#ifndef LLVM_CODEGEN_LIVEINTERVAL_H
#define LLVM_CODEGEN_LIVEINTERVAL_H
-#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/IntEqClasses.h"
+#include "llvm/CodeGen/SlotIndexes.h"
+#include "llvm/Support/AlignOf.h"
#include "llvm/Support/Allocator.h"
-#include <iosfwd>
#include <cassert>
+#include <climits>
namespace llvm {
+ class CoalescerPair;
+ class LiveIntervals;
class MachineInstr;
+ class MachineRegisterInfo;
class TargetRegisterInfo;
- struct LiveInterval;
-
- /// VNInfo - If the value number definition is undefined (e.g. phi
- /// merge point), it contains ~0u,x. If the value number is not in use, it
- /// contains ~1u,x to indicate that the value # is not used.
- /// def - Instruction # of the definition.
- /// - or reg # of the definition if it's a stack slot liveinterval.
- /// copy - Copy iff val# is defined by a copy; zero otherwise.
- /// hasPHIKill - One or more of the kills are PHI nodes.
- /// redefByEC - Re-defined by early clobber somewhere during the live range.
- /// kills - Instruction # of the kills.
- struct VNInfo {
+ class raw_ostream;
+
+ /// VNInfo - Value Number Information.
+ /// This class holds information about a machine level values, including
+ /// definition and use points.
+ ///
+ class VNInfo {
+ public:
+ typedef BumpPtrAllocator Allocator;
+
+ /// The ID number of this value.
unsigned id;
- unsigned def;
- MachineInstr *copy;
- bool hasPHIKill : 1;
- bool redefByEC : 1;
- SmallVector<unsigned, 4> kills;
- VNInfo()
- : id(~1U), def(~1U), copy(0), hasPHIKill(false), redefByEC(false) {}
- VNInfo(unsigned i, unsigned d, MachineInstr *c)
- : id(i), def(d), copy(c), hasPHIKill(false), redefByEC(false) {}
+
+ /// The index of the defining instruction.
+ SlotIndex def;
+
+ /// VNInfo constructor.
+ VNInfo(unsigned i, SlotIndex d)
+ : id(i), def(d)
+ { }
+
+ /// VNInfo construtor, copies values from orig, except for the value number.
+ VNInfo(unsigned i, const VNInfo &orig)
+ : id(i), def(orig.def)
+ { }
+
+ /// Copy from the parameter into this VNInfo.
+ void copyFrom(VNInfo &src) {
+ def = src.def;
+ }
+
+ /// Returns true if this value is defined by a PHI instruction (or was,
+ /// PHI instrucions may have been eliminated).
+ /// PHI-defs begin at a block boundary, all other defs begin at register or
+ /// EC slots.
+ bool isPHIDef() const { return def.isBlock(); }
+
+ /// Returns true if this value is unused.
+ bool isUnused() const { return !def.isValid(); }
+
+ /// Mark this value as unused.
+ void markUnused() { def = SlotIndex(); }
};
/// LiveRange structure - This represents a simple register range in the
/// program, with an inclusive start point and an exclusive end point.
/// These ranges are rendered as [start,end).
struct LiveRange {
- unsigned start; // Start point of the interval (inclusive)
- unsigned end; // End point of the interval (exclusive)
+ SlotIndex start; // Start point of the interval (inclusive)
+ SlotIndex end; // End point of the interval (exclusive)
VNInfo *valno; // identifier for the value contained in this interval.
- LiveRange(unsigned S, unsigned E, VNInfo *V) : start(S), end(E), valno(V) {
+ LiveRange(SlotIndex S, SlotIndex E, VNInfo *V)
+ : start(S), end(E), valno(V) {
+
assert(S < E && "Cannot create empty or backwards range");
}
/// contains - Return true if the index is covered by this range.
///
- bool contains(unsigned I) const {
+ bool contains(SlotIndex I) const {
return start <= I && I < end;
}
+ /// containsRange - Return true if the given range, [S, E), is covered by
+ /// this range.
+ bool containsRange(SlotIndex S, SlotIndex E) const {
+ assert((S < E) && "Backwards interval?");
+ return (start <= S && S < end) && (start < E && E <= end);
+ }
+
bool operator<(const LiveRange &LR) const {
return start < LR.start || (start == LR.start && end < LR.end);
}
}
void dump() const;
- void print(std::ostream &os) const;
- void print(std::ostream *os) const { if (os) print(*os); }
-
- private:
- LiveRange(); // DO NOT IMPLEMENT
+ void print(raw_ostream &os) const;
};
- std::ostream& operator<<(std::ostream& os, const LiveRange &LR);
+ template <> struct isPodLike<LiveRange> { static const bool value = true; };
+
+ raw_ostream& operator<<(raw_ostream& os, const LiveRange &LR);
- inline bool operator<(unsigned V, const LiveRange &LR) {
+ inline bool operator<(SlotIndex V, const LiveRange &LR) {
return V < LR.start;
}
- inline bool operator<(const LiveRange &LR, unsigned V) {
+ inline bool operator<(const LiveRange &LR, SlotIndex V) {
return LR.start < V;
}
/// LiveInterval - This class represents some number of live ranges for a
/// register or value. This class also contains a bit of register allocator
/// state.
- struct LiveInterval {
+ class LiveInterval {
+ public:
+
typedef SmallVector<LiveRange,4> Ranges;
typedef SmallVector<VNInfo*,4> VNInfoList;
- unsigned reg; // the register or stack slot of this interval
- // if the top bits is set, it represents a stack slot.
+ const unsigned reg; // the register or stack slot of this interval.
float weight; // weight of this interval
- unsigned short preference; // preferred register for this interval
Ranges ranges; // the ranges in which this register is live
VNInfoList valnos; // value#'s
- public:
- LiveInterval(unsigned Reg, float Weight, bool IsSS = false)
- : reg(Reg), weight(Weight), preference(0) {
- if (IsSS)
- reg = reg | (1U << (sizeof(unsigned)*8-1));
- }
+ struct InstrSlots {
+ enum {
+ LOAD = 0,
+ USE = 1,
+ DEF = 2,
+ STORE = 3,
+ NUM = 4
+ };
+
+ };
+
+ LiveInterval(unsigned Reg, float Weight)
+ : reg(Reg), weight(Weight) {}
typedef Ranges::iterator iterator;
iterator begin() { return ranges.begin(); }
/// advanceTo - Advance the specified iterator to point to the LiveRange
/// containing the specified position, or end() if the position is past the
/// end of the interval. If no LiveRange contains this position, but the
- /// position is in a hole, this method returns an iterator pointing the the
+ /// position is in a hole, this method returns an iterator pointing to the
/// LiveRange immediately after the hole.
- iterator advanceTo(iterator I, unsigned Pos) {
- if (Pos >= endNumber())
+ iterator advanceTo(iterator I, SlotIndex Pos) {
+ assert(I != end());
+ if (Pos >= endIndex())
return end();
while (I->end <= Pos) ++I;
return I;
}
-
- void clear() {
- while (!valnos.empty()) {
- VNInfo *VNI = valnos.back();
- valnos.pop_back();
- VNI->~VNInfo();
- }
-
- ranges.clear();
- }
- /// isStackSlot - Return true if this is a stack slot interval.
+ /// find - Return an iterator pointing to the first range that ends after
+ /// Pos, or end(). This is the same as advanceTo(begin(), Pos), but faster
+ /// when searching large intervals.
///
- bool isStackSlot() const {
- return reg & (1U << (sizeof(unsigned)*8-1));
+ /// If Pos is contained in a LiveRange, that range is returned.
+ /// If Pos is in a hole, the following LiveRange is returned.
+ /// If Pos is beyond endIndex, end() is returned.
+ iterator find(SlotIndex Pos);
+
+ const_iterator find(SlotIndex Pos) const {
+ return const_cast<LiveInterval*>(this)->find(Pos);
}
- /// getStackSlotIndex - Return stack slot index if this is a stack slot
- /// interval.
- int getStackSlotIndex() const {
- assert(isStackSlot() && "Interval is not a stack slot interval!");
- return reg & ~(1U << (sizeof(unsigned)*8-1));
+ void clear() {
+ valnos.clear();
+ ranges.clear();
}
bool hasAtLeastOneValue() const { return !valnos.empty(); }
bool containsOneValue() const { return valnos.size() == 1; }
unsigned getNumValNums() const { return (unsigned)valnos.size(); }
-
+
/// getValNumInfo - Returns pointer to the specified val#.
///
inline VNInfo *getValNumInfo(unsigned ValNo) {
inline const VNInfo *getValNumInfo(unsigned ValNo) const {
return valnos[ValNo];
}
-
- /// copyValNumInfo - Copy the value number info for one value number to
- /// another.
- void copyValNumInfo(VNInfo *DstValNo, const VNInfo *SrcValNo) {
- DstValNo->def = SrcValNo->def;
- DstValNo->copy = SrcValNo->copy;
- DstValNo->hasPHIKill = SrcValNo->hasPHIKill;
- DstValNo->redefByEC = SrcValNo->redefByEC;
- DstValNo->kills = SrcValNo->kills;
+
+ /// containsValue - Returns true if VNI belongs to this interval.
+ bool containsValue(const VNInfo *VNI) const {
+ return VNI && VNI->id < getNumValNums() && VNI == getValNumInfo(VNI->id);
}
/// getNextValue - Create a new value number and return it. MIIdx specifies
/// the instruction that defines the value number.
- VNInfo *getNextValue(unsigned MIIdx, MachineInstr *CopyMI,
- BumpPtrAllocator &VNInfoAllocator) {
-#ifdef __GNUC__
- unsigned Alignment = (unsigned)__alignof__(VNInfo);
-#else
- // FIXME: ugly.
- unsigned Alignment = 8;
-#endif
+ VNInfo *getNextValue(SlotIndex def, VNInfo::Allocator &VNInfoAllocator) {
VNInfo *VNI =
- static_cast<VNInfo*>(VNInfoAllocator.Allocate((unsigned)sizeof(VNInfo),
- Alignment));
- new (VNI) VNInfo((unsigned)valnos.size(), MIIdx, CopyMI);
+ new (VNInfoAllocator) VNInfo((unsigned)valnos.size(), def);
valnos.push_back(VNI);
return VNI;
}
- /// getUnknownValNo - Find a value# for unknown values, if there isn't one
- /// create a new one.
- VNInfo *getUnknownValNo(BumpPtrAllocator &VNInfoAllocator);
-
- /// addKill - Add a kill instruction index to the specified value
- /// number.
- static void addKill(VNInfo *VNI, unsigned KillIdx) {
- SmallVector<unsigned, 4> &kills = VNI->kills;
- if (kills.empty()) {
- kills.push_back(KillIdx);
- } else {
- SmallVector<unsigned, 4>::iterator
- I = std::lower_bound(kills.begin(), kills.end(), KillIdx);
- kills.insert(I, KillIdx);
- }
- }
+ /// createDeadDef - Make sure the interval has a value defined at Def.
+ /// If one already exists, return it. Otherwise allocate a new value and
+ /// add liveness for a dead def.
+ VNInfo *createDeadDef(SlotIndex Def, VNInfo::Allocator &VNInfoAllocator);
- /// addKills - Add a number of kills into the VNInfo kill vector. If this
- /// interval is live at a kill point, then the kill is not added.
- void addKills(VNInfo *VNI, const SmallVector<unsigned, 4> &kills) {
- for (unsigned i = 0, e = static_cast<unsigned>(kills.size());
- i != e; ++i) {
- unsigned KillIdx = kills[i];
- if (!liveBeforeAndAt(KillIdx)) {
- SmallVector<unsigned, 4>::iterator
- I = std::lower_bound(VNI->kills.begin(), VNI->kills.end(), KillIdx);
- VNI->kills.insert(I, KillIdx);
- }
- }
+ /// Create a copy of the given value. The new value will be identical except
+ /// for the Value number.
+ VNInfo *createValueCopy(const VNInfo *orig,
+ VNInfo::Allocator &VNInfoAllocator) {
+ VNInfo *VNI =
+ new (VNInfoAllocator) VNInfo((unsigned)valnos.size(), *orig);
+ valnos.push_back(VNI);
+ return VNI;
}
- /// removeKill - Remove the specified kill from the list of kills of
- /// the specified val#.
- static bool removeKill(VNInfo *VNI, unsigned KillIdx) {
- SmallVector<unsigned, 4> &kills = VNI->kills;
- SmallVector<unsigned, 4>::iterator
- I = std::lower_bound(kills.begin(), kills.end(), KillIdx);
- if (I != kills.end() && *I == KillIdx) {
- kills.erase(I);
- return true;
- }
- return false;
- }
-
- /// removeKills - Remove all the kills in specified range
- /// [Start, End] of the specified val#.
- static void removeKills(VNInfo *VNI, unsigned Start, unsigned End) {
- SmallVector<unsigned, 4> &kills = VNI->kills;
- SmallVector<unsigned, 4>::iterator
- I = std::lower_bound(kills.begin(), kills.end(), Start);
- SmallVector<unsigned, 4>::iterator
- E = std::upper_bound(kills.begin(), kills.end(), End);
- kills.erase(I, E);
- }
-
- /// isKill - Return true if the specified index is a kill of the
- /// specified val#.
- static bool isKill(const VNInfo *VNI, unsigned KillIdx) {
- const SmallVector<unsigned, 4> &kills = VNI->kills;
- SmallVector<unsigned, 4>::const_iterator
- I = std::lower_bound(kills.begin(), kills.end(), KillIdx);
- return I != kills.end() && *I == KillIdx;
- }
-
- /// isOnlyLROfValNo - Return true if the specified live range is the only
- /// one defined by the its val#.
- bool isOnlyLROfValNo( const LiveRange *LR) {
- for (const_iterator I = begin(), E = end(); I != E; ++I) {
- const LiveRange *Tmp = I;
- if (Tmp != LR && Tmp->valno == LR->valno)
- return false;
- }
- return true;
- }
-
+ /// RenumberValues - Renumber all values in order of appearance and remove
+ /// unused values.
+ void RenumberValues(LiveIntervals &lis);
+
/// 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.
VNInfo* MergeValueNumberInto(VNInfo *V1, VNInfo *V2);
- /// 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. Caller must pass in reference to
- /// VNInfoAllocator since it will create a new val#.
- void MergeInClobberRanges(const LiveInterval &Clobbers,
- BumpPtrAllocator &VNInfoAllocator);
-
- /// MergeInClobberRange - Same as MergeInClobberRanges except it merge in a
- /// single LiveRange only.
- void MergeInClobberRange(unsigned Start, unsigned End,
- BumpPtrAllocator &VNInfoAllocator);
-
/// 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
void MergeValueInAsValue(const LiveInterval &RHS,
const VNInfo *RHSValNo, VNInfo *LHSValNo);
- /// Copy - Copy the specified live interval. This copies all the fields
- /// except for the register of the interval.
- void Copy(const LiveInterval &RHS, BumpPtrAllocator &VNInfoAllocator);
-
bool empty() const { return ranges.empty(); }
- /// beginNumber - Return the lowest numbered slot covered by interval.
- unsigned beginNumber() const {
- if (empty())
- return 0;
+ /// beginIndex - Return the lowest numbered slot covered by interval.
+ SlotIndex beginIndex() const {
+ assert(!empty() && "Call to beginIndex() on empty interval.");
return ranges.front().start;
}
/// endNumber - return the maximum point of the interval of the whole,
/// exclusive.
- unsigned endNumber() const {
- if (empty())
- return 0;
+ SlotIndex endIndex() const {
+ assert(!empty() && "Call to endIndex() on empty interval.");
return ranges.back().end;
}
- bool expiredAt(unsigned index) const {
- return index >= endNumber();
+ bool expiredAt(SlotIndex index) const {
+ return index >= endIndex();
}
- bool liveAt(unsigned index) const;
+ bool liveAt(SlotIndex index) const {
+ const_iterator r = find(index);
+ return r != end() && r->start <= index;
+ }
- // 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 liveBeforeAndAt(unsigned index) const;
+ /// killedAt - Return true if a live range ends at index. Note that the kill
+ /// point is not contained in the half-open live range. It is usually the
+ /// getDefIndex() slot following its last use.
+ bool killedAt(SlotIndex index) const {
+ const_iterator r = find(index.getRegSlot(true));
+ return r != end() && r->end == index;
+ }
/// getLiveRangeContaining - Return the live range that contains the
/// specified index, or null if there is none.
- const LiveRange *getLiveRangeContaining(unsigned Idx) const {
+ const LiveRange *getLiveRangeContaining(SlotIndex Idx) const {
const_iterator I = FindLiveRangeContaining(Idx);
return I == end() ? 0 : &*I;
}
- /// FindLiveRangeContaining - Return an iterator to the live range that
- /// contains the specified index, or end() if there is none.
- const_iterator FindLiveRangeContaining(unsigned Idx) const;
+ /// getLiveRangeContaining - Return the live range that contains the
+ /// specified index, or null if there is none.
+ LiveRange *getLiveRangeContaining(SlotIndex Idx) {
+ iterator I = FindLiveRangeContaining(Idx);
+ return I == end() ? 0 : &*I;
+ }
+
+ /// getVNInfoAt - Return the VNInfo that is live at Idx, or NULL.
+ VNInfo *getVNInfoAt(SlotIndex Idx) const {
+ const_iterator I = FindLiveRangeContaining(Idx);
+ return I == end() ? 0 : I->valno;
+ }
+
+ /// getVNInfoBefore - Return the VNInfo that is live up to but not
+ /// necessarilly including Idx, or NULL. Use this to find the reaching def
+ /// used by an instruction at this SlotIndex position.
+ VNInfo *getVNInfoBefore(SlotIndex Idx) const {
+ const_iterator I = FindLiveRangeContaining(Idx.getPrevSlot());
+ return I == end() ? 0 : I->valno;
+ }
/// FindLiveRangeContaining - Return an iterator to the live range that
/// contains the specified index, or end() if there is none.
- iterator FindLiveRangeContaining(unsigned Idx);
+ iterator FindLiveRangeContaining(SlotIndex Idx) {
+ iterator I = find(Idx);
+ return I != end() && I->start <= Idx ? I : end();
+ }
+
+ const_iterator FindLiveRangeContaining(SlotIndex Idx) const {
+ const_iterator I = find(Idx);
+ return I != end() && I->start <= Idx ? I : end();
+ }
- /// findDefinedVNInfo - Find the VNInfo that's defined at the specified
- /// index (register interval) or defined by the specified register (stack
- /// inteval).
- VNInfo *findDefinedVNInfo(unsigned DefIdxOrReg) const;
-
/// overlaps - Return true if the intersection of the two live intervals is
/// not empty.
bool overlaps(const LiveInterval& other) const {
+ if (other.empty())
+ return false;
return overlapsFrom(other, other.begin());
}
+ /// overlaps - Return true if the two intervals have overlapping segments
+ /// that are not coalescable according to CP.
+ ///
+ /// Overlapping segments where one interval is defined by a coalescable
+ /// copy are allowed.
+ bool overlaps(const LiveInterval &Other, const CoalescerPair &CP,
+ const SlotIndexes&) const;
+
+ /// overlaps - Return true if the live interval overlaps a range specified
+ /// by [Start, End).
+ bool overlaps(SlotIndex Start, SlotIndex End) const;
+
/// overlapsFrom - Return true if the intersection of the two live intervals
/// is not empty. The specified iterator is a hint that we can begin
/// scanning the Other interval starting at I.
addRangeFrom(LR, ranges.begin());
}
+ /// 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 *extendInBlock(SlotIndex StartIdx, SlotIndex Kill);
+
/// 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 join(LiveInterval &Other, const int *ValNoAssignments,
+ void join(LiveInterval &Other,
+ const int *ValNoAssignments,
const int *RHSValNoAssignments,
- SmallVector<VNInfo*, 16> &NewVNInfo);
+ SmallVector<VNInfo*, 16> &NewVNInfo,
+ MachineRegisterInfo *MRI);
/// isInOneLiveRange - Return true if the range specified is entirely in the
/// a single LiveRange of the live interval.
- bool isInOneLiveRange(unsigned Start, unsigned End);
+ bool isInOneLiveRange(SlotIndex Start, SlotIndex End) const {
+ const_iterator r = find(Start);
+ return r != end() && r->containsRange(Start, End);
+ }
/// removeRange - Remove the specified range from this interval. Note that
/// the range must be a single LiveRange in its entirety.
- void removeRange(unsigned Start, unsigned End, bool RemoveDeadValNo = false);
+ void removeRange(SlotIndex Start, SlotIndex End,
+ bool RemoveDeadValNo = false);
void removeRange(LiveRange LR, bool RemoveDeadValNo = false) {
removeRange(LR.start, LR.end, RemoveDeadValNo);
///
unsigned getSize() const;
- bool operator<(const LiveInterval& other) const {
- return beginNumber() < other.beginNumber();
+ /// Returns true if the live interval is zero length, i.e. no live ranges
+ /// span instructions. It doesn't pay to spill such an interval.
+ bool isZeroLength(SlotIndexes *Indexes) const {
+ for (const_iterator i = begin(), e = end(); i != e; ++i)
+ if (Indexes->getNextNonNullIndex(i->start).getBaseIndex() <
+ i->end.getBaseIndex())
+ return false;
+ return true;
+ }
+
+ /// isSpillable - Can this interval be spilled?
+ bool isSpillable() const {
+ return weight != HUGE_VALF;
}
- void print(std::ostream &OS, const TargetRegisterInfo *TRI = 0) const;
- void print(std::ostream *OS, const TargetRegisterInfo *TRI = 0) const {
- if (OS) print(*OS, TRI);
+ /// markNotSpillable - Mark interval as not spillable
+ void markNotSpillable() {
+ weight = HUGE_VALF;
}
+
+ bool operator<(const LiveInterval& other) const {
+ const SlotIndex &thisIndex = beginIndex();
+ const SlotIndex &otherIndex = other.beginIndex();
+ return (thisIndex < otherIndex ||
+ (thisIndex == otherIndex && reg < other.reg));
+ }
+
+ void print(raw_ostream &OS) const;
void dump() const;
+ /// \brief Walk the interval and assert if any invariants fail to hold.
+ ///
+ /// Note that this is a no-op when asserts are disabled.
+#ifdef NDEBUG
+ void verify() const {}
+#else
+ void verify() const;
+#endif
+
private:
+
Ranges::iterator addRangeFrom(LiveRange LR, Ranges::iterator From);
- void extendIntervalEndTo(Ranges::iterator I, unsigned NewEnd);
- Ranges::iterator extendIntervalStartTo(Ranges::iterator I, unsigned NewStr);
- LiveInterval& operator=(const LiveInterval& rhs); // DO NOT IMPLEMENT
+ void extendIntervalEndTo(Ranges::iterator I, SlotIndex NewEnd);
+ Ranges::iterator extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStr);
+ void markValNoForDeletion(VNInfo *V);
+ void mergeIntervalRanges(const LiveInterval &RHS,
+ VNInfo *LHSValNo = 0,
+ const VNInfo *RHSValNo = 0);
+
+ LiveInterval& operator=(const LiveInterval& rhs) LLVM_DELETED_FUNCTION;
+
};
- inline std::ostream &operator<<(std::ostream &OS, const LiveInterval &LI) {
+ inline raw_ostream &operator<<(raw_ostream &OS, const LiveInterval &LI) {
LI.print(OS);
return OS;
}
-}
+ /// LiveRangeQuery - Query information about a live range around a given
+ /// instruction. This class hides the implementation details of live ranges,
+ /// and it should be used as the primary interface for examining live ranges
+ /// around instructions.
+ ///
+ class LiveRangeQuery {
+ VNInfo *EarlyVal;
+ VNInfo *LateVal;
+ SlotIndex EndPoint;
+ bool Kill;
+
+ public:
+ /// Create a LiveRangeQuery for the given live range and instruction index.
+ /// The sub-instruction slot of Idx doesn't matter, only the instruction it
+ /// refers to is considered.
+ LiveRangeQuery(const LiveInterval &LI, SlotIndex Idx)
+ : EarlyVal(0), LateVal(0), Kill(false) {
+ // Find the segment that enters the instruction.
+ LiveInterval::const_iterator I = LI.find(Idx.getBaseIndex());
+ LiveInterval::const_iterator E = LI.end();
+ if (I == E)
+ return;
+ // Is this an instruction live-in segment?
+ // If Idx is the start index of a basic block, include live-in segments
+ // that start at Idx.getBaseIndex().
+ if (I->start <= Idx.getBaseIndex()) {
+ EarlyVal = I->valno;
+ EndPoint = I->end;
+ // Move to the potentially live-out segment.
+ if (SlotIndex::isSameInstr(Idx, I->end)) {
+ Kill = true;
+ if (++I == E)
+ return;
+ }
+ // Special case: A PHIDef value can have its def in the middle of a
+ // segment if the value happens to be live out of the layout
+ // predecessor.
+ // Such a value is not live-in.
+ if (EarlyVal->def == Idx.getBaseIndex())
+ EarlyVal = 0;
+ }
+ // I now points to the segment that may be live-through, or defined by
+ // this instr. Ignore segments starting after the current instr.
+ if (SlotIndex::isEarlierInstr(Idx, I->start))
+ return;
+ LateVal = I->valno;
+ EndPoint = I->end;
+ }
+
+ /// Return the value that is live-in to the instruction. This is the value
+ /// that will be read by the instruction's use operands. Return NULL if no
+ /// value is live-in.
+ VNInfo *valueIn() const {
+ return EarlyVal;
+ }
+
+ /// Return true if the live-in value is killed by this instruction. This
+ /// means that either the live range ends at the instruction, or it changes
+ /// value.
+ bool isKill() const {
+ return Kill;
+ }
+
+ /// Return true if this instruction has a dead def.
+ bool isDeadDef() const {
+ return EndPoint.isDead();
+ }
+
+ /// Return the value leaving the instruction, if any. This can be a
+ /// live-through value, or a live def. A dead def returns NULL.
+ VNInfo *valueOut() const {
+ return isDeadDef() ? 0 : LateVal;
+ }
+
+ /// Return the value defined by this instruction, if any. This includes
+ /// dead defs, it is the value created by the instruction's def operands.
+ VNInfo *valueDefined() const {
+ return EarlyVal == LateVal ? 0 : LateVal;
+ }
+
+ /// Return the end point of the last live range segment to interact with
+ /// the instruction, if any.
+ ///
+ /// The end point is an invalid SlotIndex only if the live range doesn't
+ /// intersect the instruction at all.
+ ///
+ /// The end point may be at or past the end of the instruction's basic
+ /// block. That means the value was live out of the block.
+ SlotIndex endPoint() const {
+ return EndPoint;
+ }
+ };
+
+ /// ConnectedVNInfoEqClasses - Helper class that can divide VNInfos in a
+ /// LiveInterval into equivalence clases of connected components. A
+ /// LiveInterval that has multiple connected components can be broken into
+ /// multiple LiveIntervals.
+ ///
+ /// Given a LiveInterval that may have multiple connected components, run:
+ ///
+ /// unsigned numComps = ConEQ.Classify(LI);
+ /// if (numComps > 1) {
+ /// // allocate numComps-1 new LiveIntervals into LIS[1..]
+ /// ConEQ.Distribute(LIS);
+ /// }
+
+ class ConnectedVNInfoEqClasses {
+ LiveIntervals &LIS;
+ IntEqClasses EqClass;
+
+ // Note that values a and b are connected.
+ void Connect(unsigned a, unsigned b);
+
+ unsigned Renumber();
+
+ public:
+ explicit ConnectedVNInfoEqClasses(LiveIntervals &lis) : LIS(lis) {}
+
+ /// Classify - Classify the values in LI into connected components.
+ /// Return the number of connected components.
+ unsigned Classify(const LiveInterval *LI);
+
+ /// getEqClass - Classify creates equivalence classes numbered 0..N. Return
+ /// the equivalence class assigned the VNI.
+ unsigned getEqClass(const VNInfo *VNI) const { return EqClass[VNI->id]; }
+
+ /// Distribute - Distribute values in LIV[0] into a separate LiveInterval
+ /// for each connected component. LIV must have a LiveInterval for each
+ /// connected component. The LiveIntervals in Liv[1..] must be empty.
+ /// Instructions using LIV[0] are rewritten.
+ void Distribute(LiveInterval *LIV[], MachineRegisterInfo &MRI);
+
+ };
+
+}
#endif
projects / oota-llvm.git / blobdiff