119 lines · cpp
1//===-------- EdgeBundles.cpp - Bundles of CFG edges ----------------------===//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-exception6//7//===----------------------------------------------------------------------===//8//9// This file provides the implementation of the EdgeBundles analysis.10//11//===----------------------------------------------------------------------===//12 13#include "llvm/CodeGen/EdgeBundles.h"14#include "llvm/ADT/Twine.h"15#include "llvm/CodeGen/MachineBasicBlock.h"16#include "llvm/CodeGen/MachineFunction.h"17#include "llvm/CodeGen/Passes.h"18#include "llvm/InitializePasses.h"19#include "llvm/Support/CommandLine.h"20#include "llvm/Support/GraphWriter.h"21#include "llvm/Support/raw_ostream.h"22 23using namespace llvm;24 25static cl::opt<bool>26ViewEdgeBundles("view-edge-bundles", cl::Hidden,27 cl::desc("Pop up a window to show edge bundle graphs"));28 29char EdgeBundlesWrapperLegacy::ID = 0;30 31INITIALIZE_PASS(EdgeBundlesWrapperLegacy, "edge-bundles",32 "Bundle Machine CFG Edges",33 /* cfg = */ true, /* is_analysis = */ true)34 35char &llvm::EdgeBundlesWrapperLegacyID = EdgeBundlesWrapperLegacy::ID;36 37void EdgeBundlesWrapperLegacy::getAnalysisUsage(AnalysisUsage &AU) const {38 AU.setPreservesAll();39 MachineFunctionPass::getAnalysisUsage(AU);40}41 42AnalysisKey EdgeBundlesAnalysis::Key;43 44EdgeBundles EdgeBundlesAnalysis::run(MachineFunction &MF,45 MachineFunctionAnalysisManager &MFAM) {46 EdgeBundles Impl(MF);47 return Impl;48}49 50bool EdgeBundlesWrapperLegacy::runOnMachineFunction(MachineFunction &MF) {51 Impl.reset(new EdgeBundles(MF));52 return false;53}54 55EdgeBundles::EdgeBundles(MachineFunction &MF) : MF(&MF) { init(); }56 57void EdgeBundles::init() {58 EC.clear();59 EC.grow(2 * MF->getNumBlockIDs());60 61 for (const auto &MBB : *MF) {62 unsigned OutE = 2 * MBB.getNumber() + 1;63 // Join the outgoing bundle with the ingoing bundles of all successors.64 for (const MachineBasicBlock *Succ : MBB.successors())65 EC.join(OutE, 2 * Succ->getNumber());66 }67 EC.compress();68 if (ViewEdgeBundles)69 view();70 71 // Compute the reverse mapping.72 Blocks.clear();73 Blocks.resize(getNumBundles());74 75 for (unsigned i = 0, e = MF->getNumBlockIDs(); i != e; ++i) {76 unsigned b0 = getBundle(i, false);77 unsigned b1 = getBundle(i, true);78 Blocks[b0].push_back(i);79 if (b1 != b0)80 Blocks[b1].push_back(i);81 }82}83 84/// Specialize WriteGraph, the standard implementation won't work.85template <>86raw_ostream &llvm::WriteGraph<>(raw_ostream &O, const EdgeBundles &G,87 bool ShortNames, const Twine &Title) {88 const MachineFunction *MF = G.getMachineFunction();89 90 O << "digraph {\n";91 for (const auto &MBB : *MF) {92 unsigned BB = MBB.getNumber();93 O << "\t\"" << printMBBReference(MBB) << "\" [ shape=box, label=\""94 << printMBBReference(MBB) << "\" ]\n"95 << '\t' << G.getBundle(BB, false) << " -> \"" << printMBBReference(MBB)96 << "\"\n"97 << "\t\"" << printMBBReference(MBB) << "\" -> " << G.getBundle(BB, true)98 << '\n';99 for (const MachineBasicBlock *Succ : MBB.successors())100 O << "\t\"" << printMBBReference(MBB) << "\" -> \""101 << printMBBReference(*Succ) << "\" [ color=lightgray ]\n";102 }103 O << "}\n";104 return O;105}106 107/// view - Visualize the annotated bipartite CFG with Graphviz.108void EdgeBundles::view() const {109 ViewGraph(*this, "EdgeBundles");110}111 112bool EdgeBundles::invalidate(MachineFunction &MF, const PreservedAnalyses &PA,113 MachineFunctionAnalysisManager::Invalidator &Inv) {114 // Invalidated when CFG is not preserved115 auto PAC = PA.getChecker<EdgeBundlesAnalysis>();116 return !PAC.preserved() && !PAC.preservedSet<CFGAnalyses>() &&117 !PAC.preservedSet<AllAnalysesOn<MachineFunction>>();118}119