PseudoSourceValue.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
1//===-- llvm/CodeGen/PseudoSourceValue.cpp ----------------------*- C++ -*-===//
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 PseudoSourceValue class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/CodeGen/PseudoSourceValue.h"
15#include "llvm/CodeGen/MachineFrameInfo.h"
16#include "llvm/IR/DerivedTypes.h"
17#include "llvm/IR/LLVMContext.h"
18#include "llvm/Support/ErrorHandling.h"
19#include "llvm/Support/ManagedStatic.h"
20#include "llvm/Support/Mutex.h"
21#include "llvm/Support/raw_ostream.h"
22#include <map>
23using namespace llvm;
24
25namespace {
26struct PSVGlobalsTy {
27  // PseudoSourceValues are immutable so don't need locking.
28  const PseudoSourceValue PSVs[4];
29  sys::Mutex Lock;  // Guards FSValues, but not the values inside it.
30  std::map<int, const PseudoSourceValue *> FSValues;
31
32  PSVGlobalsTy() : PSVs() {}
33  ~PSVGlobalsTy() {
34    for (std::map<int, const PseudoSourceValue *>::iterator
35           I = FSValues.begin(), E = FSValues.end(); I != E; ++I) {
36      delete I->second;
37    }
38  }
39};
40
41static ManagedStatic<PSVGlobalsTy> PSVGlobals;
42
43}  // anonymous namespace
44
45const PseudoSourceValue *PseudoSourceValue::getStack()
46{ return &PSVGlobals->PSVs[0]; }
47const PseudoSourceValue *PseudoSourceValue::getGOT()
48{ return &PSVGlobals->PSVs[1]; }
49const PseudoSourceValue *PseudoSourceValue::getJumpTable()
50{ return &PSVGlobals->PSVs[2]; }
51const PseudoSourceValue *PseudoSourceValue::getConstantPool()
52{ return &PSVGlobals->PSVs[3]; }
53
54static const char *const PSVNames[] = {
55  "Stack",
56  "GOT",
57  "JumpTable",
58  "ConstantPool"
59};
60
61PseudoSourceValue::PseudoSourceValue(bool isFixed) : isFixed(isFixed) {}
62
63PseudoSourceValue::~PseudoSourceValue() {}
64
65void PseudoSourceValue::printCustom(raw_ostream &O) const {
66  O << PSVNames[this - PSVGlobals->PSVs];
67}
68
69const PseudoSourceValue *PseudoSourceValue::getFixedStack(int FI) {
70  PSVGlobalsTy &PG = *PSVGlobals;
71  sys::ScopedLock locked(PG.Lock);
72  const PseudoSourceValue *&V = PG.FSValues[FI];
73  if (!V)
74    V = new FixedStackPseudoSourceValue(FI);
75  return V;
76}
77
78bool PseudoSourceValue::isConstant(const MachineFrameInfo *) const {
79  if (this == getStack())
80    return false;
81  if (this == getGOT() ||
82      this == getConstantPool() ||
83      this == getJumpTable())
84    return true;
85  llvm_unreachable("Unknown PseudoSourceValue!");
86}
87
88bool PseudoSourceValue::isAliased(const MachineFrameInfo *MFI) const {
89  if (this == getStack() ||
90      this == getGOT() ||
91      this == getConstantPool() ||
92      this == getJumpTable())
93    return false;
94  llvm_unreachable("Unknown PseudoSourceValue!");
95}
96
97bool PseudoSourceValue::mayAlias(const MachineFrameInfo *MFI) const {
98  if (this == getGOT() ||
99      this == getConstantPool() ||
100      this == getJumpTable())
101    return false;
102  return true;
103}
104
105bool FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const{
106  return MFI && MFI->isImmutableObjectIndex(FI);
107}
108
109bool FixedStackPseudoSourceValue::isAliased(const MachineFrameInfo *MFI) const {
110  // Negative frame indices are used for special things that don't
111  // appear in LLVM IR. Non-negative indices may be used for things
112  // like static allocas.
113  if (!MFI)
114    return FI >= 0;
115  // Spill slots should not alias others.
116  return !MFI->isFixedObjectIndex(FI) && !MFI->isSpillSlotObjectIndex(FI);
117}
118
119bool FixedStackPseudoSourceValue::mayAlias(const MachineFrameInfo *MFI) const {
120  if (!MFI)
121    return true;
122  // Spill slots will not alias any LLVM IR value.
123  return !MFI->isSpillSlotObjectIndex(FI);
124}
125
126void FixedStackPseudoSourceValue::printCustom(raw_ostream &OS) const {
127  OS << "FixedStack" << FI;
128}
129