1 //===-- LiveStackAnalysis.cpp - Live Stack Slot Analysis ------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the live stack slot analysis pass. It is analogous to
11 // live interval analysis except it's analyzing liveness of stack slots rather
14 //===----------------------------------------------------------------------===//
16 #define DEBUG_TYPE "livestacks"
17 #include "llvm/CodeGen/LiveStackAnalysis.h"
18 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
19 #include "llvm/CodeGen/Passes.h"
20 #include "llvm/Target/TargetRegisterInfo.h"
21 #include "llvm/Support/Debug.h"
22 #include "llvm/Support/raw_ostream.h"
23 #include "llvm/ADT/Statistic.h"
27 char LiveStacks::ID = 0;
28 static RegisterPass<LiveStacks> X("livestacks", "Live Stack Slot Analysis");
30 void LiveStacks::getAnalysisUsage(AnalysisUsage &AU) const {
32 AU.addPreserved<SlotIndexes>();
33 AU.addRequiredTransitive<SlotIndexes>();
34 MachineFunctionPass::getAnalysisUsage(AU);
37 void LiveStacks::releaseMemory() {
38 // Release VNInfo memroy regions after all VNInfo objects are dtor'd.
39 VNInfoAllocator.Reset();
44 bool LiveStacks::runOnMachineFunction(MachineFunction &) {
45 // FIXME: No analysis is being done right now. We are relying on the
46 // register allocators to provide the information.
50 /// print - Implement the dump method.
51 void LiveStacks::print(raw_ostream &OS, const Module*) const {
53 OS << "********** INTERVALS **********\n";
54 for (const_iterator I = begin(), E = end(); I != E; ++I) {
57 const TargetRegisterClass *RC = getIntervalRegClass(Slot);
59 OS << " [" << RC->getName() << "]\n";