buffer.h

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/*
 * 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.
 */

#ifndef TVM_TIR_BUFFER_H_
#define TVM_TIR_BUFFER_H_

#include <tvm/ir/expr.h>
#include <tvm/runtime/container/array.h>
#include <tvm/runtime/container/string.h>
#include <tvm/tir/var.h>

#include <string>

namespace tvm {
namespace tir {

// forward declare Stmt
class Stmt;

enum BufferType : int {
  kDefault = 1,
  // Maps buffer[i][j][k] -> buffer[i][0][k] if dimension i's shape equals 1.
  kAutoBroadcast = 2,
};

class BufferNode : public Object {
 public:
  // Data fields.
  Var data;
  DataType dtype;
  Array<PrimExpr> shape;
  Array<PrimExpr> strides;
  PrimExpr elem_offset;
  // Meta data
  String name;
  int data_alignment;
  int offset_factor;
  BufferType buffer_type;
  mutable Span span;
  BufferNode() {}

  void VisitAttrs(AttrVisitor* v) {
    v->Visit("data", &data);
    v->Visit("dtype", &dtype);
    v->Visit("shape", &shape);
    v->Visit("strides", &strides);
    v->Visit("elem_offset", &elem_offset);
    v->Visit("name", &name);
    v->Visit("data_alignment", &data_alignment);
    v->Visit("offset_factor", &offset_factor);
    v->Visit("buffer_type", &buffer_type);
    v->Visit("span", &span);
  }

  bool SEqualReduce(const BufferNode* other, SEqualReducer equal) const {
    // Use DefEqual as buffer can define variables
    // in its semantics, skip name as name is not important.
    return equal.DefEqual(data, other->data) && equal(dtype, other->dtype) &&
           equal.DefEqual(shape, other->shape) && equal.DefEqual(strides, other->strides) &&
           equal.DefEqual(elem_offset, other->elem_offset) &&
           equal(data_alignment, other->data_alignment) && equal(buffer_type, other->buffer_type);
  }

  void SHashReduce(SHashReducer hash_reduce) const {
    hash_reduce.DefHash(data);
    hash_reduce(dtype);
    hash_reduce.DefHash(shape);
    hash_reduce.DefHash(strides);
    hash_reduce.DefHash(elem_offset);
    hash_reduce(data_alignment);
    hash_reduce(buffer_type);
  }

  DataType DefaultIndexType() const {
    return shape.size() != 0 ? shape[0].dtype() : DataType::Int(32);
  }

  PrimExpr ElemOffset(Array<PrimExpr> index) const;

  static constexpr const char* _type_key = "tir.Buffer";
  static constexpr const bool _type_has_method_sequal_reduce = true;
  static constexpr const bool _type_has_method_shash_reduce = true;
  TVM_DECLARE_FINAL_OBJECT_INFO(BufferNode, Object);
};

class Buffer : public ObjectRef {
 public:
  // User can specify data_alignment and offset_factor to be 0
  // A default value will be picked.
  TVM_DLL Buffer(Var ptr, DataType dtype, Array<PrimExpr> shape, Array<PrimExpr> strides,
                 PrimExpr elem_offset, String name, int data_alignment, int offset_factor,
                 BufferType buffer_type, Span span = Span());

  TVM_DLL Buffer MakeStrideView() const;
  TVM_DLL Buffer MakeSlice(Array<PrimExpr> begins, Array<PrimExpr> extents) const;
  TVM_DLL PrimExpr access_ptr(int access_mask, DataType ptr_type = DataType::Handle(),
                              int content_lanes = 1,
                              PrimExpr offset = IntImm(DataType::Int(32), 0)) const;
  TVM_DLL PrimExpr vload(Array<PrimExpr> begin, DataType dtype) const;
  TVM_DLL Stmt vstore(Array<PrimExpr> begin, PrimExpr value) const;

  TVM_DLL String scope() const;

  TVM_DEFINE_OBJECT_REF_METHODS(Buffer, ObjectRef, BufferNode);
  TVM_DEFINE_OBJECT_REF_COW_METHOD(BufferNode);
};

TVM_DLL Buffer decl_buffer(Array<PrimExpr> shape, DataType dtype = DataType::Float(32),
                           String name = "buffer", String storage_scope = "", Span span = Span());

class DataProducerNode : public Object {
 public:
  virtual ~DataProducerNode() {}
  virtual Array<PrimExpr> GetShape() const = 0;
  virtual DataType GetDataType() const = 0;
  virtual String GetNameHint() const = 0;

  bool SEqualReduce(const DataProducerNode* other, SEqualReducer equal) const {
    // because buffer producer is opaque, we just do pointer equality.
    return this == other;
  }

  void SHashReduce(SHashReducer hash_reduce) const {}

  static constexpr const char* _type_key = "tir.DataProducer";
  static constexpr const bool _type_has_method_sequal_reduce = true;
  static constexpr const bool _type_has_method_shash_reduce = true;
  TVM_DECLARE_BASE_OBJECT_INFO(DataProducerNode, Object);
};

class DataProducer : public ObjectRef {
 public:
  TVM_DEFINE_OBJECT_REF_METHODS(DataProducer, ObjectRef, DataProducerNode);
};

}  // namespace tir
}  // namespace tvm
#endif  // TVM_TIR_BUFFER_H_