#include <algorithm>
using namespace llvm;
-// An example for liveAt():
-//
-// this = [1,4), liveAt(0) will return false. The instruction defining this
-// spans slots [0,3]. The interval belongs to an spilled definition of the
-// variable it represents. This is because slot 1 is used (def slot) and spans
-// up to slot 3 (store slot).
-//
-bool LiveInterval::liveAt(SlotIndex I) const {
- Ranges::const_iterator r = std::upper_bound(ranges.begin(), ranges.end(), I);
-
- if (r == ranges.begin())
- return false;
-
- --r;
- return r->contains(I);
-}
-
-// liveBeforeAndAt - Check if the interval is live at the index and the index
-// just before it. If index is liveAt, check if it starts a new live range.
-// If it does, then check if the previous live range ends at index-1.
-bool LiveInterval::liveBeforeAndAt(SlotIndex I) const {
- Ranges::const_iterator r = std::upper_bound(ranges.begin(), ranges.end(), I);
-
- if (r == ranges.begin())
- return false;
-
- --r;
- if (!r->contains(I))
- return false;
- if (I != r->start)
- return true;
- // I is the start of a live range. Check if the previous live range ends
- // at I-1.
- if (r == ranges.begin())
- return false;
- return r->end == I;
-}
-
-/// killedAt - Return true if a live range ends at index. Note that the kill
-/// point is not contained in the half-open live range. It is usually the
-/// getDefIndex() slot following its last use.
-bool LiveInterval::killedAt(SlotIndex I) const {
- Ranges::const_iterator r = std::lower_bound(ranges.begin(), ranges.end(), I);
-
- // Now r points to the first interval with start >= I, or ranges.end().
- if (r == ranges.begin())
- return false;
-
- --r;
- // Now r points to the last interval with end <= I.
- // r->end is the kill point.
- return r->end == I;
+LiveInterval::iterator LiveInterval::find(SlotIndex Pos) {
+ // This algorithm is basically std::upper_bound.
+ // Unfortunately, std::upper_bound cannot be used with mixed types until we
+ // adopt C++0x. Many libraries can do it, but not all.
+ if (empty() || Pos >= endIndex())
+ return end();
+ iterator I = begin();
+ size_t Len = ranges.size();
+ do {
+ size_t Mid = Len >> 1;
+ if (Pos < I[Mid].end)
+ Len = Mid;
+ else
+ I += Mid + 1, Len -= Mid + 1;
+ } while (Len);
+ return I;
}
/// killedInRange - Return true if the interval has kills in [Start,End).
/// remaining unused values.
void LiveInterval::RenumberValues(LiveIntervals &lis) {
SmallPtrSet<VNInfo*, 8> Seen;
- bool seenPHIDef = false;
valnos.clear();
for (const_iterator I = begin(), E = end(); I != E; ++I) {
VNInfo *VNI = I->valno;
assert(!VNI->isUnused() && "Unused valno used by live range");
VNI->id = (unsigned)valnos.size();
valnos.push_back(VNI);
- VNI->setHasPHIKill(false);
- if (VNI->isPHIDef())
- seenPHIDef = true;
- }
-
- // Recompute phi kill flags.
- if (!seenPHIDef)
- return;
- for (const_vni_iterator I = vni_begin(), E = vni_end(); I != E; ++I) {
- VNInfo *VNI = *I;
- if (!VNI->isPHIDef())
- continue;
- const MachineBasicBlock *PHIBB = lis.getMBBFromIndex(VNI->def);
- assert(PHIBB && "No basic block for phi-def");
- for (MachineBasicBlock::const_pred_iterator PI = PHIBB->pred_begin(),
- PE = PHIBB->pred_end(); PI != PE; ++PI) {
- VNInfo *KVNI = getVNInfoAt(lis.getMBBEndIdx(*PI).getPrevSlot());
- if (KVNI)
- KVNI->setHasPHIKill(true);
- }
}
}
return ranges.insert(it, LR);
}
-/// isInOneLiveRange - Return true if the range specified is entirely in
-/// a single LiveRange of the live interval.
-bool LiveInterval::isInOneLiveRange(SlotIndex Start, SlotIndex End) {
- Ranges::iterator I = std::upper_bound(ranges.begin(), ranges.end(), Start);
- if (I == ranges.begin())
- return false;
+/// extendInBlock - If this interval is live before Kill in the basic
+/// block that starts at StartIdx, extend it to be live up to Kill and return
+/// the value. If there is no live range before Kill, return NULL.
+VNInfo *LiveInterval::extendInBlock(SlotIndex StartIdx, SlotIndex Kill) {
+ if (empty())
+ return 0;
+ iterator I = std::upper_bound(begin(), end(), Kill.getPrevSlot());
+ if (I == begin())
+ return 0;
--I;
- return I->containsRange(Start, End);
+ if (I->end <= StartIdx)
+ return 0;
+ if (I->end < Kill)
+ extendIntervalEndTo(I, Kill);
+ return I->valno;
}
-
/// removeRange - Remove the specified range from this interval. Note that
/// the range must be in a single LiveRange in its entirety.
void LiveInterval::removeRange(SlotIndex Start, SlotIndex End,
bool RemoveDeadValNo) {
// Find the LiveRange containing this span.
- Ranges::iterator I = std::upper_bound(ranges.begin(), ranges.end(), Start);
- assert(I != ranges.begin() && "Range is not in interval!");
- --I;
+ Ranges::iterator I = find(Start);
+ assert(I != ranges.end() && "Range is not in interval!");
assert(I->containsRange(Start, End) && "Range is not entirely in interval!");
// If the span we are removing is at the start of the LiveRange, adjust it.
markValNoForDeletion(ValNo);
}
-/// getLiveRangeContaining - Return the live range that contains the
-/// specified index, or null if there is none.
-LiveInterval::const_iterator
-LiveInterval::FindLiveRangeContaining(SlotIndex Idx) const {
- const_iterator It = std::upper_bound(begin(), end(), Idx);
- if (It != ranges.begin()) {
- --It;
- if (It->contains(Idx))
- return It;
- }
-
- return end();
-}
-
-LiveInterval::iterator
-LiveInterval::FindLiveRangeContaining(SlotIndex Idx) {
- iterator It = std::upper_bound(begin(), end(), Idx);
- if (It != begin()) {
- --It;
- if (It->contains(Idx))
- return It;
- }
-
- return end();
-}
-
/// findDefinedVNInfo - Find the VNInfo defined by the specified
/// index (register interval).
VNInfo *LiveInterval::findDefinedVNInfoForRegInt(SlotIndex Idx) const {
return 0;
}
-/// findDefinedVNInfo - Find the VNInfo defined by the specified
-/// register (stack inteval).
-VNInfo *LiveInterval::findDefinedVNInfoForStackInt(unsigned reg) const {
- for (LiveInterval::const_vni_iterator i = vni_begin(), e = vni_end();
- i != e; ++i) {
- if ((*i)->getReg() == reg)
- return *i;
- }
- return 0;
-}
-
/// join - Join two live intervals (this, and other) together. This applies
/// mappings to the value numbers in the LHS/RHS intervals as specified. If
/// the intervals are not joinable, this aborts.
void LiveInterval::MergeValueInAsValue(
const LiveInterval &RHS,
const VNInfo *RHSValNo, VNInfo *LHSValNo) {
- SmallVector<VNInfo*, 4> ReplacedValNos;
- iterator IP = begin();
+ // TODO: Make this more efficient.
+ iterator InsertPos = begin();
for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) {
- assert(I->valno == RHS.getValNumInfo(I->valno->id) && "Bad VNInfo");
if (I->valno != RHSValNo)
continue;
- SlotIndex Start = I->start, End = I->end;
- IP = std::upper_bound(IP, end(), Start);
- // If the start of this range overlaps with an existing liverange, trim it.
- if (IP != begin() && IP[-1].end > Start) {
- if (IP[-1].valno != LHSValNo) {
- ReplacedValNos.push_back(IP[-1].valno);
- IP[-1].valno = LHSValNo; // Update val#.
- }
- Start = IP[-1].end;
- // Trimmed away the whole range?
- if (Start >= End) continue;
- }
- // If the end of this range overlaps with an existing liverange, trim it.
- if (IP != end() && End > IP->start) {
- if (IP->valno != LHSValNo) {
- ReplacedValNos.push_back(IP->valno);
- IP->valno = LHSValNo; // Update val#.
- }
- End = IP->start;
- // If this trimmed away the whole range, ignore it.
- if (Start == End) continue;
- }
-
// Map the valno in the other live range to the current live range.
- IP = addRangeFrom(LiveRange(Start, End, LHSValNo), IP);
- }
-
-
- SmallSet<VNInfo*, 4> Seen;
- for (unsigned i = 0, e = ReplacedValNos.size(); i != e; ++i) {
- VNInfo *V1 = ReplacedValNos[i];
- if (Seen.insert(V1)) {
- bool isDead = true;
- for (const_iterator I = begin(), E = end(); I != E; ++I)
- if (I->valno == V1) {
- isDead = false;
- break;
- }
- if (isDead) {
- // Now that V1 is dead, remove it.
- markValNoForDeletion(V1);
- }
- }
+ LiveRange Tmp = *I;
+ Tmp.valno = LHSValNo;
+ InsertPos = addRangeFrom(Tmp, InsertPos);
}
}
-
/// MergeValueNumberInto - This method is called when two value nubmers
/// are found to be equivalent. This eliminates V1, replacing all
/// LiveRanges with the V1 value number with the V2 value number. This can
}
}
+ // Merge the relevant flags.
+ V2->mergeFlags(V1);
+
// Now that V1 is dead, remove it.
markValNoForDeletion(V1);
}
void LiveInterval::print(raw_ostream &OS, const TargetRegisterInfo *TRI) const {
- if (isStackSlot())
- OS << "SS#" << getStackSlotIndex();
- else if (TRI && TargetRegisterInfo::isPhysicalRegister(reg))
- OS << TRI->getName(reg);
- else
- OS << "%reg" << reg;
-
- OS << ',' << weight;
+ OS << PrintReg(reg, TRI);
+ if (weight != 0)
+ OS << ',' << weight;
if (empty())
OS << " EMPTY";
if (vni->isUnused()) {
OS << "x";
} else {
- if (!vni->isDefAccurate() && !vni->isPHIDef())
- OS << "?";
- else
- OS << vni->def;
+ OS << vni->def;
+ if (vni->isPHIDef())
+ OS << "-phidef";
if (vni->hasPHIKill())
OS << "-phikill";
if (vni->hasRedefByEC())
void LiveRange::print(raw_ostream &os) const {
os << *this;
}
+
+unsigned ConnectedVNInfoEqClasses::Classify(const LiveInterval *LI) {
+ // Create initial equivalence classes.
+ EqClass.clear();
+ EqClass.grow(LI->getNumValNums());
+
+ const VNInfo *used = 0, *unused = 0;
+
+ // Determine connections.
+ for (LiveInterval::const_vni_iterator I = LI->vni_begin(), E = LI->vni_end();
+ I != E; ++I) {
+ const VNInfo *VNI = *I;
+ // Group all unused values into one class.
+ if (VNI->isUnused()) {
+ if (unused)
+ EqClass.join(unused->id, VNI->id);
+ unused = VNI;
+ continue;
+ }
+ used = VNI;
+ if (VNI->isPHIDef()) {
+ const MachineBasicBlock *MBB = LIS.getMBBFromIndex(VNI->def);
+ assert(MBB && "Phi-def has no defining MBB");
+ // Connect to values live out of predecessors.
+ for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
+ PE = MBB->pred_end(); PI != PE; ++PI)
+ if (const VNInfo *PVNI =
+ LI->getVNInfoAt(LIS.getMBBEndIdx(*PI).getPrevSlot()))
+ EqClass.join(VNI->id, PVNI->id);
+ } else {
+ // Normal value defined by an instruction. Check for two-addr redef.
+ // FIXME: This could be coincidental. Should we really check for a tied
+ // operand constraint?
+ // Note that VNI->def may be a use slot for an early clobber def.
+ if (const VNInfo *UVNI = LI->getVNInfoAt(VNI->def.getPrevSlot()))
+ EqClass.join(VNI->id, UVNI->id);
+ }
+ }
+
+ // Lump all the unused values in with the last used value.
+ if (used && unused)
+ EqClass.join(used->id, unused->id);
+
+ EqClass.compress();
+ return EqClass.getNumClasses();
+}
+
+void ConnectedVNInfoEqClasses::Distribute(LiveInterval *LIV[],
+ MachineRegisterInfo &MRI) {
+ assert(LIV[0] && "LIV[0] must be set");
+ LiveInterval &LI = *LIV[0];
+
+ // Rewrite instructions.
+ for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LI.reg),
+ RE = MRI.reg_end(); RI != RE;) {
+ MachineOperand &MO = RI.getOperand();
+ MachineInstr *MI = MO.getParent();
+ ++RI;
+ if (MO.isUse() && MO.isUndef())
+ continue;
+ // DBG_VALUE instructions should have been eliminated earlier.
+ SlotIndex Idx = LIS.getInstructionIndex(MI);
+ Idx = MO.isUse() ? Idx.getUseIndex() : Idx.getDefIndex();
+ const VNInfo *VNI = LI.getVNInfoAt(Idx);
+ assert(VNI && "Interval not live at use.");
+ MO.setReg(LIV[getEqClass(VNI)]->reg);
+ }
+
+ // Move runs to new intervals.
+ LiveInterval::iterator J = LI.begin(), E = LI.end();
+ while (J != E && EqClass[J->valno->id] == 0)
+ ++J;
+ for (LiveInterval::iterator I = J; I != E; ++I) {
+ if (unsigned eq = EqClass[I->valno->id]) {
+ assert((LIV[eq]->empty() || LIV[eq]->expiredAt(I->start)) &&
+ "New intervals should be empty");
+ LIV[eq]->ranges.push_back(*I);
+ } else
+ *J++ = *I;
+ }
+ LI.ranges.erase(J, E);
+
+ // Transfer VNInfos to their new owners and renumber them.
+ unsigned j = 0, e = LI.getNumValNums();
+ while (j != e && EqClass[j] == 0)
+ ++j;
+ for (unsigned i = j; i != e; ++i) {
+ VNInfo *VNI = LI.getValNumInfo(i);
+ if (unsigned eq = EqClass[i]) {
+ VNI->id = LIV[eq]->getNumValNums();
+ LIV[eq]->valnos.push_back(VNI);
+ } else {
+ VNI->id = j;
+ LI.valnos[j++] = VNI;
+ }
+ }
+ LI.valnos.resize(j);
+}
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