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Remove AsmThatEarlyClobber etc. from LiveIntervalAnalysis 

and redo as linked list walk.  Logic moved into RA.
Per review feedback.

llvm-svn: 56326
This commit is contained in:
Dale Johannesen 2008-09-19 01:02:35 +00:00
parent c25be3b2de
commit e519bd4183
5 changed files with 86 additions and 96 deletions
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9
llvm/include/llvm/CodeGen/LiveInterval.h
View File

@ -105,12 +105,17 @@ namespace llvm {
// if the top bits is set, it represents a stack slot.
unsigned preference; // preferred register to allocate for this interval
float weight; // weight of this interval
bool isEarlyClobber;
bool overlapsEarlyClobber;
Ranges ranges; // the ranges in which this register is live
VNInfoList valnos; // value#'s
public:
LiveInterval(unsigned Reg, float Weight, bool IsSS = false)
: reg(Reg), preference(0), weight(Weight) {
LiveInterval(unsigned Reg, float Weight, bool IsSS = false,
bool IsEarlyClobber = false, bool OverlapsEarlyClobber = false)
: reg(Reg), preference(0), weight(Weight),
isEarlyClobber(IsEarlyClobber),
overlapsEarlyClobber(OverlapsEarlyClobber) {
if (IsSS)
reg = reg | (1U << (sizeof(unsigned)*8-1));
}

21
llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h
View File

@ -65,22 +65,6 @@ namespace llvm {
AliasAnalysis *aa_;
LiveVariables* lv_;
/// AsmsWithEarlyClobber - maps a virtual register number to all the
/// inline asm's that have the register marked earlyclobber.
///
std::multimap<unsigned, MachineInstr*> AsmsThatEarlyClobber;
/// AsmsWithEarlyClobberConflict - maps a virtual register number
/// to all the inline asm's that have earlyclobber operands elsewhere
/// and use the register as a (non-earlyclobber) input.
///
/// Note: earlyclobber operands may not be assigned the same register as
/// each other, or as earlyclobber-conflict operands. However two
/// earlyclobber-conflict operands may be assigned the same register if
/// they happen to contain the same value.
///
std::multimap<unsigned, MachineInstr*> AsmsWithEarlyClobberConflict;
/// Special pool allocator for VNInfo's (LiveInterval val#).
///
BumpPtrAllocator VNInfoAllocator;
@ -353,11 +337,6 @@ namespace llvm {
unsigned getNumConflictsWithPhysReg(const LiveInterval &li,
unsigned PhysReg) const;
/// noEarlyclobberConflict - see whether virtual reg VReg has a conflict
/// with hard reg HReg because HReg is used as an earlyclobber register in
/// asm that also has VReg live into or across it.
bool noEarlyclobberConflict(unsigned VReg, VirtRegMap &vrm, unsigned HReg);
/// computeNumbering - Compute the index numbering.
void computeNumbering();

4
llvm/lib/CodeGen/LiveInterval.cpp
View File

@ -686,6 +686,10 @@ void LiveInterval::print(std::ostream &OS,
OS << "%reg" << reg;
OS << ',' << weight;
if (isEarlyClobber)
OS << ",earlyclobber";
if (overlapsEarlyClobber)
OS << ",overlapsearly";
if (empty())
OS << " EMPTY";

75
llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
View File

@ -674,8 +674,6 @@ exit:
/// live interval is an interval [i, j) where 1 <= i <= j < N for
/// which a variable is live
void LiveIntervals::computeIntervals() {
AsmsThatEarlyClobber.clear();
AsmsWithEarlyClobberConflict.clear();
DOUT << "********** COMPUTING LIVE INTERVALS **********\n"
<< "********** Function: "
@ -716,13 +714,15 @@ void LiveIntervals::computeIntervals() {
if (MO.isRegister() && MO.getReg() && MO.isDef()) {
handleRegisterDef(MBB, MI, MIIndex, MO, i);
if (MO.isEarlyClobber()) {
AsmsThatEarlyClobber.insert(std::make_pair(MO.getReg(), MI));
LiveInterval &interval = getOrCreateInterval(MO.getReg());
interval.isEarlyClobber = true;
}
}
if (MO.isRegister() && !MO.isDef() &&
MO.getReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg()) &&
MO.overlapsEarlyClobber()) {
AsmsWithEarlyClobberConflict.insert(std::make_pair(MO.getReg(), MI));
LiveInterval &interval = getOrCreateInterval(MO.getReg());
interval.overlapsEarlyClobber = true;
}
}
@ -752,73 +752,6 @@ bool LiveIntervals::findLiveInMBBs(const LiveRange &LR,
return ResVal;
}
/// noEarlyclobberConflict - see whether virtual reg VReg has a conflict with
/// hard reg HReg because of earlyclobbers.
///
/// Earlyclobber operands may not be assigned the same register as
/// each other, or as earlyclobber-conflict operands (i.e. those that
/// are non-earlyclobbered inputs to an asm that also has earlyclobbers).
///
/// Thus there are two cases to check for:
/// 1. VReg is an earlyclobber-conflict register and HReg is an earlyclobber
/// register in some asm that also has VReg as an input.
/// 2. VReg is an earlyclobber register and HReg is an earlyclobber-conflict
/// input elsewhere in some asm.
/// In both cases HReg can be assigned by the user, or assigned early in
/// register allocation.
///
/// Dropping the distinction between earlyclobber and earlyclobber-conflict,
/// keeping only one multimap, looks promising, but two earlyclobber-conflict
/// operands may be assigned the same register if they happen to contain the
/// same value, and that implementation would prevent this.
///
bool LiveIntervals::noEarlyclobberConflict(unsigned VReg, VirtRegMap &vrm,
unsigned HReg) {
typedef std::multimap<unsigned, MachineInstr*>::iterator It;
// Short circuit the most common case.
if (AsmsWithEarlyClobberConflict.size()!=0) {
std::pair<It, It> x = AsmsWithEarlyClobberConflict.equal_range(VReg);
for (It I = x.first; I!=x.second; I++) {
MachineInstr* MI = I->second;
for (int i = MI->getNumOperands() - 1; i >= 0; --i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.isEarlyClobber()) {
unsigned PhysReg = MO.getReg();
if (PhysReg && TargetRegisterInfo::isVirtualRegister(PhysReg)) {
if (!vrm.hasPhys(PhysReg))
continue;
PhysReg = vrm.getPhys(PhysReg);
}
if (PhysReg==HReg)
return false;
}
}
}
}
// Short circuit the most common case.
if (AsmsThatEarlyClobber.size()!=0) {
std::pair<It, It> x = AsmsThatEarlyClobber.equal_range(VReg);
for (It I = x.first; I!=x.second; I++) {
MachineInstr* MI = I->second;
for (int i = MI->getNumOperands() - 1; i >= 0; --i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.overlapsEarlyClobber()) {
unsigned PhysReg = MO.getReg();
if (PhysReg && TargetRegisterInfo::isVirtualRegister(PhysReg)) {
if (!vrm.hasPhys(PhysReg))
continue;
PhysReg = vrm.getPhys(PhysReg);
}
if (PhysReg==HReg)
return false;
}
}
}
}
return true;
}
LiveInterval* LiveIntervals::createInterval(unsigned reg) {
float Weight = TargetRegisterInfo::isPhysicalRegister(reg) ?
HUGE_VALF : 0.0F;

73
llvm/lib/CodeGen/RegAllocLinearScan.cpp
View File

@ -173,6 +173,8 @@ namespace {
void ComputeRelatedRegClasses();
bool noEarlyClobberConflict(LiveInterval *cur, unsigned RegNo);
template <typename ItTy>
void printIntervals(const char* const str, ItTy i, ItTy e) const {
if (str) DOUT << str << " intervals:\n";
@ -1001,6 +1003,73 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur)
unhandled_.push(added[i]);
}
/// noEarlyClobberConflict - see whether LiveInternal cur has a conflict with
/// hard reg HReg because of earlyclobbers.
///
/// Earlyclobber operands may not be assigned the same register as
/// each other, or as earlyclobber-conflict operands (i.e. those that
/// are non-earlyclobbered inputs to an asm that also has earlyclobbers).
///
/// Thus there are two cases to check for:
/// 1. cur->reg is an earlyclobber-conflict register and HReg is an
/// earlyclobber register in some asm that also has cur->reg as an input.
/// 2. cur->reg is an earlyclobber register and HReg is an
/// earlyclobber-conflict input, or a different earlyclobber register,
/// elsewhere in some asm.
/// In both cases HReg can be assigned by the user, or assigned early in
/// register allocation.
///
/// Dropping the distinction between earlyclobber and earlyclobber-conflict,
/// keeping only one bit, looks promising, but two earlyclobber-conflict
/// operands may be assigned the same register if they happen to contain the
/// same value, and that implementation would prevent this.
///
bool RALinScan::noEarlyClobberConflict(LiveInterval *cur, unsigned HReg) {
if (cur->overlapsEarlyClobber) {
for (MachineRegisterInfo::use_iterator I = mri_->use_begin(cur->reg),
E = mri_->use_end(); I!=E; ++I) {
MachineInstr *MI = I.getOperand().getParent();
if (MI->getOpcode()==TargetInstrInfo::INLINEASM) {
for (int i = MI->getNumOperands()-1; i>=0; --i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.getReg() && MO.isEarlyClobber() &&
HReg==MO.getReg()) {
DOUT << " earlyclobber conflict: " <<
"%reg" << cur->reg << ", " << tri_->getName(HReg) << "\n\t";
return false;
}
}
}
}
}
if (cur->isEarlyClobber) {
for (MachineRegisterInfo::def_iterator I = mri_->def_begin(cur->reg),
E = mri_->def_end(); I!=E; ++I) {
MachineInstr *MI = I.getOperand().getParent();
if (MI->getOpcode()==TargetInstrInfo::INLINEASM) {
// make sure cur->reg is really clobbered in this instruction.
bool earlyClobberFound = false, overlapFound = false;
for (int i = MI->getNumOperands()-1; i>=0; --i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isRegister() && MO.getReg()) {
if ((MO.overlapsEarlyClobber() || MO.isEarlyClobber()) &&
HReg==MO.getReg())
overlapFound = true;
if (MO.isEarlyClobber() && cur->reg==MO.getReg())
earlyClobberFound = true;
}
}
if (earlyClobberFound && overlapFound) {
DOUT << " earlyclobber conflict: " <<
"%reg" << cur->reg << ", " << tri_->getName(HReg) << "\n\t";
return false;
}
}
}
}
return true;
}
/// getFreePhysReg - return a free physical register for this virtual register
/// interval if we have one, otherwise return 0.
unsigned RALinScan::getFreePhysReg(LiveInterval *cur) {
@ -1049,7 +1118,7 @@ unsigned RALinScan::getFreePhysReg(LiveInterval *cur) {
assert(I != E && "No allocatable register in this register class!");
for (; I != E; ++I)
if (prt_->isRegAvail(*I) &&
li_->noEarlyclobberConflict(cur->reg, *vrm_, *I)) {
noEarlyClobberConflict(cur, *I)) {
FreeReg = *I;
if (FreeReg < inactiveCounts.size())
FreeRegInactiveCount = inactiveCounts[FreeReg];
@ -1070,7 +1139,7 @@ unsigned RALinScan::getFreePhysReg(LiveInterval *cur) {
unsigned Reg = *I;
if (prt_->isRegAvail(Reg) && Reg < inactiveCounts.size() &&
FreeRegInactiveCount < inactiveCounts[Reg] &&
li_->noEarlyclobberConflict(cur->reg, *vrm_, Reg)) {
noEarlyClobberConflict(cur, *I)) {
FreeReg = Reg;
FreeRegInactiveCount = inactiveCounts[Reg];
if (FreeRegInactiveCount == MaxInactiveCount)