283 lines
9.8 KiB
C++
283 lines
9.8 KiB
C++
//===-- llvm/CodeGen/VirtRegMap.cpp - Virtual Register Map ----------------===//
|
|
//
|
|
// 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 VirtRegMap class.
|
|
//
|
|
// It also contains implementations of the the Spiller interface, which, given a
|
|
// virtual register map and a machine function, eliminates all virtual
|
|
// references by replacing them with physical register references - adding spill
|
|
// code as necessary.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#define DEBUG_TYPE "virtregmap"
|
|
#include "VirtRegMap.h"
|
|
#include "llvm/Function.h"
|
|
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
|
|
#include "llvm/CodeGen/MachineFrameInfo.h"
|
|
#include "llvm/CodeGen/MachineFunction.h"
|
|
#include "llvm/CodeGen/MachineInstrBuilder.h"
|
|
#include "llvm/CodeGen/MachineRegisterInfo.h"
|
|
#include "llvm/Target/TargetMachine.h"
|
|
#include "llvm/Target/TargetInstrInfo.h"
|
|
#include "llvm/Target/TargetRegisterInfo.h"
|
|
#include "llvm/Support/CommandLine.h"
|
|
#include "llvm/Support/Compiler.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
#include "llvm/ADT/BitVector.h"
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/ADT/DepthFirstIterator.h"
|
|
#include "llvm/ADT/Statistic.h"
|
|
#include "llvm/ADT/STLExtras.h"
|
|
#include "llvm/ADT/SmallSet.h"
|
|
#include <algorithm>
|
|
using namespace llvm;
|
|
|
|
STATISTIC(NumSpills , "Number of register spills");
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// VirtRegMap implementation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
char VirtRegMap::ID = 0;
|
|
|
|
static RegisterPass<VirtRegMap>
|
|
X("virtregmap", "Virtual Register Map");
|
|
|
|
bool VirtRegMap::runOnMachineFunction(MachineFunction &mf) {
|
|
MRI = &mf.getRegInfo();
|
|
TII = mf.getTarget().getInstrInfo();
|
|
TRI = mf.getTarget().getRegisterInfo();
|
|
MF = &mf;
|
|
|
|
ReMatId = MAX_STACK_SLOT+1;
|
|
LowSpillSlot = HighSpillSlot = NO_STACK_SLOT;
|
|
|
|
Virt2PhysMap.clear();
|
|
Virt2StackSlotMap.clear();
|
|
Virt2ReMatIdMap.clear();
|
|
Virt2SplitMap.clear();
|
|
Virt2SplitKillMap.clear();
|
|
ReMatMap.clear();
|
|
ImplicitDefed.clear();
|
|
SpillSlotToUsesMap.clear();
|
|
MI2VirtMap.clear();
|
|
SpillPt2VirtMap.clear();
|
|
RestorePt2VirtMap.clear();
|
|
EmergencySpillMap.clear();
|
|
EmergencySpillSlots.clear();
|
|
|
|
SpillSlotToUsesMap.resize(8);
|
|
ImplicitDefed.resize(MF->getRegInfo().getLastVirtReg()+1-
|
|
TargetRegisterInfo::FirstVirtualRegister);
|
|
|
|
allocatableRCRegs.clear();
|
|
for (TargetRegisterInfo::regclass_iterator I = TRI->regclass_begin(),
|
|
E = TRI->regclass_end(); I != E; ++I)
|
|
allocatableRCRegs.insert(std::make_pair(*I,
|
|
TRI->getAllocatableSet(mf, *I)));
|
|
|
|
grow();
|
|
|
|
return false;
|
|
}
|
|
|
|
void VirtRegMap::grow() {
|
|
unsigned LastVirtReg = MF->getRegInfo().getLastVirtReg();
|
|
Virt2PhysMap.grow(LastVirtReg);
|
|
Virt2StackSlotMap.grow(LastVirtReg);
|
|
Virt2ReMatIdMap.grow(LastVirtReg);
|
|
Virt2SplitMap.grow(LastVirtReg);
|
|
Virt2SplitKillMap.grow(LastVirtReg);
|
|
ReMatMap.grow(LastVirtReg);
|
|
ImplicitDefed.resize(LastVirtReg-TargetRegisterInfo::FirstVirtualRegister+1);
|
|
}
|
|
|
|
unsigned VirtRegMap::getRegAllocPref(unsigned virtReg) {
|
|
std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(virtReg);
|
|
unsigned physReg = Hint.second;
|
|
if (physReg &&
|
|
TargetRegisterInfo::isVirtualRegister(physReg) && hasPhys(physReg))
|
|
physReg = getPhys(physReg);
|
|
if (Hint.first == 0)
|
|
return (physReg && TargetRegisterInfo::isPhysicalRegister(physReg))
|
|
? physReg : 0;
|
|
return TRI->ResolveRegAllocHint(Hint.first, physReg, *MF);
|
|
}
|
|
|
|
int VirtRegMap::assignVirt2StackSlot(unsigned virtReg) {
|
|
assert(TargetRegisterInfo::isVirtualRegister(virtReg));
|
|
assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT &&
|
|
"attempt to assign stack slot to already spilled register");
|
|
const TargetRegisterClass* RC = MF->getRegInfo().getRegClass(virtReg);
|
|
int SS = MF->getFrameInfo()->CreateSpillStackObject(RC->getSize(),
|
|
RC->getAlignment());
|
|
if (LowSpillSlot == NO_STACK_SLOT)
|
|
LowSpillSlot = SS;
|
|
if (HighSpillSlot == NO_STACK_SLOT || SS > HighSpillSlot)
|
|
HighSpillSlot = SS;
|
|
unsigned Idx = SS-LowSpillSlot;
|
|
while (Idx >= SpillSlotToUsesMap.size())
|
|
SpillSlotToUsesMap.resize(SpillSlotToUsesMap.size()*2);
|
|
Virt2StackSlotMap[virtReg] = SS;
|
|
++NumSpills;
|
|
return SS;
|
|
}
|
|
|
|
void VirtRegMap::assignVirt2StackSlot(unsigned virtReg, int SS) {
|
|
assert(TargetRegisterInfo::isVirtualRegister(virtReg));
|
|
assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT &&
|
|
"attempt to assign stack slot to already spilled register");
|
|
assert((SS >= 0 ||
|
|
(SS >= MF->getFrameInfo()->getObjectIndexBegin())) &&
|
|
"illegal fixed frame index");
|
|
Virt2StackSlotMap[virtReg] = SS;
|
|
}
|
|
|
|
int VirtRegMap::assignVirtReMatId(unsigned virtReg) {
|
|
assert(TargetRegisterInfo::isVirtualRegister(virtReg));
|
|
assert(Virt2ReMatIdMap[virtReg] == NO_STACK_SLOT &&
|
|
"attempt to assign re-mat id to already spilled register");
|
|
Virt2ReMatIdMap[virtReg] = ReMatId;
|
|
return ReMatId++;
|
|
}
|
|
|
|
void VirtRegMap::assignVirtReMatId(unsigned virtReg, int id) {
|
|
assert(TargetRegisterInfo::isVirtualRegister(virtReg));
|
|
assert(Virt2ReMatIdMap[virtReg] == NO_STACK_SLOT &&
|
|
"attempt to assign re-mat id to already spilled register");
|
|
Virt2ReMatIdMap[virtReg] = id;
|
|
}
|
|
|
|
int VirtRegMap::getEmergencySpillSlot(const TargetRegisterClass *RC) {
|
|
std::map<const TargetRegisterClass*, int>::iterator I =
|
|
EmergencySpillSlots.find(RC);
|
|
if (I != EmergencySpillSlots.end())
|
|
return I->second;
|
|
int SS = MF->getFrameInfo()->CreateSpillStackObject(RC->getSize(),
|
|
RC->getAlignment());
|
|
if (LowSpillSlot == NO_STACK_SLOT)
|
|
LowSpillSlot = SS;
|
|
if (HighSpillSlot == NO_STACK_SLOT || SS > HighSpillSlot)
|
|
HighSpillSlot = SS;
|
|
EmergencySpillSlots[RC] = SS;
|
|
return SS;
|
|
}
|
|
|
|
void VirtRegMap::addSpillSlotUse(int FI, MachineInstr *MI) {
|
|
if (!MF->getFrameInfo()->isFixedObjectIndex(FI)) {
|
|
// If FI < LowSpillSlot, this stack reference was produced by
|
|
// instruction selection and is not a spill
|
|
if (FI >= LowSpillSlot) {
|
|
assert(FI >= 0 && "Spill slot index should not be negative!");
|
|
assert((unsigned)FI-LowSpillSlot < SpillSlotToUsesMap.size()
|
|
&& "Invalid spill slot");
|
|
SpillSlotToUsesMap[FI-LowSpillSlot].insert(MI);
|
|
}
|
|
}
|
|
}
|
|
|
|
void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *OldMI,
|
|
MachineInstr *NewMI, ModRef MRInfo) {
|
|
// Move previous memory references folded to new instruction.
|
|
MI2VirtMapTy::iterator IP = MI2VirtMap.lower_bound(NewMI);
|
|
for (MI2VirtMapTy::iterator I = MI2VirtMap.lower_bound(OldMI),
|
|
E = MI2VirtMap.end(); I != E && I->first == OldMI; ) {
|
|
MI2VirtMap.insert(IP, std::make_pair(NewMI, I->second));
|
|
MI2VirtMap.erase(I++);
|
|
}
|
|
|
|
// add new memory reference
|
|
MI2VirtMap.insert(IP, std::make_pair(NewMI, std::make_pair(VirtReg, MRInfo)));
|
|
}
|
|
|
|
void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *MI, ModRef MRInfo) {
|
|
MI2VirtMapTy::iterator IP = MI2VirtMap.lower_bound(MI);
|
|
MI2VirtMap.insert(IP, std::make_pair(MI, std::make_pair(VirtReg, MRInfo)));
|
|
}
|
|
|
|
void VirtRegMap::RemoveMachineInstrFromMaps(MachineInstr *MI) {
|
|
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
|
|
MachineOperand &MO = MI->getOperand(i);
|
|
if (!MO.isFI())
|
|
continue;
|
|
int FI = MO.getIndex();
|
|
if (MF->getFrameInfo()->isFixedObjectIndex(FI))
|
|
continue;
|
|
// This stack reference was produced by instruction selection and
|
|
// is not a spill
|
|
if (FI < LowSpillSlot)
|
|
continue;
|
|
assert((unsigned)FI-LowSpillSlot < SpillSlotToUsesMap.size()
|
|
&& "Invalid spill slot");
|
|
SpillSlotToUsesMap[FI-LowSpillSlot].erase(MI);
|
|
}
|
|
MI2VirtMap.erase(MI);
|
|
SpillPt2VirtMap.erase(MI);
|
|
RestorePt2VirtMap.erase(MI);
|
|
EmergencySpillMap.erase(MI);
|
|
}
|
|
|
|
/// FindUnusedRegisters - Gather a list of allocatable registers that
|
|
/// have not been allocated to any virtual register.
|
|
bool VirtRegMap::FindUnusedRegisters(LiveIntervals* LIs) {
|
|
unsigned NumRegs = TRI->getNumRegs();
|
|
UnusedRegs.reset();
|
|
UnusedRegs.resize(NumRegs);
|
|
|
|
BitVector Used(NumRegs);
|
|
for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
|
|
e = MF->getRegInfo().getLastVirtReg(); i <= e; ++i)
|
|
if (Virt2PhysMap[i] != (unsigned)VirtRegMap::NO_PHYS_REG)
|
|
Used.set(Virt2PhysMap[i]);
|
|
|
|
BitVector Allocatable = TRI->getAllocatableSet(*MF);
|
|
bool AnyUnused = false;
|
|
for (unsigned Reg = 1; Reg < NumRegs; ++Reg) {
|
|
if (Allocatable[Reg] && !Used[Reg] && !LIs->hasInterval(Reg)) {
|
|
bool ReallyUnused = true;
|
|
for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
|
|
if (Used[*AS] || LIs->hasInterval(*AS)) {
|
|
ReallyUnused = false;
|
|
break;
|
|
}
|
|
}
|
|
if (ReallyUnused) {
|
|
AnyUnused = true;
|
|
UnusedRegs.set(Reg);
|
|
}
|
|
}
|
|
}
|
|
|
|
return AnyUnused;
|
|
}
|
|
|
|
void VirtRegMap::print(raw_ostream &OS, const Module* M) const {
|
|
const TargetRegisterInfo* TRI = MF->getTarget().getRegisterInfo();
|
|
|
|
OS << "********** REGISTER MAP **********\n";
|
|
for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
|
|
e = MF->getRegInfo().getLastVirtReg(); i <= e; ++i) {
|
|
if (Virt2PhysMap[i] != (unsigned)VirtRegMap::NO_PHYS_REG)
|
|
OS << "[reg" << i << " -> " << TRI->getName(Virt2PhysMap[i])
|
|
<< "]\n";
|
|
}
|
|
|
|
for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
|
|
e = MF->getRegInfo().getLastVirtReg(); i <= e; ++i)
|
|
if (Virt2StackSlotMap[i] != VirtRegMap::NO_STACK_SLOT)
|
|
OS << "[reg" << i << " -> fi#" << Virt2StackSlotMap[i] << "]\n";
|
|
OS << '\n';
|
|
}
|
|
|
|
void VirtRegMap::dump() const {
|
|
print(errs());
|
|
}
|