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Diffstat (limited to 'contrib/llvm/lib/CodeGen/LiveInterval.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/LiveInterval.cpp | 1416 |
1 files changed, 0 insertions, 1416 deletions
diff --git a/contrib/llvm/lib/CodeGen/LiveInterval.cpp b/contrib/llvm/lib/CodeGen/LiveInterval.cpp deleted file mode 100644 index 70b2a77fe800..000000000000 --- a/contrib/llvm/lib/CodeGen/LiveInterval.cpp +++ /dev/null @@ -1,1416 +0,0 @@ -//===- LiveInterval.cpp - Live Interval Representation --------------------===// -// -// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. -// See https://llvm.org/LICENSE.txt for license information. -// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception -// -//===----------------------------------------------------------------------===// -// -// This file implements the LiveRange and LiveInterval classes. Given some -// numbering of each the machine instructions an interval [i, j) is said to be a -// live range for register v if there is no instruction with number j' >= j -// such that v is live at j' and there is no instruction with number i' < i such -// that v is live at i'. In this implementation ranges can have holes, -// i.e. a range might look like [1,20), [50,65), [1000,1001). Each -// individual segment is represented as an instance of LiveRange::Segment, -// and the whole range is represented as an instance of LiveRange. -// -//===----------------------------------------------------------------------===// - -#include "llvm/CodeGen/LiveInterval.h" -#include "LiveRangeUtils.h" -#include "RegisterCoalescer.h" -#include "llvm/ADT/ArrayRef.h" -#include "llvm/ADT/STLExtras.h" -#include "llvm/ADT/SmallPtrSet.h" -#include "llvm/ADT/SmallVector.h" -#include "llvm/ADT/iterator_range.h" -#include "llvm/CodeGen/LiveIntervals.h" -#include "llvm/CodeGen/MachineBasicBlock.h" -#include "llvm/CodeGen/MachineInstr.h" -#include "llvm/CodeGen/MachineOperand.h" -#include "llvm/CodeGen/MachineRegisterInfo.h" -#include "llvm/CodeGen/SlotIndexes.h" -#include "llvm/CodeGen/TargetRegisterInfo.h" -#include "llvm/Config/llvm-config.h" -#include "llvm/MC/LaneBitmask.h" -#include "llvm/Support/Compiler.h" -#include "llvm/Support/Debug.h" -#include "llvm/Support/raw_ostream.h" -#include <algorithm> -#include <cassert> -#include <cstddef> -#include <iterator> -#include <utility> - -using namespace llvm; - -namespace { - -//===----------------------------------------------------------------------===// -// Implementation of various methods necessary for calculation of live ranges. -// The implementation of the methods abstracts from the concrete type of the -// segment collection. -// -// Implementation of the class follows the Template design pattern. The base -// class contains generic algorithms that call collection-specific methods, -// which are provided in concrete subclasses. In order to avoid virtual calls -// these methods are provided by means of C++ template instantiation. -// The base class calls the methods of the subclass through method impl(), -// which casts 'this' pointer to the type of the subclass. -// -//===----------------------------------------------------------------------===// - -template <typename ImplT, typename IteratorT, typename CollectionT> -class CalcLiveRangeUtilBase { -protected: - LiveRange *LR; - -protected: - CalcLiveRangeUtilBase(LiveRange *LR) : LR(LR) {} - -public: - using Segment = LiveRange::Segment; - using iterator = IteratorT; - - /// A counterpart of LiveRange::createDeadDef: Make sure the range has a - /// value defined at @p Def. - /// If @p ForVNI is null, and there is no value defined at @p Def, a new - /// value will be allocated using @p VNInfoAllocator. - /// If @p ForVNI is null, the return value is the value defined at @p Def, - /// either a pre-existing one, or the one newly created. - /// If @p ForVNI is not null, then @p Def should be the location where - /// @p ForVNI is defined. If the range does not have a value defined at - /// @p Def, the value @p ForVNI will be used instead of allocating a new - /// one. If the range already has a value defined at @p Def, it must be - /// same as @p ForVNI. In either case, @p ForVNI will be the return value. - VNInfo *createDeadDef(SlotIndex Def, VNInfo::Allocator *VNInfoAllocator, - VNInfo *ForVNI) { - assert(!Def.isDead() && "Cannot define a value at the dead slot"); - assert((!ForVNI || ForVNI->def == Def) && - "If ForVNI is specified, it must match Def"); - iterator I = impl().find(Def); - if (I == segments().end()) { - VNInfo *VNI = ForVNI ? ForVNI : LR->getNextValue(Def, *VNInfoAllocator); - impl().insertAtEnd(Segment(Def, Def.getDeadSlot(), VNI)); - return VNI; - } - - Segment *S = segmentAt(I); - if (SlotIndex::isSameInstr(Def, S->start)) { - assert((!ForVNI || ForVNI == S->valno) && "Value number mismatch"); - assert(S->valno->def == S->start && "Inconsistent existing value def"); - - // It is possible to have both normal and early-clobber defs of the same - // register on an instruction. It doesn't make a lot of sense, but it is - // possible to specify in inline assembly. - // - // Just convert everything to early-clobber. - Def = std::min(Def, S->start); - if (Def != S->start) - S->start = S->valno->def = Def; - return S->valno; - } - assert(SlotIndex::isEarlierInstr(Def, S->start) && "Already live at def"); - VNInfo *VNI = ForVNI ? ForVNI : LR->getNextValue(Def, *VNInfoAllocator); - segments().insert(I, Segment(Def, Def.getDeadSlot(), VNI)); - return VNI; - } - - VNInfo *extendInBlock(SlotIndex StartIdx, SlotIndex Use) { - if (segments().empty()) - return nullptr; - iterator I = - impl().findInsertPos(Segment(Use.getPrevSlot(), Use, nullptr)); - if (I == segments().begin()) - return nullptr; - --I; - if (I->end <= StartIdx) - return nullptr; - if (I->end < Use) - extendSegmentEndTo(I, Use); - return I->valno; - } - - std::pair<VNInfo*,bool> extendInBlock(ArrayRef<SlotIndex> Undefs, - SlotIndex StartIdx, SlotIndex Use) { - if (segments().empty()) - return std::make_pair(nullptr, false); - SlotIndex BeforeUse = Use.getPrevSlot(); - iterator I = impl().findInsertPos(Segment(BeforeUse, Use, nullptr)); - if (I == segments().begin()) - return std::make_pair(nullptr, LR->isUndefIn(Undefs, StartIdx, BeforeUse)); - --I; - if (I->end <= StartIdx) - return std::make_pair(nullptr, LR->isUndefIn(Undefs, StartIdx, BeforeUse)); - if (I->end < Use) { - if (LR->isUndefIn(Undefs, I->end, BeforeUse)) - return std::make_pair(nullptr, true); - extendSegmentEndTo(I, Use); - } - return std::make_pair(I->valno, false); - } - - /// This method is used when we want to extend the segment specified - /// by I to end at the specified endpoint. To do this, we should - /// merge and eliminate all segments that this will overlap - /// with. The iterator is not invalidated. - void extendSegmentEndTo(iterator I, SlotIndex NewEnd) { - assert(I != segments().end() && "Not a valid segment!"); - Segment *S = segmentAt(I); - VNInfo *ValNo = I->valno; - - // Search for the first segment that we can't merge with. - iterator MergeTo = std::next(I); - for (; MergeTo != segments().end() && NewEnd >= MergeTo->end; ++MergeTo) - assert(MergeTo->valno == ValNo && "Cannot merge with differing values!"); - - // If NewEnd was in the middle of a segment, make sure to get its endpoint. - S->end = std::max(NewEnd, std::prev(MergeTo)->end); - - // If the newly formed segment now touches the segment after it and if they - // have the same value number, merge the two segments into one segment. - if (MergeTo != segments().end() && MergeTo->start <= I->end && - MergeTo->valno == ValNo) { - S->end = MergeTo->end; - ++MergeTo; - } - - // Erase any dead segments. - segments().erase(std::next(I), MergeTo); - } - - /// This method is used when we want to extend the segment specified - /// by I to start at the specified endpoint. To do this, we should - /// merge and eliminate all segments that this will overlap with. - iterator extendSegmentStartTo(iterator I, SlotIndex NewStart) { - assert(I != segments().end() && "Not a valid segment!"); - Segment *S = segmentAt(I); - VNInfo *ValNo = I->valno; - - // Search for the first segment that we can't merge with. - iterator MergeTo = I; - do { - if (MergeTo == segments().begin()) { - S->start = NewStart; - segments().erase(MergeTo, I); - return I; - } - assert(MergeTo->valno == ValNo && "Cannot merge with differing values!"); - --MergeTo; - } while (NewStart <= MergeTo->start); - - // If we start in the middle of another segment, just delete a range and - // extend that segment. - if (MergeTo->end >= NewStart && MergeTo->valno == ValNo) { - segmentAt(MergeTo)->end = S->end; - } else { - // Otherwise, extend the segment right after. - ++MergeTo; - Segment *MergeToSeg = segmentAt(MergeTo); - MergeToSeg->start = NewStart; - MergeToSeg->end = S->end; - } - - segments().erase(std::next(MergeTo), std::next(I)); - return MergeTo; - } - - iterator addSegment(Segment S) { - SlotIndex Start = S.start, End = S.end; - iterator I = impl().findInsertPos(S); - - // If the inserted segment starts in the middle or right at the end of - // another segment, just extend that segment to contain the segment of S. - if (I != segments().begin()) { - iterator B = std::prev(I); - if (S.valno == B->valno) { - if (B->start <= Start && B->end >= Start) { - extendSegmentEndTo(B, End); - return B; - } - } else { - // Check to make sure that we are not overlapping two live segments with - // different valno's. - assert(B->end <= Start && - "Cannot overlap two segments with differing ValID's" - " (did you def the same reg twice in a MachineInstr?)"); - } - } - - // Otherwise, if this segment ends in the middle of, or right next - // to, another segment, merge it into that segment. - if (I != segments().end()) { - if (S.valno == I->valno) { - if (I->start <= End) { - I = extendSegmentStartTo(I, Start); - - // If S is a complete superset of a segment, we may need to grow its - // endpoint as well. - if (End > I->end) - extendSegmentEndTo(I, End); - return I; - } - } else { - // Check to make sure that we are not overlapping two live segments with - // different valno's. - assert(I->start >= End && - "Cannot overlap two segments with differing ValID's"); - } - } - - // Otherwise, this is just a new segment that doesn't interact with - // anything. - // Insert it. - return segments().insert(I, S); - } - -private: - ImplT &impl() { return *static_cast<ImplT *>(this); } - - CollectionT &segments() { return impl().segmentsColl(); } - - Segment *segmentAt(iterator I) { return const_cast<Segment *>(&(*I)); } -}; - -//===----------------------------------------------------------------------===// -// Instantiation of the methods for calculation of live ranges -// based on a segment vector. -//===----------------------------------------------------------------------===// - -class CalcLiveRangeUtilVector; -using CalcLiveRangeUtilVectorBase = - CalcLiveRangeUtilBase<CalcLiveRangeUtilVector, LiveRange::iterator, - LiveRange::Segments>; - -class CalcLiveRangeUtilVector : public CalcLiveRangeUtilVectorBase { -public: - CalcLiveRangeUtilVector(LiveRange *LR) : CalcLiveRangeUtilVectorBase(LR) {} - -private: - friend CalcLiveRangeUtilVectorBase; - - LiveRange::Segments &segmentsColl() { return LR->segments; } - - void insertAtEnd(const Segment &S) { LR->segments.push_back(S); } - - iterator find(SlotIndex Pos) { return LR->find(Pos); } - - iterator findInsertPos(Segment S) { return llvm::upper_bound(*LR, S.start); } -}; - -//===----------------------------------------------------------------------===// -// Instantiation of the methods for calculation of live ranges -// based on a segment set. -//===----------------------------------------------------------------------===// - -class CalcLiveRangeUtilSet; -using CalcLiveRangeUtilSetBase = - CalcLiveRangeUtilBase<CalcLiveRangeUtilSet, LiveRange::SegmentSet::iterator, - LiveRange::SegmentSet>; - -class CalcLiveRangeUtilSet : public CalcLiveRangeUtilSetBase { -public: - CalcLiveRangeUtilSet(LiveRange *LR) : CalcLiveRangeUtilSetBase(LR) {} - -private: - friend CalcLiveRangeUtilSetBase; - - LiveRange::SegmentSet &segmentsColl() { return *LR->segmentSet; } - - void insertAtEnd(const Segment &S) { - LR->segmentSet->insert(LR->segmentSet->end(), S); - } - - iterator find(SlotIndex Pos) { - iterator I = - LR->segmentSet->upper_bound(Segment(Pos, Pos.getNextSlot(), nullptr)); - if (I == LR->segmentSet->begin()) - return I; - iterator PrevI = std::prev(I); - if (Pos < (*PrevI).end) - return PrevI; - return I; - } - - iterator findInsertPos(Segment S) { - iterator I = LR->segmentSet->upper_bound(S); - if (I != LR->segmentSet->end() && !(S.start < *I)) - ++I; - return I; - } -}; - -} // end anonymous namespace - -//===----------------------------------------------------------------------===// -// LiveRange methods -//===----------------------------------------------------------------------===// - -LiveRange::iterator LiveRange::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 = 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; -} - -VNInfo *LiveRange::createDeadDef(SlotIndex Def, VNInfo::Allocator &VNIAlloc) { - // Use the segment set, if it is available. - if (segmentSet != nullptr) - return CalcLiveRangeUtilSet(this).createDeadDef(Def, &VNIAlloc, nullptr); - // Otherwise use the segment vector. - return CalcLiveRangeUtilVector(this).createDeadDef(Def, &VNIAlloc, nullptr); -} - -VNInfo *LiveRange::createDeadDef(VNInfo *VNI) { - // Use the segment set, if it is available. - if (segmentSet != nullptr) - return CalcLiveRangeUtilSet(this).createDeadDef(VNI->def, nullptr, VNI); - // Otherwise use the segment vector. - return CalcLiveRangeUtilVector(this).createDeadDef(VNI->def, nullptr, VNI); -} - -// overlaps - Return true if the intersection of the two live ranges is -// not empty. -// -// An example for overlaps(): -// -// 0: A = ... -// 4: B = ... -// 8: C = A + B ;; last use of A -// -// The live ranges should look like: -// -// A = [3, 11) -// B = [7, x) -// C = [11, y) -// -// A->overlaps(C) should return false since we want to be able to join -// A and C. -// -bool LiveRange::overlapsFrom(const LiveRange& other, - const_iterator StartPos) const { - assert(!empty() && "empty range"); - const_iterator i = begin(); - const_iterator ie = end(); - const_iterator j = StartPos; - const_iterator je = other.end(); - - assert((StartPos->start <= i->start || StartPos == other.begin()) && - StartPos != other.end() && "Bogus start position hint!"); - - if (i->start < j->start) { - i = std::upper_bound(i, ie, j->start); - if (i != begin()) --i; - } else if (j->start < i->start) { - ++StartPos; - if (StartPos != other.end() && StartPos->start <= i->start) { - assert(StartPos < other.end() && i < end()); - j = std::upper_bound(j, je, i->start); - if (j != other.begin()) --j; - } - } else { - return true; - } - - if (j == je) return false; - - while (i != ie) { - if (i->start > j->start) { - std::swap(i, j); - std::swap(ie, je); - } - - if (i->end > j->start) - return true; - ++i; - } - - return false; -} - -bool LiveRange::overlaps(const LiveRange &Other, const CoalescerPair &CP, - const SlotIndexes &Indexes) const { - assert(!empty() && "empty range"); - if (Other.empty()) - return false; - - // Use binary searches to find initial positions. - const_iterator I = find(Other.beginIndex()); - const_iterator IE = end(); - if (I == IE) - return false; - const_iterator J = Other.find(I->start); - const_iterator JE = Other.end(); - if (J == JE) - return false; - - while (true) { - // J has just been advanced to satisfy: - assert(J->end >= I->start); - // Check for an overlap. - if (J->start < I->end) { - // I and J are overlapping. Find the later start. - SlotIndex Def = std::max(I->start, J->start); - // Allow the overlap if Def is a coalescable copy. - if (Def.isBlock() || - !CP.isCoalescable(Indexes.getInstructionFromIndex(Def))) - return true; - } - // Advance the iterator that ends first to check for more overlaps. - if (J->end > I->end) { - std::swap(I, J); - std::swap(IE, JE); - } - // Advance J until J->end >= I->start. - do - if (++J == JE) - return false; - while (J->end < I->start); - } -} - -/// overlaps - Return true if the live range overlaps an interval specified -/// by [Start, End). -bool LiveRange::overlaps(SlotIndex Start, SlotIndex End) const { - assert(Start < End && "Invalid range"); - const_iterator I = std::lower_bound(begin(), end(), End); - return I != begin() && (--I)->end > Start; -} - -bool LiveRange::covers(const LiveRange &Other) const { - if (empty()) - return Other.empty(); - - const_iterator I = begin(); - for (const Segment &O : Other.segments) { - I = advanceTo(I, O.start); - if (I == end() || I->start > O.start) - return false; - - // Check adjacent live segments and see if we can get behind O.end. - while (I->end < O.end) { - const_iterator Last = I; - // Get next segment and abort if it was not adjacent. - ++I; - if (I == end() || Last->end != I->start) - return false; - } - } - return true; -} - -/// 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. -void LiveRange::markValNoForDeletion(VNInfo *ValNo) { - if (ValNo->id == getNumValNums()-1) { - do { - valnos.pop_back(); - } while (!valnos.empty() && valnos.back()->isUnused()); - } else { - ValNo->markUnused(); - } -} - -/// RenumberValues - Renumber all values in order of appearance and delete the -/// remaining unused values. -void LiveRange::RenumberValues() { - SmallPtrSet<VNInfo*, 8> Seen; - valnos.clear(); - for (const Segment &S : segments) { - VNInfo *VNI = S.valno; - if (!Seen.insert(VNI).second) - continue; - assert(!VNI->isUnused() && "Unused valno used by live segment"); - VNI->id = (unsigned)valnos.size(); - valnos.push_back(VNI); - } -} - -void LiveRange::addSegmentToSet(Segment S) { - CalcLiveRangeUtilSet(this).addSegment(S); -} - -LiveRange::iterator LiveRange::addSegment(Segment S) { - // Use the segment set, if it is available. - if (segmentSet != nullptr) { - addSegmentToSet(S); - return end(); - } - // Otherwise use the segment vector. - return CalcLiveRangeUtilVector(this).addSegment(S); -} - -void LiveRange::append(const Segment S) { - // Check that the segment belongs to the back of the list. - assert(segments.empty() || segments.back().end <= S.start); - segments.push_back(S); -} - -std::pair<VNInfo*,bool> LiveRange::extendInBlock(ArrayRef<SlotIndex> Undefs, - SlotIndex StartIdx, SlotIndex Kill) { - // Use the segment set, if it is available. - if (segmentSet != nullptr) - return CalcLiveRangeUtilSet(this).extendInBlock(Undefs, StartIdx, Kill); - // Otherwise use the segment vector. - return CalcLiveRangeUtilVector(this).extendInBlock(Undefs, StartIdx, Kill); -} - -VNInfo *LiveRange::extendInBlock(SlotIndex StartIdx, SlotIndex Kill) { - // Use the segment set, if it is available. - if (segmentSet != nullptr) - return CalcLiveRangeUtilSet(this).extendInBlock(StartIdx, Kill); - // Otherwise use the segment vector. - return CalcLiveRangeUtilVector(this).extendInBlock(StartIdx, Kill); -} - -/// Remove the specified segment from this range. Note that the segment must -/// be in a single Segment in its entirety. -void LiveRange::removeSegment(SlotIndex Start, SlotIndex End, - bool RemoveDeadValNo) { - // Find the Segment containing this span. - iterator I = find(Start); - assert(I != end() && "Segment is not in range!"); - assert(I->containsInterval(Start, End) - && "Segment is not entirely in range!"); - - // If the span we are removing is at the start of the Segment, adjust it. - VNInfo *ValNo = I->valno; - if (I->start == Start) { - if (I->end == 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. - markValNoForDeletion(ValNo); - } - } - - segments.erase(I); // Removed the whole Segment. - } else - I->start = End; - return; - } - - // Otherwise if the span we are removing is at the end of the Segment, - // adjust the other way. - if (I->end == End) { - I->end = Start; - return; - } - - // Otherwise, we are splitting the Segment into two pieces. - SlotIndex OldEnd = I->end; - I->end = Start; // Trim the old segment. - - // Insert the new one. - segments.insert(std::next(I), Segment(End, OldEnd, ValNo)); -} - -/// removeValNo - Remove all the segments defined by the specified value#. -/// Also remove the value# from value# list. -void LiveRange::removeValNo(VNInfo *ValNo) { - if (empty()) return; - segments.erase(remove_if(*this, [ValNo](const Segment &S) { - return S.valno == ValNo; - }), end()); - // Now that ValNo is dead, remove it. - markValNoForDeletion(ValNo); -} - -void LiveRange::join(LiveRange &Other, - const int *LHSValNoAssignments, - const int *RHSValNoAssignments, - SmallVectorImpl<VNInfo *> &NewVNInfo) { - verify(); - - // Determine if any of our values are mapped. This is uncommon, so we want - // to avoid the range scan if not. - bool MustMapCurValNos = false; - 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 range assignment, rewrite it now. - if (MustMapCurValNos && !empty()) { - // Map the first live range. - - iterator OutIt = begin(); - OutIt->valno = NewVNInfo[LHSValNoAssignments[OutIt->valno->id]]; - for (iterator I = std::next(OutIt), E = end(); I != E; ++I) { - VNInfo* nextValNo = NewVNInfo[LHSValNoAssignments[I->valno->id]]; - assert(nextValNo && "Huh?"); - - // If this live range has the same value # as its immediate predecessor, - // and if they are neighbors, remove one Segment. This happens when we - // have [0,4:0)[4,7:1) and map 0/1 onto the same value #. - if (OutIt->valno == nextValNo && OutIt->end == I->start) { - OutIt->end = I->end; - } else { - // Didn't merge. Move OutIt to the next segment, - ++OutIt; - OutIt->valno = nextValNo; - if (OutIt != I) { - OutIt->start = I->start; - OutIt->end = I->end; - } - } - } - // If we merge some segments, chop off the end. - ++OutIt; - segments.erase(OutIt, end()); - } - - // Rewrite Other values before changing the VNInfo ids. - // This can leave Other in an invalid state because we're not coalescing - // touching segments that now have identical values. That's OK since Other is - // not supposed to be valid after calling join(); - for (Segment &S : Other.segments) - S.valno = NewVNInfo[RHSValNoAssignments[S.valno->id]]; - - // Update val# info. Renumber them and make sure they all belong to this - // LiveRange now. Also remove dead val#'s. - unsigned NumValNos = 0; - for (unsigned i = 0; i < NumNewVals; ++i) { - VNInfo *VNI = NewVNInfo[i]; - 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 segments into the LHS. - LiveRangeUpdater Updater(this); - for (Segment &S : Other.segments) - Updater.add(S); -} - -/// Merge all of the segments in RHS into this live range as the specified -/// value number. The segments in RHS are allowed to overlap with segments in -/// the current range, but only if the overlapping segments have the -/// specified value number. -void LiveRange::MergeSegmentsInAsValue(const LiveRange &RHS, - VNInfo *LHSValNo) { - LiveRangeUpdater Updater(this); - for (const Segment &S : RHS.segments) - Updater.add(S.start, S.end, LHSValNo); -} - -/// MergeValueInAsValue - Merge all of the live segments of a specific val# -/// in RHS into this live range as the specified value number. -/// The segments in RHS are allowed to overlap with segments in the -/// current range, it will replace the value numbers of the overlaped -/// segments with the specified value number. -void LiveRange::MergeValueInAsValue(const LiveRange &RHS, - const VNInfo *RHSValNo, - VNInfo *LHSValNo) { - LiveRangeUpdater Updater(this); - for (const Segment &S : RHS.segments) - if (S.valno == RHSValNo) - Updater.add(S.start, S.end, LHSValNo); -} - -/// MergeValueNumberInto - This method is called when two value nubmers -/// are found to be equivalent. This eliminates V1, replacing all -/// segments 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. -VNInfo *LiveRange::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 - // smaller value number, which is likely to allow us to compactify the value - // space. The only thing we have to be careful of is to preserve the - // instruction that defines the result value. - - // Make sure V2 is smaller than V1. - if (V1->id < V2->id) { - V1->copyFrom(*V2); - std::swap(V1, V2); - } - - // Merge V1 segments into V2. - for (iterator I = begin(); I != end(); ) { - iterator S = I++; - if (S->valno != V1) continue; // Not a V1 Segment. - - // Okay, we found a V1 live range. If it had a previous, touching, V2 live - // range, extend it. - if (S != begin()) { - iterator Prev = S-1; - if (Prev->valno == V2 && Prev->end == S->start) { - Prev->end = S->end; - - // Erase this live-range. - segments.erase(S); - I = Prev+1; - S = Prev; - } - } - - // Okay, now we have a V1 or V2 live range that is maximally merged forward. - // Ensure that it is a V2 live-range. - S->valno = V2; - - // If we can merge it into later V2 segments, do so now. We ignore any - // following V1 segments, as they will be merged in subsequent iterations - // of the loop. - if (I != end()) { - if (I->start == S->end && I->valno == V2) { - S->end = I->end; - segments.erase(I); - I = S+1; - } - } - } - - // Now that V1 is dead, remove it. - markValNoForDeletion(V1); - - return V2; -} - -void LiveRange::flushSegmentSet() { - assert(segmentSet != nullptr && "segment set must have been created"); - assert( - segments.empty() && - "segment set can be used only initially before switching to the array"); - segments.append(segmentSet->begin(), segmentSet->end()); - segmentSet = nullptr; - verify(); -} - -bool LiveRange::isLiveAtIndexes(ArrayRef<SlotIndex> Slots) const { - ArrayRef<SlotIndex>::iterator SlotI = Slots.begin(); - ArrayRef<SlotIndex>::iterator SlotE = Slots.end(); - - // If there are no regmask slots, we have nothing to search. - if (SlotI == SlotE) - return false; - - // Start our search at the first segment that ends after the first slot. - const_iterator SegmentI = find(*SlotI); - const_iterator SegmentE = end(); - - // If there are no segments that end after the first slot, we're done. - if (SegmentI == SegmentE) - return false; - - // Look for each slot in the live range. - for ( ; SlotI != SlotE; ++SlotI) { - // Go to the next segment that ends after the current slot. - // The slot may be within a hole in the range. - SegmentI = advanceTo(SegmentI, *SlotI); - if (SegmentI == SegmentE) - return false; - - // If this segment contains the slot, we're done. - if (SegmentI->contains(*SlotI)) - return true; - // Otherwise, look for the next slot. - } - - // We didn't find a segment containing any of the slots. - return false; -} - -void LiveInterval::freeSubRange(SubRange *S) { - S->~SubRange(); - // Memory was allocated with BumpPtr allocator and is not freed here. -} - -void LiveInterval::removeEmptySubRanges() { - SubRange **NextPtr = &SubRanges; - SubRange *I = *NextPtr; - while (I != nullptr) { - if (!I->empty()) { - NextPtr = &I->Next; - I = *NextPtr; - continue; - } - // Skip empty subranges until we find the first nonempty one. - do { - SubRange *Next = I->Next; - freeSubRange(I); - I = Next; - } while (I != nullptr && I->empty()); - *NextPtr = I; - } -} - -void LiveInterval::clearSubRanges() { - for (SubRange *I = SubRanges, *Next; I != nullptr; I = Next) { - Next = I->Next; - freeSubRange(I); - } - SubRanges = nullptr; -} - -/// For each VNI in \p SR, check whether or not that value defines part -/// of the mask describe by \p LaneMask and if not, remove that value -/// from \p SR. -static void stripValuesNotDefiningMask(unsigned Reg, LiveInterval::SubRange &SR, - LaneBitmask LaneMask, - const SlotIndexes &Indexes, - const TargetRegisterInfo &TRI) { - // Phys reg should not be tracked at subreg level. - // Same for noreg (Reg == 0). - if (!TargetRegisterInfo::isVirtualRegister(Reg) || !Reg) - return; - // Remove the values that don't define those lanes. - SmallVector<VNInfo *, 8> ToBeRemoved; - for (VNInfo *VNI : SR.valnos) { - if (VNI->isUnused()) - continue; - // PHI definitions don't have MI attached, so there is nothing - // we can use to strip the VNI. - if (VNI->isPHIDef()) - continue; - const MachineInstr *MI = Indexes.getInstructionFromIndex(VNI->def); - assert(MI && "Cannot find the definition of a value"); - bool hasDef = false; - for (ConstMIBundleOperands MOI(*MI); MOI.isValid(); ++MOI) { - if (!MOI->isReg() || !MOI->isDef()) - continue; - if (MOI->getReg() != Reg) - continue; - if ((TRI.getSubRegIndexLaneMask(MOI->getSubReg()) & LaneMask).none()) - continue; - hasDef = true; - break; - } - - if (!hasDef) - ToBeRemoved.push_back(VNI); - } - for (VNInfo *VNI : ToBeRemoved) - SR.removeValNo(VNI); - - assert(!SR.empty() && "At least one value should be defined by this mask"); -} - -void LiveInterval::refineSubRanges( - BumpPtrAllocator &Allocator, LaneBitmask LaneMask, - std::function<void(LiveInterval::SubRange &)> Apply, - const SlotIndexes &Indexes, const TargetRegisterInfo &TRI) { - LaneBitmask ToApply = LaneMask; - for (SubRange &SR : subranges()) { - LaneBitmask SRMask = SR.LaneMask; - LaneBitmask Matching = SRMask & LaneMask; - if (Matching.none()) - continue; - - SubRange *MatchingRange; - if (SRMask == Matching) { - // The subrange fits (it does not cover bits outside \p LaneMask). - MatchingRange = &SR; - } else { - // We have to split the subrange into a matching and non-matching part. - // Reduce lanemask of existing lane to non-matching part. - SR.LaneMask = SRMask & ~Matching; - // Create a new subrange for the matching part - MatchingRange = createSubRangeFrom(Allocator, Matching, SR); - // Now that the subrange is split in half, make sure we - // only keep in the subranges the VNIs that touch the related half. - stripValuesNotDefiningMask(reg, *MatchingRange, Matching, Indexes, TRI); - stripValuesNotDefiningMask(reg, SR, SR.LaneMask, Indexes, TRI); - } - Apply(*MatchingRange); - ToApply &= ~Matching; - } - // Create a new subrange if there are uncovered bits left. - if (ToApply.any()) { - SubRange *NewRange = createSubRange(Allocator, ToApply); - Apply(*NewRange); - } -} - -unsigned LiveInterval::getSize() const { - unsigned Sum = 0; - for (const Segment &S : segments) - Sum += S.start.distance(S.end); - return Sum; -} - -void LiveInterval::computeSubRangeUndefs(SmallVectorImpl<SlotIndex> &Undefs, - LaneBitmask LaneMask, - const MachineRegisterInfo &MRI, - const SlotIndexes &Indexes) const { - assert(TargetRegisterInfo::isVirtualRegister(reg)); - LaneBitmask VRegMask = MRI.getMaxLaneMaskForVReg(reg); - assert((VRegMask & LaneMask).any()); - const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo(); - for (const MachineOperand &MO : MRI.def_operands(reg)) { - if (!MO.isUndef()) - continue; - unsigned SubReg = MO.getSubReg(); - assert(SubReg != 0 && "Undef should only be set on subreg defs"); - LaneBitmask DefMask = TRI.getSubRegIndexLaneMask(SubReg); - LaneBitmask UndefMask = VRegMask & ~DefMask; - if ((UndefMask & LaneMask).any()) { - const MachineInstr &MI = *MO.getParent(); - bool EarlyClobber = MO.isEarlyClobber(); - SlotIndex Pos = Indexes.getInstructionIndex(MI).getRegSlot(EarlyClobber); - Undefs.push_back(Pos); - } - } -} - -raw_ostream& llvm::operator<<(raw_ostream& OS, const LiveRange::Segment &S) { - return OS << '[' << S.start << ',' << S.end << ':' << S.valno->id << ')'; -} - -#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) -LLVM_DUMP_METHOD void LiveRange::Segment::dump() const { - dbgs() << *this << '\n'; -} -#endif - -void LiveRange::print(raw_ostream &OS) const { - if (empty()) - OS << "EMPTY"; - else { - for (const Segment &S : segments) { - OS << S; - assert(S.valno == getValNumInfo(S.valno->id) && "Bad VNInfo"); - } - } - - // Print value number info. - if (getNumValNums()) { - OS << " "; - unsigned vnum = 0; - for (const_vni_iterator i = vni_begin(), e = vni_end(); i != e; - ++i, ++vnum) { - const VNInfo *vni = *i; - if (vnum) OS << ' '; - OS << vnum << '@'; - if (vni->isUnused()) { - OS << 'x'; - } else { - OS << vni->def; - if (vni->isPHIDef()) - OS << "-phi"; - } - } - } -} - -void LiveInterval::SubRange::print(raw_ostream &OS) const { - OS << " L" << PrintLaneMask(LaneMask) << ' ' - << static_cast<const LiveRange&>(*this); -} - -void LiveInterval::print(raw_ostream &OS) const { - OS << printReg(reg) << ' '; - super::print(OS); - // Print subranges - for (const SubRange &SR : subranges()) - OS << SR; - OS << " weight:" << weight; -} - -#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) -LLVM_DUMP_METHOD void LiveRange::dump() const { - dbgs() << *this << '\n'; -} - -LLVM_DUMP_METHOD void LiveInterval::SubRange::dump() const { - dbgs() << *this << '\n'; -} - -LLVM_DUMP_METHOD void LiveInterval::dump() const { - dbgs() << *this << '\n'; -} -#endif - -#ifndef NDEBUG -void LiveRange::verify() const { - for (const_iterator I = begin(), E = end(); I != E; ++I) { - assert(I->start.isValid()); - assert(I->end.isValid()); - assert(I->start < I->end); - assert(I->valno != nullptr); - assert(I->valno->id < valnos.size()); - assert(I->valno == valnos[I->valno->id]); - if (std::next(I) != E) { - assert(I->end <= std::next(I)->start); - if (I->end == std::next(I)->start) - assert(I->valno != std::next(I)->valno); - } - } -} - -void LiveInterval::verify(const MachineRegisterInfo *MRI) const { - super::verify(); - - // Make sure SubRanges are fine and LaneMasks are disjunct. - LaneBitmask Mask; - LaneBitmask MaxMask = MRI != nullptr ? MRI->getMaxLaneMaskForVReg(reg) - : LaneBitmask::getAll(); - for (const SubRange &SR : subranges()) { - // Subrange lanemask should be disjunct to any previous subrange masks. - assert((Mask & SR.LaneMask).none()); - Mask |= SR.LaneMask; - - // subrange mask should not contained in maximum lane mask for the vreg. - assert((Mask & ~MaxMask).none()); - // empty subranges must be removed. - assert(!SR.empty()); - - SR.verify(); - // Main liverange should cover subrange. - assert(covers(SR)); - } -} -#endif - -//===----------------------------------------------------------------------===// -// LiveRangeUpdater class -//===----------------------------------------------------------------------===// -// -// The LiveRangeUpdater class always maintains these invariants: -// -// - When LastStart is invalid, Spills is empty and the iterators are invalid. -// This is the initial state, and the state created by flush(). -// In this state, isDirty() returns false. -// -// Otherwise, segments are kept in three separate areas: -// -// 1. [begin; WriteI) at the front of LR. -// 2. [ReadI; end) at the back of LR. -// 3. Spills. -// -// - LR.begin() <= WriteI <= ReadI <= LR.end(). -// - Segments in all three areas are fully ordered and coalesced. -// - Segments in area 1 precede and can't coalesce with segments in area 2. -// - Segments in Spills precede and can't coalesce with segments in area 2. -// - No coalescing is possible between segments in Spills and segments in area -// 1, and there are no overlapping segments. -// -// The segments in Spills are not ordered with respect to the segments in area -// 1. They need to be merged. -// -// When they exist, Spills.back().start <= LastStart, -// and WriteI[-1].start <= LastStart. - -#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) -void LiveRangeUpdater::print(raw_ostream &OS) const { - if (!isDirty()) { - if (LR) - OS << "Clean updater: " << *LR << '\n'; - else - OS << "Null updater.\n"; - return; - } - assert(LR && "Can't have null LR in dirty updater."); - OS << " updater with gap = " << (ReadI - WriteI) - << ", last start = " << LastStart - << ":\n Area 1:"; - for (const auto &S : make_range(LR->begin(), WriteI)) - OS << ' ' << S; - OS << "\n Spills:"; - for (unsigned I = 0, E = Spills.size(); I != E; ++I) - OS << ' ' << Spills[I]; - OS << "\n Area 2:"; - for (const auto &S : make_range(ReadI, LR->end())) - OS << ' ' << S; - OS << '\n'; -} - -LLVM_DUMP_METHOD void LiveRangeUpdater::dump() const { - print(errs()); -} -#endif - -// Determine if A and B should be coalesced. -static inline bool coalescable(const LiveRange::Segment &A, - const LiveRange::Segment &B) { - assert(A.start <= B.start && "Unordered live segments."); - if (A.end == B.start) - return A.valno == B.valno; - if (A.end < B.start) - return false; - assert(A.valno == B.valno && "Cannot overlap different values"); - return true; -} - -void LiveRangeUpdater::add(LiveRange::Segment Seg) { - assert(LR && "Cannot add to a null destination"); - - // Fall back to the regular add method if the live range - // is using the segment set instead of the segment vector. - if (LR->segmentSet != nullptr) { - LR->addSegmentToSet(Seg); - return; - } - - // Flush the state if Start moves backwards. - if (!LastStart.isValid() || LastStart > Seg.start) { - if (isDirty()) - flush(); - // This brings us to an uninitialized state. Reinitialize. - assert(Spills.empty() && "Leftover spilled segments"); - WriteI = ReadI = LR->begin(); - } - - // Remember start for next time. - LastStart = Seg.start; - - // Advance ReadI until it ends after Seg.start. - LiveRange::iterator E = LR->end(); - if (ReadI != E && ReadI->end <= Seg.start) { - // First try to close the gap between WriteI and ReadI with spills. - if (ReadI != WriteI) - mergeSpills(); - // Then advance ReadI. - if (ReadI == WriteI) - ReadI = WriteI = LR->find(Seg.start); - else - while (ReadI != E && ReadI->end <= Seg.start) - *WriteI++ = *ReadI++; - } - - assert(ReadI == E || ReadI->end > Seg.start); - - // Check if the ReadI segment begins early. - if (ReadI != E && ReadI->start <= Seg.start) { - assert(ReadI->valno == Seg.valno && "Cannot overlap different values"); - // Bail if Seg is completely contained in ReadI. - if (ReadI->end >= Seg.end) - return; - // Coalesce into Seg. - Seg.start = ReadI->start; - ++ReadI; - } - - // Coalesce as much as possible from ReadI into Seg. - while (ReadI != E && coalescable(Seg, *ReadI)) { - Seg.end = std::max(Seg.end, ReadI->end); - ++ReadI; - } - - // Try coalescing Spills.back() into Seg. - if (!Spills.empty() && coalescable(Spills.back(), Seg)) { - Seg.start = Spills.back().start; - Seg.end = std::max(Spills.back().end, Seg.end); - Spills.pop_back(); - } - - // Try coalescing Seg into WriteI[-1]. - if (WriteI != LR->begin() && coalescable(WriteI[-1], Seg)) { - WriteI[-1].end = std::max(WriteI[-1].end, Seg.end); - return; - } - - // Seg doesn't coalesce with anything, and needs to be inserted somewhere. - if (WriteI != ReadI) { - *WriteI++ = Seg; - return; - } - - // Finally, append to LR or Spills. - if (WriteI == E) { - LR->segments.push_back(Seg); - WriteI = ReadI = LR->end(); - } else - Spills.push_back(Seg); -} - -// Merge as many spilled segments as possible into the gap between WriteI -// and ReadI. Advance WriteI to reflect the inserted instructions. -void LiveRangeUpdater::mergeSpills() { - // Perform a backwards merge of Spills and [SpillI;WriteI). - size_t GapSize = ReadI - WriteI; - size_t NumMoved = std::min(Spills.size(), GapSize); - LiveRange::iterator Src = WriteI; - LiveRange::iterator Dst = Src + NumMoved; - LiveRange::iterator SpillSrc = Spills.end(); - LiveRange::iterator B = LR->begin(); - - // This is the new WriteI position after merging spills. - WriteI = Dst; - - // Now merge Src and Spills backwards. - while (Src != Dst) { - if (Src != B && Src[-1].start > SpillSrc[-1].start) - *--Dst = *--Src; - else - *--Dst = *--SpillSrc; - } - assert(NumMoved == size_t(Spills.end() - SpillSrc)); - Spills.erase(SpillSrc, Spills.end()); -} - -void LiveRangeUpdater::flush() { - if (!isDirty()) - return; - // Clear the dirty state. - LastStart = SlotIndex(); - - assert(LR && "Cannot add to a null destination"); - - // Nothing to merge? - if (Spills.empty()) { - LR->segments.erase(WriteI, ReadI); - LR->verify(); - return; - } - - // Resize the WriteI - ReadI gap to match Spills. - size_t GapSize = ReadI - WriteI; - if (GapSize < Spills.size()) { - // The gap is too small. Make some room. - size_t WritePos = WriteI - LR->begin(); - LR->segments.insert(ReadI, Spills.size() - GapSize, LiveRange::Segment()); - // This also invalidated ReadI, but it is recomputed below. - WriteI = LR->begin() + WritePos; - } else { - // Shrink the gap if necessary. - LR->segments.erase(WriteI + Spills.size(), ReadI); - } - ReadI = WriteI + Spills.size(); - mergeSpills(); - LR->verify(); -} - -unsigned ConnectedVNInfoEqClasses::Classify(const LiveRange &LR) { - // Create initial equivalence classes. - EqClass.clear(); - EqClass.grow(LR.getNumValNums()); - - const VNInfo *used = nullptr, *unused = nullptr; - - // Determine connections. - for (const VNInfo *VNI : LR.valnos) { - // 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 = LR.getVNInfoBefore(LIS.getMBBEndIdx(*PI))) - 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 = LR.getVNInfoBefore(VNI->def)) - 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 &LI, LiveInterval *LIV[], - MachineRegisterInfo &MRI) { - // Rewrite instructions. - for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LI.reg), - RE = MRI.reg_end(); RI != RE;) { - MachineOperand &MO = *RI; - MachineInstr *MI = RI->getParent(); - ++RI; - const VNInfo *VNI; - if (MI->isDebugValue()) { - // DBG_VALUE instructions don't have slot indexes, so get the index of - // the instruction before them. The value is defined there too. - SlotIndex Idx = LIS.getSlotIndexes()->getIndexBefore(*MI); - VNI = LI.Query(Idx).valueOut(); - } else { - SlotIndex Idx = LIS.getInstructionIndex(*MI); - LiveQueryResult LRQ = LI.Query(Idx); - VNI = MO.readsReg() ? LRQ.valueIn() : LRQ.valueDefined(); - } - // In the case of an <undef> use that isn't tied to any def, VNI will be - // NULL. If the use is tied to a def, VNI will be the defined value. - if (!VNI) - continue; - if (unsigned EqClass = getEqClass(VNI)) - MO.setReg(LIV[EqClass-1]->reg); - } - - // Distribute subregister liveranges. - if (LI.hasSubRanges()) { - unsigned NumComponents = EqClass.getNumClasses(); - SmallVector<unsigned, 8> VNIMapping; - SmallVector<LiveInterval::SubRange*, 8> SubRanges; - BumpPtrAllocator &Allocator = LIS.getVNInfoAllocator(); - for (LiveInterval::SubRange &SR : LI.subranges()) { - // Create new subranges in the split intervals and construct a mapping - // for the VNInfos in the subrange. - unsigned NumValNos = SR.valnos.size(); - VNIMapping.clear(); - VNIMapping.reserve(NumValNos); - SubRanges.clear(); - SubRanges.resize(NumComponents-1, nullptr); - for (unsigned I = 0; I < NumValNos; ++I) { - const VNInfo &VNI = *SR.valnos[I]; - unsigned ComponentNum; - if (VNI.isUnused()) { - ComponentNum = 0; - } else { - const VNInfo *MainRangeVNI = LI.getVNInfoAt(VNI.def); - assert(MainRangeVNI != nullptr - && "SubRange def must have corresponding main range def"); - ComponentNum = getEqClass(MainRangeVNI); - if (ComponentNum > 0 && SubRanges[ComponentNum-1] == nullptr) { - SubRanges[ComponentNum-1] - = LIV[ComponentNum-1]->createSubRange(Allocator, SR.LaneMask); - } - } - VNIMapping.push_back(ComponentNum); - } - DistributeRange(SR, SubRanges.data(), VNIMapping); - } - LI.removeEmptySubRanges(); - } - - // Distribute main liverange. - DistributeRange(LI, LIV, EqClass); -} |