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 using namespace llvm; 21 22 TEMPLATE_INSTANTIATION(class LoopBase<MachineBasicBlock>); 23 TEMPLATE_INSTANTIATION(class LoopInfoBase<MachineBasicBlock>); 24 25 char MachineLoopInfo::ID = 0; 26 namespace { 27 RegisterPass<MachineLoopInfo> 28 X("machine-loops", "Machine Natural Loop Construction", true); 29 } 30 31 const PassInfo *llvm::MachineLoopInfoID = X.getPassInfo(); 32 33 bool MachineLoopInfo::runOnMachineFunction(MachineFunction &) { 34 releaseMemory(); 35 LI->Calculate(getAnalysis<MachineDominatorTree>().getBase()); // Update 36 return false; 37 } 38 39 void MachineLoopInfo::getAnalysisUsage(AnalysisUsage &AU) const { 40 AU.setPreservesAll(); 41 AU.addRequired<MachineDominatorTree>(); 42 } 43 44 // Ensure this file gets linked when MachineLoopInfo.h is used. 45 DEFINING_FILE_FOR(MachineLoopInfo) 46