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Handle multiple virtual register definitions gracefully. 

Move some of the longer LiveIntervals::Interval method out of the
header and add debug information to them. Fix bug and simplify range
merging code.

llvm-svn: 10509
This commit is contained in:
Alkis Evlogimenos 2003-12-18 08:48:48 +00:00
parent b3fdf83d17
commit 40874c708f
2 changed files with 71 additions and 98 deletions
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51
llvm/include/llvm/CodeGen/LiveIntervals.h
View File

@ -59,55 +59,12 @@ namespace llvm {
return end() <= index;
}
bool overlaps(unsigned index) const {
for (Ranges::const_iterator
i = ranges.begin(), e = ranges.end(); i != e; ++i) {
if (index >= i->first && index < i->second) {
return true;
}
}
return false;
}
void addRange(unsigned start, unsigned end) {
Range range = std::make_pair(start, end);
Ranges::iterator it =
std::lower_bound(ranges.begin(), ranges.end(), range);
if (it == ranges.end()) {
it = ranges.insert(it, range);
goto exit;
}
assert(range.first <= it->first && "got wrong iterator?");
// merge ranges if necesary
if (range.first < it->first) {
if (range.second >= it->first) {
it->first = range.first;
}
else {
it = ranges.insert(it, range);
assert(it != ranges.end() && "wtf?");
goto exit;
}
}
exit:
mergeRangesIfNecessary(it);
}
void addRange(unsigned start, unsigned end);
private:
void mergeRangesIfNecessary(Ranges::iterator it) {
while (it != ranges.begin()) {
Ranges::iterator prev = it - 1;
if (prev->second < it->first) {
break;
}
prev->second = it->second;
ranges.erase(it);
it = prev;
}
}
void mergeRangesForward(Ranges::iterator it);
void mergeRangesBackward(Ranges::iterator it);
};
struct StartPointComp {

118
llvm/lib/CodeGen/LiveIntervals.cpp
View File

@ -122,60 +122,46 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
LiveVariables::VarInfo& vi = lv_->getVarInfo(reg);
Interval* interval = 0;
Reg2IntervalMap::iterator r2iit = r2iMap_.find(reg);
// handle multiple definition case (machine instructions violating
// ssa after phi-elimination
if (r2iit != r2iMap_.end()) {
unsigned ii = r2iit->second;
Interval& interval = intervals_[ii];
unsigned end = getInstructionIndex(mbb->back()) + 1;
DEBUG(std::cerr << "\t\t\t\tadding range: ["
<< instrIndex << ',' << end << "]\n");
interval.addRange(instrIndex, end);
DEBUG(std::cerr << "\t\t\t\t" << interval << '\n');
}
else {
if (r2iit == r2iMap_.end()) {
// add new interval
intervals_.push_back(Interval(reg));
Interval& interval = intervals_.back();
// update interval index for this register
r2iMap_[reg] = intervals_.size() - 1;
interval = &intervals_.back();
}
else {
interval = &intervals_[r2iit->second];
}
for (MbbIndex2MbbMap::iterator
it = mbbi2mbbMap_.begin(), itEnd = mbbi2mbbMap_.end();
it != itEnd; ++it) {
unsigned liveBlockIndex = it->first;
MachineBasicBlock* liveBlock = it->second;
if (liveBlockIndex < vi.AliveBlocks.size() &&
vi.AliveBlocks[liveBlockIndex]) {
unsigned start = getInstructionIndex(liveBlock->front());
unsigned end = getInstructionIndex(liveBlock->back()) + 1;
DEBUG(std::cerr << "\t\t\t\tadding range: ["
<< start << ',' << end << "]\n");
interval.addRange(start, end);
}
for (MbbIndex2MbbMap::iterator
it = mbbi2mbbMap_.begin(), itEnd = mbbi2mbbMap_.end();
it != itEnd; ++it) {
unsigned liveBlockIndex = it->first;
MachineBasicBlock* liveBlock = it->second;
if (liveBlockIndex < vi.AliveBlocks.size() &&
vi.AliveBlocks[liveBlockIndex]) {
unsigned start = getInstructionIndex(liveBlock->front());
unsigned end = getInstructionIndex(liveBlock->back()) + 1;
interval->addRange(start, end);
}
}
bool killedInDefiningBasicBlock = false;
for (int i = 0, e = vi.Kills.size(); i != e; ++i) {
MachineBasicBlock* killerBlock = vi.Kills[i].first;
MachineInstr* killerInstr = vi.Kills[i].second;
killedInDefiningBasicBlock |= mbb == killerBlock;
unsigned start = (mbb == killerBlock ?
instrIndex :
getInstructionIndex(killerBlock->front()));
unsigned end = getInstructionIndex(killerInstr) + 1;
DEBUG(std::cerr << "\t\t\t\tadding range: ["
<< start << ',' << end << "]\n");
interval.addRange(start, end);
}
bool killedInDefiningBasicBlock = false;
for (int i = 0, e = vi.Kills.size(); i != e; ++i) {
MachineBasicBlock* killerBlock = vi.Kills[i].first;
MachineInstr* killerInstr = vi.Kills[i].second;
killedInDefiningBasicBlock |= mbb == killerBlock;
unsigned start = (mbb == killerBlock ?
instrIndex :
getInstructionIndex(killerBlock->front()));
unsigned end = getInstructionIndex(killerInstr) + 1;
}
if (!killedInDefiningBasicBlock) {
unsigned end = getInstructionIndex(mbb->back()) + 1;
interval.addRange(instrIndex, end);
}
DEBUG(std::cerr << "\t\t\t\t" << interval << '\n');
if (!killedInDefiningBasicBlock) {
unsigned end = getInstructionIndex(mbb->back()) + 1;
interval->addRange(instrIndex, end);
}
}
@ -220,20 +206,14 @@ exit:
if (r2iit != r2iMap_.end()) {
unsigned ii = r2iit->second;
Interval& interval = intervals_[ii];
DEBUG(std::cerr << "\t\t\t\tadding range: ["
<< start << ',' << end << "]\n");
interval.addRange(start, end);
DEBUG(std::cerr << "\t\t\t\t" << interval << '\n');
}
else {
intervals_.push_back(Interval(reg));
Interval& interval = intervals_.back();
// update interval index for this register
r2iMap_[reg] = intervals_.size() - 1;
DEBUG(std::cerr << "\t\t\t\tadding range: ["
<< start << ',' << end << "]\n");
interval.addRange(start, end);
DEBUG(std::cerr << "\t\t\t\t" << interval << '\n');
}
}
@ -310,6 +290,42 @@ void LiveIntervals::computeIntervals()
std::ostream_iterator<Interval>(std::cerr, "\n")));
}
void LiveIntervals::Interval::addRange(unsigned start, unsigned end)
{
DEBUG(std::cerr << "\t\t\t\tadding range: [" << start <<','<< end << "]\n");
//assert(start < end && "invalid range?");
Range range = std::make_pair(start, end);
Ranges::iterator it =
ranges.insert(std::upper_bound(ranges.begin(), ranges.end(), range),
range);
DEBUG(std::cerr << "\t\t\t\tbefore merge forward: " << *this << '\n');
mergeRangesForward(it);
DEBUG(std::cerr << "\t\t\t\tbefore merge backward: " << *this << '\n');
mergeRangesBackward(it);
DEBUG(std::cerr << "\t\t\t\tafter merging: " << *this << '\n');
}
void LiveIntervals::Interval::mergeRangesForward(Ranges::iterator it)
{
for (Ranges::iterator next = it + 1;
next != ranges.end() && it->second >= next->first; ) {
it->second = std::max(it->second, next->second);
next = ranges.erase(next);
}
}
void LiveIntervals::Interval::mergeRangesBackward(Ranges::iterator it)
{
for (Ranges::iterator prev = it - 1;
it != ranges.begin() && it->first <= prev->second; ) {
it->first = std::min(it->first, prev->first);
it->second = std::max(it->second, prev->second);
it = ranges.erase(prev);
prev = it - 1;
}
}
std::ostream& llvm::operator<<(std::ostream& os,
const LiveIntervals::Interval& li)
{