X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FSplitKit.h;h=d9f16dc9155beef7448807b1d06afb5ec0e31e98;hb=1de4aa904e9672abfc2e755d798c926d324e2d36;hp=ad9b92f5aed3ef788d076c70cfd38624471d138e;hpb=fc412d85c46a8656361fe1e9197ea85922e2cd61;p=oota-llvm.git diff --git a/lib/CodeGen/SplitKit.h b/lib/CodeGen/SplitKit.h index ad9b92f5aed..d9f16dc9155 100644 --- a/lib/CodeGen/SplitKit.h +++ b/lib/CodeGen/SplitKit.h @@ -1,4 +1,4 @@ -//===---------- SplitKit.cpp - Toolkit for splitting live ranges ----------===// +//===-------- SplitKit.cpp - Toolkit for splitting live ranges --*- C++ -*-===// // // The LLVM Compiler Infrastructure // @@ -20,6 +20,7 @@ namespace llvm { class LiveInterval; class LiveIntervals; +class LiveRangeEdit; class MachineInstr; class MachineLoop; class MachineLoopInfo; @@ -27,6 +28,7 @@ class MachineRegisterInfo; class TargetInstrInfo; class VirtRegMap; class VNInfo; +class raw_ostream; /// SplitAnalysis - Analyze a LiveInterval, looking for live range splitting /// opportunities. @@ -68,11 +70,6 @@ public: /// split. void analyze(const LiveInterval *li); - /// removeUse - Update statistics by noting that mi no longer uses curli. - void removeUse(const MachineInstr *mi); - - const LiveInterval *getCurLI() { return curli_; } - /// clear - clear all data structures so SplitAnalysis is ready to analyze a /// new interval. void clear(); @@ -80,6 +77,9 @@ public: typedef SmallPtrSet BlockPtrSet; typedef SmallPtrSet 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. @@ -93,6 +93,9 @@ public: } }; + // 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); @@ -135,6 +138,94 @@ public: 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_; + + // The parent interval is never changed. + const LiveInterval &parentli_; + + // The child interval's values are fully contained inside parentli_ values. + LiveInterval *li_; + + typedef DenseMap 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_; + +public: + LiveIntervalMap(LiveIntervals &lis, + const LiveInterval &parentli) + : lis_(lis), 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(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); + + /// defByCopyFrom - Insert a copy from Reg to li, assuming that Reg carries + /// ParentVNI. Add a minimal live range for the new value and return it. + VNInfo *defByCopyFrom(unsigned Reg, + const VNInfo *ParentVNI, + MachineBasicBlock &MBB, + MachineBasicBlock::iterator I); + +}; + + /// SplitEditor - Edit machine code and LiveIntervals for live range /// splitting. /// @@ -144,7 +235,7 @@ public: /// - Mark the ranges where the new interval is used with useIntv* /// - Mark the places where the interval is exited with exitIntv*. /// - Finish the current interval with closeIntv and repeat from 2. -/// - Rewrite instructions with rewrite(). +/// - Rewrite instructions with finish(). /// class SplitEditor { SplitAnalysis &sa_; @@ -153,53 +244,39 @@ class SplitEditor { MachineRegisterInfo &mri_; const TargetInstrInfo &tii_; - /// curli_ - The immutable interval we are currently splitting. - const LiveInterval *const curli_; + /// edit_ - The current parent register and new intervals created. + LiveRangeEdit &edit_; /// 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_. - LiveInterval *dupli_; + LiveIntervalMap dupli_; /// Currently open LiveInterval. - LiveInterval *openli_; - - /// createInterval - Create a new virtual register and LiveInterval with same - /// register class and spill slot as curli. - LiveInterval *createInterval(); - - /// getDupLI - Ensure dupli is created and return it. - LiveInterval *getDupLI(); + LiveIntervalMap openli_; - /// valueMap_ - Map values in cupli to values in openli. These are direct 1-1 - /// mappings, and do not include values created by inserted copies. - DenseMap valueMap_; + /// intervalsLiveAt - Return true if any member of intervals_ is live at Idx. + bool intervalsLiveAt(SlotIndex Idx) const; - /// mapValue - Return the openIntv value that corresponds to the given curli - /// value. - VNInfo *mapValue(const VNInfo *curliVNI); + /// Values in curli whose live range has been truncated when entering an open + /// li. + SmallPtrSet truncatedValues; - /// A dupli value is live through openIntv. - bool liveThrough_; + /// addTruncSimpleRange - Add the given simple range to dupli_ after + /// truncating any overlap with intervals_. + void addTruncSimpleRange(SlotIndex Start, SlotIndex End, VNInfo *VNI); - /// All the new intervals created for this split are added to intervals_. - std::vector &intervals_; + /// computeRemainder - Compute the dupli liveness as the complement of all the + /// new intervals. + void computeRemainder(); - /// The index into intervals_ of the first interval we added. There may be - /// others from before we got it. - unsigned firstInterval; - - /// Insert a COPY instruction curli -> li. Allocate a new value from li - /// defined by the COPY - VNInfo *insertCopy(LiveInterval &LI, - MachineBasicBlock &MBB, - MachineBasicBlock::iterator I); + /// rewrite - Rewrite all uses of reg to use the new registers. + void rewrite(unsigned reg); 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&, - std::vector &newIntervals); + SplitEditor(SplitAnalysis &SA, LiveIntervals&, VirtRegMap&, LiveRangeEdit&); /// getAnalysis - Get the corresponding analysis. SplitAnalysis &getAnalysis() { return sa_; } @@ -212,9 +289,7 @@ public: void enterIntvBefore(SlotIndex Idx); /// enterIntvAtEnd - Enter openli at the end of MBB. - /// PhiMBB is a successor inside openli where a PHI value is created. - /// Currently, all entries must share the same PhiMBB. - void enterIntvAtEnd(MachineBasicBlock &MBB, MachineBasicBlock &PhiMBB); + void enterIntvAtEnd(MachineBasicBlock &MBB); /// useIntv - indicate that all instructions in MBB should use openli. void useIntv(const MachineBasicBlock &MBB); @@ -233,26 +308,22 @@ public: /// LiveInterval, and ranges can be trimmed. void closeIntv(); - /// rewrite - after all the new live ranges have been created, rewrite - /// instructions using curli to use the new intervals. - void rewrite(); + /// 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(); // ===--- High level methods ---=== /// splitAroundLoop - Split curli into a separate live interval inside - /// the loop. Return true if curli has been completely replaced, false if - /// curli is still intact, and needs to be spilled or split further. - bool splitAroundLoop(const MachineLoop*); + /// the loop. + void splitAroundLoop(const MachineLoop*); /// splitSingleBlocks - Split curli into a separate live interval inside each - /// basic block in Blocks. Return true if curli has been completely replaced, - /// false if curli is still intact, and needs to be spilled or split further. - bool splitSingleBlocks(const SplitAnalysis::BlockPtrSet &Blocks); - - /// splitInsideBlock - Split curli into multiple intervals inside MBB. Return - /// true if curli has been completely replaced, false if curli is still - /// intact, and needs to be spilled or split further. - bool splitInsideBlock(const MachineBasicBlock *); + /// basic block in Blocks. + void splitSingleBlocks(const SplitAnalysis::BlockPtrSet &Blocks); + + /// splitInsideBlock - Split curli into multiple intervals inside MBB. + void splitInsideBlock(const MachineBasicBlock *); }; }