llvm/llvm/utils/TableGen/DAGISelEmitter.cpp

//===- DAGISelEmitter.cpp - Generate an instruction selector --------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This tablegen backend emits a DAG instruction selector.
//
//===----------------------------------------------------------------------===//

#include "Common/CodeGenDAGPatterns.h"
#include "Common/CodeGenInstruction.h"
#include "Common/CodeGenTarget.h"
#include "Common/DAGISelMatcher.h"
#include "llvm/Support/Debug.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/TableGenBackend.h"
usingnamespacellvm;

#define DEBUG_TYPE …

namespace {
/// DAGISelEmitter - The top-level class which coordinates construction
/// and emission of the instruction selector.
class DAGISelEmitter { … };
} // End anonymous namespace

//===----------------------------------------------------------------------===//
// DAGISelEmitter Helper methods
//

/// Compute the number of instructions for this pattern.
/// This is a temporary hack.  We should really include the instruction
/// latencies in this calculation.
static unsigned getResultPatternCost(TreePatternNode &P,
                                     const CodeGenDAGPatterns &CGP) { … }

/// getResultPatternCodeSize - Compute the code size of instructions for this
/// pattern.
static unsigned getResultPatternSize(TreePatternNode &P,
                                     const CodeGenDAGPatterns &CGP) { … }

namespace {
// PatternSortingPredicate - return true if we prefer to match LHS before RHS.
// In particular, we want to match maximal patterns first and lowest cost within
// a particular complexity first.
struct PatternSortingPredicate { … };
} // End anonymous namespace

void DAGISelEmitter::run(raw_ostream &OS) { … }

static TableGen::Emitter::OptClass<DAGISelEmitter>
    X("gen-dag-isel", "Generate a DAG instruction selector");