chromium/v8/src/compiler/turboshaft/type-inference-analysis.h

// Copyright 2023 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_COMPILER_TURBOSHAFT_TYPE_INFERENCE_ANALYSIS_H_
#define V8_COMPILER_TURBOSHAFT_TYPE_INFERENCE_ANALYSIS_H_

#include <limits>
#include <optional>

#include "src/base/logging.h"
#include "src/base/vector.h"
#include "src/compiler/common-operator.h"
#include "src/compiler/turboshaft/assembler.h"
#include "src/compiler/turboshaft/operations.h"
#include "src/compiler/turboshaft/representations.h"
#include "src/compiler/turboshaft/sidetable.h"
#include "src/compiler/turboshaft/snapshot-table.h"
#include "src/compiler/turboshaft/typer.h"
#include "src/compiler/turboshaft/types.h"

namespace v8::internal::compiler::turboshaft {

// This analysis infers types for all operations. It does so by running a
// fixpoint analysis on the input graph in order to properly type PhiOps. The
// analysis visits blocks in order and computes operation types using
// Turboshaft's Typer. For Goto operations, the analysis checks if this is a
// back edge (the Goto's target is a loop block with an index less than the
// index of the current block). If this is the case, the analysis revisits the
// loop block (this is when ProcessBlock<true> is called). During this revisit,
// two things are different to the normal processing of a block:
//
// 1.) PhiOps are handled specially, which means applying proper
// widening/narrowing mechanics to accelerate termination while still computing
// somewhat precise types for Phis. 2.) If the type of any of the loop's Phis
// grows, we reset the index of unprocessed blocks to the block after the loop
// header, such that the entire loop body is revisited with the new type
// information.
class TypeInferenceAnalysis { … };

}  // namespace v8::internal::compiler::turboshaft

#endif  // V8_COMPILER_TURBOSHAFT_TYPE_INFERENCE_ANALYSIS_H_