[Unity] Relax VM (#13878)

This PR implements a flexible register-based VM to execute relax programs with dynamic shape and control flow. Design: https://github.com/tlc-pack/relax/wiki/Relax-VM-Design.

Co-Authored-by: Ziheng Jiang <ziheng@apache.org>
Co-Authored-by: Ruihang Lai <ruihangl@cs.cmu.edu>
Co-Authored-by: Sunghyun Park <49998730+sunggg@users.noreply.github.com>
Co-Authored-by: Junru Shao <junrushao1994@gmail.com>
Co-Authored-by: Prakalp Srivastava <prakalp@octoml.ai>
Co-Authored-by: Yong Wu <yongcale@gmail.com>
Co-Authored-by: Steven S. Lyubomirsky <slyubomirsky@octoml.ai>
Co-Authored-by: Tianqi Chen <tianqi.tchen@gmail.com>
Co-Authored-by: Hongyi Jin <3231950289@qq.com>

CMakeLists.txt

@@ -289,6 +289,7 @@ tvm_file_glob(GLOB_RECURSE COMPILER_SRCS
     src/driver/*.cc
     src/support/*.cc
     src/script/*.cc
+    src/relax/backend/vm/*.cc
     )
 
 tvm_file_glob(GLOB CODEGEN_SRCS
@@ -335,6 +336,7 @@ tvm_file_glob(GLOB RUNTIME_SRCS
   src/runtime/*.cc
   src/runtime/vm/*.cc
   src/runtime/minrpc/*.cc
+  src/runtime/relax_vm/*.cc
 )
 
 if(BUILD_FOR_HEXAGON)

include/tvm/relax/exec_builder.h

@@ -0,0 +1,181 @@
+/*
+ * 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/exec_builder.h
+ */
+#ifndef TVM_RELAX_EXEC_BUILDER_H_
+#define TVM_RELAX_EXEC_BUILDER_H_
+
+#include <tvm/ir/expr.h>
+#include <tvm/node/reflection.h>
+#include <tvm/node/repr_printer.h>
+#include <tvm/runtime/object.h>
+#include <tvm/runtime/registry.h>
+#include <tvm/runtime/relax_vm/bytecode.h>
+#include <tvm/runtime/relax_vm/executable.h>
+
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+namespace tvm {
+namespace relax {
+
+namespace vm = tvm::runtime::relax_vm;
+
+class ExecBuilder;
+
+/*!
+ * \brief A builder provides api to build VM executable with instructions.
+ */
+class ExecBuilderNode : public Object {
+ public:
+  /*!
+   * \brief Declare a function, it is OK to have multiple declarations.
+   * \param func The function name.
+   * \param kind The kind of the function.
+   */
+  void DeclareFunction(const std::string& func, vm::VMFuncInfo::FuncKind kind);
+  /*!
+   * \brief To annotate the start of a vm function.
+   * \param func The function name.
+   * \param num_inputs The number of inputs.
+   * \param param_names The function parameter names.
+   * \param kind The kind of the function.
+   * \param init_register_size Initial setting of register file size.
+   */
+  void EmitFunction(const std::string& func, int64_t num_inputs,
+                    Optional<Array<String>> param_names,
+                    vm::VMFuncInfo::FuncKind kind = vm::VMFuncInfo::FuncKind::kVMFunc,
+                    int64_t init_register_size = 0);
+  /*!
+   * \brief Annotate the end of a vm function.
+   * \param func The function name.
+   */
+  void EndFunction(const std::string& func);
+  /*!
+   * \brief Emit a call instruction for a packed function.
+   * \param func The packed function name.
+   * \param args The arguments of the function.
+   * \param ret The return register.
+   */
+  void EmitCall(const std::string& func, std::vector<vm::Instruction::Arg> args, vm::RegName ret);
+  /*!
+   * \brief Emit a call instruction with func as argument.
+   * \param func The packed function index.
+   * \param args The arguments of the function.
+   * \param ret The return register.
+   */
+  void EmitCall(vm::Instruction::Arg func, std::vector<vm::Instruction::Arg> args, vm::RegName ret);
+  /*!
+   * \brief Emit a ret instruction.
+   * \param result The return result.
+   * \note result must be a register.
+   */
+  void EmitRet(vm::Instruction::Arg result);
+  /*!
+   * \brief Emit a goto instruction.
+   * \param pc_offset The program counter offset as the jump offset.
+   */
+  void EmitGoto(vm::Index pc_offset);
+  /*!
+   * \brief Emit an If instruction.
+   * \param cond The register containing the cond value.
+   * \param false_offset The program counter offset for the false branch.
+   * \note result must be a register.
+   */
+  void EmitIf(vm::Instruction::Arg cond, vm::Index false_offset);
+  /*!
+   * \brief Get function index by its name.
+   * \param name The name of the function.
+   * \return The argument corresponding to the function index.
+   */
+  vm::Instruction::Arg GetFunction(const std::string& name);
+  /*!
+   * \brief Convert a constant value something that exec builder can understand.
+   *
+   * This function may update the constant pool to include the obj value.
+   *
+   * \param value The input constant value
+   * \return An Arg that represents the result of constant argument.
+   */
+  template <typename T>
+  vm::Instruction::Arg ConvertConstant(T value) {
+    TVMRetValue rv;
+    rv = value;
+    return ConvertConstant_(rv);
+  }
+  /*!
+   * \brief Raw access to underlying executable build in progress.
+   */
+  vm::Executable* exec() const;
+  /*!
+   * \brief Finalize the build, run formalize and get the final result.
+   * \note This function should not be called during construction.
+   */
+  ObjectPtr<vm::Executable> Get();
+  /*!
+   * \brief Create an ExecBuilder.
+   * \return The ExecBuilder.
+   */
+  TVM_DLL static ExecBuilder Create();
+
+  void VisitAttrs(AttrVisitor* v) {}
+
+  static constexpr const uint32_t _type_index = TypeIndex::kDynamic;
+  static constexpr const char* _type_key = "relax.ExecBuilder";
+  TVM_DECLARE_FINAL_OBJECT_INFO(ExecBuilderNode, Object);
+
+ private:
+  /*!
+   * \brief Convert a constant value something that exec builder can understand.
+   *
+   * This function may update the constant pool to include the obj value.
+   *
+   * \param obj The constant value to be emitted
+   * \return An Arg that represents the result of constant argument.
+   */
+  vm::Instruction::Arg ConvertConstant_(TVMRetValue obj);
+
+  /*!
+   * \brief A helper function to check if an executable is legal by checking if registers are used
+   * properly
+   */
+  void CheckExecutable();
+  /*!
+   * \brief Formalize the executable.
+   */
+  void Formalize();
+
+  /*! \brief The mutable internal executable. */
+  ObjectPtr<vm::Executable> exec_;  // mutable
+  /*! \brief internal dedup map when creating index for a new constant */
+  std::unordered_map<ObjectRef, vm::Index, StructuralHash, StructuralEqual> const_dedup_map_;
+};
+
+class ExecBuilder : public ObjectRef {
+ public:
+  TVM_DEFINE_MUTABLE_OBJECT_REF_METHODS(ExecBuilder, ObjectRef, ExecBuilderNode);
+};
+
+}  // namespace relax
+}  // namespace tvm
+
+#endif  // TVM_RELAX_EXEC_BUILDER_H_

include/tvm/runtime/relax_vm/builtin.h

@@ -0,0 +1,89 @@
+/*
+ * 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/runtime/relax_vm/builtin.h
+ * \brief Builtin runtime APIs.
+ */
+#ifndef TVM_RUNTIME_RELAX_VM_BUILTIN_H_
+#define TVM_RUNTIME_RELAX_VM_BUILTIN_H_
+
+namespace tvm {
+namespace runtime {
+namespace relax_vm {
+
+/*!
+ * \brief Op code used in built-in match-shape function.
+ *
+ * The function takes the following signature:
+
+ * MatchShape(input_shape, shape_heap, n, c[0], r[0], c[1], r[1], ... c[n], r[n], err_ctx)
+ *
+ * This function provides runtime shape population and checking support for match-cast.
+ * When a shape variable appears in the first time, we should load the shape and
+ * populate the variable. When a shape variable already appears, we should
+ * assert that it already equals an existing shape value.
+ *
+ * NOTE: It is OK to pass nullptr shape_heap if all code are AssertEqualToImm.
+ */
+enum class MatchShapeCode : int {
+  /*!
+   * \brief Perform an assertion that shape equals immediate.
+   *
+   * assert input_shape[i] == r[i]
+   */
+  kAssertEqualToImm = 0,
+  /*!
+   * \brief This is the first time we see a symbolic shape variable, store to heap.
+   *
+   * shape_heap[r[i]] = input_shape[i]
+   */
+  kStoreToHeap = 1,
+  /*!
+   * \brief skip and do not do anything.
+   */
+  kNoOp = 2,
+  /*!
+   * \brief Peform an assertion that the shape equals a loaded value.
+   *
+   * assert input_shape[i] == shape_heap[r[i]]
+   */
+  kAssertEqualToLoad = 3,
+};
+
+/*!
+ * \brief Op code used in builtin function MakeShape.
+ *
+ * MakeShape(shape_heap, n, c[0], r[0], c[1], r[1], ... c[n], r[n]).
+ *
+ * \note It is OK to pass nullptr to shape_heap if all code are UseImm.
+ */
+enum class MakeShapeCode : int {
+  /*! \brief Use the following r[i] as immediate shape value. */
+  kUseImm = 0,
+  /*!
+   * \brief Load shape value from the shape_heap[[r[i]].
+   */
+  kLoadShape = 1,
+};
+
+}  // namespace relax_vm
+}  // namespace runtime
+}  // namespace tvm
+#endif  // TVM_RUNTIME_RELAX_VM_BUILTIN_H_