MachineLoopInfo.cpp revision e4ad9c70e4a1261c212b11623d99e2477ef02783 
1//===- MachineLoopInfo.cpp - Natural Loop Calculator ----------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Owen Anderson and is distributed under
6// the University of Illinois Open Source 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
20using namespace llvm;
21
22TEMPLATE_INSTANTIATION(class LoopBase<MachineBasicBlock>);
23TEMPLATE_INSTANTIATION(class LoopInfoBase<MachineBasicBlock>);
24
25char MachineLoopInfo::ID = 0;
26static RegisterPass<MachineLoopInfo>
27X("machine-loops", "Machine Natural Loop Construction", true);
28
29bool MachineLoopInfo::runOnMachineFunction(MachineFunction &) {
30  releaseMemory();
31  LI->Calculate(getAnalysis<MachineDominatorTree>().getBase());    // Update
32  return false;
33}
34
35void MachineLoopInfo::getAnalysisUsage(AnalysisUsage &AU) const {
36  AU.setPreservesAll();
37  AU.addRequired<MachineDominatorTree>();
38}
39
40// Ensure this file gets linked when MachineLoopInfo.h is used.
41DEFINING_FILE_FOR(MachineLoopInfo)