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/MachineFrameInfo.h"
15 #include "llvm/CodeGen/PseudoSourceValue.h"
16 #include "llvm/DerivedTypes.h"
17 #include "llvm/Support/Compiler.h"
18 #include "llvm/Support/ErrorHandling.h"
19 #include "llvm/Support/ManagedStatic.h"
20 #include "llvm/Support/raw_ostream.h"
21 #include <map>
22 using namespace llvm;
23 
24 static ManagedStatic<PseudoSourceValue[4]> PSVs;
25 
26 const PseudoSourceValue *PseudoSourceValue::getStack()
27 { return &(*PSVs)[0]; }
28 const PseudoSourceValue *PseudoSourceValue::getGOT()
29 { return &(*PSVs)[1]; }
30 const PseudoSourceValue *PseudoSourceValue::getJumpTable()
31 { return &(*PSVs)[2]; }
32 const PseudoSourceValue *PseudoSourceValue::getConstantPool()
33 { return &(*PSVs)[3]; }
34 
35 static const char *const PSVNames[] = {
36   "Stack",
37   "GOT",
38   "JumpTable",
39   "ConstantPool"
40 };
41 
42 PseudoSourceValue::PseudoSourceValue() :
43   Value(PointerType::getUnqual(Type::Int8Ty), PseudoSourceValueVal) {}
44 
45 void PseudoSourceValue::dump() const {
46   print(errs()); errs() << '\n';
47 }
48 
49 void PseudoSourceValue::print(raw_ostream &OS) const {
50   OS << PSVNames[this - *PSVs];
51 }
52 
53 namespace {
54   /// FixedStackPseudoSourceValue - A specialized PseudoSourceValue
55   /// for holding FixedStack values, which must include a frame
56   /// index.
57   class VISIBILITY_HIDDEN FixedStackPseudoSourceValue
58     : public PseudoSourceValue {
59     const int FI;
60   public:
61     explicit FixedStackPseudoSourceValue(int fi) : FI(fi) {}
62 
63     virtual bool isConstant(const MachineFrameInfo *MFI) const;
64 
65     virtual void print(raw_ostream &OS) const {
66       OS << "FixedStack" << FI;
67     }
68   };
69 }
70 
71 static ManagedStatic<std::map<int, const PseudoSourceValue *> > FSValues;
72 
73 const PseudoSourceValue *PseudoSourceValue::getFixedStack(int FI) {
74   const PseudoSourceValue *&V = (*FSValues)[FI];
75   if (!V)
76     V = new FixedStackPseudoSourceValue(FI);
77   return V;
78 }
79 
80 bool PseudoSourceValue::isConstant(const MachineFrameInfo *) const {
81   if (this == getStack())
82     return false;
83   if (this == getGOT() ||
84       this == getConstantPool() ||
85       this == getJumpTable())
86     return true;
87   llvm_unreachable("Unknown PseudoSourceValue!");
88   return false;
89 }
90 
91 bool FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const{
92   return MFI && MFI->isImmutableObjectIndex(FI);
93 }
94