Track Refactor Items and Update Guide

[tqchen]

We are in the process of refactoring recently. Some of them are cleanup of legacy code in the new version, some other prepares code changes for #4617

This thread tracks related infra changes and guides to sync the code with the mainline as suggested by @merrymercy . Please feel free to reply to add more suggestions

DataType to runtime

• Rationale: DataType is a runtime data structure
• PRs [REFACTOR][DTYPE] Isolate dtype to runtime #4560
• Rename all old reference of tvm::Type to DataType
• ExprNode.type -> ExprNode.dtype, Expr.type() -> Expr.dtype()
• Move type constructors as static function: Int(bits) -> DataType::Int(bits)

Node Object Unification

• Rationale: remove a few redirected macros and alias, unify node and object
• PRs: [REFACTOR][OBJECT] Consoldiate NodePtr/Ref/Hash/Equal to Object #4603
• NodeXYZ -> ObjectXYZ
• TVM_DEFINE_NODE_REF: define the class and TVM_DEFINE_OBJECT_REF_METHODS

IRMutator/Visitor Functor Unification

• Rationale: Unify mutator and functor
• PRs: [REFACTOR] Migrate Low-level IR Passes into the New Stmt/Expr Mutator #4607 [REFACTOR] Unify approach to Visitor/Mutator under Functor #4606
• Add #include<tvm/tir/stmt_functor.h> for places that need mutator
• IRMutator: sub-class StmtMutator or StmtExprMutator instead
• IRVisitor: sub-class StmtVisitor or StmtExprVisitor instead

TVM_REGISTER_API -> TVM_REGISTER_GLOBAL

• Rationale: remove indirection
• PR: [REFACTOR] TVM_REGISTER_API -> TVM_REGISTER_GLOBAL #4621
• Rename to TVM_REGISTER_GLOBAL in runtime/registry.h

SeqStmt

• Rationale: avoid nested recursion in long blocks
• PR [REFACTOR][IR] Introduce SeqStmt to replace ir::Block #4627
• Use SeqStmt instead to constructs sequences

tir::Call.name -> op

• Use op(RelayExpr) to replace the string name. see [TIR][REFACTOR][API-CHANGE] Change Call.name to Call.op(RelayExpr) #5863
• Remove the call_type field [TIR][OP][API-CHANGE] Remove CallNode.call_type in favor of attribute. #5937

IRPrinter -> ReprPrinter

• Rationale: repr printer is shared across all variants in the stack
• PRs [REFACTOR] IRPrinter->NodePrinter, move to node/printer.h #4622 [REFACTOR] Establish printer in the source folder #4752
• Rename IRPrinter -> ReprPrinter

set_body_typed

• Rationale: avoid duplication in terms of type signatures
• [REFACTOR] Automatically deduce ftype signature in Registry.set_body_typed #4623
• Remove type signature argument in set_body_typed

// before
TVM_REGISTER_GLOBAL("add")
.set_body_typed<int(int)>([](int x) { return x + 1; }

// after
TVM_REGISTER_GLOBAL("add")
.set_body_typed([](int x) { return x + 1; }

Node suffix Convention

• Rationale: unify the naming convention throughout the codebase see also [RFC] Unify IR Node and Reference Class Naming Convention #4648
• PRs [REFACTOR][IR] Add Node suffix to low-level IR nodes #4649
• Add Node suffix to low level IR nodes
• Add ObjectRef classes to the TIR nodes
• [TIR][REFACTOR][API-Change] Migrate the tvm/tir/expr.h to constructor #5773
• [TIR][REFACTOR][API-Change] Migrate tir/stmt.h to use constructor. #5778
• [REFACTOR][API-Change] Migrate all Object construction to constructor. #5784

tvm::Expr -> PrimExpr

• Rationale: the low-level expression is renamed to "primitive" expression in order to bring more unifications.
• PR [REFACTOR][IR] tvm::Expr -> PrimExpr(Primitive Expr) #4669
• tvm::Expr -> PrimExpr, ExprHash/ExprEqual->ObjectHash/ObjectEqual, VarExpr->Var

Relay Type/Module/Op

• Rationale: unify type system, and module across the stack.
• PRs [REFACTOR] Initialize Unified IR Type Data Structures #4616 [REFACTOR][IR] Allow Module to store BaseFunc #4678 [REFACTOR][IR] Unified IR IRModule structure. #4699
• tvm/relay/module.h -> tvm/ir/module.h
• relay::Module -> IRModule

Unified IR file Reorg

• Rationale: reorganize code to fit into the new unified ir proposal

New Subfolders and Namespaces

• ir: Common set of types and IR structures
  • attrs.h -> ir/attrs.h [REFACTOR][IR] attrs.h -> ir #4709
• arith: Arithmetic simplification and integer analysis
  • arithmetic.h -> arith/analyzer.h arith/bound.h arith/int_set.h arith/pattern.h
  • [REFACTOR][ARITH] Unified IR, introduce include/tvm/arith/ #4722
• target: Target dependent information and codegen
  • target_info.h -> target/target_info.h [REFACTOR] Introduce include/tvm/target #4721
  • codegen.h -> target/codegen.h [REFACTOR][CODEGEN] codegen->target, build_module->driver #4742
• te namespace: Tensor expression DSL(compute and schedule)
  • Add namespace to compute/schedule
  • operation.h -> te/operation.h
  • schedule.h -> te/schedule.h
  • schedule_pass.h -> te/schedule_pass.h
  • tensor.h -> te/tensor.h
  • [REFACTOR] top - namespace for Tensor Operation DSL #4727, [REFACTOR] top->te #4759
• tir namespace: tensor-level IR
  • lowered_func.h,buffer.h,data_layout.h -> tir/buffer.h,tir/data_layout.h,tir/lowered_func.h
  • ir.h -> tir/expr.h, tir/stmt.h
  • ir_functor_ext.h -> tir/expr_functor.h, tir/stmt_functor.h
  • [REFACTOR][IR] Establish tir namespace #4740

LoweredFunc

TIR uses IRModule as basic unit of transformation instead of LoweredFunc.

• [REFACTOR][TIR] Migrate all low-level passes to the Pass Manager. #5233

ir_pass.h

• The IRModule->IRModule transformations are moved to tir/transform.h
• The IRModule->Analaysis result passes are moved to tir/analysis.h

Simplify

• Simplify function is removed, use Analyzer in arith/analyzer.h instead
• [REFACTOR][ARITH] Remove the legacy Simplify, migrate to Analyzer. #5385

BuildConfig

• BuildConfig-> PassContext
  [REFACTOR][TIR][API-Change] Migrate BuildConfig to PassContext. #5668

Runtime Misc

• ThreadScope::make -> ThreadScope::Create
• StorageScope::make -> StorageScope::Create
• [REFACTOR][API-Change] Migrate all Object construction to constructor. #5784

Python

tvm.module -> tvm.runtime.module

API changes wrt to runtime.Module #4837

• tvm.module.load -> tvm.runtime.load_module
• tvm.module.enabled -> tvm.runtime.enabled
• tvm.module.system_lib -> tvm.runtime.system_lib

tvm.ir

API changes wrt to tvm.ir #4862

• tvm.relay.Module -> tvm.IRModule

tvm.target

API change wrt to tvm.target #4872

tvm.te

API change wrt to #4943

• tvm.create_schedule -> tvm.te.create_schedule
• tvm.placeholder -> tvm.te.placeholder
• tvm.compute -> tvm.te.compute

[tqchen]

cc @merrymercy @Hzfengsy