diff options
Diffstat (limited to 'llvm/lib/CodeGen/LiveRangeCalc.h')
| -rw-r--r-- | llvm/lib/CodeGen/LiveRangeCalc.h | 119 |
1 files changed, 48 insertions, 71 deletions
diff --git a/llvm/lib/CodeGen/LiveRangeCalc.h b/llvm/lib/CodeGen/LiveRangeCalc.h index fd494797918..1b9099b5fc7 100644 --- a/llvm/lib/CodeGen/LiveRangeCalc.h +++ b/llvm/lib/CodeGen/LiveRangeCalc.h @@ -47,44 +47,30 @@ class LiveRangeCalc { /// LiveOutMap - Map basic blocks to the value leaving the block. typedef IndexedMap<LiveOutPair, MBB2NumberFunctor> LiveOutMap; - struct LiveOutData { - /// Seen - Bit vector of active entries in LiveOut, also used as a visited - /// set by findReachingDefs. One entry per basic block, indexed by block - /// number. This is kept as a separate bit vector because it can be cleared - /// quickly when switching live ranges. - BitVector Seen; - - /// LiveOut - Map each basic block where a live range is live out to the - /// live-out value and its defining block. - /// - /// For every basic block, MBB, one of these conditions shall be true: - /// - /// 1. !Seen.count(MBB->getNumber()) - /// Blocks without a Seen bit are ignored. - /// 2. LiveOut[MBB].second.getNode() == MBB - /// The live-out value is defined in MBB. - /// 3. forall P in preds(MBB): LiveOut[P] == LiveOut[MBB] - /// The live-out value passses through MBB. All predecessors must carry - /// the same value. - /// - /// The domtree node may be null, it can be computed. - /// - /// The map can be shared by multiple live ranges as long as no two are - /// live-out of the same block. - LiveOutMap Map; - - void reset(unsigned NumBlocks) { - Seen.clear(); - Seen.resize(NumBlocks); - Map.resize(NumBlocks); - } - - void setLiveOutValue(MachineBasicBlock *MBB, VNInfo *VNI) { - Seen.set(MBB->getNumber()); - Map[MBB] = LiveOutPair(VNI, nullptr); - } - }; - LiveOutData MainLiveOutData; + /// Bit vector of active entries in LiveOut, also used as a visited set by + /// findReachingDefs. One entry per basic block, indexed by block number. + /// This is kept as a separate bit vector because it can be cleared quickly + /// when switching live ranges. + BitVector Seen; + + /// Map each basic block where a live range is live out to the live-out value + /// and its defining block. + /// + /// For every basic block, MBB, one of these conditions shall be true: + /// + /// 1. !Seen.count(MBB->getNumber()) + /// Blocks without a Seen bit are ignored. + /// 2. LiveOut[MBB].second.getNode() == MBB + /// The live-out value is defined in MBB. + /// 3. forall P in preds(MBB): LiveOut[P] == LiveOut[MBB] + /// The live-out value passses through MBB. All predecessors must carry + /// the same value. + /// + /// The domtree node may be null, it can be computed. + /// + /// The map can be shared by multiple live ranges as long as no two are + /// live-out of the same block. + LiveOutMap Map; /// LiveInBlock - Information about a basic block where a live range is known /// to be live-in, but the value has not yet been determined. @@ -126,19 +112,27 @@ class LiveRangeCalc { /// /// PhysReg, when set, is used to verify live-in lists on basic blocks. bool findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB, - SlotIndex Kill, unsigned PhysReg, - LiveOutData &LiveOuts); + SlotIndex Kill, unsigned PhysReg); /// updateSSA - Compute the values that will be live in to all requested /// blocks in LiveIn. Create PHI-def values as required to preserve SSA form. /// /// Every live-in block must be jointly dominated by the added live-out /// blocks. No values are read from the live ranges. - void updateSSA(LiveOutData &LiveOuts); + void updateSSA(); /// Transfer information from the LiveIn vector to the live ranges and update /// the given @p LiveOuts. - void updateFromLiveIns(LiveOutData &LiveOuts); + void updateFromLiveIns(); + + /// Extend the live range of @p LR to reach all uses of Reg. + /// + /// All uses must be jointly dominated by existing liveness. PHI-defs are + /// inserted as needed to preserve SSA form. + void extendToUses(LiveRange &LR, unsigned Reg, unsigned LaneMask); + + /// Reset Map and Seen fields. + void resetLiveOutMap(); public: LiveRangeCalc() : MF(nullptr), MRI(nullptr), Indexes(nullptr), @@ -176,39 +170,25 @@ public: /// single existing value, Alloc may be null. /// /// PhysReg, when set, is used to verify live-in lists on basic blocks. - void extend(LiveRange &LR, SlotIndex Kill, unsigned PhysReg, - LiveOutData &LiveOuts); - - void extend(LiveRange &LR, SlotIndex Kill) { - extend(LR, Kill, 0, MainLiveOutData); - } + void extend(LiveRange &LR, SlotIndex Kill, unsigned PhysReg = 0); /// createDeadDefs - Create a dead def in LI for every def operand of Reg. /// Each instruction defining Reg gets a new VNInfo with a corresponding /// minimal live range. void createDeadDefs(LiveRange &LR, unsigned Reg); - /// Subregister aware version of createDeadDefs(LiveRange &LR, unsigned Reg). - /// If subregister liveness tracking is enabled new subranges are created as - /// necessary when subregister defs are found. As with - /// createDeadDefs(LiveRange &LR, unsigned Reg) new short live segments are - /// created for every def of LI.reg. The new segments start and end at the - /// defining instruction (hence the name "DeadDef"). - void createDeadDefs(LiveInterval &LI); - - /// extendToUses - Extend the live range of LI to reach all uses of Reg. + /// Extend the live range of @p LR to reach all uses of Reg. /// /// All uses must be jointly dominated by existing liveness. PHI-defs are /// inserted as needed to preserve SSA form. - void extendToUses(LiveRange &LR, unsigned Reg); + void extendToUses(LiveRange &LR, unsigned PhysReg) { + extendToUses(LR, PhysReg, ~0u); + } - /// Subregister aware version of extendToUses(LiveRange &LR, unsigned Reg). - /// If subregister liveness tracking is enabled new subranges are created - /// as necessary when subregister uses are found. As with - /// extendToUses(LiveRange &LR, unsigned Reg) the segments existing at the - /// defs are extend until they reach all uses. New value numbers are created - /// at CFG joins as necessary (SSA construction). - void extendToUses(LiveInterval &LI); + /// Calculates liveness for the register specified in live interval @p LI. + /// Creates subregister live ranges as needed if subreg liveness tracking is + /// enabled. + void calculate(LiveInterval &LI); //===--------------------------------------------------------------------===// // Low-level interface. @@ -230,7 +210,8 @@ public: /// VNI may be null only if MBB is a live-through block also passed to /// addLiveInBlock(). void setLiveOutValue(MachineBasicBlock *MBB, VNInfo *VNI) { - MainLiveOutData.setLiveOutValue(MBB, VNI); + Seen.set(MBB->getNumber()); + Map[MBB] = LiveOutPair(VNI, nullptr); } /// addLiveInBlock - Add a block with an unknown live-in value. This @@ -255,11 +236,7 @@ public: /// /// Every predecessor of a live-in block must have been given a value with /// setLiveOutValue, the value may be null for live-trough blocks. - void calculateValues(LiveOutData &LiveOuts); - - void calculateValues() { - calculateValues(MainLiveOutData); - } + void calculateValues(); }; } // end namespace llvm |
