[llvm-commits] CVS: llvm/lib/CodeGen/RegAllocLinearScan.cpp
Alkis Evlogimenos
alkis at cs.uiuc.edu
Thu Jul 22 01:14:54 PDT 2004
Changes in directory llvm/lib/CodeGen:
RegAllocLinearScan.cpp updated: 1.81 -> 1.82
---
Log message:
Some compile time improvements resulting in a 1sec speedup in the 5sec
compilation of gcc:
* Use vectors instead of lists for the intervals sets
* Use a heap for the unhandled set to keep intervals always sorted and
makes insertions back to the heap very fast (compared to scanning a
list)
---
Diffs of the changes: (+53 -75)
Index: llvm/lib/CodeGen/RegAllocLinearScan.cpp
diff -u llvm/lib/CodeGen/RegAllocLinearScan.cpp:1.81 llvm/lib/CodeGen/RegAllocLinearScan.cpp:1.82
--- llvm/lib/CodeGen/RegAllocLinearScan.cpp:1.81 Wed Jul 21 15:50:33 2004
+++ llvm/lib/CodeGen/RegAllocLinearScan.cpp Thu Jul 22 03:14:44 2004
@@ -29,6 +29,7 @@
#include <algorithm>
#include <cmath>
#include <set>
+#include <queue>
using namespace llvm;
@@ -46,9 +47,12 @@
const TargetMachine* tm_;
const MRegisterInfo* mri_;
LiveIntervals* li_;
- typedef std::list<LiveInterval*> IntervalPtrs;
- IntervalPtrs unhandled_, fixed_, active_, inactive_, handled_;
-
+ typedef std::vector<LiveInterval*> IntervalPtrs;
+ IntervalPtrs handled_, fixed_, active_, inactive_;
+ typedef std::priority_queue<LiveInterval*,
+ IntervalPtrs,
+ greater_ptr<LiveInterval> > IntervalHeap;
+ IntervalHeap unhandled_;
std::auto_ptr<PhysRegTracker> prt_;
std::auto_ptr<VirtRegMap> vrm_;
std::auto_ptr<Spiller> spiller_;
@@ -82,11 +86,11 @@
/// processActiveIntervals - expire old intervals and move
/// non-overlapping ones to the incative list
- void processActiveIntervals(IntervalPtrs::value_type cur);
+ void processActiveIntervals(LiveInterval* cur);
/// processInactiveIntervals - expire old intervals and move
/// overlapping ones to the active list
- void processInactiveIntervals(IntervalPtrs::value_type cur);
+ void processInactiveIntervals(LiveInterval* cur);
/// updateSpillWeights - updates the spill weights of the
/// specifed physical register and its weight
@@ -94,7 +98,7 @@
/// assignRegOrStackSlotAtInterval - assign a register if one
/// is available, or spill.
- void assignRegOrStackSlotAtInterval(IntervalPtrs::value_type cur);
+ void assignRegOrStackSlotAtInterval(LiveInterval* cur);
///
/// register handling helpers
@@ -103,15 +107,14 @@
/// getFreePhysReg - return a free physical register for this
/// virtual register interval if we have one, otherwise return
/// 0
- unsigned getFreePhysReg(IntervalPtrs::value_type cur);
+ unsigned getFreePhysReg(LiveInterval* cur);
/// assignVirt2StackSlot - assigns this virtual register to a
/// stack slot. returns the stack slot
int assignVirt2StackSlot(unsigned virtReg);
- void printIntervals(const char* const str,
- RA::IntervalPtrs::const_iterator i,
- RA::IntervalPtrs::const_iterator e) const {
+ template <typename ItTy>
+ void printIntervals(const char* const str, ItTy i, ItTy e) const {
if (str) std::cerr << str << " intervals:\n";
for (; i != e; ++i) {
std::cerr << "\t" << **i << " -> ";
@@ -127,7 +130,7 @@
void RA::releaseMemory()
{
- unhandled_.clear();
+ while (!unhandled_.empty()) unhandled_.pop();
fixed_.clear();
active_.clear();
inactive_.clear();
@@ -159,15 +162,15 @@
DEBUG(std::cerr << "********** Function: "
<< mf_->getFunction()->getName() << '\n');
- DEBUG(printIntervals("unhandled", unhandled_.begin(), unhandled_.end()));
+ // DEBUG(printIntervals("unhandled", unhandled_.begin(), unhandled_.end()));
DEBUG(printIntervals("fixed", fixed_.begin(), fixed_.end()));
DEBUG(printIntervals("active", active_.begin(), active_.end()));
DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
while (!unhandled_.empty()) {
// pick the interval with the earliest start point
- IntervalPtrs::value_type cur = unhandled_.front();
- unhandled_.pop_front();
+ LiveInterval* cur = unhandled_.top();
+ unhandled_.pop();
++numIterations;
DEBUG(std::cerr << "\n*** CURRENT ***: " << *cur << '\n');
@@ -189,18 +192,26 @@
DEBUG(printIntervals("active", active_.begin(), active_.end()));
DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
- // DEBUG(verifyAssignment());
}
numIntervals += li_->getIntervals().size();
efficiency = double(numIterations) / double(numIntervals);
// expire any remaining active intervals
- for (IntervalPtrs::iterator i = active_.begin(); i != active_.end(); ++i) {
+ for (IntervalPtrs::reverse_iterator
+ i = active_.rbegin(); i != active_.rend(); ) {
unsigned reg = (*i)->reg;
DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
+ i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ }
+
+ // expire any remaining inactive intervals
+ for (IntervalPtrs::reverse_iterator
+ i = inactive_.rbegin(); i != inactive_.rend(); ) {
+ DEBUG(std::cerr << "\tinterval " << **i << " expired\n");
+ i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
}
DEBUG(std::cerr << *vrm_);
@@ -214,7 +225,7 @@
for (LiveIntervals::Intervals::iterator i = li.begin(), e = li.end();
i != e; ++i) {
- unhandled_.push_back(&*i);
+ unhandled_.push(&*i);
if (MRegisterInfo::isPhysicalRegister(i->reg))
fixed_.push_back(&*i);
}
@@ -223,7 +234,8 @@
void RA::processActiveIntervals(IntervalPtrs::value_type cur)
{
DEBUG(std::cerr << "\tprocessing active intervals:\n");
- for (IntervalPtrs::iterator i = active_.begin(); i != active_.end();) {
+ for (IntervalPtrs::reverse_iterator
+ i = active_.rbegin(); i != active_.rend();) {
unsigned reg = (*i)->reg;
// remove expired intervals
if ((*i)->expiredAt(cur->start())) {
@@ -232,7 +244,7 @@
reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
// remove from active
- i = active_.erase(i);
+ i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
}
// move inactive intervals to inactive list
else if (!(*i)->liveAt(cur->start())) {
@@ -243,7 +255,7 @@
// add to inactive
inactive_.push_back(*i);
// remove from active
- i = active_.erase(i);
+ i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
}
else {
++i;
@@ -254,14 +266,15 @@
void RA::processInactiveIntervals(IntervalPtrs::value_type cur)
{
DEBUG(std::cerr << "\tprocessing inactive intervals:\n");
- for (IntervalPtrs::iterator i = inactive_.begin(); i != inactive_.end();) {
+ for (IntervalPtrs::reverse_iterator
+ i = inactive_.rbegin(); i != inactive_.rend();) {
unsigned reg = (*i)->reg;
// remove expired intervals
if ((*i)->expiredAt(cur->start())) {
DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
// remove from inactive
- i = inactive_.erase(i);
+ i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
}
// move re-activated intervals in active list
else if ((*i)->liveAt(cur->start())) {
@@ -272,7 +285,7 @@
// add to active
active_.push_back(*i);
// remove from inactive
- i = inactive_.erase(i);
+ i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
}
else {
++i;
@@ -287,7 +300,7 @@
spillWeights_[*as] += weight;
}
-void RA::assignRegOrStackSlotAtInterval(IntervalPtrs::value_type cur)
+void RA::assignRegOrStackSlotAtInterval(LiveInterval* cur)
{
DEBUG(std::cerr << "\tallocating current interval: ");
@@ -370,47 +383,19 @@
li_->addIntervalsForSpills(*cur, *vrm_, slot);
if (added.empty())
return; // Early exit if all spills were folded.
-#ifndef NDEBUG
- int OldStart = -1;
-#endif
// Merge added with unhandled. Note that we know that
// addIntervalsForSpills returns intervals sorted by their starting
// point.
- std::vector<LiveInterval*>::iterator addedIt = added.begin();
- std::vector<LiveInterval*>::iterator addedItEnd = added.end();
- for (IntervalPtrs::iterator i = unhandled_.begin(), e =unhandled_.end();
- i != e && addedIt != addedItEnd; ++i) {
- while (addedIt != addedItEnd &&
- (*i)->start() > (*addedIt)->start()) {
-#ifndef NDEBUG
- // This code only works if addIntervalsForSpills retursn a
- // sorted interval list. Assert this is the case now.
- assert(OldStart <= (int)(*addedIt)->start() &&
- "addIntervalsForSpills didn't return sorted interval list!");
- OldStart = (*addedIt)->start();
-#endif
- i = unhandled_.insert(i, *(addedIt++));
- }
- }
-
- while (addedIt != addedItEnd) {
-#ifndef NDEBUG
- // This code only works if addIntervalsForSpills retursn a
- // sorted interval list. Assert this is the case now.
- assert(OldStart <= (int)(*addedIt)->start() &&
- "addIntervalsForSpills didn't return sorted interval list!");
- OldStart = (*addedIt)->start();
-#endif
- unhandled_.push_back(*(addedIt++));
- }
+ for (unsigned i = 0, e = added.size(); i != e; ++i)
+ unhandled_.push(added[i]);
return;
}
// push the current interval back to unhandled since we are going
// to re-run at least this iteration. Since we didn't modify it it
// should go back right in the front of the list
- unhandled_.push_front(cur);
+ unhandled_.push(cur);
// otherwise we spill all intervals aliasing the register with
// minimum weight, rollback to the interval with the earliest
@@ -426,7 +411,8 @@
std::set<unsigned> spilled;
- for (IntervalPtrs::iterator i = active_.begin(); i != active_.end(); ++i) {
+ for (IntervalPtrs::iterator
+ i = active_.begin(); i != active_.end(); ++i) {
unsigned reg = (*i)->reg;
if (MRegisterInfo::isVirtualRegister(reg) &&
toSpill[vrm_->getPhys(reg)] &&
@@ -440,8 +426,8 @@
spilled.insert(reg);
}
}
- for (IntervalPtrs::iterator i = inactive_.begin();
- i != inactive_.end(); ++i) {
+ for (IntervalPtrs::iterator
+ i = inactive_.begin(); i != inactive_.end(); ++i) {
unsigned reg = (*i)->reg;
if (MRegisterInfo::isVirtualRegister(reg) &&
toSpill[vrm_->getPhys(reg)] &&
@@ -460,7 +446,7 @@
// scan handled in reverse order and undo each one, restoring the
// state of unhandled
while (!handled_.empty()) {
- IntervalPtrs::value_type i = handled_.back();
+ LiveInterval* i = handled_.back();
// if this interval starts before t we are done
if (i->start() < earliestStart)
break;
@@ -471,11 +457,11 @@
active_.erase(it);
if (MRegisterInfo::isPhysicalRegister(i->reg)) {
prt_->delRegUse(i->reg);
- unhandled_.push_front(i);
+ unhandled_.push(i);
}
else {
if (!spilled.count(i->reg))
- unhandled_.push_front(i);
+ unhandled_.push(i);
prt_->delRegUse(vrm_->getPhys(i->reg));
vrm_->clearVirt(i->reg);
}
@@ -483,17 +469,17 @@
else if ((it = find(inactive_.begin(), inactive_.end(), i)) != inactive_.end()) {
inactive_.erase(it);
if (MRegisterInfo::isPhysicalRegister(i->reg))
- unhandled_.push_front(i);
+ unhandled_.push(i);
else {
if (!spilled.count(i->reg))
- unhandled_.push_front(i);
+ unhandled_.push(i);
vrm_->clearVirt(i->reg);
}
}
else {
if (MRegisterInfo::isVirtualRegister(i->reg))
vrm_->clearVirt(i->reg);
- unhandled_.push_front(i);
+ unhandled_.push(i);
}
}
@@ -514,19 +500,11 @@
std::sort(added.begin(), added.end(), less_ptr<LiveInterval>());
// merge added with unhandled
- std::vector<LiveInterval*>::iterator addedIt = added.begin();
- std::vector<LiveInterval*>::iterator addedItEnd = added.end();
- for (IntervalPtrs::iterator i = unhandled_.begin(), e = unhandled_.end();
- i != e && addedIt != addedItEnd; ++i) {
- if ((*i)->start() > (*addedIt)->start())
- i = unhandled_.insert(i, *(addedIt++));
- }
- while (addedIt != addedItEnd)
- unhandled_.push_back(*(addedIt++));
-
+ for (unsigned i = 0, e = added.size(); i != e; ++i)
+ unhandled_.push(added[i]);
}
-unsigned RA::getFreePhysReg(IntervalPtrs::value_type cur)
+unsigned RA::getFreePhysReg(LiveInterval* cur)
{
const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
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