[IR][SIBuilder]

- Add SIBuilder to handle the span propagation between passes
- Add SequentialSpan for multiple source expressions conversion between
passes
- Add test cases for SIBuilder and SequentialSpan

include/tvm/ir/si_builder.h

@@ -0,0 +1,103 @@
+/*
+ * 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/ir/si_builder.h
+ * \brief build a source info during rewriting expressions.
+ */
+#ifndef TVM_IR_SI_BUILDER_H_
+#define TVM_IR_SI_BUILDER_H_
+
+#include <tvm/relay/expr.h>
+#include <tvm/relay/expr_functor.h>
+#include <tvm/tir/stmt.h>
+
+#include <memory>
+#include <unordered_set>
+
+namespace tvm {
+
+/*!
+ * \brief SIBuilder provides helper APIs for filling spans,
+ *        particularly useful for one-to-many, many-to-one and many-to-many pass transformations.
+ */
+class SIBuilder {
+ public:
+  /*!
+   * \brief Create SIBuilder from a given span
+   */
+  explicit SIBuilder(const Span& span = Span());
+
+  /*!
+   * \brief Create SIBuilder from a given span sequence
+   */
+  explicit SIBuilder(const Array<Span>& spans = Array<Span>());
+  explicit SIBuilder(const std::initializer_list<Span>& init);
+
+  /*!
+   * \brief Create SIBuilder via a subgraph,
+   *        Will construct span based on the exprs in the subgraph. Including the inputs exprs.
+   *
+   * \param entry Entry expr for subgraph
+   * \param inputs End exprs for subgraph
+   */
+  template <typename T, typename = std::enable_if_t<std::is_base_of<BaseExpr, T>::value>>
+  explicit SIBuilder(const T& entry, const tvm::Array<T>& inputs = {});
+  explicit SIBuilder(const tir::Stmt& entry, const tvm::Array<PrimExpr>& inputs = {});
+  explicit SIBuilder(const tir::Stmt& entry, const tvm::Array<tir::Stmt>& inputs = {});
+
+  ~SIBuilder();
+
+  SIBuilder(const SIBuilder&) = delete;
+  SIBuilder& operator=(const SIBuilder&) = delete;
+
+  /*!
+   * \brief create new source info based on the given span or subgraph.
+   *
+   * \return The given span, or reconstructed span from subgraph.
+   */
+  Span CreateSpan() const;
+
+  /*!
+   * \brief Recursively fill all span of exprs in subgraph from entry until inputs.
+   *
+   * \param entry Entry expr for subgraph.
+   * \param inputs End exprs for subgraph, will not be filled with new span.
+   */
+  template <typename T, typename = std::enable_if_t<std::is_base_of<BaseExpr, T>::value>>
+  void RecursivelyFillSpan(
+      const T& entry, const std::unordered_set<T, ObjectPtrHash, ObjectPtrEqual>& inputs) const;
+
+  void RecursivelyFillSpan(
+      const tir::Stmt& entry,
+      const std::unordered_set<PrimExpr, ObjectPtrHash, ObjectPtrEqual>& inputs) const;
+  void RecursivelyFillSpan(
+      const tir::Stmt& entry,
+      const std::unordered_set<tir::Stmt, ObjectPtrHash, ObjectPtrEqual>& inputs) const;
+
+ private:
+  struct Impl;
+  std::unique_ptr<Impl> impl_;
+
+  std::unique_ptr<Impl> CreateImpl(const Span& span);
+};
+
+}  // namespace tvm
+
+#endif  // TVM_IR_SI_BUILDER_H_

include/tvm/ir/source_map.h

@@ -114,7 +114,7 @@ class SpanNode : public Object {
   }
 
   static constexpr const char* _type_key = "Span";
-  TVM_DECLARE_FINAL_OBJECT_INFO(SpanNode, Object);
+  TVM_DECLARE_BASE_OBJECT_INFO(SpanNode, Object);
 };
 
 class Span : public ObjectRef {
@@ -127,6 +127,50 @@ class Span : public ObjectRef {
   TVM_DEFINE_OBJECT_REF_METHODS(Span, ObjectRef, SpanNode);
 };
 
+/*!
+ * \brief Store a list of spans for an expr generated from mulitple source exprs
+ */
+class SequentialSpanNode : public SpanNode {
+ public:
+  /*! \brief The original source list of spans to construct a sequential span. */
+  Array<Span> spans;
+
+  // override attr visitor
+  void VisitAttrs(AttrVisitor* v) {
+    SpanNode::VisitAttrs(v);
+    v->Visit("spans", &spans);
+  }
+
+  static constexpr const char* _type_key = "SequentialSpan";
+  TVM_DECLARE_FINAL_OBJECT_INFO(SequentialSpanNode, SpanNode);
+
+  bool SEqualReduce(const SequentialSpanNode* other, SEqualReducer equal) const {
+    if (spans.size() != other->spans.size()) {
+      return false;
+    }
+
+    for (size_t i = 0, e = spans.size(); i != e; ++i) {
+      if (!StructuralEqual()(spans[i], other->spans[i])) {
+        return false;
+      }
+    }
+    return true;
+  }
+};
+
+/*!
+ * \brief Reference class of SequentialSpanNode.
+ * \sa SequentialSpanNode
+ */
+class SequentialSpan : public Span {
+ public:
+  TVM_DLL SequentialSpan(Array<Span> spans);
+
+  TVM_DLL SequentialSpan(std::initializer_list<Span> init);
+
+  TVM_DEFINE_OBJECT_REF_METHODS(SequentialSpan, Span, SequentialSpanNode);
+};
+
 /*! \brief A program source in any language.
  *
  * Could represent the source from an ML framework or a source

python/tvm/ir/__init__.py

@@ -25,6 +25,7 @@
     Node,
     SourceName,
     Span,
+    SequentialSpan,
     assert_structural_equal,
     load_json,
     save_json,

python/tvm/ir/base.py

@@ -69,6 +69,20 @@ def __init__(self, source_name, line, end_line, column, end_column):
         )
 
 
+@register_object("SequentialSpan")
+class SequentialSpan(Object):
+    """Specifies a location in a source program.
+
+    Parameters
+    ----------
+    spans : Array
+        The array of spans.
+    """
+
+    def __init__(self, spans):
+        self.__init_handle_by_constructor__(_ffi_api.SequentialSpan, spans)
+
+
 @register_object
 class EnvFunc(Object):
     """Environment function.

python/tvm/relay/__init__.py

@@ -73,6 +73,7 @@
 
 # Span
 Span = base.Span
+SequentialSpan = base.SequentialSpan
 SourceName = base.SourceName
 
 # Type

python/tvm/relay/base.py

@@ -20,7 +20,7 @@
 
 import tvm._ffi
 from tvm.ir import Node as RelayNode
-from tvm.ir import SourceName, Span
+from tvm.ir import SourceName, Span, SequentialSpan
 from tvm.runtime import Object
 
 from . import _ffi_api