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 INITIALIZE_PASS(LiveStacks, "livestacks",
29 "Live Stack Slot Analysis", false, false)
31 char &llvm::LiveStacksID = LiveStacks::ID;
33 void LiveStacks::getAnalysisUsage(AnalysisUsage &AU) const {
35 AU.addPreserved<SlotIndexes>();
36 AU.addRequiredTransitive<SlotIndexes>();
37 MachineFunctionPass::getAnalysisUsage(AU);
40 void LiveStacks::releaseMemory() {
41 // Release VNInfo memory regions, VNInfo objects don't need to be dtor'd.
42 VNInfoAllocator.Reset();
47 bool LiveStacks::runOnMachineFunction(MachineFunction &) {
48 // FIXME: No analysis is being done right now. We are relying on the
49 // register allocators to provide the information.
53 /// print - Implement the dump method.
54 void LiveStacks::print(raw_ostream &OS, const Module*) const {
56 OS << "********** INTERVALS **********\n";
57 for (const_iterator I = begin(), E = end(); I != E; ++I) {
60 const TargetRegisterClass *RC = getIntervalRegClass(Slot);
62 OS << " [" << RC->getName() << "]\n";