-//===-------- SplitKit.cpp - Toolkit for splitting live ranges --*- C++ -*-===//
+//===-------- SplitKit.h - Toolkit for splitting live ranges ----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
-#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/IndexedMap.h"
+#include "llvm/ADT/IntervalMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/CodeGen/SlotIndexes.h"
namespace llvm {
+class ConnectedVNInfoEqClasses;
class LiveInterval;
class LiveIntervals;
class LiveRangeEdit;
class MachineInstr;
-class MachineLoop;
class MachineLoopInfo;
class MachineRegisterInfo;
class TargetInstrInfo;
template <class NodeT> class DomTreeNodeBase;
typedef DomTreeNodeBase<MachineBasicBlock> MachineDomTreeNode;
+
/// SplitAnalysis - Analyze a LiveInterval, looking for live range splitting
/// opportunities.
class SplitAnalysis {
public:
- const MachineFunction &mf_;
- const LiveIntervals &lis_;
- const MachineLoopInfo &loops_;
- const TargetInstrInfo &tii_;
+ const MachineFunction &MF;
+ const VirtRegMap &VRM;
+ const LiveIntervals &LIS;
+ const MachineLoopInfo &Loops;
+ const TargetInstrInfo &TII;
+
+ // Sorted slot indexes of using instructions.
+ SmallVector<SlotIndex, 8> UseSlots;
+
+ /// Additional information about basic blocks where the current variable is
+ /// live. Such a block will look like one of these templates:
+ ///
+ /// 1. | o---x | Internal to block. Variable is only live in this block.
+ /// 2. |---x | Live-in, kill.
+ /// 3. | o---| Def, live-out.
+ /// 4. |---x o---| Live-in, kill, def, live-out.
+ /// 5. |---o---o---| Live-through with uses or defs.
+ /// 6. |-----------| Live-through without uses. Transparent.
+ ///
+ struct BlockInfo {
+ MachineBasicBlock *MBB;
+ SlotIndex FirstUse; ///< First instr using current reg.
+ SlotIndex LastUse; ///< Last instr using current reg.
+ SlotIndex Kill; ///< Interval end point inside block.
+ SlotIndex Def; ///< Interval start point inside block.
+ bool LiveThrough; ///< Live in whole block (Templ 5. or 6. above).
+ bool LiveIn; ///< Current reg is live in.
+ bool LiveOut; ///< Current reg is live out.
+ };
- // Instructions using the the current register.
- typedef SmallPtrSet<const MachineInstr*, 16> InstrPtrSet;
- InstrPtrSet usingInstrs_;
+private:
+ // Current live interval.
+ const LiveInterval *CurLI;
- // The number of instructions using curli in each basic block.
- typedef DenseMap<const MachineBasicBlock*, unsigned> BlockCountMap;
- BlockCountMap usingBlocks_;
+ /// LastSplitPoint - Last legal split point in each basic block in the current
+ /// function. The first entry is the first terminator, the second entry is the
+ /// last valid split point for a variable that is live in to a landing pad
+ /// successor.
+ SmallVector<std::pair<SlotIndex, SlotIndex>, 8> LastSplitPoint;
- // The number of basic block using curli in each loop.
- typedef DenseMap<const MachineLoop*, unsigned> LoopCountMap;
- LoopCountMap usingLoops_;
+ /// UseBlocks - Blocks where CurLI has uses.
+ SmallVector<BlockInfo, 8> UseBlocks;
-private:
- // Current live interval.
- const LiveInterval *curli_;
+ /// ThroughBlocks - Block numbers where CurLI is live through without uses.
+ BitVector ThroughBlocks;
- // Sumarize statistics by counting instructions using curli_.
+ /// NumThroughBlocks - Number of live-through blocks.
+ unsigned NumThroughBlocks;
+
+ SlotIndex computeLastSplitPoint(unsigned Num);
+
+ // Sumarize statistics by counting instructions using CurLI.
void analyzeUses();
- /// canAnalyzeBranch - Return true if MBB ends in a branch that can be
- /// analyzed.
- bool canAnalyzeBranch(const MachineBasicBlock *MBB);
+ /// calcLiveBlockInfo - Compute per-block information about CurLI.
+ bool calcLiveBlockInfo();
public:
- SplitAnalysis(const MachineFunction &mf, const LiveIntervals &lis,
+ SplitAnalysis(const VirtRegMap &vrm, const LiveIntervals &lis,
const MachineLoopInfo &mli);
- /// analyze - set curli to the specified interval, and analyze how it may be
+ /// analyze - set CurLI to the specified interval, and analyze how it may be
/// split.
void analyze(const LiveInterval *li);
/// new interval.
void clear();
- typedef SmallPtrSet<const MachineBasicBlock*, 16> BlockPtrSet;
- typedef SmallPtrSet<const MachineLoop*, 16> LoopPtrSet;
-
- // Print a set of blocks with use counts.
- void print(const BlockPtrSet&, raw_ostream&) const;
-
- // Sets of basic blocks surrounding a machine loop.
- struct LoopBlocks {
- BlockPtrSet Loop; // Blocks in the loop.
- BlockPtrSet Preds; // Loop predecessor blocks.
- BlockPtrSet Exits; // Loop exit blocks.
-
- void clear() {
- Loop.clear();
- Preds.clear();
- Exits.clear();
- }
- };
-
- // Print loop blocks with use counts.
- void print(const LoopBlocks&, raw_ostream&) const;
-
- // Calculate the block sets surrounding the loop.
- void getLoopBlocks(const MachineLoop *Loop, LoopBlocks &Blocks);
+ /// getParent - Return the last analyzed interval.
+ const LiveInterval &getParent() const { return *CurLI; }
+
+ /// getLastSplitPoint - Return that base index of the last valid split point
+ /// in the basic block numbered Num.
+ SlotIndex getLastSplitPoint(unsigned Num) {
+ // Inline the common simple case.
+ if (LastSplitPoint[Num].first.isValid() &&
+ !LastSplitPoint[Num].second.isValid())
+ return LastSplitPoint[Num].first;
+ return computeLastSplitPoint(Num);
+ }
- /// LoopPeripheralUse - how is a variable used in and around a loop?
- /// Peripheral blocks are the loop predecessors and exit blocks.
- enum LoopPeripheralUse {
- ContainedInLoop, // All uses are inside the loop.
- SinglePeripheral, // At most one instruction per peripheral block.
- MultiPeripheral, // Multiple instructions in some peripheral blocks.
- OutsideLoop // Uses outside loop periphery.
- };
+ /// isOriginalEndpoint - Return true if the original live range was killed or
+ /// (re-)defined at Idx. Idx should be the 'def' slot for a normal kill/def,
+ /// and 'use' for an early-clobber def.
+ /// This can be used to recognize code inserted by earlier live range
+ /// splitting.
+ bool isOriginalEndpoint(SlotIndex Idx) const;
- /// analyzeLoopPeripheralUse - Return an enum describing how curli_ is used in
- /// and around the Loop.
- LoopPeripheralUse analyzeLoopPeripheralUse(const LoopBlocks&);
+ /// getUseBlocks - Return an array of BlockInfo objects for the basic blocks
+ /// where CurLI has uses.
+ ArrayRef<BlockInfo> getUseBlocks() { return UseBlocks; }
- /// getCriticalExits - It may be necessary to partially break critical edges
- /// leaving the loop if an exit block has phi uses of curli. Collect the exit
- /// blocks that need special treatment into CriticalExits.
- void getCriticalExits(const LoopBlocks &Blocks, BlockPtrSet &CriticalExits);
+ /// getNumThroughBlocks - Return the number of through blocks.
+ unsigned getNumThroughBlocks() const { return NumThroughBlocks; }
- /// canSplitCriticalExits - Return true if it is possible to insert new exit
- /// blocks before the blocks in CriticalExits.
- bool canSplitCriticalExits(const LoopBlocks &Blocks,
- BlockPtrSet &CriticalExits);
+ /// isThroughBlock - Return true if CurLI is live through MBB without uses.
+ bool isThroughBlock(unsigned MBB) const { return ThroughBlocks.test(MBB); }
- /// getCriticalPreds - Get the set of loop predecessors with critical edges to
- /// blocks outside the loop that have curli live in. We don't have to break
- /// these edges, but they do require special treatment.
- void getCriticalPreds(const LoopBlocks &Blocks, BlockPtrSet &CriticalPreds);
+ /// getThroughBlocks - Return the set of through blocks.
+ const BitVector &getThroughBlocks() const { return ThroughBlocks; }
- /// getBestSplitLoop - Return the loop where curli may best be split to a
- /// separate register, or NULL.
- const MachineLoop *getBestSplitLoop();
+ typedef SmallPtrSet<const MachineBasicBlock*, 16> BlockPtrSet;
/// getMultiUseBlocks - Add basic blocks to Blocks that may benefit from
- /// having curli split to a new live interval. Return true if Blocks can be
+ /// having CurLI split to a new live interval. Return true if Blocks can be
/// passed to SplitEditor::splitSingleBlocks.
bool getMultiUseBlocks(BlockPtrSet &Blocks);
-
- /// getBlockForInsideSplit - If curli is contained inside a single basic block,
- /// and it wou pay to subdivide the interval inside that block, return it.
- /// Otherwise return NULL. The returned block can be passed to
- /// SplitEditor::splitInsideBlock.
- const MachineBasicBlock *getBlockForInsideSplit();
-};
-
-
-/// LiveIntervalMap - Map values from a large LiveInterval into a small
-/// interval that is a subset. Insert phi-def values as needed. This class is
-/// used by SplitEditor to create new smaller LiveIntervals.
-///
-/// parentli_ is the larger interval, li_ is the subset interval. Every value
-/// in li_ corresponds to exactly one value in parentli_, and the live range
-/// of the value is contained within the live range of the parentli_ value.
-/// Values in parentli_ may map to any number of openli_ values, including 0.
-class LiveIntervalMap {
- LiveIntervals &lis_;
- MachineDominatorTree &mdt_;
-
- // The parent interval is never changed.
- const LiveInterval &parentli_;
-
- // The child interval's values are fully contained inside parentli_ values.
- LiveInterval *li_;
-
- typedef DenseMap<const VNInfo*, VNInfo*> ValueMap;
-
- // Map parentli_ values to simple values in li_ that are defined at the same
- // SlotIndex, or NULL for parentli_ values that have complex li_ defs.
- // Note there is a difference between values mapping to NULL (complex), and
- // values not present (unknown/unmapped).
- ValueMap valueMap_;
-
- typedef std::pair<VNInfo*, MachineDomTreeNode*> LiveOutPair;
- typedef DenseMap<MachineBasicBlock*,LiveOutPair> LiveOutMap;
-
- // liveOutCache_ - Map each basic block where li_ is live out to the live-out
- // value and its defining block. One of these conditions shall be true:
- //
- // 1. !liveOutCache_.count(MBB)
- // 2. liveOutCache_[MBB].second.getNode() == MBB
- // 3. forall P in preds(MBB): liveOutCache_[P] == liveOutCache_[MBB]
- //
- // This is only a cache, the values can be computed as:
- //
- // VNI = li_->getVNInfoAt(lis_.getMBBEndIdx(MBB))
- // Node = mbt_[lis_.getMBBFromIndex(VNI->def)]
- //
- // The cache is also used as a visiteed set by mapValue().
- LiveOutMap liveOutCache_;
-
-public:
- LiveIntervalMap(LiveIntervals &lis,
- MachineDominatorTree &mdt,
- const LiveInterval &parentli)
- : lis_(lis), mdt_(mdt), parentli_(parentli), li_(0) {}
-
- /// reset - clear all data structures and start a new live interval.
- void reset(LiveInterval *);
-
- /// getLI - return the current live interval.
- LiveInterval *getLI() const { return li_; }
-
- /// defValue - define a value in li_ from the parentli_ value VNI and Idx.
- /// Idx does not have to be ParentVNI->def, but it must be contained within
- /// ParentVNI's live range in parentli_.
- /// Return the new li_ value.
- VNInfo *defValue(const VNInfo *ParentVNI, SlotIndex Idx);
-
- /// mapValue - map ParentVNI to the corresponding li_ value at Idx. It is
- /// assumed that ParentVNI is live at Idx.
- /// If ParentVNI has not been defined by defValue, it is assumed that
- /// ParentVNI->def dominates Idx.
- /// If ParentVNI has been defined by defValue one or more times, a value that
- /// dominates Idx will be returned. This may require creating extra phi-def
- /// values and adding live ranges to li_.
- /// If simple is not NULL, *simple will indicate if ParentVNI is a simply
- /// mapped value.
- VNInfo *mapValue(const VNInfo *ParentVNI, SlotIndex Idx, bool *simple = 0);
-
- // extendTo - Find the last li_ value defined in MBB at or before Idx. The
- // parentli is assumed to be live at Idx. Extend the live range to include
- // Idx. Return the found VNInfo, or NULL.
- VNInfo *extendTo(const MachineBasicBlock *MBB, SlotIndex Idx);
-
- /// isMapped - Return true is ParentVNI is a known mapped value. It may be a
- /// simple 1-1 mapping or a complex mapping to later defs.
- bool isMapped(const VNInfo *ParentVNI) const {
- return valueMap_.count(ParentVNI);
- }
-
- /// isComplexMapped - Return true if ParentVNI has received new definitions
- /// with defValue.
- bool isComplexMapped(const VNInfo *ParentVNI) const;
-
- // addSimpleRange - Add a simple range from parentli_ to li_.
- // ParentVNI must be live in the [Start;End) interval.
- void addSimpleRange(SlotIndex Start, SlotIndex End, const VNInfo *ParentVNI);
-
- /// addRange - Add live ranges to li_ where [Start;End) intersects parentli_.
- /// All needed values whose def is not inside [Start;End) must be defined
- /// beforehand so mapValue will work.
- void addRange(SlotIndex Start, SlotIndex End);
};
/// - Rewrite instructions with finish().
///
class SplitEditor {
- SplitAnalysis &sa_;
- LiveIntervals &lis_;
- VirtRegMap &vrm_;
- MachineRegisterInfo &mri_;
- const TargetInstrInfo &tii_;
- const TargetRegisterInfo &tri_;
+ SplitAnalysis &SA;
+ LiveIntervals &LIS;
+ VirtRegMap &VRM;
+ MachineRegisterInfo &MRI;
+ MachineDominatorTree &MDT;
+ const TargetInstrInfo &TII;
+ const TargetRegisterInfo &TRI;
+
+ /// Edit - The current parent register and new intervals created.
+ LiveRangeEdit *Edit;
+
+ /// Index into Edit of the currently open interval.
+ /// The index 0 is used for the complement, so the first interval started by
+ /// openIntv will be 1.
+ unsigned OpenIdx;
+
+ typedef IntervalMap<SlotIndex, unsigned> RegAssignMap;
+
+ /// Allocator for the interval map. This will eventually be shared with
+ /// SlotIndexes and LiveIntervals.
+ RegAssignMap::Allocator Allocator;
+
+ /// RegAssign - Map of the assigned register indexes.
+ /// Edit.get(RegAssign.lookup(Idx)) is the register that should be live at
+ /// Idx.
+ RegAssignMap RegAssign;
+
+ typedef DenseMap<std::pair<unsigned, unsigned>, VNInfo*> ValueMap;
+
+ /// Values - keep track of the mapping from parent values to values in the new
+ /// intervals. Given a pair (RegIdx, ParentVNI->id), Values contains:
+ ///
+ /// 1. No entry - the value is not mapped to Edit.get(RegIdx).
+ /// 2. Null - the value is mapped to multiple values in Edit.get(RegIdx).
+ /// Each value is represented by a minimal live range at its def.
+ /// 3. A non-null VNInfo - the value is mapped to a single new value.
+ /// The new value has no live ranges anywhere.
+ ValueMap Values;
+
+ typedef std::pair<VNInfo*, MachineDomTreeNode*> LiveOutPair;
+ typedef IndexedMap<LiveOutPair, MBB2NumberFunctor> LiveOutMap;
- /// edit_ - The current parent register and new intervals created.
- LiveRangeEdit &edit_;
+ // LiveOutCache - Map each basic block where a new register is live out to the
+ // live-out value and its defining block.
+ // One of these conditions shall be true:
+ //
+ // 1. !LiveOutCache.count(MBB)
+ // 2. LiveOutCache[MBB].second.getNode() == MBB
+ // 3. forall P in preds(MBB): LiveOutCache[P] == LiveOutCache[MBB]
+ //
+ // This is only a cache, the values can be computed as:
+ //
+ // VNI = Edit.get(RegIdx)->getVNInfoAt(LIS.getMBBEndIdx(MBB))
+ // Node = mbt_[LIS.getMBBFromIndex(VNI->def)]
+ //
+ // The cache is also used as a visited set by extendRange(). It can be shared
+ // by all the new registers because at most one is live out of each block.
+ LiveOutMap LiveOutCache;
+
+ // LiveOutSeen - Indexed by MBB->getNumber(), a bit is set for each valid
+ // entry in LiveOutCache.
+ BitVector LiveOutSeen;
+
+ /// LiveInBlock - Info for updateSSA() about a block where a register is
+ /// live-in.
+ /// The updateSSA caller provides DomNode and Kill inside MBB, updateSSA()
+ /// adds the computed live-in value.
+ struct LiveInBlock {
+ // Dominator tree node for the block.
+ // Cleared by updateSSA when the final value has been determined.
+ MachineDomTreeNode *DomNode;
+
+ // Live-in value filled in by updateSSA once it is known.
+ VNInfo *Value;
+
+ // Position in block where the live-in range ends, or SlotIndex() if the
+ // range passes through the block.
+ SlotIndex Kill;
+
+ LiveInBlock(MachineDomTreeNode *node) : DomNode(node), Value(0) {}
+ };
- /// dupli_ - Created as a copy of curli_, ranges are carved out as new
- /// intervals get added through openIntv / closeIntv. This is used to avoid
- /// editing curli_.
- LiveIntervalMap dupli_;
+ /// LiveInBlocks - List of live-in blocks used by findReachingDefs() and
+ /// updateSSA(). This list is usually empty, it exists here to avoid frequent
+ /// reallocations.
+ SmallVector<LiveInBlock, 16> LiveInBlocks;
+
+ /// defValue - define a value in RegIdx from ParentVNI at Idx.
+ /// Idx does not have to be ParentVNI->def, but it must be contained within
+ /// ParentVNI's live range in ParentLI. The new value is added to the value
+ /// map.
+ /// Return the new LI value.
+ VNInfo *defValue(unsigned RegIdx, const VNInfo *ParentVNI, SlotIndex Idx);
- /// Currently open LiveInterval.
- LiveIntervalMap openli_;
+ /// markComplexMapped - Mark ParentVNI as complex mapped in RegIdx regardless
+ /// of the number of defs.
+ void markComplexMapped(unsigned RegIdx, const VNInfo *ParentVNI);
/// defFromParent - Define Reg from ParentVNI at UseIdx using either
/// rematerialization or a COPY from parent. Return the new value.
- VNInfo *defFromParent(LiveIntervalMap &Reg,
+ VNInfo *defFromParent(unsigned RegIdx,
VNInfo *ParentVNI,
SlotIndex UseIdx,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator I);
- /// intervalsLiveAt - Return true if any member of intervals_ is live at Idx.
- bool intervalsLiveAt(SlotIndex Idx) const;
+ /// extendRange - Extend the live range of Edit.get(RegIdx) so it reaches Idx.
+ /// Insert PHIDefs as needed to preserve SSA form.
+ void extendRange(unsigned RegIdx, SlotIndex Idx);
- /// Values in curli whose live range has been truncated when entering an open
- /// li.
- SmallPtrSet<const VNInfo*, 8> truncatedValues;
+ /// findReachingDefs - Starting from MBB, add blocks to LiveInBlocks until all
+ /// reaching defs for LI are found.
+ /// @param LI Live interval whose value is needed.
+ /// @param MBB Block where LI should be live-in.
+ /// @param Kill Kill point in MBB.
+ /// @return Unique value seen, or NULL.
+ VNInfo *findReachingDefs(LiveInterval *LI, MachineBasicBlock *MBB,
+ SlotIndex Kill);
- /// addTruncSimpleRange - Add the given simple range to dupli_ after
- /// truncating any overlap with intervals_.
- void addTruncSimpleRange(SlotIndex Start, SlotIndex End, VNInfo *VNI);
+ /// updateSSA - Compute and insert PHIDefs such that all blocks in
+ // LiveInBlocks get a known live-in value. Add live ranges to the blocks.
+ void updateSSA();
- /// criticalPreds_ - Set of basic blocks where both dupli and openli should be
- /// live out because of a critical edge.
- SplitAnalysis::BlockPtrSet criticalPreds_;
+ /// transferValues - Transfer values to the new ranges.
+ /// Return true if any ranges were skipped.
+ bool transferValues();
- /// computeRemainder - Compute the dupli liveness as the complement of all the
- /// new intervals.
- void computeRemainder();
+ /// extendPHIKillRanges - Extend the ranges of all values killed by original
+ /// parent PHIDefs.
+ void extendPHIKillRanges();
- /// rewrite - Rewrite all uses of reg to use the new registers.
- void rewrite(unsigned reg);
+ /// rewriteAssigned - Rewrite all uses of Edit.getReg() to assigned registers.
+ void rewriteAssigned(bool ExtendRanges);
+
+ /// deleteRematVictims - Delete defs that are dead after rematerializing.
+ void deleteRematVictims();
public:
/// Create a new SplitEditor for editing the LiveInterval analyzed by SA.
/// Newly created intervals will be appended to newIntervals.
SplitEditor(SplitAnalysis &SA, LiveIntervals&, VirtRegMap&,
- MachineDominatorTree&, LiveRangeEdit&);
+ MachineDominatorTree&);
- /// getAnalysis - Get the corresponding analysis.
- SplitAnalysis &getAnalysis() { return sa_; }
+ /// reset - Prepare for a new split.
+ void reset(LiveRangeEdit&);
/// Create a new virtual register and live interval.
- void openIntv();
+ /// Return the interval index, starting from 1. Interval index 0 is the
+ /// implicit complement interval.
+ unsigned openIntv();
+
+ /// currentIntv - Return the current interval index.
+ unsigned currentIntv() const { return OpenIdx; }
- /// enterIntvBefore - Enter openli before the instruction at Idx. If curli is
- /// not live before Idx, a COPY is not inserted.
- void enterIntvBefore(SlotIndex Idx);
+ /// selectIntv - Select a previously opened interval index.
+ void selectIntv(unsigned Idx);
- /// enterIntvAtEnd - Enter openli at the end of MBB.
- void enterIntvAtEnd(MachineBasicBlock &MBB);
+ /// enterIntvBefore - Enter the open interval before the instruction at Idx.
+ /// If the parent interval is not live before Idx, a COPY is not inserted.
+ /// Return the beginning of the new live range.
+ SlotIndex enterIntvBefore(SlotIndex Idx);
- /// useIntv - indicate that all instructions in MBB should use openli.
+ /// enterIntvAtEnd - Enter the open interval at the end of MBB.
+ /// Use the open interval from he inserted copy to the MBB end.
+ /// Return the beginning of the new live range.
+ SlotIndex enterIntvAtEnd(MachineBasicBlock &MBB);
+
+ /// useIntv - indicate that all instructions in MBB should use OpenLI.
void useIntv(const MachineBasicBlock &MBB);
- /// useIntv - indicate that all instructions in range should use openli.
+ /// useIntv - indicate that all instructions in range should use OpenLI.
void useIntv(SlotIndex Start, SlotIndex End);
- /// leaveIntvAfter - Leave openli after the instruction at Idx.
- void leaveIntvAfter(SlotIndex Idx);
+ /// leaveIntvAfter - Leave the open interval after the instruction at Idx.
+ /// Return the end of the live range.
+ SlotIndex leaveIntvAfter(SlotIndex Idx);
- /// leaveIntvAtTop - Leave the interval at the top of MBB.
- /// Currently, only one value can leave the interval.
- void leaveIntvAtTop(MachineBasicBlock &MBB);
+ /// leaveIntvBefore - Leave the open interval before the instruction at Idx.
+ /// Return the end of the live range.
+ SlotIndex leaveIntvBefore(SlotIndex Idx);
- /// closeIntv - Indicate that we are done editing the currently open
- /// LiveInterval, and ranges can be trimmed.
- void closeIntv();
+ /// leaveIntvAtTop - Leave the interval at the top of MBB.
+ /// Add liveness from the MBB top to the copy.
+ /// Return the end of the live range.
+ SlotIndex leaveIntvAtTop(MachineBasicBlock &MBB);
+
+ /// overlapIntv - Indicate that all instructions in range should use the open
+ /// interval, but also let the complement interval be live.
+ ///
+ /// This doubles the register pressure, but is sometimes required to deal with
+ /// register uses after the last valid split point.
+ ///
+ /// The Start index should be a return value from a leaveIntv* call, and End
+ /// should be in the same basic block. The parent interval must have the same
+ /// value across the range.
+ ///
+ void overlapIntv(SlotIndex Start, SlotIndex End);
/// finish - after all the new live ranges have been created, compute the
/// remaining live range, and rewrite instructions to use the new registers.
void finish();
+ /// dump - print the current interval maping to dbgs().
+ void dump() const;
+
// ===--- High level methods ---===
- /// splitAroundLoop - Split curli into a separate live interval inside
- /// the loop.
- void splitAroundLoop(const MachineLoop*);
+ /// splitSingleBlock - Split CurLI into a separate live interval around the
+ /// uses in a single block. This is intended to be used as part of a larger
+ /// split, and doesn't call finish().
+ void splitSingleBlock(const SplitAnalysis::BlockInfo &BI);
- /// splitSingleBlocks - Split curli into a separate live interval inside each
+ /// splitSingleBlocks - Split CurLI into a separate live interval inside each
/// basic block in Blocks.
void splitSingleBlocks(const SplitAnalysis::BlockPtrSet &Blocks);
-
- /// splitInsideBlock - Split curli into multiple intervals inside MBB.
- void splitInsideBlock(const MachineBasicBlock *);
};
}
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