//
// 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
+// live interval 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 intervals can have holes,
// i.e. an interval might look like [1,20), [50,65), [1000,1001). Each
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Allocator.h"
-#include <iosfwd>
+#include "llvm/Support/AlignOf.h"
+#include "llvm/CodeGen/SlotIndexes.h"
#include <cassert>
+#include <climits>
namespace llvm {
+ 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.
- /// kills - Instruction # of the kills.
- struct VNInfo {
- unsigned id;
- unsigned def;
+ class raw_ostream;
+
+ /// VNInfo - Value Number Information.
+ /// This class holds information about a machine level values, including
+ /// definition and use points.
+ ///
+ class VNInfo {
+ private:
+ enum {
+ HAS_PHI_KILL = 1,
+ REDEF_BY_EC = 1 << 1,
+ IS_PHI_DEF = 1 << 2,
+ IS_UNUSED = 1 << 3
+ };
+
MachineInstr *copy;
- bool hasPHIKill;
- SmallVector<unsigned, 4> kills;
- VNInfo() : id(~1U), def(~1U), copy(0), hasPHIKill(false) {}
- VNInfo(unsigned i, unsigned d, MachineInstr *c)
- : id(i), def(d), copy(c), hasPHIKill(false) {}
+ unsigned char flags;
+
+ public:
+ typedef BumpPtrAllocator Allocator;
+
+ /// The ID number of this value.
+ unsigned id;
+
+ /// The index of the defining instruction (if isDefAccurate() returns true).
+ SlotIndex def;
+
+ /// VNInfo constructor.
+ VNInfo(unsigned i, SlotIndex d, MachineInstr *c)
+ : copy(c), flags(0), id(i), def(d)
+ { }
+
+ /// VNInfo construtor, copies values from orig, except for the value number.
+ VNInfo(unsigned i, const VNInfo &orig)
+ : copy(orig.copy), flags(orig.flags), id(i), def(orig.def)
+ { }
+
+ /// Copy from the parameter into this VNInfo.
+ void copyFrom(VNInfo &src) {
+ flags = src.flags;
+ copy = src.copy;
+ def = src.def;
+ }
+
+ /// Used for copying value number info.
+ unsigned getFlags() const { return flags; }
+ void setFlags(unsigned flags) { this->flags = flags; }
+
+ /// Merge flags from another VNInfo
+ void mergeFlags(const VNInfo *VNI) {
+ flags = (flags | VNI->flags) & ~IS_UNUSED;
+ }
+
+ /// For a register interval, if this VN was definied by a copy instr
+ /// getCopy() returns a pointer to it, otherwise returns 0.
+ /// For a stack interval the behaviour of this method is undefined.
+ MachineInstr* getCopy() const { return copy; }
+ /// For a register interval, set the copy member.
+ /// This method should not be called on stack intervals as it may lead to
+ /// undefined behavior.
+ void setCopy(MachineInstr *c) { copy = c; }
+
+ /// isDefByCopy - Return true when this value was defined by a copy-like
+ /// instruction as determined by MachineInstr::isCopyLike.
+ bool isDefByCopy() const { return copy != 0; }
+
+ /// Returns true if one or more kills are PHI nodes.
+ bool hasPHIKill() const { return flags & HAS_PHI_KILL; }
+ /// Set the PHI kill flag on this value.
+ void setHasPHIKill(bool hasKill) {
+ if (hasKill)
+ flags |= HAS_PHI_KILL;
+ else
+ flags &= ~HAS_PHI_KILL;
+ }
+
+ /// Returns true if this value is re-defined by an early clobber somewhere
+ /// during the live range.
+ bool hasRedefByEC() const { return flags & REDEF_BY_EC; }
+ /// Set the "redef by early clobber" flag on this value.
+ void setHasRedefByEC(bool hasRedef) {
+ if (hasRedef)
+ flags |= REDEF_BY_EC;
+ else
+ flags &= ~REDEF_BY_EC;
+ }
+
+ /// Returns true if this value is defined by a PHI instruction (or was,
+ /// PHI instrucions may have been eliminated).
+ bool isPHIDef() const { return flags & IS_PHI_DEF; }
+ /// Set the "phi def" flag on this value.
+ void setIsPHIDef(bool phiDef) {
+ if (phiDef)
+ flags |= IS_PHI_DEF;
+ else
+ flags &= ~IS_PHI_DEF;
+ }
+
+ /// Returns true if this value is unused.
+ bool isUnused() const { return flags & IS_UNUSED; }
+ /// Set the "is unused" flag on this value.
+ void setIsUnused(bool unused) {
+ if (unused)
+ flags |= IS_UNUSED;
+ else
+ flags &= ~IS_UNUSED;
+ }
};
/// 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); }
+ void print(raw_ostream &os) const;
private:
LiveRange(); // DO NOT IMPLEMENT
};
- 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.
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:
+ struct InstrSlots {
+ enum {
+ LOAD = 0,
+ USE = 1,
+ DEF = 2,
+ STORE = 3,
+ NUM = 4
+ };
+
+ };
+
LiveInterval(unsigned Reg, float Weight, bool IsSS = false)
- : reg(Reg), weight(Weight), preference(0) {
+ : reg(Reg), weight(Weight) {
if (IsSS)
- reg = reg | (1U << (sizeof(unsigned)*8-1));
+ reg = reg | (1U << (sizeof(unsigned)*CHAR_BIT-1));
}
typedef Ranges::iterator iterator;
/// 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;
}
+ /// 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.
+ ///
+ /// 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);
+ }
+
+ void clear() {
+ valnos.clear();
+ ranges.clear();
+ }
+
/// isStackSlot - Return true if this is a stack slot interval.
///
bool isStackSlot() const {
- return reg & (1U << (sizeof(unsigned)*8-1));
+ return reg & (1U << (sizeof(unsigned)*CHAR_BIT-1));
}
/// 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));
+ return reg & ~(1U << (sizeof(unsigned)*CHAR_BIT-1));
}
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->kills = SrcValNo->kills;
- }
/// 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, MachineInstr *CopyMI,
+ 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, CopyMI);
valnos.push_back(VNI);
return VNI;
}
- /// 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);
- }
- }
-
- /// 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;
+ /// RenumberValues - Renumber all values in order of appearance and remove
+ /// unused values.
+ /// Recalculate phi-kill flags in case any phi-def values were removed.
+ void RenumberValues(LiveIntervals &lis);
+
+ /// 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 false;
+ return true;
}
- /// removeKills - Remove all the kills in specified range
- /// [Start, End] of the specified val#.
- 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#.
- bool isKill(const VNInfo *VNI, unsigned KillIdx) const {
- 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;
- }
-
/// MergeValueNumberInto - This method is called when two value nubmers
/// are found to be equivalent. This eliminates V1, replacing all
/// LiveRanges with the V1 value number with the V2 value number. This can
/// cause merging of V1/V2 values numbers and compaction of the value space.
- void 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);
+ VNInfo* MergeValueNumberInto(VNInfo *V1, VNInfo *V2);
/// MergeValueInAsValue - Merge all of the live ranges of a specific val#
/// in RHS into this live interval as the specified value number.
/// 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);
-
+ void Copy(const LiveInterval &RHS, MachineRegisterInfo *MRI,
+ VNInfo::Allocator &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.getUseIndex());
+ return r != end() && r->end == index;
+ }
+
+ /// killedInRange - Return true if the interval has kills in [Start,End).
+ /// Note that the kill point is considered the end of a live range, so it is
+ /// not contained in the live range. If a live range ends at End, it won't
+ /// be counted as a kill by this method.
+ bool killedInRange(SlotIndex Start, SlotIndex End) const;
/// 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;
+ }
/// 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 by the specified
+ /// index (register interval) or defined
+ VNInfo *findDefinedVNInfoForRegInt(SlotIndex Idx) const;
+
- /// 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 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.
/// 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(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 already be in this interval in its entirety.
- void removeRange(unsigned Start, unsigned End, bool RemoveDeadValNo = false);
+ /// the range must be a single LiveRange in its entirety.
+ 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() const {
+ for (const_iterator i = begin(), e = end(); i != e; ++i)
+ if (i->end.getPrevIndex() > i->start)
+ return false;
+ return true;
}
- 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);
+ /// isSpillable - Can this interval be spilled?
+ bool isSpillable() const {
+ return weight != HUGE_VALF;
}
+
+ /// markNotSpillable - Mark interval as not spillable
+ void markNotSpillable() {
+ weight = HUGE_VALF;
+ }
+
+ /// ComputeJoinedWeight - Set the weight of a live interval after
+ /// Other has been merged into it.
+ void ComputeJoinedWeight(const LiveInterval &Other);
+
+ 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 TargetRegisterInfo *TRI = 0) const;
void dump() const;
private:
+
Ranges::iterator addRangeFrom(LiveRange LR, Ranges::iterator From);
- void extendIntervalEndTo(Ranges::iterator I, unsigned NewEnd);
- Ranges::iterator extendIntervalStartTo(Ranges::iterator I, unsigned NewStr);
+ void extendIntervalEndTo(Ranges::iterator I, SlotIndex NewEnd);
+ Ranges::iterator extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStr);
+ void markValNoForDeletion(VNInfo *V);
+
LiveInterval& operator=(const LiveInterval& rhs); // DO NOT IMPLEMENT
+
};
- 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;
}
-}
+ /// 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_;
+
+ // Map each value number to its equivalence class.
+ // The invariant is that EqClass[x] <= x.
+ // Two values are connected iff EqClass[x] == EqClass[b].
+ SmallVector<unsigned, 8> 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) { 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.
+ void Distribute(LiveInterval *LIV[]);
+
+ };
+
+}
#endif
projects / oota-llvm.git / blobdiff