X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FLiveInterval.cpp;h=dccd847d070c8bbc74bdca81f2438d355fd1ec25;hb=46abfcf4187432da728cbe452c32143da077e07f;hp=26722a3ca11a4c8bccbe9dc4467a5e0f3470f541;hpb=98d5982e0020e0c18d2847798ba2f40c4711af5a;p=oota-llvm.git diff --git a/lib/CodeGen/LiveInterval.cpp b/lib/CodeGen/LiveInterval.cpp index 26722a3ca11..dccd847d070 100644 --- a/lib/CodeGen/LiveInterval.cpp +++ b/lib/CodeGen/LiveInterval.cpp @@ -10,7 +10,7 @@ // 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 interval for register v if there is no instruction with number j' > j -// such that v is live at j' abd there is no instruction with number i' < i such +// 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 intervals can have holes, // i.e. an interval might look like [1,20), [50,65), [1000,1001). Each // individual range is represented as an instance of LiveRange, and the whole @@ -19,52 +19,62 @@ //===----------------------------------------------------------------------===// #include "llvm/CodeGen/LiveInterval.h" -#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "RegisterCoalescer.h" #include "llvm/ADT/DenseMap.h" -#include "llvm/ADT/SmallSet.h" #include "llvm/ADT/STLExtras.h" -#include "llvm/Support/Streams.h" +#include "llvm/ADT/SmallSet.h" +#include "llvm/CodeGen/LiveIntervalAnalysis.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetRegisterInfo.h" #include -#include 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(unsigned 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); +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; } -// 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; +VNInfo *LiveInterval::createDeadDef(SlotIndex Def, + VNInfo::Allocator &VNInfoAllocator) { + assert(!Def.isDead() && "Cannot define a value at the dead slot"); + iterator I = find(Def); + if (I == end()) { + VNInfo *VNI = getNextValue(Def, VNInfoAllocator); + ranges.push_back(LiveRange(Def, Def.getDeadSlot(), VNI)); + return VNI; + } + if (SlotIndex::isSameInstr(Def, I->start)) { + assert(I->valno->def == I->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, I->start); + if (Def != I->start) + I->start = I->valno->def = Def; + return I->valno; + } + assert(SlotIndex::isEarlierInstr(Def, I->start) && "Already live at def"); + VNInfo *VNI = getNextValue(Def, VNInfoAllocator); + ranges.insert(I, LiveRange(Def, Def.getDeadSlot(), VNI)); + return VNI; } // overlaps - Return true if the intersection of the two live intervals is @@ -87,6 +97,7 @@ bool LiveInterval::liveBeforeAndAt(unsigned I) const { // bool LiveInterval::overlapsFrom(const LiveInterval& other, const_iterator StartPos) const { + assert(!empty() && "empty interval"); const_iterator i = begin(); const_iterator ie = end(); const_iterator j = StartPos; @@ -125,33 +136,95 @@ bool LiveInterval::overlapsFrom(const LiveInterval& other, return false; } +bool LiveInterval::overlaps(const LiveInterval &Other, + const CoalescerPair &CP, + const SlotIndexes &Indexes) const { + assert(!empty() && "empty interval"); + 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; + + for (;;) { + // 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 interval overlaps a range specified /// by [Start, End). -bool LiveInterval::overlaps(unsigned Start, unsigned End) const { +bool LiveInterval::overlaps(SlotIndex Start, SlotIndex 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); + const_iterator I = std::lower_bound(begin(), end(), End); + return I != begin() && (--I)->end > Start; +} + + +/// 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 LiveInterval::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 LiveInterval::RenumberValues(LiveIntervals &lis) { + SmallPtrSet Seen; + valnos.clear(); + for (const_iterator I = begin(), E = end(); I != E; ++I) { + VNInfo *VNI = I->valno; + if (!Seen.insert(VNI)) + continue; + assert(!VNI->isUnused() && "Unused valno used by live range"); + VNI->id = (unsigned)valnos.size(); + valnos.push_back(VNI); + } } /// 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 /// not invalidated. -void LiveInterval::extendIntervalEndTo(Ranges::iterator I, unsigned NewEnd) { +void LiveInterval::extendIntervalEndTo(Ranges::iterator I, SlotIndex NewEnd) { assert(I != ranges.end() && "Not a valid interval!"); VNInfo *ValNo = I->valno; - unsigned OldEnd = I->end; // Search for the first interval that we can't merge with. - Ranges::iterator MergeTo = next(I); + Ranges::iterator MergeTo = llvm::next(I); for (; MergeTo != ranges.end() && NewEnd >= MergeTo->end; ++MergeTo) { assert(MergeTo->valno == ValNo && "Cannot merge with differing values!"); } @@ -159,19 +232,16 @@ void LiveInterval::extendIntervalEndTo(Ranges::iterator I, unsigned NewEnd) { // If NewEnd was in the middle of an interval, make sure to get its endpoint. I->end = std::max(NewEnd, prior(MergeTo)->end); - // Erase any dead ranges. - ranges.erase(next(I), MergeTo); - - // Update kill info. - 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. - Ranges::iterator Next = next(I); - if (Next != ranges.end() && Next->start <= I->end && Next->valno == ValNo) { - I->end = Next->end; - ranges.erase(Next); + if (MergeTo != ranges.end() && MergeTo->start <= I->end && + MergeTo->valno == ValNo) { + I->end = MergeTo->end; + ++MergeTo; } + + // Erase any dead ranges. + ranges.erase(llvm::next(I), MergeTo); } @@ -179,7 +249,7 @@ void LiveInterval::extendIntervalEndTo(Ranges::iterator I, unsigned NewEnd) { /// specified by I to start at the specified endpoint. To do this, we should /// merge and eliminate all ranges that this will overlap with. LiveInterval::Ranges::iterator -LiveInterval::extendIntervalStartTo(Ranges::iterator I, unsigned NewStart) { +LiveInterval::extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStart) { assert(I != ranges.end() && "Not a valid interval!"); VNInfo *ValNo = I->valno; @@ -206,13 +276,13 @@ LiveInterval::extendIntervalStartTo(Ranges::iterator I, unsigned NewStart) { MergeTo->end = I->end; } - ranges.erase(next(MergeTo), next(I)); + ranges.erase(llvm::next(MergeTo), llvm::next(I)); return MergeTo; } LiveInterval::iterator LiveInterval::addRangeFrom(LiveRange LR, iterator From) { - unsigned Start = LR.start, End = LR.end; + SlotIndex Start = LR.start, End = LR.end; iterator it = std::upper_bound(From, ranges.end(), Start); // If the inserted interval starts in the middle or right at the end of @@ -244,9 +314,6 @@ LiveInterval::addRangeFrom(LiveRange LR, iterator From) { // 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 { @@ -262,33 +329,36 @@ LiveInterval::addRangeFrom(LiveRange LR, iterator From) { 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; +/// 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->contains(Start) && I->contains(End-1); + 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(unsigned Start, unsigned End, +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; - assert(I->contains(Start) && I->contains(End-1) && - "Range is not entirely in interval!"); + 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. VNInfo *ValNo = I->valno; if (I->start == Start) { if (I->end == End) { - removeKills(I->valno, Start, End); if (RemoveDeadValNo) { // Check if val# is dead. bool isDead = true; @@ -296,20 +366,10 @@ void LiveInterval::removeRange(unsigned Start, unsigned End, 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); } + if (isDead) { + // Now that ValNo is dead, remove it. + markValNoForDeletion(ValNo); } } @@ -322,17 +382,16 @@ void LiveInterval::removeRange(unsigned Start, unsigned End, // Otherwise if the span we are removing is at the end of the LiveRange, // adjust the other way. if (I->end == End) { - removeKills(ValNo, Start, End); I->end = Start; return; } // Otherwise, we are splitting the LiveRange into two pieces. - unsigned OldEnd = I->end; + SlotIndex OldEnd = I->end; I->end = Start; // Trim the old interval. // Insert the new one. - ranges.insert(next(I), LiveRange(End, OldEnd, ValNo)); + ranges.insert(llvm::next(I), LiveRange(End, OldEnd, ValNo)); } /// removeValNo - Remove all the ranges defined by the specified value#. @@ -346,135 +405,71 @@ void LiveInterval::removeValNo(VNInfo *ValNo) { 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] != 0) - vni->kills[i] = InstrSlots::scale(vni->kills[i], factor); - } - } -} - -/// getLiveRangeContaining - Return the live range that contains the -/// specified index, or null if there is none. -LiveInterval::const_iterator -LiveInterval::FindLiveRangeContaining(unsigned 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(unsigned 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 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; + // Now that ValNo is dead, remove it. + markValNoForDeletion(ValNo); } /// 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, const int *LHSValNoAssignments, - const int *RHSValNoAssignments, +void LiveInterval::join(LiveInterval &Other, + const int *LHSValNoAssignments, + const int *RHSValNoAssignments, SmallVector &NewVNInfo, MachineRegisterInfo *MRI) { + verify(); + // 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; 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))) + (NewVNInfo[LHSValID] && NewVNInfo[LHSValID] != getValNumInfo(i))) { MustMapCurValNos = true; + break; + } } // If we have to apply a mapping to our base interval assignment, rewrite it // now. - if (MustMapCurValNos) { + if (MustMapCurValNos && !empty()) { // Map the first live range. + iterator OutIt = begin(); OutIt->valno = NewVNInfo[LHSValNoAssignments[OutIt->valno->id]]; - ++OutIt; - for (iterator I = OutIt, E = end(); I != E; ++I) { - OutIt->valno = NewVNInfo[LHSValNoAssignments[I->valno->id]]; - + for (iterator I = llvm::next(OutIt), E = end(); I != E; ++I) { + VNInfo* nextValNo = NewVNInfo[LHSValNoAssignments[I->valno->id]]; + assert(nextValNo != 0 && "Huh?"); + // If this live range has the same value # as its immediate predecessor, // and if they are neighbors, remove one LiveRange. This happens when we - // have [0,3:0)[4,7:1) and map 0/1 onto the same value #. - if (OutIt->valno == (OutIt-1)->valno && (OutIt-1)->end == OutIt->start) { - (OutIt-1)->end = OutIt->end; + // 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 { - if (I != OutIt) { + // Didn't merge. Move OutIt to the next interval, + ++OutIt; + OutIt->valno = nextValNo; + if (OutIt != I) { OutIt->start = I->start; OutIt->end = I->end; } - - // Didn't merge, on to the next one. - ++OutIt; } } - // If we merge some live ranges, chop off the end. + ++OutIt; ranges.erase(OutIt, end()); } - // Remember assignements because val# ids are changing. - SmallVector OtherAssignments; + // 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 (iterator I = Other.begin(), E = Other.end(); I != E; ++I) - OtherAssignments.push_back(RHSValNoAssignments[I->valno->id]); + I->valno = NewVNInfo[RHSValNoAssignments[I->valno->id]]; // Update val# info. Renumber them and make sure they all belong to this // LiveInterval now. Also remove dead val#'s. @@ -484,7 +479,7 @@ void LiveInterval::join(LiveInterval &Other, const int *LHSValNoAssignments, if (VNI) { if (NumValNos >= NumVals) valnos.push_back(VNI); - else + else valnos[NumValNos] = VNI; VNI->id = NumValNos++; // Renumber val#. } @@ -493,208 +488,34 @@ void LiveInterval::join(LiveInterval &Other, const int *LHSValNoAssignments, valnos.resize(NumNewVals); // shrinkify // Okay, now insert the RHS live ranges into the LHS. - iterator InsertPos = begin(); - unsigned RangeNo = 0; - 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; - - // Update regalloc hint if currently there isn't one. - if (TargetRegisterInfo::isVirtualRegister(reg) && - TargetRegisterInfo::isVirtualRegister(Other.reg)) { - std::pair Hint = MRI->getRegAllocationHint(reg); - if (Hint.first == 0 && Hint.second == 0) { - std::pair OtherHint = - MRI->getRegAllocationHint(Other.reg); - if (OtherHint.first || OtherHint.second) - MRI->setRegAllocationHint(reg, OtherHint.first, OtherHint.second); - } - } + LiveRangeUpdater Updater(this); + for (iterator I = Other.begin(), E = Other.end(); I != E; ++I) + Updater.add(*I); } /// MergeRangesInAsValue - Merge all of the intervals 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, but only if /// the overlapping LiveRanges have the specified value number. -void LiveInterval::MergeRangesInAsValue(const LiveInterval &RHS, +void LiveInterval::MergeRangesInAsValue(const LiveInterval &RHS, VNInfo *LHSValNo) { - // TODO: Make this more efficient. - iterator InsertPos = begin(); - for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) { - // Map the valno in the other live range to the current live range. - LiveRange Tmp = *I; - Tmp.valno = LHSValNo; - InsertPos = addRangeFrom(Tmp, InsertPos); - } + LiveRangeUpdater Updater(this); + for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) + Updater.add(I->start, I->end, LHSValNo); } - /// 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 ReplacedValNos; - iterator IP = begin(); - 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; - } - - // Map the valno in the other live range to the current live range. - IP = addRangeFrom(LiveRange(Start, End, LHSValNo), IP); - } - - - SmallSet 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 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::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); + const VNInfo *RHSValNo, + VNInfo *LHSValNo) { + LiveRangeUpdater Updater(this); + for (const_iterator I = RHS.begin(), E = RHS.end(); I != E; ++I) + if (I->valno == RHSValNo) + Updater.add(I->start, I->end, LHSValNo); } /// MergeValueNumberInto - This method is called when two value nubmers @@ -711,7 +532,7 @@ VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) { // Make sure V2 is smaller than V1. if (V1->id < V2->id) { - copyValNumInfo(V1, V2); + V1->copyFrom(*V2); std::swap(V1, V2); } @@ -719,7 +540,7 @@ VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) { for (iterator I = begin(); I != end(); ) { iterator LR = I++; if (LR->valno != V1) continue; // Not a V1 LiveRange. - + // Okay, we found a V1 live range. If it had a previous, touching, V2 live // range, extend it. if (LR != begin()) { @@ -733,11 +554,11 @@ VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) { LR = Prev; } } - + // Okay, now we have a V1 or V2 live range that is maximally merged forward. // Ensure that it is a V2 live-range. LR->valno = V2; - + // If we can merge it into later V2 live ranges, do so now. We ignore any // following V1 live ranges, as they will be merged in subsequent iterations // of the loop. @@ -749,77 +570,41 @@ VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) { } } } - - // 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.back()->isUnused()); - } else { - V1->setIsUnused(true); - } - - return V2; -} -void LiveInterval::Copy(const LiveInterval &RHS, - MachineRegisterInfo *MRI, - BumpPtrAllocator &VNInfoAllocator) { - ranges.clear(); - valnos.clear(); - std::pair Hint = MRI->getRegAllocationHint(RHS.reg); - MRI->setRegAllocationHint(reg, Hint.first, Hint.second); + // Now that V1 is dead, remove it. + markValNoForDeletion(V1); - 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 V2; } unsigned LiveInterval::getSize() const { unsigned Sum = 0; for (const_iterator I = begin(), E = end(); I != E; ++I) - Sum += I->end - I->start; + Sum += I->start.distance(I->end); return Sum; } -std::ostream& llvm::operator<<(std::ostream& os, const LiveRange &LR) { +raw_ostream& llvm::operator<<(raw_ostream& os, const LiveRange &LR) { return os << '[' << LR.start << ',' << LR.end << ':' << LR.valno->id << ")"; } +#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) void LiveRange::dump() const { - cerr << *this << "\n"; + dbgs() << *this << "\n"; } +#endif -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; - +void LiveInterval::print(raw_ostream &OS) const { if (empty()) - OS << " EMPTY"; + OS << "EMPTY"; else { - OS << " = "; for (LiveInterval::Ranges::const_iterator I = ranges.begin(), - E = ranges.end(); I != E; ++I) - OS << *I; + E = ranges.end(); I != E; ++I) { + OS << *I; + assert(I->valno == getValNumInfo(I->valno->id) && "Bad VNInfo"); + } } - + // Print value number info. if (getNumValNums()) { OS << " "; @@ -832,35 +617,335 @@ void LiveInterval::print(std::ostream &OS, if (vni->isUnused()) { OS << "x"; } else { - if (!vni->isDefAccurate()) - OS << "?"; - else - OS << vni->def; - unsigned ee = vni->kills.size(); - if (ee || vni->hasPHIKill()) { - OS << "-("; - for (unsigned j = 0; j != ee; ++j) { - OS << vni->kills[j]; - if (j != ee-1) - OS << " "; - } - if (vni->hasPHIKill()) { - if (ee) - OS << " "; - OS << "phi"; - } - OS << ")"; - } + OS << vni->def; + if (vni->isPHIDef()) + OS << "-phi"; } } } } +#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) void LiveInterval::dump() const { - cerr << *this << "\n"; + dbgs() << *this << "\n"; +} +#endif + +#ifndef NDEBUG +void LiveInterval::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 != 0); + assert(I->valno == valnos[I->valno->id]); + if (llvm::next(I) != E) { + assert(I->end <= llvm::next(I)->start); + if (I->end == llvm::next(I)->start) + assert(I->valno != llvm::next(I)->valno); + } + } } +#endif -void LiveRange::print(std::ostream &os) const { +void LiveRange::print(raw_ostream &os) const { os << *this; } + +//===----------------------------------------------------------------------===// +// 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 LI. +// 2. [ReadI; end) at the back of LI. +// 3. Spills. +// +// - LI.begin() <= WriteI <= ReadI <= LI.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. + +void LiveRangeUpdater::print(raw_ostream &OS) const { + if (!isDirty()) { + if (LI) + OS << "Clean " << PrintReg(LI->reg) << " updater: " << *LI << '\n'; + else + OS << "Null updater.\n"; + return; + } + assert(LI && "Can't have null LI in dirty updater."); + OS << PrintReg(LI->reg) << " updater with gap = " << (ReadI - WriteI) + << ", last start = " << LastStart + << ":\n Area 1:"; + for (LiveInterval::const_iterator I = LI->begin(); I != WriteI; ++I) + OS << ' ' << *I; + OS << "\n Spills:"; + for (unsigned I = 0, E = Spills.size(); I != E; ++I) + OS << ' ' << Spills[I]; + OS << "\n Area 2:"; + for (LiveInterval::const_iterator I = ReadI, E = LI->end(); I != E; ++I) + OS << ' ' << *I; + OS << '\n'; +} + +void LiveRangeUpdater::dump() const +{ + print(errs()); +} + +// Determine if A and B should be coalesced. +static inline bool coalescable(const LiveRange &A, const LiveRange &B) { + assert(A.start <= B.start && "Unordered live ranges."); + 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 Seg) { + assert(LI && "Cannot add to a null destination"); + + // 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 = LI->begin(); + } + + // Remember start for next time. + LastStart = Seg.start; + + // Advance ReadI until it ends after Seg.start. + LiveInterval::iterator E = LI->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 = LI->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 != LI->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 LI or Spills. + if (WriteI == E) { + LI->ranges.push_back(Seg); + WriteI = ReadI = LI->ranges.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); + LiveInterval::iterator Src = WriteI; + LiveInterval::iterator Dst = Src + NumMoved; + LiveInterval::iterator SpillSrc = Spills.end(); + LiveInterval::iterator B = LI->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(LI && "Cannot add to a null destination"); + + // Nothing to merge? + if (Spills.empty()) { + LI->ranges.erase(WriteI, ReadI); + LI->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 - LI->begin(); + LI->ranges.insert(ReadI, Spills.size() - GapSize, LiveRange()); + // This also invalidated ReadI, but it is recomputed below. + WriteI = LI->ranges.begin() + WritePos; + } else { + // Shrink the gap if necessary. + LI->ranges.erase(WriteI + Spills.size(), ReadI); + } + ReadI = WriteI + Spills.size(); + mergeSpills(); + LI->verify(); +} + +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->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 = LI->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 *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; + // DBG_VALUE instructions should have been eliminated earlier. + LiveRangeQuery LRQ(LI, LIS.getInstructionIndex(MI)); + const VNInfo *VNI = MO.readsReg() ? LRQ.valueIn() : LRQ.valueDefined(); + // In the case of an 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; + 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); +}