var.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_VAR_H_
#define TVM_TIR_VAR_H_
 
#include <tvm/ir/expr.h>
#include <tvm/node/node.h>
#include <tvm/runtime/data_type.h>
 
#include <functional>
#include <string>
 
namespace tvm {
namespace tir {
 
class VarNode : public PrimExprNode {
 public:
  ffi::String name_hint;
  Type type_annotation;
 
  static void RegisterReflection() {
    namespace refl = tvm::ffi::reflection;
    refl::ObjectDef<VarNode>()
        .def_ro("name", &VarNode::name_hint, refl::AttachFieldFlag::SEqHashIgnore())
        .def_ro("type_annotation", &VarNode::type_annotation);
  }
 
  static constexpr TVMFFISEqHashKind _type_s_eq_hash_kind = kTVMFFISEqHashKindFreeVar;
  static constexpr const uint32_t _type_child_slots = 1;
  TVM_FFI_DECLARE_OBJECT_INFO("tir.Var", VarNode, PrimExprNode);
};
 
class Var : public PrimExpr {
 public:
  explicit Var(ffi::UnsafeInit tag) : PrimExpr(tag) {}
  explicit Var(ObjectPtr<VarNode> n) : PrimExpr(n) {}
  TVM_DLL explicit Var(ffi::String name_hint = "v", DataType dtype = DataType::Int(32),
                       Span span = Span());
  TVM_DLL explicit Var(ffi::String name_hint, Type type_annotation, Span span = Span());
  TVM_DLL Var copy_with_name(const ffi::String& name) const;
  TVM_DLL Var copy_with_suffix(const ffi::String& suffix) const;
  TVM_DLL Var copy_with_dtype(DataType dtype) const;
 
  const VarNode* operator->() const { return get(); }
  const VarNode* get() const { return static_cast<const VarNode*>(data_.get()); }
  using ContainerType = VarNode;
};
 
class SizeVarNode : public VarNode {
 public:
  static void RegisterReflection() {
    namespace refl = tvm::ffi::reflection;
    refl::ObjectDef<SizeVarNode>();
  }
  TVM_FFI_DECLARE_OBJECT_INFO_FINAL("tir.SizeVar", SizeVarNode, VarNode);
};
 
class SizeVar : public Var {
 public:
  explicit SizeVar(ObjectPtr<SizeVarNode> n) : Var(n) {}
  explicit SizeVar(ffi::UnsafeInit tag) : Var(tag) {}
  TVM_DLL explicit SizeVar(ffi::String name_hint = "s", DataType t = DataType::Int(32),
                           Span span = Span());
  TVM_DLL explicit SizeVar(ffi::String name_hint, Type type_annotation, Span span = Span());
  const SizeVarNode* operator->() const { return get(); }
  const SizeVarNode* get() const { return static_cast<const SizeVarNode*>(data_.get()); }
  using ContainerType = SizeVarNode;
};
 
using Region = ffi::Array<Range>;
 
enum IterVarType : int {
  kDataPar = 0,
  kThreadIndex = 1,
  kCommReduce = 2,
  kOrdered = 3,
  kOpaque = 4,
  // The following are possible additional
  // types that are provided during schedule
  kUnrolled = 5,
  kVectorized = 6,
  kParallelized = 7,
  kTensorized = 8
};
 
class IterVarNode : public PrimExprConvertibleNode {
 public:
  Range dom;
  Var var;
  IterVarType iter_type;
  ffi::String thread_tag;
  mutable Span span;
 
  PrimExpr ToPrimExpr() const final { return var; }
 
  static void RegisterReflection() {
    namespace refl = tvm::ffi::reflection;
    refl::ObjectDef<IterVarNode>()
        .def_ro("dom", &IterVarNode::dom)
        .def_ro("var", &IterVarNode::var, refl::AttachFieldFlag::SEqHashDef())
        .def_ro("iter_type", &IterVarNode::iter_type)
        .def_ro("thread_tag", &IterVarNode::thread_tag);
  }
 
  static constexpr TVMFFISEqHashKind _type_s_eq_hash_kind = kTVMFFISEqHashKindTreeNode;
  TVM_FFI_DECLARE_OBJECT_INFO_FINAL("tir.IterVar", IterVarNode, PrimExprConvertibleNode);
};
 
class IterVar : public PrimExprConvertible {
 public:
  TVM_DLL IterVar(Range dom, Var var, IterVarType iter_type, ffi::String thread_tag = "",
                  Span span = Span());
  inline operator PrimExpr() const;
 
  TVM_FFI_DEFINE_OBJECT_REF_METHODS_NULLABLE(IterVar, PrimExprConvertible, IterVarNode);
  TVM_DEFINE_OBJECT_REF_COW_METHOD(IterVarNode);
};
 
// inline implementations
inline IterVar::operator PrimExpr() const { return (*this)->var; }
 
inline const char* IterVarType2String(IterVarType t) {
  switch (t) {
    case kDataPar:
      return "DataPar";
    case kThreadIndex:
      return "ThreadIndex";
    case kCommReduce:
      return "CommReduce";
    case kOrdered:
      return "Ordered";
    case kOpaque:
      return "Opaque";
    case kUnrolled:
      return "Unrolled";
    case kVectorized:
      return "Vectorized";
    case kParallelized:
      return "Parallelized";
    case kTensorized:
      return "Tensorized";
  }
  return "Unknown";
}
}  // namespace tir
}  // namespace tvm
 
/* \brief Allow tir.Var as key in STL tables
 *
 * For most TIR expressions, it would be ambiguous whether the
 * expression should follow reference equality or structural equality.
 * This is not the case for variables, which do not contain nested
 * internal structure, and are frequently used as keys in lookup
 * tables.
 *
 * Providing `std::hash` and `std::equal_to` specializations for
 * `tir::Var` allows it to be used as a key in STL tables.  For
 * `PrimExpr`, the user must specify the type of equality used
 * (e.g. `std::unordered_set<T, StructuralHash, StructuralEqual>` or
 * `std::unordered_set<T, ObjectPtrHash, ObjectPtrEqual>`).
 */
template <>
struct std::hash<tvm::tir::Var> {
  std::size_t operator()(const tvm::tir::Var& var) const {
    return tvm::runtime::ObjectPtrHash()(var);
  }
};
 
template <>
struct std::equal_to<tvm::tir::Var> {
  bool operator()(const tvm::tir::Var& var_a, const tvm::tir::Var& var_b) const {
    return tvm::runtime::ObjectPtrEqual()(var_a, var_b);
  }
};
 
#endif  // TVM_TIR_VAR_H_