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Use an explicit LiveRange class to represent ranges instead of an std::pair.
This is a minor cleanup, but is really intended to make a future patch simpler
and less invasive.

Alkis, could you please take a look at LiveInterval::liveAt?  I suspect that
you can add an operator<(unsigned) to LiveRange, allowing us to speed up the
upper_bound call by quite a bit (this would also apply to other callers of
upper/lower_bound).  I would do it myself, but I still don't understand that
crazy liveAt function, despite the comment. :)

Basically I would like to see this:
    LiveRange dummy(index, index+1);
    Ranges::const_iterator r = std::upper_bound(ranges.begin(),
                                                ranges.end(),
                                                dummy);

Turn into:
    Ranges::const_iterator r = std::upper_bound(ranges.begin(),
                                                ranges.end(),
                                                index);


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@15130 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-07-23 08:24:23 +00:00
parent 5c2e282865
commit ec2bc64505
3 changed files with 101 additions and 60 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
include/llvm/CodeGen/LiveIntervalAnalysis.h
View File

@ -29,9 +29,29 @@ namespace llvm {
class MRegisterInfo;
class VirtRegMap;
/// LiveRange structure - This represents a simple register range in the
/// program, with an inclusive start point and an exclusive end point.
/// These ranges are rendered as [start,end).
struct LiveRange {
unsigned start; // Start point of the interval (inclusive)
unsigned end; // End point of the interval (exclusive)
LiveRange(unsigned S, unsigned E) : start(S), end(E) {
assert(S < E && "Cannot create empty or backwards range");
}
bool operator<(const LiveRange &LR) const {
return start < LR.start || (start == LR.start && end < LR.end);
}
bool operator==(const LiveRange &LR) const {
return start == LR.start && end == LR.end;
}
private:
LiveRange(); // DO NOT IMPLEMENT
};
std::ostream& operator<<(std::ostream& os, const LiveRange &LR);
struct LiveInterval {
typedef std::pair<unsigned, unsigned> Range;
typedef std::vector<Range> Ranges;
typedef std::vector<LiveRange> Ranges;
unsigned reg; // the register of this interval
float weight; // weight of this interval:
// (number of uses *10^loopDepth)
@ -44,14 +64,17 @@ namespace llvm {
bool spilled() const;
/// start - Return the lowest numbered slot covered by interval.
unsigned start() const {
assert(!empty() && "empty interval for register");
return ranges.front().first;
return ranges.front().start;
}
/// end - return the maximum point of the interval of the whole,
/// exclusive.
unsigned end() const {
assert(!empty() && "empty interval for register");
return ranges.back().second;
return ranges.back().end;
}
bool expiredAt(unsigned index) const {
@ -62,7 +85,7 @@ namespace llvm {
bool overlaps(const LiveInterval& other) const;
void addRange(unsigned start, unsigned end);
void addRange(LiveRange R);
void join(const LiveInterval& other);

95
lib/CodeGen/LiveIntervalAnalysis.cpp
View File

@ -194,8 +194,8 @@ std::vector<LiveInterval*> LiveIntervals::addIntervalsForSpills(
for (LiveInterval::Ranges::const_iterator
i = li.ranges.begin(), e = li.ranges.end(); i != e; ++i) {
unsigned index = getBaseIndex(i->first);
unsigned end = getBaseIndex(i->second-1) + InstrSlots::NUM;
unsigned index = getBaseIndex(i->start);
unsigned end = getBaseIndex(i->end-1) + InstrSlots::NUM;
for (; index != end; index += InstrSlots::NUM) {
// skip deleted instructions
while (index != end && !getInstructionFromIndex(index))
@ -250,7 +250,7 @@ std::vector<LiveInterval*> LiveIntervals::addIntervalsForSpills(
// the spill weight is now infinity as it
// cannot be spilled again
nI.weight = HUGE_VAL;
nI.addRange(start, end);
nI.addRange(LiveRange(start, end));
added.push_back(&nI);
// update live variables
lv_->addVirtualRegisterKilled(nReg, mi);
@ -308,7 +308,7 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
if (killIdx > defIndex) {
assert(vi.AliveBlocks.empty() &&
"Shouldn't be alive across any blocks!");
interval.addRange(defIndex, killIdx);
interval.addRange(LiveRange(defIndex, killIdx));
DEBUG(std::cerr << "\n");
return;
}
@ -318,8 +318,9 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
// of the defining block, potentially live across some blocks, then is
// live into some number of blocks, but gets killed. Start by adding a
// range that goes from this definition to the end of the defining block.
interval.addRange(defIndex,
getInstructionIndex(&mbb->back()) + InstrSlots::NUM);
interval.addRange(LiveRange(defIndex,
getInstructionIndex(&mbb->back()) +
InstrSlots::NUM));
// Iterate over all of the blocks that the variable is completely
// live in, adding [insrtIndex(begin), instrIndex(end)+4) to the
@ -328,9 +329,9 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
if (vi.AliveBlocks[i]) {
MachineBasicBlock* mbb = mf_->getBlockNumbered(i);
if (!mbb->empty()) {
interval.addRange(
interval.addRange(LiveRange(
getInstructionIndex(&mbb->front()),
getInstructionIndex(&mbb->back()) + InstrSlots::NUM);
getInstructionIndex(&mbb->back()) + InstrSlots::NUM));
}
}
}
@ -339,8 +340,9 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
// block to the 'use' slot of the killing instruction.
for (unsigned i = 0, e = vi.Kills.size(); i != e; ++i) {
MachineInstr *Kill = vi.Kills[i];
interval.addRange(getInstructionIndex(Kill->getParent()->begin()),
getUseIndex(getInstructionIndex(Kill))+1);
interval.addRange(LiveRange(
getInstructionIndex(Kill->getParent()->begin()),
getUseIndex(getInstructionIndex(Kill))+1));
}
} else {
@ -357,8 +359,8 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock* mbb,
// the defined value will be live until the end of the basic block it
// is defined in.
unsigned defIndex = getDefIndex(getInstructionIndex(mi));
interval.addRange(defIndex,
getInstructionIndex(&mbb->back()) + InstrSlots::NUM);
interval.addRange(LiveRange(defIndex,
getInstructionIndex(&mbb->back()) +InstrSlots::NUM));
}
interval.isDefinedOnce = false;
}
@ -410,7 +412,7 @@ void LiveIntervals::handlePhysicalRegisterDef(MachineBasicBlock* mbb,
exit:
assert(start < end && "did not find end of interval?");
interval.addRange(start, end);
interval.addRange(LiveRange(start, end));
DEBUG(std::cerr << '\n');
}
@ -682,7 +684,7 @@ bool LiveInterval::spilled() const
//
bool LiveInterval::liveAt(unsigned index) const
{
Range dummy(index, index+1);
LiveRange dummy(index, index+1);
Ranges::const_iterator r = std::upper_bound(ranges.begin(),
ranges.end(),
dummy);
@ -690,7 +692,7 @@ bool LiveInterval::liveAt(unsigned index) const
return false;
--r;
return index >= r->first && index < r->second;
return index >= r->start && index < r->end;
}
// An example for overlaps():
@ -713,50 +715,39 @@ bool LiveInterval::overlaps(const LiveInterval& other) const
Ranges::const_iterator ie = ranges.end();
Ranges::const_iterator j = other.ranges.begin();
Ranges::const_iterator je = other.ranges.end();
if (i->first < j->first) {
if (i->start < j->start) {
i = std::upper_bound(i, ie, *j);
if (i != ranges.begin()) --i;
}
else if (j->first < i->first) {
else if (j->start < i->start) {
j = std::upper_bound(j, je, *i);
if (j != other.ranges.begin()) --j;
}
while (i != ie && j != je) {
if (i->first == j->first) {
if (i->start == j->start)
return true;
}
else {
if (i->first > j->first) {
swap(i, j);
swap(ie, je);
}
assert(i->first < j->first);
if (i->second > j->first) {
return true;
}
else {
++i;
}
if (i->start > j->start) {
swap(i, j);
swap(ie, je);
}
assert(i->start < j->start);
if (i->end > j->start)
return true;
++i;
}
return false;
}
void LiveInterval::addRange(unsigned start, unsigned end)
{
assert(start < end && "Invalid range to add!");
DEBUG(std::cerr << " +[" << start << ',' << end << ")");
//assert(start < end && "invalid range?");
Range range = std::make_pair(start, end);
void LiveInterval::addRange(LiveRange LR) {
DEBUG(std::cerr << " +" << LR);
Ranges::iterator it =
ranges.insert(std::upper_bound(ranges.begin(), ranges.end(), range),
range);
ranges.insert(std::upper_bound(ranges.begin(), ranges.end(), LR), LR);
it = mergeRangesForward(it);
it = mergeRangesBackward(it);
mergeRangesBackward(mergeRangesForward(it));
}
void LiveInterval::join(const LiveInterval& other)
@ -779,9 +770,9 @@ mergeRangesForward(Ranges::iterator it)
{
Ranges::iterator n;
while ((n = next(it)) != ranges.end()) {
if (n->first > it->second)
if (n->start > it->end)
break;
it->second = std::max(it->second, n->second);
it->end = std::max(it->end, n->end);
n = ranges.erase(n);
}
return it;
@ -792,17 +783,22 @@ mergeRangesBackward(Ranges::iterator it)
{
while (it != ranges.begin()) {
Ranges::iterator p = prior(it);
if (it->first > p->second)
if (it->start > p->end)
break;
it->first = std::min(it->first, p->first);
it->second = std::max(it->second, p->second);
it->start = std::min(it->start, p->start);
it->end = std::max(it->end, p->end);
it = ranges.erase(p);
}
return it;
}
std::ostream& llvm::operator<<(std::ostream& os, const LiveRange &LR) {
return os << "[" << LR.start << "," << LR.end << ")";
}
std::ostream& llvm::operator<<(std::ostream& os, const LiveInterval& li)
{
os << "%reg" << li.reg << ',' << li.weight;
@ -810,9 +806,8 @@ std::ostream& llvm::operator<<(std::ostream& os, const LiveInterval& li)
return os << "EMPTY";
os << " = ";
for (LiveInterval::Ranges::const_iterator
i = li.ranges.begin(), e = li.ranges.end(); i != e; ++i) {
os << "[" << i->first << "," << i->second << ")";
}
for (LiveInterval::Ranges::const_iterator i = li.ranges.begin(),
e = li.ranges.end(); i != e; ++i)
os << *i;
return os;
}

33
lib/CodeGen/LiveIntervalAnalysis.h
View File

@ -29,9 +29,29 @@ namespace llvm {
class MRegisterInfo;
class VirtRegMap;
/// LiveRange structure - This represents a simple register range in the
/// program, with an inclusive start point and an exclusive end point.
/// These ranges are rendered as [start,end).
struct LiveRange {
unsigned start; // Start point of the interval (inclusive)
unsigned end; // End point of the interval (exclusive)
LiveRange(unsigned S, unsigned E) : start(S), end(E) {
assert(S < E && "Cannot create empty or backwards range");
}
bool operator<(const LiveRange &LR) const {
return start < LR.start || (start == LR.start && end < LR.end);
}
bool operator==(const LiveRange &LR) const {
return start == LR.start && end == LR.end;
}
private:
LiveRange(); // DO NOT IMPLEMENT
};
std::ostream& operator<<(std::ostream& os, const LiveRange &LR);
struct LiveInterval {
typedef std::pair<unsigned, unsigned> Range;
typedef std::vector<Range> Ranges;
typedef std::vector<LiveRange> Ranges;
unsigned reg; // the register of this interval
float weight; // weight of this interval:
// (number of uses *10^loopDepth)
@ -44,14 +64,17 @@ namespace llvm {
bool spilled() const;
/// start - Return the lowest numbered slot covered by interval.
unsigned start() const {
assert(!empty() && "empty interval for register");
return ranges.front().first;
return ranges.front().start;
}
/// end - return the maximum point of the interval of the whole,
/// exclusive.
unsigned end() const {
assert(!empty() && "empty interval for register");
return ranges.back().second;
return ranges.back().end;
}
bool expiredAt(unsigned index) const {
@ -62,7 +85,7 @@ namespace llvm {
bool overlaps(const LiveInterval& other) const;
void addRange(unsigned start, unsigned end);
void addRange(LiveRange R);
void join(const LiveInterval& other);