Code clean up. Bye bye PhysRegTracker.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70524 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index 17aec81..83c1cbb 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -12,7 +12,6 @@
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "regalloc"
-#include "PhysRegTracker.h"
#include "VirtRegMap.h"
#include "Spiller.h"
#include "llvm/Function.h"
@@ -118,8 +117,14 @@
SmallVector<LiveInterval*, 64>,
greater_ptr<LiveInterval> > IntervalHeap;
IntervalHeap unhandled_;
- std::auto_ptr<PhysRegTracker> prt_;
+
+ /// regUse_ - Tracks register usage.
+ SmallVector<unsigned, 32> regUse_;
+ SmallVector<unsigned, 32> regUseBackUp_;
+
+ /// vrm_ - Tracks register assignments.
VirtRegMap* vrm_;
+
std::auto_ptr<Spiller> spiller_;
public:
@@ -202,7 +207,54 @@
unsigned attemptTrivialCoalescing(LiveInterval &cur, unsigned Reg);
///
- /// register handling helpers
+ /// Register usage / availability tracking helpers.
+ ///
+
+ void initRegUses() {
+ regUse_.resize(tri_->getNumRegs(), 0);
+ regUseBackUp_.resize(tri_->getNumRegs(), 0);
+ }
+
+ void finalizeRegUses() {
+ regUse_.clear();
+ regUseBackUp_.clear();
+ }
+
+ void addRegUse(unsigned physReg) {
+ assert(TargetRegisterInfo::isPhysicalRegister(physReg) &&
+ "should be physical register!");
+ ++regUse_[physReg];
+ for (const unsigned* as = tri_->getAliasSet(physReg); *as; ++as)
+ ++regUse_[*as];
+ }
+
+ void delRegUse(unsigned physReg) {
+ assert(TargetRegisterInfo::isPhysicalRegister(physReg) &&
+ "should be physical register!");
+ assert(regUse_[physReg] != 0);
+ --regUse_[physReg];
+ for (const unsigned* as = tri_->getAliasSet(physReg); *as; ++as) {
+ assert(regUse_[*as] != 0);
+ --regUse_[*as];
+ }
+ }
+
+ bool isRegAvail(unsigned physReg) const {
+ assert(TargetRegisterInfo::isPhysicalRegister(physReg) &&
+ "should be physical register!");
+ return regUse_[physReg] == 0;
+ }
+
+ void backUpRegUses() {
+ regUseBackUp_ = regUse_;
+ }
+
+ void restoreRegUses() {
+ regUse_ = regUseBackUp_;
+ }
+
+ ///
+ /// Register handling helpers.
///
/// getFreePhysReg - return a free physical register for this virtual
@@ -335,8 +387,10 @@
// If this is the first function compiled, compute the related reg classes.
if (RelatedRegClasses.empty())
ComputeRelatedRegClasses();
-
- if (!prt_.get()) prt_.reset(new PhysRegTracker(*tri_));
+
+ // Also resize register usage trackers.
+ initRegUses();
+
vrm_ = &getAnalysis<VirtRegMap>();
if (!spiller_.get()) spiller_.reset(createSpiller());
@@ -348,6 +402,9 @@
spiller_->runOnMachineFunction(*mf_, *vrm_, li_);
assert(unhandled_.empty() && "Unhandled live intervals remain!");
+
+ finalizeRegUses();
+
fixed_.clear();
active_.clear();
inactive_.clear();
@@ -410,7 +467,7 @@
DEBUG(printIntervals("inactive", inactive_.begin(), inactive_.end()));
}
- // expire any remaining active intervals
+ // Expire any remaining active intervals
while (!active_.empty()) {
IntervalPtr &IP = active_.back();
unsigned reg = IP.first->reg;
@@ -418,11 +475,11 @@
assert(TargetRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
- prt_->delRegUse(reg);
+ delRegUse(reg);
active_.pop_back();
}
- // expire any remaining inactive intervals
+ // Expire any remaining inactive intervals
DEBUG(for (IntervalPtrs::reverse_iterator
i = inactive_.rbegin(); i != inactive_.rend(); ++i)
DOUT << "\tinterval " << *i->first << " expired\n");
@@ -477,7 +534,7 @@
assert(TargetRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
- prt_->delRegUse(reg);
+ delRegUse(reg);
// Pop off the end of the list.
active_[i] = active_.back();
@@ -490,7 +547,7 @@
assert(TargetRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
- prt_->delRegUse(reg);
+ delRegUse(reg);
// add to inactive.
inactive_.push_back(std::make_pair(Interval, IntervalPos));
@@ -531,7 +588,7 @@
assert(TargetRegisterInfo::isVirtualRegister(reg) &&
"Can only allocate virtual registers!");
reg = vrm_->getPhys(reg);
- prt_->addRegUse(reg);
+ addRegUse(reg);
// add to active
active_.push_back(std::make_pair(Interval, IntervalPos));
@@ -776,7 +833,7 @@
return;
}
- PhysRegTracker backupPrt = *prt_;
+ backUpRegUses();
std::vector<std::pair<unsigned, float> > SpillWeightsToAdd;
unsigned StartPosition = cur->beginNumber();
@@ -811,7 +868,7 @@
}
}
- // for every interval in inactive we overlap with, mark the
+ // 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) {
@@ -824,7 +881,7 @@
if (RelatedRegClasses.getLeaderValue(RegRC) == RCLeader &&
cur->overlapsFrom(*i->first, i->second-1)) {
Reg = vrm_->getPhys(Reg);
- prt_->addRegUse(Reg);
+ addRegUse(Reg);
SpillWeightsToAdd.push_back(std::make_pair(Reg, i->first->weight));
}
}
@@ -866,7 +923,7 @@
// Okay, the register picked by our speculative getFreePhysReg call turned
// out to be in use. Actually add all of the conflicting fixed registers to
- // prt so we can do an accurate query.
+ // regUse_ so we can do an accurate query.
if (ConflictsWithFixed) {
// For every interval in fixed we overlap with, mark the register as not
// free and update spill weights.
@@ -883,13 +940,13 @@
--II;
if (cur->overlapsFrom(*I, II)) {
unsigned reg = I->reg;
- prt_->addRegUse(reg);
+ addRegUse(reg);
SpillWeightsToAdd.push_back(std::make_pair(reg, I->weight));
}
}
}
- // Using the newly updated prt_ object, which includes conflicts in the
+ // Using the newly updated regUse_ object, which includes conflicts in the
// future, see if there are any registers available.
physReg = getFreePhysReg(cur);
}
@@ -897,15 +954,15 @@
// Restore the physical register tracker, removing information about the
// future.
- *prt_ = backupPrt;
+ restoreRegUses();
- // if we find a free register, we are done: assign this virtual to
+ // If we find a free register, we are done: assign this virtual to
// the free physical register and add this interval to the active
// list.
if (physReg) {
DOUT << tri_->getName(physReg) << '\n';
vrm_->assignVirt2Phys(cur->reg, physReg);
- prt_->addRegUse(physReg);
+ addRegUse(physReg);
active_.push_back(std::make_pair(cur, cur->begin()));
handled_.push_back(cur);
@@ -1114,14 +1171,14 @@
handled_.pop_back();
// When undoing a live interval allocation we must know if it is active or
- // inactive to properly update the PhysRegTracker and the VirtRegMap.
+ // inactive to properly update regUse_ and the VirtRegMap.
IntervalPtrs::iterator it;
if ((it = FindIntervalInVector(active_, i)) != active_.end()) {
active_.erase(it);
assert(!TargetRegisterInfo::isPhysicalRegister(i->reg));
if (!spilled.count(i->reg))
unhandled_.push(i);
- prt_->delRegUse(vrm_->getPhys(i->reg));
+ delRegUse(vrm_->getPhys(i->reg));
vrm_->clearVirt(i->reg);
} else if ((it = FindIntervalInVector(inactive_, i)) != inactive_.end()) {
inactive_.erase(it);
@@ -1163,7 +1220,7 @@
DOUT << "\t\t\tundo changes for: " << *HI << '\n';
active_.push_back(std::make_pair(HI, HI->begin()));
assert(!TargetRegisterInfo::isPhysicalRegister(HI->reg));
- prt_->addRegUse(vrm_->getPhys(HI->reg));
+ addRegUse(vrm_->getPhys(HI->reg));
}
}
@@ -1214,7 +1271,7 @@
// Ignore "downgraded" registers.
if (SkipDGRegs && DowngradedRegs.count(Reg))
continue;
- if (prt_->isRegAvail(Reg)) {
+ if (isRegAvail(Reg)) {
FreeReg = Reg;
if (FreeReg < inactiveCounts.size())
FreeRegInactiveCount = inactiveCounts[FreeReg];
@@ -1238,7 +1295,7 @@
// Ignore "downgraded" registers.
if (SkipDGRegs && DowngradedRegs.count(Reg))
continue;
- if (prt_->isRegAvail(Reg) && Reg < inactiveCounts.size() &&
+ if (isRegAvail(Reg) && Reg < inactiveCounts.size() &&
FreeRegInactiveCount < inactiveCounts[Reg]) {
FreeReg = Reg;
FreeRegInactiveCount = inactiveCounts[Reg];
@@ -1281,7 +1338,7 @@
// available first.
if (cur->preference) {
DOUT << "(preferred: " << tri_->getName(cur->preference) << ") ";
- if (prt_->isRegAvail(cur->preference) &&
+ if (isRegAvail(cur->preference) &&
RC->contains(cur->preference))
return cur->preference;
}