| 1 | //===-- FuncletLayout.cpp - Contiguously lay out funclets -----------------===// |
|---|
| 2 | // |
|---|
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
|---|
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
|---|
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
|---|
| 6 | // |
|---|
| 7 | //===----------------------------------------------------------------------===// |
|---|
| 8 | // |
|---|
| 9 | // This file implements basic block placement transformations which result in |
|---|
| 10 | // funclets being contiguous. |
|---|
| 11 | // |
|---|
| 12 | //===----------------------------------------------------------------------===// |
|---|
| 13 | #include "llvm/CodeGen/Analysis.h" |
|---|
| 14 | #include "llvm/CodeGen/MachineFunction.h" |
|---|
| 15 | #include "llvm/CodeGen/MachineFunctionPass.h" |
|---|
| 16 | #include "llvm/CodeGen/Passes.h" |
|---|
| 17 | #include "llvm/InitializePasses.h" |
|---|
| 18 | using namespace llvm; |
|---|
| 19 | |
|---|
| 20 | #define DEBUG_TYPE "funclet-layout" |
|---|
| 21 | |
|---|
| 22 | namespace { |
|---|
| 23 | class FuncletLayout : public MachineFunctionPass { |
|---|
| 24 | public: |
|---|
| 25 | static char ID; // Pass identification, replacement for typeid |
|---|
| 26 | FuncletLayout() : MachineFunctionPass(ID) { |
|---|
| 27 | initializeFuncletLayoutPass(*PassRegistry::getPassRegistry()); |
|---|
| 28 | } |
|---|
| 29 | |
|---|
| 30 | bool runOnMachineFunction(MachineFunction &F) override; |
|---|
| 31 | MachineFunctionProperties getRequiredProperties() const override { |
|---|
| 32 | return MachineFunctionProperties().set( |
|---|
| 33 | MachineFunctionProperties::Property::NoVRegs); |
|---|
| 34 | } |
|---|
| 35 | }; |
|---|
| 36 | } |
|---|
| 37 | |
|---|
| 38 | char FuncletLayout::ID = 0; |
|---|
| 39 | char &llvm::FuncletLayoutID = FuncletLayout::ID; |
|---|
| 40 | INITIALIZE_PASS(FuncletLayout, DEBUG_TYPE, |
|---|
| 41 | "Contiguously Lay Out Funclets" , false, false) |
|---|
| 42 | |
|---|
| 43 | bool FuncletLayout::runOnMachineFunction(MachineFunction &F) { |
|---|
| 44 | // Even though this gets information from getEHScopeMembership(), this pass is |
|---|
| 45 | // only necessary for funclet-based EH personalities, in which these EH scopes |
|---|
| 46 | // are outlined at the end. |
|---|
| 47 | DenseMap<const MachineBasicBlock *, int> FuncletMembership = |
|---|
| 48 | getEHScopeMembership(MF: F); |
|---|
| 49 | if (FuncletMembership.empty()) |
|---|
| 50 | return false; |
|---|
| 51 | |
|---|
| 52 | F.sort(comp: [&](MachineBasicBlock &X, MachineBasicBlock &Y) { |
|---|
| 53 | auto FuncletX = FuncletMembership.find(Val: &X); |
|---|
| 54 | auto FuncletY = FuncletMembership.find(Val: &Y); |
|---|
| 55 | assert(FuncletX != FuncletMembership.end()); |
|---|
| 56 | assert(FuncletY != FuncletMembership.end()); |
|---|
| 57 | return FuncletX->second < FuncletY->second; |
|---|
| 58 | }); |
|---|
| 59 | |
|---|
| 60 | // Conservatively assume we changed something. |
|---|
| 61 | return true; |
|---|
| 62 | } |
|---|
| 63 | |
|---|
