1 //===-------- EdgeBundles.cpp - Bundles of CFG edges ----------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file provides the implementation of the EdgeBundles analysis. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/CodeGen/EdgeBundles.h" 15 #include "llvm/CodeGen/MachineBasicBlock.h" 16 #include "llvm/CodeGen/MachineFunction.h" 17 #include "llvm/CodeGen/Passes.h" 18 #include "llvm/Support/GraphWriter.h" 19 20 using namespace llvm; 21 22 char EdgeBundles::ID = 0; 23 24 INITIALIZE_PASS(EdgeBundles, "edge-bundles", "Bundle Machine CFG Edges", 25 /* cfg = */true, /* analysis = */ true) 26 27 char &llvm::EdgeBundlesID = EdgeBundles::ID; 28 29 void EdgeBundles::getAnalysisUsage(AnalysisUsage &AU) const { 30 AU.setPreservesAll(); 31 MachineFunctionPass::getAnalysisUsage(AU); 32 } 33 34 bool EdgeBundles::runOnMachineFunction(MachineFunction &mf) { 35 MF = &mf; 36 EC.clear(); 37 EC.grow(2 * MF->size()); 38 39 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E; 40 ++I) { 41 const MachineBasicBlock &MBB = *I; 42 unsigned OutE = 2 * MBB.getNumber() + 1; 43 // Join the outgoing bundle with the ingoing bundles of all successors. 44 for (MachineBasicBlock::const_succ_iterator SI = MBB.succ_begin(), 45 SE = MBB.succ_end(); SI != SE; ++SI) 46 EC.join(OutE, 2 * (*SI)->getNumber()); 47 } 48 EC.compress(); 49 return false; 50 } 51 52 /// view - Visualize the annotated bipartite CFG with Graphviz. 53 void EdgeBundles::view() const { 54 ViewGraph(*this, "EdgeBundles"); 55 } 56 57 /// Specialize WriteGraph, the standard implementation won't work. 58 raw_ostream &llvm::WriteGraph(raw_ostream &O, const EdgeBundles &G, 59 bool ShortNames, 60 const std::string &Title) { 61 const MachineFunction *MF = G.getMachineFunction(); 62 63 O << "digraph {\n"; 64 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 65 I != E; ++I) { 66 unsigned BB = I->getNumber(); 67 O << "\t\"BB#" << BB << "\" [ shape=box ]\n" 68 << '\t' << G.getBundle(BB, false) << " -> \"BB#" << BB << "\"\n" 69 << "\t\"BB#" << BB << "\" -> " << G.getBundle(BB, true) << '\n'; 70 for (MachineBasicBlock::const_succ_iterator SI = I->succ_begin(), 71 SE = I->succ_end(); SI != SE; ++SI) 72 O << "\t\"BB#" << BB << "\" -> \"BB#" << (*SI)->getNumber() 73 << "\" [ color=lightgray ]\n"; 74 } 75 O << "}\n"; 76 return O; 77 } 78 79 80