1 //===- MachineLoopInfo.cpp - Natural Loop Calculator ----------------------===// 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 defines the MachineLoopInfo class that is used to identify natural 11 // loops and determine the loop depth of various nodes of the CFG. Note that 12 // the loops identified may actually be several natural loops that share the 13 // same header node... not just a single natural loop. 14 // 15 //===----------------------------------------------------------------------===// 16 17 #include "llvm/CodeGen/MachineLoopInfo.h" 18 #include "llvm/CodeGen/MachineDominators.h" 19 #include "llvm/CodeGen/Passes.h" 20 21 using namespace llvm; 22 23 TEMPLATE_INSTANTIATION(class LoopBase<MachineBasicBlock>); 24 TEMPLATE_INSTANTIATION(class LoopInfoBase<MachineBasicBlock>); 25 26 namespace { 27 char MachineLoopInfo::ID = 0; 28 RegisterPass<MachineLoopInfo> 29 X("machine-loops", "Machine Natural Loop Construction", true); 30 } 31 32 const PassInfo *llvm::MachineLoopInfoID = X.getPassInfo(); 33 34 bool MachineLoopInfo::runOnMachineFunction(MachineFunction &) { 35 releaseMemory(); 36 LI->Calculate(getAnalysis<MachineDominatorTree>().getBase()); // Update 37 return false; 38 } 39 40 void MachineLoopInfo::getAnalysisUsage(AnalysisUsage &AU) const { 41 AU.setPreservesAll(); 42 AU.addRequired<MachineDominatorTree>(); 43 } 44 45 // Ensure this file gets linked when MachineLoopInfo.h is used. 46 DEFINING_FILE_FOR(MachineLoopInfo) 47