| //===- LiveIntervalCalc.h - Calculate live intervals -----------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // The LiveIntervalCalc class is an extension of LiveRangeCalc targeted to the |
| // computation and modification of the LiveInterval variants of LiveRanges. |
| // LiveIntervals are meant to track liveness of registers and stack slots and |
| // LiveIntervalCalc adds to LiveRangeCalc all the machinery required to |
| // construct the liveness of virtual registers tracked by a LiveInterval. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CODEGEN_LIVEINTERVALCALC_H |
| #define LLVM_CODEGEN_LIVEINTERVALCALC_H |
| |
| #include "llvm/CodeGen/LiveRangeCalc.h" |
| |
| namespace llvm { |
| |
| template <class NodeT> class DomTreeNodeBase; |
| |
| using MachineDomTreeNode = DomTreeNodeBase<MachineBasicBlock>; |
| |
| class LiveIntervalCalc : public LiveRangeCalc { |
| /// Extend the live range of @p LR to reach all uses of Reg. |
| /// |
| /// If @p LR is a main range, or if @p LI is null, then all uses must be |
| /// jointly dominated by the definitions from @p LR. If @p LR is a subrange |
| /// of the live interval @p LI, corresponding to lane mask @p LaneMask, |
| /// all uses must be jointly dominated by the definitions from @p LR |
| /// together with definitions of other lanes where @p LR becomes undefined |
| /// (via <def,read-undef> operands). |
| /// If @p LR is a main range, the @p LaneMask should be set to ~0, i.e. |
| /// LaneBitmask::getAll(). |
| void extendToUses(LiveRange &LR, Register Reg, LaneBitmask LaneMask, |
| LiveInterval *LI = nullptr); |
| |
| public: |
| LiveIntervalCalc() = default; |
| |
| /// 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, Register 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, MCRegister PhysReg) { |
| extendToUses(LR, PhysReg, LaneBitmask::getAll()); |
| } |
| |
| /// 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); |
| |
| /// For live interval \p LI with correct SubRanges construct matching |
| /// information for the main live range. Expects the main live range to not |
| /// have any segments or value numbers. |
| void constructMainRangeFromSubranges(LiveInterval &LI); |
| }; |
| |
| } // end namespace llvm |
| |
| #endif // LLVM_CODEGEN_LIVEINTERVALCALC_H |