[llvm-commits] CVS: llvm/lib/CodeGen/RegAllocLinearScan.cpp
Alkis Evlogimenos
alkis at niobe.cs.uiuc.edu
Fri Feb 6 12:09:01 PST 2004
Changes in directory llvm/lib/CodeGen:
RegAllocLinearScan.cpp updated: 1.42 -> 1.43
---
Log message:
Increase code clarity.
---
Diffs of the changes: (+100 -127)
Index: llvm/lib/CodeGen/RegAllocLinearScan.cpp
diff -u llvm/lib/CodeGen/RegAllocLinearScan.cpp:1.42 llvm/lib/CodeGen/RegAllocLinearScan.cpp:1.43
--- llvm/lib/CodeGen/RegAllocLinearScan.cpp:1.42 Thu Feb 5 21:15:40 2004
+++ llvm/lib/CodeGen/RegAllocLinearScan.cpp Fri Feb 6 12:08:18 2004
@@ -119,6 +119,9 @@
int instrAdded_;
+ typedef std::vector<float> SpillWeights;
+ SpillWeights spillWeights_;
+
public:
RA()
: prt_(NULL) {
@@ -153,12 +156,13 @@
/// overlapping ones to the active list
void processInactiveIntervals(IntervalPtrs::value_type cur);
- /// assignStackSlotAtInterval - choose and spill
- /// interval. Currently we spill the interval with the last
- /// end point in the active and inactive lists and the current
- /// interval
- void assignStackSlotAtInterval(IntervalPtrs::value_type cur,
- const PhysRegTracker& backupPtr);
+ /// updateSpillWeights - updates the spill weights of the
+ /// specifed physical register and its weight
+ void updateSpillWeights(unsigned reg, SpillWeights::value_type weight);
+
+ /// assignRegOrStackSlotAtInterval - assign a register if one
+ /// is available, or spill.
+ void assignRegOrStackSlotAtInterval(IntervalPtrs::value_type cur);
///
/// register handling helpers
@@ -329,42 +333,7 @@
// a free physical register or spill an interval in order to
// assign it one (we could spill the current though).
else {
- PhysRegTracker backupPrt = prt_;
-
- // for every interval in inactive we overlap with, mark the
- // register as not free
- for (IntervalPtrs::const_iterator i = inactive_.begin(),
- e = inactive_.end(); i != e; ++i) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg))
- reg = v2pMap_[reg];
-
- if (cur->overlaps(**i)) {
- prt_.addPhysRegUse(reg);
- }
- }
-
- // for every interval in fixed we overlap with,
- // mark the register as not free
- for (IntervalPtrs::const_iterator i = fixed_.begin(),
- e = fixed_.end(); i != e; ++i) {
- assert(MRegisterInfo::isPhysicalRegister((*i)->reg) &&
- "virtual register interval in fixed set?");
- if (cur->overlaps(**i))
- prt_.addPhysRegUse((*i)->reg);
- }
-
- DEBUG(std::cerr << "\tallocating current interval:\n");
-
- unsigned physReg = getFreePhysReg(cur);
- if (!physReg) {
- assignStackSlotAtInterval(cur, backupPrt);
- }
- else {
- prt_ = backupPrt;
- assignVirt2PhysReg(cur->reg, physReg);
- active_.push_back(cur);
- }
+ assignRegOrStackSlotAtInterval(cur);
}
DEBUG(printIntervals("\tactive", active_.begin(), active_.end()));
@@ -609,132 +578,136 @@
}
}
-namespace {
- template <typename T>
- void updateWeight(std::vector<T>& rw, int reg, T w)
- {
- if (rw[reg] == std::numeric_limits<T>::max() ||
- w == std::numeric_limits<T>::max())
- rw[reg] = std::numeric_limits<T>::max();
- else
- rw[reg] += w;
- }
+void RA::updateSpillWeights(unsigned reg, SpillWeights::value_type weight)
+{
+ spillWeights_[reg] += weight;
+ for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as)
+ spillWeights_[*as] += weight;
}
-void RA::assignStackSlotAtInterval(IntervalPtrs::value_type cur,
- const PhysRegTracker& backupPrt)
+void RA::assignRegOrStackSlotAtInterval(IntervalPtrs::value_type cur)
{
- DEBUG(std::cerr << "\t\tassigning stack slot at interval "
- << *cur << ":\n");
+ DEBUG(std::cerr << "\tallocating current interval:\n");
- std::vector<float> regWeight(mri_->getNumRegs(), 0.0);
+ PhysRegTracker backupPrt = prt_;
- // for each interval in active
+ spillWeights_.assign(mri_->getNumRegs(), 0.0);
+
+ // for each interval in active update spill weights
for (IntervalPtrs::const_iterator i = active_.begin(), e = active_.end();
i != e; ++i) {
unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg)) {
+ if (MRegisterInfo::isVirtualRegister(reg))
reg = v2pMap_[reg];
- }
- updateWeight(regWeight, reg, (*i)->weight);
- for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as)
- updateWeight(regWeight, *as, (*i)->weight);
+ updateSpillWeights(reg, (*i)->weight);
}
- // for each interval in inactive that overlaps
+ // for every interval in inactive we overlap with, mark the
+ // register as not free and update spill weights
for (IntervalPtrs::const_iterator i = inactive_.begin(),
e = inactive_.end(); i != e; ++i) {
- if (!cur->overlaps(**i))
- continue;
-
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg)) {
- reg = v2pMap_[reg];
+ if (cur->overlaps(**i)) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg))
+ reg = v2pMap_[reg];
+ prt_.addPhysRegUse(reg);
+ updateSpillWeights(reg, (*i)->weight);
}
- updateWeight(regWeight, reg, (*i)->weight);
- for (const unsigned* as = mri_->getAliasSet(reg); *as; ++as)
- updateWeight(regWeight, *as, (*i)->weight);
}
- // for each fixed interval that overlaps
- for (IntervalPtrs::const_iterator i = fixed_.begin(), e = fixed_.end();
- i != e; ++i) {
- if (!cur->overlaps(**i))
- continue;
+ // for every interval in fixed we overlap with,
+ // mark the register as not free and update spill weights
+ for (IntervalPtrs::const_iterator i = fixed_.begin(),
+ e = fixed_.end(); i != e; ++i) {
+ if (cur->overlaps(**i)) {
+ unsigned reg = (*i)->reg;
+ prt_.addPhysRegUse(reg);
+ updateSpillWeights(reg, (*i)->weight);
+ }
+ }
- assert(MRegisterInfo::isPhysicalRegister((*i)->reg) &&
- "virtual register interval in fixed set?");
- updateWeight(regWeight, (*i)->reg, (*i)->weight);
- for (const unsigned* as = mri_->getAliasSet((*i)->reg); *as; ++as)
- updateWeight(regWeight, *as, (*i)->weight);
+ unsigned physReg = getFreePhysReg(cur);
+ // if we find a free register, we are done: restore original
+ // register tracker, assign this virtual to the free physical
+ // register and add this interval to the active list.
+ if (physReg) {
+ prt_ = backupPrt;
+ assignVirt2PhysReg(cur->reg, physReg);
+ active_.push_back(cur);
+ return;
}
+ DEBUG(std::cerr << "\t\tassigning stack slot at interval "<< *cur << ":\n");
+
float minWeight = std::numeric_limits<float>::max();
unsigned minReg = 0;
const TargetRegisterClass* rc = mf_->getSSARegMap()->getRegClass(cur->reg);
for (TargetRegisterClass::iterator i = rc->allocation_order_begin(*mf_);
i != rc->allocation_order_end(*mf_); ++i) {
unsigned reg = *i;
- if (!prt_.isPhysRegReserved(reg) && minWeight > regWeight[reg]) {
- minWeight = regWeight[reg];
+ if (!prt_.isPhysRegReserved(reg) && minWeight > spillWeights_[reg]) {
+ minWeight = spillWeights_[reg];
minReg = reg;
}
}
DEBUG(std::cerr << "\t\t\tregister with min weight: "
<< mri_->getName(minReg) << " (" << minWeight << ")\n");
+ // if the current has the minimum weight, we are done: restore
+ // original register tracker and assign a stack slot to this
+ // virtual register
if (cur->weight < minWeight) {
prt_ = backupPrt;
DEBUG(std::cerr << "\t\t\t\tspilling: " << *cur << '\n');
assignVirt2StackSlot(cur->reg);
+ return;
}
- else {
- std::vector<bool> toSpill(mri_->getNumRegs(), false);
- toSpill[minReg] = true;
- for (const unsigned* as = mri_->getAliasSet(minReg); *as; ++as)
- toSpill[*as] = true;
-
- std::vector<unsigned> spilled;
- for (IntervalPtrs::iterator i = active_.begin();
- i != active_.end(); ) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg) &&
- toSpill[v2pMap_[reg]] &&
- cur->overlaps(**i)) {
- spilled.push_back(v2pMap_[reg]);
- DEBUG(std::cerr << "\t\t\t\tspilling : " << **i << '\n');
- assignVirt2StackSlot(reg);
- i = active_.erase(i);
- }
- else {
- ++i;
- }
+
+ std::vector<bool> toSpill(mri_->getNumRegs(), false);
+ toSpill[minReg] = true;
+ for (const unsigned* as = mri_->getAliasSet(minReg); *as; ++as)
+ toSpill[*as] = true;
+
+ std::vector<unsigned> spilled;
+ for (IntervalPtrs::iterator i = active_.begin();
+ i != active_.end(); ) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg) &&
+ toSpill[v2pMap_[reg]] &&
+ cur->overlaps(**i)) {
+ spilled.push_back(v2pMap_[reg]);
+ DEBUG(std::cerr << "\t\t\t\tspilling : " << **i << '\n');
+ assignVirt2StackSlot(reg);
+ i = active_.erase(i);
}
- for (IntervalPtrs::iterator i = inactive_.begin();
- i != inactive_.end(); ) {
- unsigned reg = (*i)->reg;
- if (MRegisterInfo::isVirtualRegister(reg) &&
- toSpill[v2pMap_[reg]] &&
- cur->overlaps(**i)) {
- DEBUG(std::cerr << "\t\t\t\tspilling : " << **i << '\n');
- assignVirt2StackSlot(reg);
- i = inactive_.erase(i);
- }
- else {
- ++i;
- }
+ else {
+ ++i;
+ }
+ }
+ for (IntervalPtrs::iterator i = inactive_.begin();
+ i != inactive_.end(); ) {
+ unsigned reg = (*i)->reg;
+ if (MRegisterInfo::isVirtualRegister(reg) &&
+ toSpill[v2pMap_[reg]] &&
+ cur->overlaps(**i)) {
+ DEBUG(std::cerr << "\t\t\t\tspilling : " << **i << '\n');
+ assignVirt2StackSlot(reg);
+ i = inactive_.erase(i);
}
+ else {
+ ++i;
+ }
+ }
- unsigned physReg = getFreePhysReg(cur);
- assert(physReg && "no free physical register after spill?");
+ physReg = getFreePhysReg(cur);
+ assert(physReg && "no free physical register after spill?");
- prt_ = backupPrt;
- for (unsigned i = 0; i < spilled.size(); ++i)
- prt_.delPhysRegUse(spilled[i]);
+ prt_ = backupPrt;
+ for (unsigned i = 0; i < spilled.size(); ++i)
+ prt_.delPhysRegUse(spilled[i]);
- assignVirt2PhysReg(cur->reg, physReg);
- active_.push_back(cur);
- }
+ assignVirt2PhysReg(cur->reg, physReg);
+ active_.push_back(cur);
}
unsigned RA::getFreePhysReg(IntervalPtrs::value_type cur)
More information about the llvm-commits
mailing list