#define LLVM_CODEGEN_LIVEINTERVAL_H
#include "llvm/ADT/IntEqClasses.h"
-#include "llvm/Support/Allocator.h"
-#include "llvm/Support/AlignOf.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;
/// 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;
- unsigned char flags;
-
public:
typedef BumpPtrAllocator Allocator;
SlotIndex def;
/// VNInfo constructor.
- VNInfo(unsigned i, SlotIndex d, MachineInstr *c)
- : copy(c), flags(0), id(i), def(d)
+ 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)
- : copy(orig.copy), flags(orig.flags), id(i), def(orig.def)
+ : 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.
- /// Obsolete, do not use!
- 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;
- }
+ 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");
}
void dump() const;
void print(raw_ostream &os) const;
-
- private:
- LiveRange(); // DO NOT IMPLEMENT
};
template <> struct isPodLike<LiveRange> { static const bool value = true; };
/// getNextValue - Create a new value number and return it. MIIdx specifies
/// the instruction that defines the value number.
- VNInfo *getNextValue(SlotIndex def, MachineInstr *CopyMI,
- VNInfo::Allocator &VNInfoAllocator) {
+ VNInfo *getNextValue(SlotIndex def, VNInfo::Allocator &VNInfoAllocator) {
VNInfo *VNI =
- new (VNInfoAllocator) VNInfo((unsigned)valnos.size(), def, CopyMI);
+ 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,
/// 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
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,
- VNInfo::Allocator &VNInfoAllocator);
-
bool empty() const { return ranges.empty(); }
/// beginIndex - Return the lowest numbered slot covered by interval.
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(SlotIndex Idx) const {
return I != end() && I->start <= Idx ? I : end();
}
- /// findDefinedVNInfo - Find the by the specified
- /// index (register interval) or defined
- VNInfo *findDefinedVNInfoForRegInt(SlotIndex Idx) const;
-
-
/// overlaps - Return true if the intersection of the two live intervals is
/// not empty.
bool overlaps(const LiveInterval& other) const {
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
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.
void removeRange(SlotIndex Start, SlotIndex End,
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();
(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);
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;
};
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
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