From ed543731fb385b55750d0c514d130a810339d739 Mon Sep 17 00:00:00 2001
From: Alkis Evlogimenos <alkis@evlogimenos.com>
Date: Wed, 1 Sep 2004 22:52:29 +0000
Subject: Be a bit more efficient when processing the active and inactive
lists. Instead of scanning the vector backwards, scan it forward and swap
each element we want to erase. Then at the end erase all removed intervals at
once. This doesn't save much: 0.08s out of 4s when compiling 176.gcc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16136 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/CodeGen/RegAllocIterativeScan.cpp | 57 +++++++++++++++++++----------------
lib/CodeGen/RegAllocLinearScan.cpp | 57 +++++++++++++++++++----------------
2 files changed, 62 insertions(+), 52 deletions(-)
diff --git a/lib/CodeGen/RegAllocIterativeScan.cpp b/lib/CodeGen/RegAllocIterativeScan.cpp
index 764c884..ffeb68d 100644
--- a/lib/CodeGen/RegAllocIterativeScan.cpp
+++ b/lib/CodeGen/RegAllocIterativeScan.cpp
@@ -264,63 +264,68 @@ void RA::initIntervalSets() {
void RA::processActiveIntervals(IntervalPtrs::value_type cur)
{
DEBUG(std::cerr << "\tprocessing active intervals:\n");
- for (IntervalPtrs::reverse_iterator
- i = active_.rbegin(); i != active_.rend();) {
- unsigned reg = (*i)->reg;
+ IntervalPtrs::iterator ii = active_.begin(), ie = active_.end();
+ while (ii != ie) {
+ LiveInterval* i = *ii;
+ unsigned reg = i->reg;
+
// remove expired intervals
- if ((*i)->expiredAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
+ if (i->expiredAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << *i << " expired\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
- // remove from active
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ // swap with last element and move end iterator back one position
+ std::iter_swap(ii, --ie);
}
// move inactive intervals to inactive list
- else if (!(*i)->liveAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " inactive\n");
+ else if (!i->liveAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << *i << " inactive\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
// add to inactive
- inactive_.push_back(*i);
- // remove from active
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ inactive_.push_back(i);
+ // swap with last element and move end iterator back one postion
+ std::iter_swap(ii, --ie);
}
else {
- ++i;
+ ++ii;
}
}
+ active_.erase(ie, active_.end());
}
void RA::processInactiveIntervals(IntervalPtrs::value_type cur)
{
DEBUG(std::cerr << "\tprocessing inactive intervals:\n");
- for (IntervalPtrs::reverse_iterator
- i = inactive_.rbegin(); i != inactive_.rend();) {
- unsigned reg = (*i)->reg;
+ IntervalPtrs::iterator ii = inactive_.begin(), ie = inactive_.end();
+ while (ii != ie) {
+ LiveInterval* i = *ii;
+ unsigned reg = i->reg;
// remove expired intervals
- if ((*i)->expiredAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
- // remove from inactive
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
+ if (i->expiredAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << *i << " expired\n");
+ // swap with last element and move end iterator back one position
+ std::iter_swap(ii, --ie);
}
// move re-activated intervals in active list
- else if ((*i)->liveAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " active\n");
+ else if (i->liveAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << *i << " active\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
prt_->addRegUse(reg);
// add to active
- active_.push_back(*i);
- // remove from inactive
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
+ active_.push_back(i);
+ // swap with last element and move end iterator back one position
+ std::iter_swap(ii, --ie);
}
else {
- ++i;
+ ++ii;
}
}
+ inactive_.erase(ie, inactive_.end());
}
void RA::updateSpillWeights(unsigned reg, SpillWeights::value_type weight)
diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index b9af397..181f061 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -231,63 +231,68 @@ void RA::initIntervalSets()
void RA::processActiveIntervals(IntervalPtrs::value_type cur)
{
DEBUG(std::cerr << "\tprocessing active intervals:\n");
- for (IntervalPtrs::reverse_iterator
- i = active_.rbegin(); i != active_.rend();) {
- unsigned reg = (*i)->reg;
+ IntervalPtrs::iterator ii = active_.begin(), ie = active_.end();
+ while (ii != ie) {
+ LiveInterval* i = *ii;
+ unsigned reg = i->reg;
+
// remove expired intervals
- if ((*i)->expiredAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
+ if (i->expiredAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << *i << " expired\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
- // remove from active
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ // swap with last element and move end iterator back one position
+ std::iter_swap(ii, --ie);
}
// move inactive intervals to inactive list
- else if (!(*i)->liveAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " inactive\n");
+ else if (!i->liveAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << *i << " inactive\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
prt_->delRegUse(reg);
// add to inactive
- inactive_.push_back(*i);
- // remove from active
- i = IntervalPtrs::reverse_iterator(active_.erase(i.base()-1));
+ inactive_.push_back(i);
+ // swap with last element and move end iterator back one postion
+ std::iter_swap(ii, --ie);
}
else {
- ++i;
+ ++ii;
}
}
+ active_.erase(ie, active_.end());
}
void RA::processInactiveIntervals(IntervalPtrs::value_type cur)
{
DEBUG(std::cerr << "\tprocessing inactive intervals:\n");
- for (IntervalPtrs::reverse_iterator
- i = inactive_.rbegin(); i != inactive_.rend();) {
- unsigned reg = (*i)->reg;
+ IntervalPtrs::iterator ii = inactive_.begin(), ie = inactive_.end();
+ while (ii != ie) {
+ LiveInterval* i = *ii;
+ unsigned reg = i->reg;
// remove expired intervals
- if ((*i)->expiredAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " expired\n");
- // remove from inactive
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
+ if (i->expiredAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << *i << " expired\n");
+ // swap with last element and move end iterator back one position
+ std::iter_swap(ii, --ie);
}
// move re-activated intervals in active list
- else if ((*i)->liveAt(cur->start())) {
- DEBUG(std::cerr << "\t\tinterval " << **i << " active\n");
+ else if (i->liveAt(cur->start())) {
+ DEBUG(std::cerr << "\t\tinterval " << *i << " active\n");
if (MRegisterInfo::isVirtualRegister(reg))
reg = vrm_->getPhys(reg);
prt_->addRegUse(reg);
// add to active
- active_.push_back(*i);
- // remove from inactive
- i = IntervalPtrs::reverse_iterator(inactive_.erase(i.base()-1));
+ active_.push_back(i);
+ // swap with last element and move end iterator back one position
+ std::iter_swap(ii, --ie);
}
else {
- ++i;
+ ++ii;
}
}
+ inactive_.erase(ie, inactive_.end());
}
void RA::updateSpillWeights(unsigned reg, SpillWeights::value_type weight)
--
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