llvm/llvm/lib/Target/WebAssembly/WebAssemblyPeephole.cpp

//===-- WebAssemblyPeephole.cpp - WebAssembly Peephole Optimiztions -------===//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// Late peephole optimizations for WebAssembly.
///
//===----------------------------------------------------------------------===//

#include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
#include "WebAssembly.h"
#include "WebAssemblyMachineFunctionInfo.h"
#include "WebAssemblySubtarget.h"
#include "WebAssemblyUtilities.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
usingnamespacellvm;

#define DEBUG_TYPE …

static cl::opt<bool> DisableWebAssemblyFallthroughReturnOpt(
    "disable-wasm-fallthrough-return-opt", cl::Hidden,
    cl::desc("WebAssembly: Disable fallthrough-return optimizations."),
    cl::init(false));

namespace {
class WebAssemblyPeephole final : public MachineFunctionPass { … };
} // end anonymous namespace

char WebAssemblyPeephole::ID = …;
INITIALIZE_PASS(…)

FunctionPass *llvm::createWebAssemblyPeephole() { … }

/// If desirable, rewrite NewReg to a drop register.
static bool maybeRewriteToDrop(unsigned OldReg, unsigned NewReg,
                               MachineOperand &MO, WebAssemblyFunctionInfo &MFI,
                               MachineRegisterInfo &MRI) { … }

static bool maybeRewriteToFallthrough(MachineInstr &MI, MachineBasicBlock &MBB,
                                      const MachineFunction &MF,
                                      WebAssemblyFunctionInfo &MFI,
                                      MachineRegisterInfo &MRI,
                                      const WebAssemblyInstrInfo &TII) { … }

bool WebAssemblyPeephole::runOnMachineFunction(MachineFunction &MF) { … }