llvm-6502/lib/CodeGen/PseudoSourceValue.cpp
Evan Cheng 38bdfc69cb Spill slots cannot alias.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84432 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-18 19:58:47 +00:00

117 lines
3.5 KiB
C++

//===-- llvm/CodeGen/PseudoSourceValue.cpp ----------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the PseudoSourceValue class.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ManagedStatic.h"
#include "llvm/Support/raw_ostream.h"
#include <map>
using namespace llvm;
static ManagedStatic<PseudoSourceValue[4]> PSVs;
const PseudoSourceValue *PseudoSourceValue::getStack()
{ return &(*PSVs)[0]; }
const PseudoSourceValue *PseudoSourceValue::getGOT()
{ return &(*PSVs)[1]; }
const PseudoSourceValue *PseudoSourceValue::getJumpTable()
{ return &(*PSVs)[2]; }
const PseudoSourceValue *PseudoSourceValue::getConstantPool()
{ return &(*PSVs)[3]; }
static const char *const PSVNames[] = {
"Stack",
"GOT",
"JumpTable",
"ConstantPool"
};
// FIXME: THIS IS A HACK!!!!
// Eventually these should be uniqued on LLVMContext rather than in a managed
// static. For now, we can safely use the global context for the time being to
// squeak by.
PseudoSourceValue::PseudoSourceValue() :
Value(Type::getInt8PtrTy(getGlobalContext()),
PseudoSourceValueVal) {}
void PseudoSourceValue::printCustom(raw_ostream &O) const {
O << PSVNames[this - *PSVs];
}
namespace {
/// FixedStackPseudoSourceValue - A specialized PseudoSourceValue
/// for holding FixedStack values, which must include a frame
/// index.
class VISIBILITY_HIDDEN FixedStackPseudoSourceValue
: public PseudoSourceValue {
const int FI;
public:
explicit FixedStackPseudoSourceValue(int fi) : FI(fi) {}
virtual bool isConstant(const MachineFrameInfo *MFI) const;
virtual bool isAliased(const MachineFrameInfo *MFI) const;
virtual void printCustom(raw_ostream &OS) const {
OS << "FixedStack" << FI;
}
};
}
static ManagedStatic<std::map<int, const PseudoSourceValue *> > FSValues;
const PseudoSourceValue *PseudoSourceValue::getFixedStack(int FI) {
const PseudoSourceValue *&V = (*FSValues)[FI];
if (!V)
V = new FixedStackPseudoSourceValue(FI);
return V;
}
bool PseudoSourceValue::isConstant(const MachineFrameInfo *) const {
if (this == getStack())
return false;
if (this == getGOT() ||
this == getConstantPool() ||
this == getJumpTable())
return true;
llvm_unreachable("Unknown PseudoSourceValue!");
return false;
}
bool PseudoSourceValue::isAliased(const MachineFrameInfo *MFI) const {
if (this == getStack() ||
this == getGOT() ||
this == getConstantPool() ||
this == getJumpTable())
return false;
llvm_unreachable("Unknown PseudoSourceValue!");
return true;
}
bool FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const{
return MFI && MFI->isImmutableObjectIndex(FI);
}
bool FixedStackPseudoSourceValue::isAliased(const MachineFrameInfo *MFI) const {
// Negative frame indices are used for special things that don't
// appear in LLVM IR. Non-negative indices may be used for things
// like static allocas.
if (!MFI)
return FI >= 0;
// Spill slots should not alias others.
return !MFI->isFixedObjectIndex(FI) && !MFI->isSpillSlotObjectIndex(FI);
}