//===-- FuncletLayout.cpp - Contiguously lay out funclets -----------------===// // // 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 file implements basic block placement transformations which result in // funclets being contiguous. // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/Analysis.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineFunctionPass.h" #include "llvm/CodeGen/Passes.h" #include "llvm/InitializePasses.h" using namespace llvm; #define DEBUG_TYPE "funclet-layout" namespace { class FuncletLayout : public MachineFunctionPass { public: static char ID; // Pass identification, replacement for typeid FuncletLayout() : MachineFunctionPass(ID) { initializeFuncletLayoutPass(*PassRegistry::getPassRegistry()); } bool runOnMachineFunction(MachineFunction &F) override; MachineFunctionProperties getRequiredProperties() const override { return MachineFunctionProperties().set( MachineFunctionProperties::Property::NoVRegs); } }; } char FuncletLayout::ID = 0; char &llvm::FuncletLayoutID = FuncletLayout::ID; INITIALIZE_PASS(FuncletLayout, DEBUG_TYPE, "Contiguously Lay Out Funclets", false, false) bool FuncletLayout::runOnMachineFunction(MachineFunction &F) { // Even though this gets information from getEHScopeMembership(), this pass is // only necessary for funclet-based EH personalities, in which these EH scopes // are outlined at the end. DenseMap<const MachineBasicBlock *, int> FuncletMembership = getEHScopeMembership(F); if (FuncletMembership.empty()) return false; F.sort([&](MachineBasicBlock &X, MachineBasicBlock &Y) { auto FuncletX = FuncletMembership.find(&X); auto FuncletY = FuncletMembership.find(&Y); assert(FuncletX != FuncletMembership.end()); assert(FuncletY != FuncletMembership.end()); return FuncletX->second < FuncletY->second; }); // Conservatively assume we changed something. return true; } |