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 // FIXME: THIS IS A HACK!!!!
43 // Eventually these should be uniqued on LLVMContext rather than in a managed
44 // static.  For now, we can safely use the global context for the time being to
45 // squeak by.
46 PseudoSourceValue::PseudoSourceValue() :
47   Value(PointerType::getUnqual(Type::getInt8Ty(getGlobalContext())),
48         PseudoSourceValueVal) {}
49 
50 void PseudoSourceValue::dump() const {
51   print(errs()); errs() << '\n';
52 }
53 
54 void PseudoSourceValue::print(raw_ostream &OS) const {
55   OS << PSVNames[this - *PSVs];
56 }
57 
58 namespace {
59   /// FixedStackPseudoSourceValue - A specialized PseudoSourceValue
60   /// for holding FixedStack values, which must include a frame
61   /// index.
62   class VISIBILITY_HIDDEN FixedStackPseudoSourceValue
63     : public PseudoSourceValue {
64     const int FI;
65   public:
66     explicit FixedStackPseudoSourceValue(int fi) : FI(fi) {}
67 
68     virtual bool isConstant(const MachineFrameInfo *MFI) const;
69 
70     virtual void print(raw_ostream &OS) const {
71       OS << "FixedStack" << FI;
72     }
73   };
74 }
75 
76 static ManagedStatic<std::map<int, const PseudoSourceValue *> > FSValues;
77 
78 const PseudoSourceValue *PseudoSourceValue::getFixedStack(int FI) {
79   const PseudoSourceValue *&V = (*FSValues)[FI];
80   if (!V)
81     V = new FixedStackPseudoSourceValue(FI);
82   return V;
83 }
84 
85 bool PseudoSourceValue::isConstant(const MachineFrameInfo *) const {
86   if (this == getStack())
87     return false;
88   if (this == getGOT() ||
89       this == getConstantPool() ||
90       this == getJumpTable())
91     return true;
92   llvm_unreachable("Unknown PseudoSourceValue!");
93   return false;
94 }
95 
96 bool FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const{
97   return MFI && MFI->isImmutableObjectIndex(FI);
98 }
99