85 lines
2.9 KiB
C++
85 lines
2.9 KiB
C++
//===- MachineLoopInfo.cpp - Natural Loop Calculator ----------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines the MachineLoopInfo class that is used to identify natural
|
|
// loops and determine the loop depth of various nodes of the CFG. Note that
|
|
// the loops identified may actually be several natural loops that share the
|
|
// same header node... not just a single natural loop.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/CodeGen/MachineLoopInfo.h"
|
|
#include "llvm/Analysis/LoopInfoImpl.h"
|
|
#include "llvm/CodeGen/MachineDominators.h"
|
|
#include "llvm/CodeGen/Passes.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
using namespace llvm;
|
|
|
|
// Explicitly instantiate methods in LoopInfoImpl.h for MI-level Loops.
|
|
template class llvm::LoopBase<MachineBasicBlock, MachineLoop>;
|
|
template class llvm::LoopInfoBase<MachineBasicBlock, MachineLoop>;
|
|
|
|
char MachineLoopInfo::ID = 0;
|
|
INITIALIZE_PASS_BEGIN(MachineLoopInfo, "machine-loops",
|
|
"Machine Natural Loop Construction", true, true)
|
|
INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
|
|
INITIALIZE_PASS_END(MachineLoopInfo, "machine-loops",
|
|
"Machine Natural Loop Construction", true, true)
|
|
|
|
char &llvm::MachineLoopInfoID = MachineLoopInfo::ID;
|
|
|
|
bool MachineLoopInfo::runOnMachineFunction(MachineFunction &) {
|
|
releaseMemory();
|
|
LI.analyze(getAnalysis<MachineDominatorTree>().getBase());
|
|
return false;
|
|
}
|
|
|
|
void MachineLoopInfo::getAnalysisUsage(AnalysisUsage &AU) const {
|
|
AU.setPreservesAll();
|
|
AU.addRequired<MachineDominatorTree>();
|
|
MachineFunctionPass::getAnalysisUsage(AU);
|
|
}
|
|
|
|
MachineBasicBlock *MachineLoop::getTopBlock() {
|
|
MachineBasicBlock *TopMBB = getHeader();
|
|
MachineFunction::iterator Begin = TopMBB->getParent()->begin();
|
|
if (TopMBB->getIterator() != Begin) {
|
|
MachineBasicBlock *PriorMBB = &*std::prev(TopMBB->getIterator());
|
|
while (contains(PriorMBB)) {
|
|
TopMBB = PriorMBB;
|
|
if (TopMBB->getIterator() == Begin)
|
|
break;
|
|
PriorMBB = &*std::prev(TopMBB->getIterator());
|
|
}
|
|
}
|
|
return TopMBB;
|
|
}
|
|
|
|
MachineBasicBlock *MachineLoop::getBottomBlock() {
|
|
MachineBasicBlock *BotMBB = getHeader();
|
|
MachineFunction::iterator End = BotMBB->getParent()->end();
|
|
if (BotMBB->getIterator() != std::prev(End)) {
|
|
MachineBasicBlock *NextMBB = &*std::next(BotMBB->getIterator());
|
|
while (contains(NextMBB)) {
|
|
BotMBB = NextMBB;
|
|
if (BotMBB == &*std::next(BotMBB->getIterator()))
|
|
break;
|
|
NextMBB = &*std::next(BotMBB->getIterator());
|
|
}
|
|
}
|
|
return BotMBB;
|
|
}
|
|
|
|
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
|
|
LLVM_DUMP_METHOD void MachineLoop::dump() const {
|
|
print(dbgs());
|
|
}
|
|
#endif
|