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//===-- LiveStackAnalysis.cpp - Live Stack Slot Analysis ------------------===//
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// The LLVM Compiler Infrastructure
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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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// This file implements the live stack slot analysis pass. It is analogous to
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// live interval analysis except it's analyzing liveness of stack slots rather
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "livestacks"
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#include "llvm/CodeGen/LiveStackAnalysis.h"
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#include "llvm/CodeGen/LiveIntervalAnalysis.h"
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/Target/TargetRegisterInfo.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/ADT/Statistic.h"
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char LiveStacks::ID = 0;
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INITIALIZE_PASS(LiveStacks, "livestacks",
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"Live Stack Slot Analysis", false, false);
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void LiveStacks::getAnalysisUsage(AnalysisUsage &AU) const {
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AU.addPreserved<SlotIndexes>();
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AU.addRequiredTransitive<SlotIndexes>();
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MachineFunctionPass::getAnalysisUsage(AU);
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void LiveStacks::releaseMemory() {
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// Release VNInfo memory regions, VNInfo objects don't need to be dtor'd.
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VNInfoAllocator.Reset();
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bool LiveStacks::runOnMachineFunction(MachineFunction &) {
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// FIXME: No analysis is being done right now. We are relying on the
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// register allocators to provide the information.
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/// print - Implement the dump method.
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void LiveStacks::print(raw_ostream &OS, const Module*) const {
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OS << "********** INTERVALS **********\n";
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for (const_iterator I = begin(), E = end(); I != E; ++I) {
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const TargetRegisterClass *RC = getIntervalRegClass(Slot);
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OS << " [" << RC->getName() << "]\n";