llvm-6502/lib/CodeGen/PseudoSourceValue.cpp
Dan Gohman 6d69ba8a69 Enable rematerialization of constants using AliasAnalysis::pointsToConstantMemory,
and knowledge of PseudoSourceValues. This unfortunately isn't sufficient to allow
constants to be rematerialized in PIC mode -- the extra indirection is a
complication.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54000 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-25 00:02:30 +00:00

88 lines
2.6 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/ManagedStatic.h"
#include <map>
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"
};
PseudoSourceValue::PseudoSourceValue() :
Value(PointerType::getUnqual(Type::Int8Ty), PseudoSourceValueVal) {}
void PseudoSourceValue::print(std::ostream &OS) const {
OS << PSVNames[this - *PSVs];
}
/// 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 void print(std::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;
assert(0 && "Unknown PseudoSourceValue!");
return false;
}
bool
FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const {
return MFI && MFI->isImmutableObjectIndex(FI);
}
}