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>
23 using namespace llvm;
24 
25 namespace {
26 struct 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 
PSVGlobalsTy__anon5f1416740111::PSVGlobalsTy32   PSVGlobalsTy() : PSVs() {}
~PSVGlobalsTy__anon5f1416740111::PSVGlobalsTy33   ~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 
41 static ManagedStatic<PSVGlobalsTy> PSVGlobals;
42 
43 }  // anonymous namespace
44 
getStack()45 const PseudoSourceValue *PseudoSourceValue::getStack()
46 { return &PSVGlobals->PSVs[0]; }
getGOT()47 const PseudoSourceValue *PseudoSourceValue::getGOT()
48 { return &PSVGlobals->PSVs[1]; }
getJumpTable()49 const PseudoSourceValue *PseudoSourceValue::getJumpTable()
50 { return &PSVGlobals->PSVs[2]; }
getConstantPool()51 const PseudoSourceValue *PseudoSourceValue::getConstantPool()
52 { return &PSVGlobals->PSVs[3]; }
53 
54 static const char *const PSVNames[] = {
55   "Stack",
56   "GOT",
57   "JumpTable",
58   "ConstantPool"
59 };
60 
PseudoSourceValue(bool isFixed)61 PseudoSourceValue::PseudoSourceValue(bool isFixed) : isFixed(isFixed) {}
62 
~PseudoSourceValue()63 PseudoSourceValue::~PseudoSourceValue() {}
64 
printCustom(raw_ostream & O) const65 void PseudoSourceValue::printCustom(raw_ostream &O) const {
66   O << PSVNames[this - PSVGlobals->PSVs];
67 }
68 
getFixedStack(int FI)69 const 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 
isConstant(const MachineFrameInfo *) const78 bool 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 
isAliased(const MachineFrameInfo * MFI) const88 bool 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 
mayAlias(const MachineFrameInfo * MFI) const97 bool PseudoSourceValue::mayAlias(const MachineFrameInfo *MFI) const {
98   if (this == getGOT() ||
99       this == getConstantPool() ||
100       this == getJumpTable())
101     return false;
102   return true;
103 }
104 
isConstant(const MachineFrameInfo * MFI) const105 bool FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const{
106   return MFI && MFI->isImmutableObjectIndex(FI);
107 }
108 
isAliased(const MachineFrameInfo * MFI) const109 bool FixedStackPseudoSourceValue::isAliased(const MachineFrameInfo *MFI) const {
110   if (!MFI)
111     return true;
112   return MFI->isAliasedObjectIndex(FI);
113 }
114 
mayAlias(const MachineFrameInfo * MFI) const115 bool FixedStackPseudoSourceValue::mayAlias(const MachineFrameInfo *MFI) const {
116   if (!MFI)
117     return true;
118   // Spill slots will not alias any LLVM IR value.
119   return !MFI->isSpillSlotObjectIndex(FI);
120 }
121 
printCustom(raw_ostream & OS) const122 void FixedStackPseudoSourceValue::printCustom(raw_ostream &OS) const {
123   OS << "FixedStack" << FI;
124 }
125