#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,
- IS_PHI_DEF = 1 << 1,
- IS_UNUSED = 1 << 2
- };
-
- unsigned char flags;
-
public:
typedef BumpPtrAllocator Allocator;
/// VNInfo constructor.
VNInfo(unsigned i, SlotIndex d)
- : flags(0), id(i), def(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), id(i), def(orig.def)
+ : id(i), def(orig.def)
{ }
/// Copy from the parameter into this VNInfo.
void copyFrom(VNInfo &src) {
- flags = src.flags;
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;
- }
-
- /// 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 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; };
Ranges ranges; // the ranges in which this register is live
VNInfoList valnos; // value#'s
- struct InstrSlots {
- enum {
- LOAD = 0,
- USE = 1,
- DEF = 2,
- STORE = 3,
- NUM = 4
- };
-
- };
-
LiveInterval(unsigned Reg, float Weight)
: reg(Reg), weight(Weight) {}
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 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
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
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,
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); // 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
if (I == E)
return;
// Is this an instruction live-in segment?
- if (SlotIndex::isEarlierInstr(I->start, Idx)) {
+ // 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 (++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.