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