//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/LiveInterval.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Streams.h"
-#include "llvm/Target/MRegisterInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
#include <algorithm>
-#include <map>
#include <ostream>
using namespace llvm;
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(unsigned 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;
+}
+
// overlaps - Return true if the intersection of the two live intervals is
// not empty.
//
return false;
}
+/// overlaps - Return true if the live interval overlaps a range specified
+/// by [Start, End).
+bool LiveInterval::overlaps(unsigned Start, unsigned End) const {
+ assert(Start < End && "Invalid range");
+ const_iterator I = begin();
+ const_iterator E = end();
+ const_iterator si = std::upper_bound(I, E, Start);
+ const_iterator ei = std::upper_bound(I, E, End);
+ if (si != ei)
+ return true;
+ if (si == I)
+ return false;
+ --si;
+ return si->contains(Start);
+}
+
/// extendIntervalEndTo - This method is used when we want to extend the range
/// specified by I to end at the specified endpoint. To do this, we should
/// merge and eliminate all ranges that this will overlap with. The iterator is
ranges.erase(next(I), MergeTo);
// Update kill info.
- removeKills(*ValNo, OldEnd, I->end-1);
+ removeKills(ValNo, OldEnd, I->end-1);
// If the newly formed range now touches the range after it and if they have
// the same value number, merge the two ranges into one range.
// Otherwise, if this range ends in the middle of, or right next to, another
// interval, merge it into that interval.
- if (it != ranges.end())
+ if (it != ranges.end()) {
if (LR.valno == it->valno) {
if (it->start <= End) {
it = extendIntervalStartTo(it, Start);
// endpoint as well.
if (End > it->end)
extendIntervalEndTo(it, End);
+ else if (End < it->end)
+ // Overlapping intervals, there might have been a kill here.
+ removeKill(it->valno, End);
return it;
}
} else {
assert(it->start >= End &&
"Cannot overlap two LiveRanges with differing ValID's");
}
+ }
// Otherwise, this is just a new range that doesn't interact with anything.
// Insert it.
return ranges.insert(it, LR);
}
+/// isInOneLiveRange - Return true if the range specified is entirely in the
+/// a single LiveRange of the live interval.
+bool LiveInterval::isInOneLiveRange(unsigned Start, unsigned End) {
+ Ranges::iterator I = std::upper_bound(ranges.begin(), ranges.end(), Start);
+ if (I == ranges.begin())
+ return false;
+ --I;
+ return I->contains(Start) && I->contains(End-1);
+}
+
/// removeRange - Remove the specified range from this interval. Note that
-/// the range must already be in this interval in its entirety.
-void LiveInterval::removeRange(unsigned Start, unsigned End) {
+/// the range must be in a single LiveRange in its entirety.
+void LiveInterval::removeRange(unsigned Start, unsigned 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!");
"Range is not entirely in interval!");
// If the span we are removing is at the start of the LiveRange, adjust it.
+ VNInfo *ValNo = I->valno;
if (I->start == Start) {
if (I->end == End) {
- removeKills(*I->valno, Start, End);
+ removeKills(I->valno, Start, End);
+ if (RemoveDeadValNo) {
+ // Check if val# is dead.
+ bool isDead = true;
+ for (const_iterator II = begin(), EE = end(); II != EE; ++II)
+ if (II != I && II->valno == ValNo) {
+ isDead = false;
+ break;
+ }
+ if (isDead) {
+ // Now that ValNo is dead, remove it. If it is the largest value
+ // number, just nuke it (and any other deleted values neighboring it),
+ // otherwise mark it as ~1U so it can be nuked later.
+ if (ValNo->id == getNumValNums()-1) {
+ do {
+ VNInfo *VNI = valnos.back();
+ valnos.pop_back();
+ VNI->~VNInfo();
+ } while (!valnos.empty() && valnos.back()->isUnused());
+ } else {
+ ValNo->setIsUnused(true);
+ }
+ }
+ }
+
ranges.erase(I); // Removed the whole LiveRange.
} else
I->start = End;
// Otherwise if the span we are removing is at the end of the LiveRange,
// adjust the other way.
if (I->end == End) {
- removeKills(*I->valno, Start, End);
+ removeKills(ValNo, Start, End);
I->end = Start;
return;
}
I->end = Start; // Trim the old interval.
// Insert the new one.
- ranges.insert(next(I), LiveRange(End, OldEnd, I->valno));
+ ranges.insert(next(I), LiveRange(End, OldEnd, ValNo));
+}
+
+/// removeValNo - Remove all the ranges defined by the specified value#.
+/// Also remove the value# from value# list.
+void LiveInterval::removeValNo(VNInfo *ValNo) {
+ if (empty()) return;
+ Ranges::iterator I = ranges.end();
+ Ranges::iterator E = ranges.begin();
+ do {
+ --I;
+ if (I->valno == ValNo)
+ ranges.erase(I);
+ } while (I != E);
+ // Now that ValNo is dead, remove it. If it is the largest value
+ // number, just nuke it (and any other deleted values neighboring it),
+ // otherwise mark it as ~1U so it can be nuked later.
+ if (ValNo->id == getNumValNums()-1) {
+ do {
+ VNInfo *VNI = valnos.back();
+ valnos.pop_back();
+ VNI->~VNInfo();
+ } while (!valnos.empty() && valnos.back()->isUnused());
+ } else {
+ ValNo->setIsUnused(true);
+ }
+}
+
+/// scaleNumbering - Renumber VNI and ranges to provide gaps for new
+/// instructions.
+void LiveInterval::scaleNumbering(unsigned factor) {
+ // Scale ranges.
+ for (iterator RI = begin(), RE = end(); RI != RE; ++RI) {
+ RI->start = InstrSlots::scale(RI->start, factor);
+ RI->end = InstrSlots::scale(RI->end, factor);
+ }
+
+ // Scale VNI info.
+ for (vni_iterator VNI = vni_begin(), VNIE = vni_end(); VNI != VNIE; ++VNI) {
+ VNInfo *vni = *VNI;
+
+ if (vni->isDefAccurate())
+ vni->def = InstrSlots::scale(vni->def, factor);
+
+ for (unsigned i = 0; i < vni->kills.size(); ++i) {
+ if (!vni->kills[i].isPHIKill)
+ vni->kills[i].killIdx =
+ InstrSlots::scale(vni->kills[i].killIdx, factor);
+ }
+ }
}
/// getLiveRangeContaining - Return the live range that contains the
return end();
}
+/// findDefinedVNInfo - Find the VNInfo that's defined at the specified index
+/// (register interval) or defined by the specified register (stack inteval).
+VNInfo *LiveInterval::findDefinedVNInfo(unsigned DefIdxOrReg) const {
+ VNInfo *VNI = NULL;
+ for (LiveInterval::const_vni_iterator i = vni_begin(), e = vni_end();
+ i != e; ++i)
+ if ((*i)->def == DefIdxOrReg) {
+ VNI = *i;
+ break;
+ }
+ return VNI;
+}
+
/// 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::join(LiveInterval &Other, int *LHSValNoAssignments,
- int *RHSValNoAssignments,
- SmallVector<VNInfo*, 16> &NewVNInfo) {
-
- // There might be some dead val#, create VNInfo for them.
- for (unsigned i = 0, e = NewVNInfo.size(); i != e; ++i) {
- VNInfo *VNI = NewVNInfo[i];
- if (!VNI) {
- VNI = new VNInfo(this, i, ~1U, 0);
- NewVNInfo[i] = VNI;
- }
- }
-
+void LiveInterval::join(LiveInterval &Other, const int *LHSValNoAssignments,
+ const int *RHSValNoAssignments,
+ SmallVector<VNInfo*, 16> &NewVNInfo,
+ MachineRegisterInfo *MRI) {
// Determine if any of our live range values are mapped. This is uncommon, so
- // we want to avoid the interval scan if not.
+ // we want to avoid the interval scan if not.
bool MustMapCurValNos = false;
- for (vni_iterator i = vni_begin(), e = vni_end(); i != e; ++i) {
- VNInfo *VNI = *i;
- unsigned VN = VNI->id;
- if (VNI->def == ~1U) continue; // tombstone value #
- if (VNI != NewVNInfo[LHSValNoAssignments[VN]]) {
+ unsigned NumVals = getNumValNums();
+ unsigned NumNewVals = NewVNInfo.size();
+ for (unsigned i = 0; i != NumVals; ++i) {
+ unsigned LHSValID = LHSValNoAssignments[i];
+ if (i != LHSValID ||
+ (NewVNInfo[LHSValID] && NewVNInfo[LHSValID] != getValNumInfo(i)))
MustMapCurValNos = true;
- break;
- }
}
// If we have to apply a mapping to our base interval assignment, rewrite it
}
// Remember assignements because val# ids are changing.
- std::vector<unsigned> OtherAssignments;
+ SmallVector<unsigned, 16> OtherAssignments;
for (iterator I = Other.begin(), E = Other.end(); I != E; ++I)
OtherAssignments.push_back(RHSValNoAssignments[I->valno->id]);
// Update val# info. Renumber them and make sure they all belong to this
- // LiveInterval now.
- valnos.clear();
- numvals = 0;
- for (unsigned i = 0, e = NewVNInfo.size(); i != e; ++i) {
+ // LiveInterval now. Also remove dead val#'s.
+ unsigned NumValNos = 0;
+ for (unsigned i = 0; i < NumNewVals; ++i) {
VNInfo *VNI = NewVNInfo[i];
- VNI->parent = this;
- VNI->id = i; // Renumber val#.
- valnos.push_back(VNI);
- ++numvals;
+ if (VNI) {
+ if (NumValNos >= NumVals)
+ valnos.push_back(VNI);
+ else
+ valnos[NumValNos] = VNI;
+ VNI->id = NumValNos++; // Renumber val#.
+ }
}
+ if (NumNewVals < NumVals)
+ valnos.resize(NumNewVals); // shrinkify
// Okay, now insert the RHS live ranges into the LHS.
iterator InsertPos = begin();
for (iterator I = Other.begin(), E = Other.end(); I != E; ++I, ++RangeNo) {
// Map the valno in the other live range to the current live range.
I->valno = NewVNInfo[OtherAssignments[RangeNo]];
+ assert(I->valno && "Adding a dead range?");
InsertPos = addRangeFrom(*I, InsertPos);
}
- weight += Other.weight;
- if (Other.preference && !preference)
- preference = Other.preference;
+ ComputeJoinedWeight(Other);
+
+ // Update regalloc hint if currently there isn't one.
+ if (TargetRegisterInfo::isVirtualRegister(reg) &&
+ TargetRegisterInfo::isVirtualRegister(Other.reg)) {
+ std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(reg);
+ if (Hint.first == 0 && Hint.second == 0) {
+ std::pair<unsigned, unsigned> OtherHint =
+ MRI->getRegAllocationHint(Other.reg);
+ if (OtherHint.first || OtherHint.second)
+ MRI->setRegAllocationHint(reg, OtherHint.first, OtherHint.second);
+ }
+ }
}
/// MergeRangesInAsValue - Merge all of the intervals in RHS into this live
}
-/// MergeInClobberRanges - For any live ranges that are not defined in the
-/// current interval, but are defined in the Clobbers interval, mark them
-/// used with an unknown definition value.
-void LiveInterval::MergeInClobberRanges(const LiveInterval &Clobbers) {
- if (Clobbers.begin() == Clobbers.end()) return;
-
- // Find a value # to use for the clobber ranges. If there is already a value#
- // for unknown values, use it.
- // FIXME: Use a single sentinal number for these!
- VNInfo *ClobberValNo = getNextValue(~0U, 0);
-
+/// MergeValueInAsValue - Merge all of the live ranges of a specific val#
+/// in RHS into this live interval as the specified value number.
+/// The LiveRanges in RHS are allowed to overlap with LiveRanges in the
+/// current interval, it will replace the value numbers of the overlaped
+/// live ranges with the specified value number.
+void LiveInterval::MergeValueInAsValue(const LiveInterval &RHS,
+ const VNInfo *RHSValNo, VNInfo *LHSValNo) {
+ SmallVector<VNInfo*, 4> ReplacedValNos;
iterator IP = begin();
- for (const_iterator I = Clobbers.begin(), E = Clobbers.end(); I != E; ++I) {
+ for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) {
+ if (I->valno != RHSValNo)
+ continue;
unsigned 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;
}
- // Insert the clobber interval.
- IP = addRangeFrom(LiveRange(Start, End, ClobberValNo), IP);
+ // 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. If it is the largest value number,
+ // just nuke it (and any other deleted values neighboring it), otherwise
+ // mark it as ~1U so it can be nuked later.
+ if (V1->id == getNumValNums()-1) {
+ do {
+ VNInfo *VNI = valnos.back();
+ valnos.pop_back();
+ VNI->~VNInfo();
+ } while (!valnos.empty() && valnos.back()->isUnused());
+ } else {
+ V1->setIsUnused(true);
+ }
+ }
+ }
}
}
+
+/// MergeInClobberRanges - For any live ranges that are not defined in the
+/// current interval, but are defined in the Clobbers interval, mark them
+/// used with an unknown definition value.
+void LiveInterval::MergeInClobberRanges(const LiveInterval &Clobbers,
+ BumpPtrAllocator &VNInfoAllocator) {
+ if (Clobbers.empty()) return;
+
+ DenseMap<VNInfo*, VNInfo*> ValNoMaps;
+ VNInfo *UnusedValNo = 0;
+ iterator IP = begin();
+ for (const_iterator I = Clobbers.begin(), E = Clobbers.end(); I != E; ++I) {
+ // For every val# in the Clobbers interval, create a new "unknown" val#.
+ VNInfo *ClobberValNo = 0;
+ DenseMap<VNInfo*, VNInfo*>::iterator VI = ValNoMaps.find(I->valno);
+ if (VI != ValNoMaps.end())
+ ClobberValNo = VI->second;
+ else if (UnusedValNo)
+ ClobberValNo = UnusedValNo;
+ else {
+ UnusedValNo = ClobberValNo = getNextValue(0, 0, false, VNInfoAllocator);
+ ValNoMaps.insert(std::make_pair(I->valno, ClobberValNo));
+ }
+
+ bool Done = false;
+ unsigned Start = I->start, End = I->end;
+ // If a clobber range starts before an existing range and ends after
+ // it, the clobber range will need to be split into multiple ranges.
+ // Loop until the entire clobber range is handled.
+ while (!Done) {
+ Done = true;
+ IP = std::upper_bound(IP, end(), Start);
+ unsigned SubRangeStart = Start;
+ unsigned SubRangeEnd = End;
+
+ // If the start of this range overlaps with an existing liverange, trim it.
+ if (IP != begin() && IP[-1].end > SubRangeStart) {
+ SubRangeStart = IP[-1].end;
+ // Trimmed away the whole range?
+ if (SubRangeStart >= SubRangeEnd) continue;
+ }
+ // If the end of this range overlaps with an existing liverange, trim it.
+ if (IP != end() && SubRangeEnd > IP->start) {
+ // If the clobber live range extends beyond the existing live range,
+ // it'll need at least another live range, so set the flag to keep
+ // iterating.
+ if (SubRangeEnd > IP->end) {
+ Start = IP->end;
+ Done = false;
+ }
+ SubRangeEnd = IP->start;
+ // If this trimmed away the whole range, ignore it.
+ if (SubRangeStart == SubRangeEnd) continue;
+ }
+
+ // Insert the clobber interval.
+ IP = addRangeFrom(LiveRange(SubRangeStart, SubRangeEnd, ClobberValNo),
+ IP);
+ UnusedValNo = 0;
+ }
+ }
+
+ if (UnusedValNo) {
+ // Delete the last unused val#.
+ valnos.pop_back();
+ UnusedValNo->~VNInfo();
+ }
+}
+
+void LiveInterval::MergeInClobberRange(unsigned Start, unsigned End,
+ BumpPtrAllocator &VNInfoAllocator) {
+ // Find a value # to use for the clobber ranges. If there is already a value#
+ // for unknown values, use it.
+ VNInfo *ClobberValNo = getNextValue(0, 0, false, VNInfoAllocator);
+
+ iterator IP = begin();
+ 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) {
+ Start = IP[-1].end;
+ // Trimmed away the whole range?
+ if (Start >= End) return;
+ }
+ // If the end of this range overlaps with an existing liverange, trim it.
+ if (IP != end() && End > IP->start) {
+ End = IP->start;
+ // If this trimmed away the whole range, ignore it.
+ if (Start == End) return;
+ }
+
+ // Insert the clobber interval.
+ addRangeFrom(LiveRange(Start, End, ClobberValNo), IP);
+}
+
/// 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
/// cause merging of V1/V2 values numbers and compaction of the value space.
-void LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) {
+VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) {
assert(V1 != V2 && "Identical value#'s are always equivalent!");
// This code actually merges the (numerically) larger value number into the
// Make sure V2 is smaller than V1.
if (V1->id < V2->id) {
- copyValNumInfo(*V1, *V2);
+ copyValNumInfo(V1, V2);
std::swap(V1, V2);
}
do {
VNInfo *VNI = valnos.back();
valnos.pop_back();
- delete VNI;
- --numvals;
- } while (valnos.back()->def == ~1U);
+ VNI->~VNInfo();
+ } while (valnos.back()->isUnused());
} else {
- V1->def = ~1U;
+ V1->setIsUnused(true);
+ }
+
+ return V2;
+}
+
+void LiveInterval::Copy(const LiveInterval &RHS,
+ MachineRegisterInfo *MRI,
+ BumpPtrAllocator &VNInfoAllocator) {
+ ranges.clear();
+ valnos.clear();
+ std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(RHS.reg);
+ MRI->setRegAllocationHint(reg, Hint.first, Hint.second);
+
+ weight = RHS.weight;
+ for (unsigned i = 0, e = RHS.getNumValNums(); i != e; ++i) {
+ const VNInfo *VNI = RHS.getValNumInfo(i);
+ createValueCopy(VNI, VNInfoAllocator);
+ }
+ for (unsigned i = 0, e = RHS.ranges.size(); i != e; ++i) {
+ const LiveRange &LR = RHS.ranges[i];
+ addRange(LiveRange(LR.start, LR.end, getValNumInfo(LR.valno->id)));
}
}
return Sum;
}
+/// ComputeJoinedWeight - Set the weight of a live interval Joined
+/// after Other has been merged into it.
+void LiveInterval::ComputeJoinedWeight(const LiveInterval &Other) {
+ // If either of these intervals was spilled, the weight is the
+ // weight of the non-spilled interval. This can only happen with
+ // iterative coalescers.
+
+ if (Other.weight != HUGE_VALF) {
+ weight += Other.weight;
+ }
+ else if (weight == HUGE_VALF &&
+ !TargetRegisterInfo::isPhysicalRegister(reg)) {
+ // Remove this assert if you have an iterative coalescer
+ assert(0 && "Joining to spilled interval");
+ weight = Other.weight;
+ }
+ else {
+ // Otherwise the weight stays the same
+ // Remove this assert if you have an iterative coalescer
+ assert(0 && "Joining from spilled interval");
+ }
+}
+
std::ostream& llvm::operator<<(std::ostream& os, const LiveRange &LR) {
return os << '[' << LR.start << ',' << LR.end << ':' << LR.valno->id << ")";
}
cerr << *this << "\n";
}
-void LiveInterval::print(std::ostream &OS, const MRegisterInfo *MRI) const {
- if (MRI && MRegisterInfo::isPhysicalRegister(reg))
- OS << MRI->getName(reg);
+void LiveInterval::print(std::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;
if (empty())
- OS << "EMPTY";
+ OS << " EMPTY";
else {
OS << " = ";
for (LiveInterval::Ranges::const_iterator I = ranges.begin(),
const VNInfo *vni = *i;
if (vnum) OS << " ";
OS << vnum << "@";
- if (vni->def == ~1U) {
+ if (vni->isUnused()) {
OS << "x";
} else {
- if (vni->def == ~0U)
+ if (!vni->isDefAccurate())
OS << "?";
else
OS << vni->def;
unsigned ee = vni->kills.size();
- if (ee) {
+ if (ee || vni->hasPHIKill()) {
OS << "-(";
for (unsigned j = 0; j != ee; ++j) {
- OS << vni->kills[j];
+ OS << vni->kills[j].killIdx;
+ if (vni->kills[j].isPHIKill)
+ OS << "*";
if (j != ee-1)
OS << " ";
}
+ if (vni->hasPHIKill()) {
+ if (ee)
+ OS << " ";
+ OS << "phi";
+ }
OS << ")";
}
}