LLVM  10.0.0svn
MachineLoopUtils.h
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1 //=- MachineLoopUtils.h - Helper functions for manipulating loops -*- C++ -*-=//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_LIB_CODEGEN_MACHINELOOPUTILS_H
10 #define LLVM_LIB_CODEGEN_MACHINELOOPUTILS_H
11 
12 namespace llvm {
13 class MachineBasicBlock;
14 class MachineRegisterInfo;
15 class TargetInstrInfo;
16 
18  LPD_Front, ///< Peel the first iteration of the loop.
19  LPD_Back ///< Peel the last iteration of the loop.
20 };
21 
22 /// Peels a single block loop. Loop must have two successors, one of which
23 /// must be itself. Similarly it must have two predecessors, one of which must
24 /// be itself.
25 ///
26 /// The loop block is copied and inserted into the CFG such that two copies of
27 /// the loop follow on from each other. The copy is inserted either before or
28 /// after the loop based on Direction.
29 ///
30 /// Phis are updated and an unconditional branch inserted at the end of the
31 /// clone so as to execute a single iteration.
32 ///
33 /// The trip count of Loop is not updated.
37  const TargetInstrInfo *TII);
38 
39 } // namespace llvm
40 
41 #endif // LLVM_LIB_CODEGEN_MACHINELOOPUTILS_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Peel the first iteration of the loop.
const HexagonInstrInfo * TII
TargetInstrInfo - Interface to description of machine instruction set.
unsigned const MachineRegisterInfo * MRI
Peel the last iteration of the loop.
MachineRegisterInfo - Keep track of information for virtual and physical registers, including vreg register classes, use/def chains for registers, etc.
Represents a single loop in the control flow graph.
Definition: LoopInfo.h:509
Loop::LoopBounds::Direction Direction
Definition: LoopInfo.cpp:226
MachineBasicBlock * PeelSingleBlockLoop(LoopPeelDirection Direction, MachineBasicBlock *Loop, MachineRegisterInfo &MRI, const TargetInstrInfo *TII)
Peels a single block loop.