LiveStackAnalysis.cpp revision 14f8a50ce74830eb97811e52914ddca26ffedaa4 
1//===-- LiveStackAnalysis.cpp - Live Stack Slot Analysis ------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
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
12// than registers.
13//
14//===----------------------------------------------------------------------===//
15
16#define DEBUG_TYPE "livestacks"
17#include "llvm/CodeGen/LiveStackAnalysis.h"
18#include "llvm/CodeGen/Passes.h"
19#include "llvm/Target/TargetRegisterInfo.h"
20#include "llvm/Support/Debug.h"
21#include "llvm/ADT/Statistic.h"
22using namespace llvm;
23
24char LiveStacks::ID = 0;
25static RegisterPass<LiveStacks> X("livestacks", "Live Stack Slot Analysis");
26
27void LiveStacks::getAnalysisUsage(AnalysisUsage &AU) const {
28  AU.setPreservesAll();
29}
30
31void LiveStacks::releaseMemory() {
32  // Release VNInfo memroy regions after all VNInfo objects are dtor'd.
33  VNInfoAllocator.Reset();
34  s2iMap.clear();
35}
36
37bool LiveStacks::runOnMachineFunction(MachineFunction &) {
38  // FIXME: No analysis is being done right now. We are relying on the
39  // register allocators to provide the information.
40  return false;
41}
42
43/// print - Implement the dump method.
44void LiveStacks::print(std::ostream &O, const Module* ) const {
45  O << "********** INTERVALS **********\n";
46  for (const_iterator I = begin(), E = end(); I != E; ++I) {
47    I->second.print(O);
48    O << "\n";
49  }
50}
51