#ifndef LLVM_CODEGEN_LIVEINTERVAL_H
#define LLVM_CODEGEN_LIVEINTERVAL_H
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/Support/Allocator.h"
-#include "llvm/Support/AlignOf.h"
+#include "llvm/ADT/IntEqClasses.h"
#include "llvm/CodeGen/SlotIndexes.h"
+#include "llvm/Support/AlignOf.h"
+#include "llvm/Support/Allocator.h"
#include <cassert>
#include <climits>
namespace llvm {
+ class CoalescerPair;
class LiveIntervals;
class MachineInstr;
class MachineRegisterInfo;
/// This class holds information about a machine level values, including
/// definition and use points.
///
- /// Care must be taken in interpreting the def index of the value. The
- /// following rules apply:
- ///
- /// If the isDefAccurate() method returns false then def does not contain the
- /// index of the defining MachineInstr, or even (necessarily) to a
- /// MachineInstr at all. In general such a def index is not meaningful
- /// and should not be used. The exception is that, for values originally
- /// defined by PHI instructions, after PHI elimination def will contain the
- /// index of the MBB in which the PHI originally existed. This can be used
- /// to insert code (spills or copies) which deals with the value, which will
- /// be live in to the block.
class VNInfo {
- private:
- enum {
- HAS_PHI_KILL = 1,
- REDEF_BY_EC = 1 << 1,
- IS_PHI_DEF = 1 << 2,
- IS_UNUSED = 1 << 3,
- IS_DEF_ACCURATE = 1 << 4
- };
-
- unsigned char flags;
- union {
- MachineInstr *copy;
- unsigned reg;
- } cr;
-
public:
-
- typedef SmallVector<SlotIndex, 4> KillSet;
+ typedef BumpPtrAllocator Allocator;
/// The ID number of this value.
unsigned id;
-
- /// The index of the defining instruction (if isDefAccurate() returns true).
- SlotIndex def;
- KillSet kills;
-
- /*
- VNInfo(LiveIntervals &li_)
- : defflags(IS_UNUSED), id(~1U) { cr.copy = 0; }
- */
+ /// The index of the defining instruction.
+ SlotIndex def;
/// VNInfo constructor.
- /// d is presumed to point to the actual defining instr. If it doesn't
- /// setIsDefAccurate(false) should be called after construction.
- VNInfo(unsigned i, SlotIndex d, MachineInstr *c)
- : flags(IS_DEF_ACCURATE), id(i), def(d) { cr.copy = c; }
+ 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)
- : flags(orig.flags), cr(orig.cr), id(i), def(orig.def), kills(orig.kills)
+ : id(i), def(orig.def)
{ }
/// Copy from the parameter into this VNInfo.
void copyFrom(VNInfo &src) {
- flags = src.flags;
- cr = src.cr;
def = src.def;
- kills = src.kills;
- }
-
- /// Used for copying value number info.
- unsigned getFlags() const { return flags; }
- void setFlags(unsigned flags) { this->flags = flags; }
-
- /// 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 cr.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) { cr.copy = c; }
-
- /// For a stack interval, returns the reg which this stack interval was
- /// defined from.
- /// For a register interval the behaviour of this method is undefined.
- unsigned getReg() const { return cr.reg; }
- /// For a stack interval, set the defining register.
- /// This method should not be called on register intervals as it may lead
- /// to undefined behaviour.
- void setReg(unsigned reg) { cr.reg = reg; }
-
- /// 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;
- }
+ /// 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 flags & IS_UNUSED; }
- /// Set the "is unused" flag on this value.
- void setIsUnused(bool unused) {
- if (unused)
- flags |= IS_UNUSED;
- else
- flags &= ~IS_UNUSED;
- }
-
- /// Returns true if the def is accurate.
- bool isDefAccurate() const { return flags & IS_DEF_ACCURATE; }
- /// Set the "is def accurate" flag on this value.
- void setIsDefAccurate(bool defAccurate) {
- if (defAccurate)
- flags |= IS_DEF_ACCURATE;
- else
- flags &= ~IS_DEF_ACCURATE;
- }
-
- /// Returns true if the given index is a kill of this value.
- bool isKill(SlotIndex k) const {
- KillSet::const_iterator
- i = std::lower_bound(kills.begin(), kills.end(), k);
- return (i != kills.end() && *i == k);
- }
-
- /// addKill - Add a kill instruction index to the specified value
- /// number.
- void addKill(SlotIndex k) {
- if (kills.empty()) {
- kills.push_back(k);
- } else {
- KillSet::iterator
- i = std::lower_bound(kills.begin(), kills.end(), k);
- kills.insert(i, k);
- }
- }
-
- /// Remove the specified kill index from this value's kills list.
- /// Returns true if the value was present, otherwise returns false.
- bool removeKill(SlotIndex k) {
- KillSet::iterator i = std::lower_bound(kills.begin(), kills.end(), k);
- if (i != kills.end() && *i == k) {
- kills.erase(i);
- return true;
- }
- return false;
- }
-
- /// Remove all kills in the range [s, e).
- void removeKills(SlotIndex s, SlotIndex e) {
- KillSet::iterator
- si = std::lower_bound(kills.begin(), kills.end(), s),
- se = std::upper_bound(kills.begin(), kills.end(), e);
-
- kills.erase(si, se);
- }
+ 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
SlotIndex end; // End point of the interval (exclusive)
VNInfo *valno; // identifier for the value contained in this interval.
+ LiveRange() : valno(0) {}
+
LiveRange(SlotIndex S, SlotIndex E, VNInfo *V)
: start(S), end(E), valno(V) {
-
assert(S < E && "Cannot create empty or backwards range");
}
}
/// containsRange - Return true if the given range, [S, E), is covered by
- /// this range.
+ /// this range.
bool containsRange(SlotIndex S, SlotIndex E) const {
assert((S < E) && "Backwards interval?");
return (start <= S && S < end) && (start < E && E <= end);
void dump() const;
void print(raw_ostream &os) const;
-
- private:
- LiveRange(); // DO NOT IMPLEMENT
};
+ template <> struct isPodLike<LiveRange> { static const bool value = true; };
+
raw_ostream& operator<<(raw_ostream& os, const LiveRange &LR);
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
Ranges ranges; // the ranges in which this register is live
VNInfoList valnos; // value#'s
-
+
struct InstrSlots {
enum {
LOAD = 0,
};
- LiveInterval(unsigned Reg, float Weight, bool IsSS = false)
- : reg(Reg), weight(Weight) {
- if (IsSS)
- reg = reg | (1U << (sizeof(unsigned)*CHAR_BIT-1));
- }
+ LiveInterval(unsigned Reg, float Weight)
+ : reg(Reg), weight(Weight) {}
typedef Ranges::iterator iterator;
iterator begin() { return ranges.begin(); }
/// position is in a hole, this method returns an iterator pointing to the
/// LiveRange immediately after the hole.
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)*CHAR_BIT-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)*CHAR_BIT-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) {
return valnos[ValNo];
}
+ /// 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(SlotIndex def, MachineInstr *CopyMI,
- bool isDefAccurate, BumpPtrAllocator &VNInfoAllocator){
+ VNInfo *getNextValue(SlotIndex def, VNInfo::Allocator &VNInfoAllocator) {
VNInfo *VNI =
- static_cast<VNInfo*>(VNInfoAllocator.Allocate((unsigned)sizeof(VNInfo),
- alignof<VNInfo>()));
- new (VNI) VNInfo((unsigned)valnos.size(), def, CopyMI);
- VNI->setIsDefAccurate(isDefAccurate);
+ new (VNInfoAllocator) VNInfo((unsigned)valnos.size(), def);
valnos.push_back(VNI);
return VNI;
}
+ /// 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);
+
/// Create a copy of the given value. The new value will be identical except
/// for the Value number.
VNInfo *createValueCopy(const VNInfo *orig,
- BumpPtrAllocator &VNInfoAllocator) {
+ VNInfo::Allocator &VNInfoAllocator) {
VNInfo *VNI =
- static_cast<VNInfo*>(VNInfoAllocator.Allocate((unsigned)sizeof(VNInfo),
- alignof<VNInfo>()));
-
- new (VNI) VNInfo((unsigned)valnos.size(), *orig);
+ new (VNInfoAllocator) VNInfo((unsigned)valnos.size(), *orig);
valnos.push_back(VNI);
return VNI;
}
- /// 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 VNInfo::KillSet &kills) {
- for (unsigned i = 0, e = static_cast<unsigned>(kills.size());
- i != e; ++i) {
- if (!liveBeforeAndAt(kills[i])) {
- VNI->addKill(kills[i]);
- }
- }
- }
+ /// RenumberValues - Renumber all values in order of appearance and remove
+ /// unused values.
+ 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 true;
- }
-
/// 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(LiveIntervals &li_,
- const LiveInterval &Clobbers,
- BumpPtrAllocator &VNInfoAllocator);
-
- /// MergeInClobberRange - Same as MergeInClobberRanges except it merge in a
- /// single LiveRange only.
- void MergeInClobberRange(LiveIntervals &li_,
- SlotIndex Start,
- SlotIndex 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, MachineRegisterInfo *MRI,
- BumpPtrAllocator &VNInfoAllocator);
-
bool empty() const { return ranges.empty(); }
/// beginIndex - Return the lowest numbered slot covered by interval.
return index >= endIndex();
}
- bool liveAt(SlotIndex 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(SlotIndex 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.
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(SlotIndex Idx) const;
+ /// 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(SlotIndex Idx);
-
- /// findDefinedVNInfo - Find the by the specified
- /// index (register interval) or defined
- VNInfo *findDefinedVNInfoForRegInt(SlotIndex Idx) const;
+ iterator FindLiveRangeContaining(SlotIndex Idx) {
+ iterator I = find(Idx);
+ return I != end() && I->start <= Idx ? I : end();
+ }
- /// findDefinedVNInfo - Find the VNInfo that's defined by the specified
- /// register (stack inteval only).
- VNInfo *findDefinedVNInfoForStackInt(unsigned Reg) const;
+ const_iterator FindLiveRangeContaining(SlotIndex Idx) const {
+ const_iterator I = find(Idx);
+ return I != end() && I->start <= Idx ? I : end();
+ }
-
/// 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;
/// addRange - Add the specified LiveRange to this interval, merging
/// intervals as appropriate. This returns an iterator to the inserted live
/// range (which may have grown since it was inserted.
- void addRange(LiveRange LR) {
- addRangeFrom(LR, ranges.begin());
+ iterator addRange(LiveRange LR) {
+ return 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,
const int *RHSValNoAssignments,
- SmallVector<VNInfo*, 16> &NewVNInfo,
+ SmallVectorImpl<VNInfo *> &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);
+ bool isInOneLiveRange(SlotIndex Start, SlotIndex End) const {
+ const_iterator r = find(Start);
+ return r != end() && r->containsRange(Start, End);
+ }
+
+ /// True iff this live range is a single segment that lies between the
+ /// specified boundaries, exclusively. Vregs live across a backedge are not
+ /// considered local. The boundaries are expected to lie within an extended
+ /// basic block, so vregs that are not live out should contain no holes.
+ bool isLocal(SlotIndex Start, SlotIndex End) const {
+ return beginIndex() > Start.getBaseIndex() &&
+ endIndex() < End.getBoundaryIndex();
+ }
/// removeRange - Remove the specified range from this interval. Note that
/// the range must be a single LiveRange in its entirety.
/// Also remove the value# from value# list.
void removeValNo(VNInfo *ValNo);
- /// scaleNumbering - Renumber VNI and ranges to provide gaps for new
- /// instructions.
- void scaleNumbering(unsigned factor);
-
/// getSize - Returns the sum of sizes of all the LiveRange's.
///
unsigned getSize() const;
- /// ComputeJoinedWeight - Set the weight of a live interval after
- /// Other has been merged into it.
- void ComputeJoinedWeight(const LiveInterval &Other);
+ /// 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;
+ }
+
+ /// markNotSpillable - Mark interval as not spillable
+ void markNotSpillable() {
+ weight = HUGE_VALF;
+ }
bool operator<(const LiveInterval& other) const {
const SlotIndex &thisIndex = beginIndex();
(thisIndex == otherIndex && reg < other.reg));
}
- void print(raw_ostream &OS, const TargetRegisterInfo *TRI = 0) const;
+ 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, SlotIndex NewEnd);
Ranges::iterator extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStr);
+ void markValNoForDeletion(VNInfo *V);
- LiveInterval& operator=(const LiveInterval& rhs); // DO NOT IMPLEMENT
+ LiveInterval& operator=(const LiveInterval& rhs) LLVM_DELETED_FUNCTION;
};
LI.print(OS);
return OS;
}
-}
+ /// Helper class for performant LiveInterval bulk updates.
+ ///
+ /// Calling LiveInterval::addRange() repeatedly can be expensive on large
+ /// live ranges because segments after the insertion point may need to be
+ /// shifted. The LiveRangeUpdater class can defer the shifting when adding
+ /// many segments in order.
+ ///
+ /// The LiveInterval will be in an invalid state until flush() is called.
+ class LiveRangeUpdater {
+ LiveInterval *LI;
+ SlotIndex LastStart;
+ LiveInterval::iterator WriteI;
+ LiveInterval::iterator ReadI;
+ SmallVector<LiveRange, 16> Spills;
+ void mergeSpills();
+
+ public:
+ /// Create a LiveRangeUpdater for adding segments to LI.
+ /// LI will temporarily be in an invalid state until flush() is called.
+ LiveRangeUpdater(LiveInterval *li = 0) : LI(li) {}
+
+ ~LiveRangeUpdater() { flush(); }
+
+ /// Add a segment to LI and coalesce when possible, just like LI.addRange().
+ /// Segments should be added in increasing start order for best performance.
+ void add(LiveRange);
+
+ void add(SlotIndex Start, SlotIndex End, VNInfo *VNI) {
+ add(LiveRange(Start, End, VNI));
+ }
+
+ /// Return true if the LI is currently in an invalid state, and flush()
+ /// needs to be called.
+ bool isDirty() const { return LastStart.isValid(); }
+
+ /// Flush the updater state to LI so it is valid and contains all added
+ /// segments.
+ void flush();
+
+ /// Select a different destination live range.
+ void setDest(LiveInterval *li) {
+ if (LI != li && isDirty())
+ flush();
+ LI = li;
+ }
+
+ /// Get the current destination live range.
+ LiveInterval *getDest() const { return LI; }
+
+ void dump() const;
+ void print(raw_ostream&) const;
+ };
+
+ inline raw_ostream &operator<<(raw_ostream &OS, const LiveRangeUpdater &X) {
+ X.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