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" 20using namespace llvm; 21 22#define MLB class LoopBase<MachineBasicBlock, MachineLoop> 23TEMPLATE_INSTANTIATION(MLB); 24#undef MLB 25#define MLIB class LoopInfoBase<MachineBasicBlock, MachineLoop> 26TEMPLATE_INSTANTIATION(MLIB); 27#undef MLIB 28 29char MachineLoopInfo::ID = 0; 30static RegisterPass<MachineLoopInfo> 31X("machine-loops", "Machine Natural Loop Construction", true); 32 33const PassInfo *const llvm::MachineLoopInfoID = &X; 34 35bool MachineLoopInfo::runOnMachineFunction(MachineFunction &) { 36 releaseMemory(); 37 LI.Calculate(getAnalysis<MachineDominatorTree>().getBase()); // Update 38 return false; 39} 40 41void MachineLoopInfo::getAnalysisUsage(AnalysisUsage &AU) const { 42 AU.setPreservesAll(); 43 AU.addRequired<MachineDominatorTree>(); 44 MachineFunctionPass::getAnalysisUsage(AU); 45} 46 47MachineBasicBlock *MachineLoop::getTopBlock() { 48 MachineBasicBlock *TopMBB = getHeader(); 49 MachineFunction::iterator Begin = TopMBB->getParent()->begin(); 50 if (TopMBB != Begin) { 51 MachineBasicBlock *PriorMBB = prior(MachineFunction::iterator(TopMBB)); 52 while (contains(PriorMBB)) { 53 TopMBB = PriorMBB; 54 if (TopMBB == Begin) break; 55 PriorMBB = prior(MachineFunction::iterator(TopMBB)); 56 } 57 } 58 return TopMBB; 59} 60 61MachineBasicBlock *MachineLoop::getBottomBlock() { 62 MachineBasicBlock *BotMBB = getHeader(); 63 MachineFunction::iterator End = BotMBB->getParent()->end(); 64 if (BotMBB != prior(End)) {
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65 MachineBasicBlock *NextMBB = next(MachineFunction::iterator(BotMBB));
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65 MachineBasicBlock *NextMBB = llvm::next(MachineFunction::iterator(BotMBB)); |
66 while (contains(NextMBB)) { 67 BotMBB = NextMBB;
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68 if (BotMBB == next(MachineFunction::iterator(BotMBB))) break;
69 NextMBB = next(MachineFunction::iterator(BotMBB));
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68 if (BotMBB == llvm::next(MachineFunction::iterator(BotMBB))) break; 69 NextMBB = llvm::next(MachineFunction::iterator(BotMBB)); |
70 } 71 } 72 return BotMBB; 73}
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