op)) { + const auto* attrs = call->attrs.as<DistributionAttrs>(); + ICHECK(attrs); + const auto* input_sinfo = call->args[0]->struct_info_.as<DTensorStructInfoNode>(); + ICHECK(input_sinfo); + // As the first step, we only support redistribute in the same device mesh, + // and the device mesh must be 1d + // todo: extend the ccl ops so that it can support 2d device mesh, and different sharding + // dimension + ICHECK(StructuralEqual()(input_sinfo->device_mesh, attrs->device_mesh)); + ICHECK(input_sinfo->device_mesh->shape.size() == 1); + // only support "S[x]"-> "R" and "R" -> "S[x]" + PlacementSpec input_spec = input_sinfo->placement->dim_specs[0]; + PlacementSpec output_spec = attrs->placement->dim_specs[0]; + if (input_spec->kind == PlacementSpecKind::kReplica && + output_spec->kind == PlacementSpecKind::kReplica) { + // "R" -> "R" + return call->args[0]; + } else if (input_spec->kind == PlacementSpecKind::kSharding && + output_spec->kind == PlacementSpecKind::kSharding) { + // "S[x]" -> "S[y]" + if (input_spec->axis != output_spec->axis) { + LOG(FATAL) << "AlltoAll not implemented yet"; + } else { + return call->args[0]; + } + } else if (input_spec->kind == PlacementSpecKind::kSharding && + output_spec->kind == PlacementSpecKind::kReplica) { + // "S[x]" -> "R" + LOG(FATAL) << "Allgather not implemented yet"; + } else if (input_spec->kind == PlacementSpecKind::kReplica && + output_spec->kind == PlacementSpecKind::kSharding) { + // "R" -> "S[x]" + return redistribute_replica_to_shard(call->args[0], attrs->device_mesh->shape[0], Review Comment: Good point, and that makes sense to have the explicit intermediate step. -- 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]
