lib/CodeGen/PseudoSourceValue.cpp

   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 }