//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_CODEGEN_LIVERANGECALC_H
-#define LLVM_CODEGEN_LIVERANGECALC_H
+#ifndef LLVM_LIB_CODEGEN_LIVERANGECALC_H
+#define LLVM_LIB_CODEGEN_LIVERANGECALC_H
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/IndexedMap.h"
typedef DomTreeNodeBase<MachineBasicBlock> MachineDomTreeNode;
class LiveRangeCalc {
- /// 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;
+ const MachineFunction *MF;
+ const MachineRegisterInfo *MRI;
+ SlotIndexes *Indexes;
+ MachineDominatorTree *DomTree;
+ VNInfo::Allocator *Alloc;
/// LiveOutPair - A value and the block that defined it. The domtree node is
/// redundant, it can be computed as: MDT[Indexes.getMBBFromIndex(VNI->def)].
/// LiveOutMap - Map basic blocks to the value leaving the block.
typedef IndexedMap<LiveOutPair, MBB2NumberFunctor> LiveOutMap;
- /// LiveOut - Map each basic block where a live range is live out to the
- /// live-out value and its defining block.
+ /// 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:
///
///
/// The map can be shared by multiple live ranges as long as no two are
/// live-out of the same block.
- LiveOutMap LiveOut;
+ 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.
struct LiveInBlock {
- // LI - The live range that is live-in to this block. The algorithms can
+ // The live range set that is live-in to this block. The algorithms can
// handle multiple non-overlapping live ranges simultaneously.
- LiveInterval *LI;
+ LiveRange &LR;
// DomNode - Dominator tree node for the block.
// Cleared when the final value has been determined and LI has been updated.
// Live-in value filled in by updateSSA once it is known.
VNInfo *Value;
- LiveInBlock(LiveInterval *li, MachineDomTreeNode *node, SlotIndex kill)
- : LI(li), DomNode(node), Kill(kill), Value(0) {}
+ LiveInBlock(LiveRange &LR, MachineDomTreeNode *node, SlotIndex kill)
+ : LR(LR), DomNode(node), Kill(kill), Value(nullptr) {}
};
/// LiveIn - Work list of blocks where the live-in value has yet to be
/// used to add entries directly.
SmallVector<LiveInBlock, 16> LiveIn;
- /// findReachingDefs - Assuming that LI is live-in to KillMBB and killed at
- /// Kill, search for values that can reach KillMBB. All blocks that need LI
- /// to be live-in are added to LiveIn. If a unique reaching def is found,
- /// its value is returned, if Kill is jointly dominated by multiple values,
- /// NULL is returned.
- VNInfo *findReachingDefs(LiveInterval *LI,
- MachineBasicBlock *KillMBB,
- SlotIndex Kill,
- SlotIndexes *Indexes,
- MachineDominatorTree *DomTree);
+ /// Assuming that @p LR is live-in to @p UseMBB, find the set of defs that can
+ /// reach it.
+ ///
+ /// If only one def can reach @p UseMBB, all paths from the def to @p UseMBB
+ /// are added to @p LR, and the function returns true.
+ ///
+ /// If multiple values can reach @p UseMBB, the blocks that need @p LR to be
+ /// live in are added to the LiveIn array, and the function returns false.
+ ///
+ /// PhysReg, when set, is used to verify live-in lists on basic blocks.
+ bool findReachingDefs(LiveRange &LR, MachineBasicBlock &UseMBB,
+ 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(SlotIndexes *Indexes,
- MachineDominatorTree *DomTree,
- VNInfo::Allocator *Alloc);
+ void updateSSA();
+
+ /// Transfer information from the LiveIn vector to the live ranges and update
+ /// the given @p 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, LaneBitmask LaneMask);
- /// updateLiveIns - Add liveness as specified in the LiveIn vector, using VNI
- /// as a wildcard value for LiveIn entries without a value.
- void updateLiveIns(VNInfo *VNI, SlotIndexes*);
+ /// Reset Map and Seen fields.
+ void resetLiveOutMap();
public:
+ LiveRangeCalc() : MF(nullptr), MRI(nullptr), Indexes(nullptr),
+ DomTree(nullptr), Alloc(nullptr) {}
+
//===--------------------------------------------------------------------===//
// High-level interface.
//===--------------------------------------------------------------------===//
/// that may overlap a previously computed live range, and before the first
/// live range in a function. If live ranges are not known to be
/// non-overlapping, call reset before each.
- void reset(const MachineFunction *MF);
-
- /// calculate - Calculate the live range of a virtual register from its defs
- /// and uses. LI must be empty with no values.
- void calculate(LiveInterval *LI,
- MachineRegisterInfo *MRI,
- SlotIndexes *Indexes,
- VNInfo::Allocator *Alloc);
+ void reset(const MachineFunction *MF,
+ SlotIndexes*,
+ MachineDominatorTree*,
+ VNInfo::Allocator*);
//===--------------------------------------------------------------------===//
// Mid-level interface.
// Modify existing live ranges.
//
- /// extend - Extend the live range of LI to reach Kill.
+ /// Extend the live range of @p LR to reach @p Use.
///
- /// The existing values in LI must be live so they jointly dominate Kill. If
- /// Kill is not dominated by a single existing value, PHI-defs are inserted
- /// as required to preserve SSA form. If Kill is known to be dominated by a
- /// single existing value, Alloc may be null.
- void extend(LiveInterval *LI,
- SlotIndex Kill,
- SlotIndexes *Indexes,
- MachineDominatorTree *DomTree,
- VNInfo::Allocator *Alloc);
-
- /// extendToUses - Extend the live range of LI to reach all uses.
+ /// The existing values in @p LR must be live so they jointly dominate @p Use.
+ /// If @p Use is not dominated by a single existing value, PHI-defs are
+ /// inserted as required to preserve SSA form.
+ ///
+ /// PhysReg, when set, is used to verify live-in lists on basic blocks.
+ void extend(LiveRange &LR, SlotIndex Use, 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);
+
+ /// 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(LiveInterval *LI,
- MachineRegisterInfo *MRI,
- SlotIndexes *Indexes,
- MachineDominatorTree *DomTree,
- VNInfo::Allocator *Alloc);
+ void extendToUses(LiveRange &LR, unsigned PhysReg) {
+ extendToUses(LR, PhysReg, ~0u);
+ }
+
+ /// 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, bool TrackSubRegs);
//===--------------------------------------------------------------------===//
// Low-level interface.
/// addLiveInBlock().
void setLiveOutValue(MachineBasicBlock *MBB, VNInfo *VNI) {
Seen.set(MBB->getNumber());
- LiveOut[MBB] = LiveOutPair(VNI, 0);
+ Map[MBB] = LiveOutPair(VNI, nullptr);
}
/// addLiveInBlock - Add a block with an unknown live-in value. This
/// function can only be called once per basic block. Once the live-in value
/// has been determined, calculateValues() will add liveness to LI.
///
- /// @param LI The live range that is live-in to the block.
+ /// @param LR The live range that is live-in to the block.
/// @param DomNode The domtree node for the block.
/// @param Kill Index in block where LI is killed. If the value is
/// live-through, set Kill = SLotIndex() and also call
/// setLiveOutValue(MBB, 0).
- void addLiveInBlock(LiveInterval *LI,
+ void addLiveInBlock(LiveRange &LR,
MachineDomTreeNode *DomNode,
SlotIndex Kill = SlotIndex()) {
- LiveIn.push_back(LiveInBlock(LI, DomNode, Kill));
+ LiveIn.push_back(LiveInBlock(LR, DomNode, Kill));
}
/// calculateValues - Calculate the value that will be live-in to each block
///
/// 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(SlotIndexes *Indexes,
- MachineDominatorTree *DomTree,
- VNInfo::Allocator *Alloc);
+ void calculateValues();
};
} // end namespace llvm