llvm/lib/CodeGen/PseudoSourceValue.cpp
David Greene cf62632d83 Make FixedStackPseudoSourceValue a first-class PseudoSourceValue by
making it visible to clients and adding LLVM-style cast capability.
This will be used by AsmPrinter to determine when to emit spill comments
for an instruction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@87019 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 20:25:07 +00:00

112 lines
3.4 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/LLVMContext.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(enum ValueTy Subclass) :
Value(Type::getInt8PtrTy(getGlobalContext()),
Subclass) {}
void PseudoSourceValue::printCustom(raw_ostream &O) const {
O << PSVNames[this - *PSVs];
}
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 PseudoSourceValue::mayAlias(const MachineFrameInfo *MFI) const {
if (this == getGOT() ||
this == getConstantPool() ||
this == getJumpTable())
return false;
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);
}
bool FixedStackPseudoSourceValue::mayAlias(const MachineFrameInfo *MFI) const {
if (!MFI)
return true;
// Spill slots will not alias any LLVM IR value.
return !MFI->isSpillSlotObjectIndex(FI);
}