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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //===- LiveIntervalCalc.h - Calculate live intervals -----------*- C++ -*-===// |
| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // The LiveIntervalCalc class is an extension of LiveRangeCalc targeted to the |
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| 10 | // computation and modification of the LiveInterval variants of LiveRanges. |
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| 11 | // LiveIntervals are meant to track liveness of registers and stack slots and |
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| 12 | // LiveIntervalCalc adds to LiveRangeCalc all the machinery required to |
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| 13 | // construct the liveness of virtual registers tracked by a LiveInterval. |
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| 14 | // |
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| 15 | //===----------------------------------------------------------------------===// |
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| 16 | |||
| 17 | #ifndef LLVM_CODEGEN_LIVEINTERVALCALC_H |
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| 18 | #define LLVM_CODEGEN_LIVEINTERVALCALC_H |
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| 19 | |||
| 20 | #include "llvm/CodeGen/LiveRangeCalc.h" |
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| 21 | |||
| 22 | namespace llvm { |
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| 23 | |||
| 24 | template <class NodeT> class DomTreeNodeBase; |
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| 25 | |||
| 26 | using MachineDomTreeNode = DomTreeNodeBase<MachineBasicBlock>; |
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| 27 | |||
| 28 | class LiveIntervalCalc : public LiveRangeCalc { |
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| 29 | /// Extend the live range of @p LR to reach all uses of Reg. |
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| 30 | /// |
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| 31 | /// If @p LR is a main range, or if @p LI is null, then all uses must be |
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| 32 | /// jointly dominated by the definitions from @p LR. If @p LR is a subrange |
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| 33 | /// of the live interval @p LI, corresponding to lane mask @p LaneMask, |
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| 34 | /// all uses must be jointly dominated by the definitions from @p LR |
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| 35 | /// together with definitions of other lanes where @p LR becomes undefined |
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| 36 | /// (via <def,read-undef> operands). |
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| 37 | /// If @p LR is a main range, the @p LaneMask should be set to ~0, i.e. |
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| 38 | /// LaneBitmask::getAll(). |
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| 39 | void extendToUses(LiveRange &LR, Register Reg, LaneBitmask LaneMask, |
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| 40 | LiveInterval *LI = nullptr); |
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| 41 | |||
| 42 | public: |
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| 43 | LiveIntervalCalc() = default; |
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| 44 | |||
| 45 | /// createDeadDefs - Create a dead def in LI for every def operand of Reg. |
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| 46 | /// Each instruction defining Reg gets a new VNInfo with a corresponding |
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| 47 | /// minimal live range. |
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| 48 | void createDeadDefs(LiveRange &LR, Register Reg); |
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| 49 | |||
| 50 | /// Extend the live range of @p LR to reach all uses of Reg. |
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| 51 | /// |
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| 52 | /// All uses must be jointly dominated by existing liveness. PHI-defs are |
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| 53 | /// inserted as needed to preserve SSA form. |
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| 54 | void extendToUses(LiveRange &LR, MCRegister PhysReg) { |
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| 55 | extendToUses(LR, PhysReg, LaneBitmask::getAll()); |
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| 56 | } |
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| 57 | |||
| 58 | /// Calculates liveness for the register specified in live interval @p LI. |
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| 59 | /// Creates subregister live ranges as needed if subreg liveness tracking is |
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| 60 | /// enabled. |
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| 61 | void calculate(LiveInterval &LI, bool TrackSubRegs); |
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| 62 | |||
| 63 | /// For live interval \p LI with correct SubRanges construct matching |
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| 64 | /// information for the main live range. Expects the main live range to not |
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| 65 | /// have any segments or value numbers. |
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| 66 | void constructMainRangeFromSubranges(LiveInterval &LI); |
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| 67 | }; |
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| 68 | |||
| 69 | } // end namespace llvm |
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| 70 | |||
| 71 | #endif // LLVM_CODEGEN_LIVEINTERVALCALC_H |