Coverage Report

Created: 2019-03-22 08:08

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/include/llvm/CodeGen/MachineJumpTableInfo.h
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//===-- CodeGen/MachineJumpTableInfo.h - Abstract Jump Tables  --*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// The MachineJumpTableInfo class keeps track of jump tables referenced by
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// lowered switch instructions in the MachineFunction.
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//
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// Instructions reference the address of these jump tables through the use of
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// MO_JumpTableIndex values.  When emitting assembly or machine code, these
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// virtual address references are converted to refer to the address of the
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// function jump tables.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CODEGEN_MACHINEJUMPTABLEINFO_H
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#define LLVM_CODEGEN_MACHINEJUMPTABLEINFO_H
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#include "llvm/Support/Printable.h"
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#include <cassert>
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#include <vector>
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namespace llvm {
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class MachineBasicBlock;
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class DataLayout;
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class raw_ostream;
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/// MachineJumpTableEntry - One jump table in the jump table info.
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///
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struct MachineJumpTableEntry {
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  /// MBBs - The vector of basic blocks from which to create the jump table.
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  std::vector<MachineBasicBlock*> MBBs;
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  explicit MachineJumpTableEntry(const std::vector<MachineBasicBlock*> &M)
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  : MBBs(M) {}
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};
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class MachineJumpTableInfo {
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public:
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  /// JTEntryKind - This enum indicates how each entry of the jump table is
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  /// represented and emitted.
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  enum JTEntryKind {
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    /// EK_BlockAddress - Each entry is a plain address of block, e.g.:
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    ///     .word LBB123
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    EK_BlockAddress,
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    /// EK_GPRel64BlockAddress - Each entry is an address of block, encoded
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    /// with a relocation as gp-relative, e.g.:
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    ///     .gpdword LBB123
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    EK_GPRel64BlockAddress,
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    /// EK_GPRel32BlockAddress - Each entry is an address of block, encoded
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    /// with a relocation as gp-relative, e.g.:
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    ///     .gprel32 LBB123
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    EK_GPRel32BlockAddress,
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    /// EK_LabelDifference32 - Each entry is the address of the block minus
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    /// the address of the jump table.  This is used for PIC jump tables where
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    /// gprel32 is not supported.  e.g.:
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    ///      .word LBB123 - LJTI1_2
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    /// If the .set directive is supported, this is emitted as:
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    ///      .set L4_5_set_123, LBB123 - LJTI1_2
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    ///      .word L4_5_set_123
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    EK_LabelDifference32,
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    /// EK_Inline - Jump table entries are emitted inline at their point of
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    /// use. It is the responsibility of the target to emit the entries.
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    EK_Inline,
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    /// EK_Custom32 - Each entry is a 32-bit value that is custom lowered by the
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    /// TargetLowering::LowerCustomJumpTableEntry hook.
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    EK_Custom32
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  };
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private:
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  JTEntryKind EntryKind;
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  std::vector<MachineJumpTableEntry> JumpTables;
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public:
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  explicit MachineJumpTableInfo(JTEntryKind Kind): EntryKind(Kind) {}
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  JTEntryKind getEntryKind() const { return EntryKind; }
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  /// getEntrySize - Return the size of each entry in the jump table.
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  unsigned getEntrySize(const DataLayout &TD) const;
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  /// getEntryAlignment - Return the alignment of each entry in the jump table.
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  unsigned getEntryAlignment(const DataLayout &TD) const;
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  /// createJumpTableIndex - Create a new jump table.
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  ///
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  unsigned createJumpTableIndex(const std::vector<MachineBasicBlock*> &DestBBs);
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  /// isEmpty - Return true if there are no jump tables.
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  ///
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  bool isEmpty() const { return JumpTables.empty(); }
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  const std::vector<MachineJumpTableEntry> &getJumpTables() const {
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    return JumpTables;
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  }
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  /// RemoveJumpTable - Mark the specific index as being dead.  This will
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  /// prevent it from being emitted.
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  void RemoveJumpTable(unsigned Idx) {
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    JumpTables[Idx].MBBs.clear();
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  }
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  /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
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  /// the jump tables to branch to New instead.
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  bool ReplaceMBBInJumpTables(MachineBasicBlock *Old, MachineBasicBlock *New);
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  /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
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  /// the jump table to branch to New instead.
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  bool ReplaceMBBInJumpTable(unsigned Idx, MachineBasicBlock *Old,
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                             MachineBasicBlock *New);
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  /// print - Used by the MachineFunction printer to print information about
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  /// jump tables.  Implemented in MachineFunction.cpp
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  ///
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  void print(raw_ostream &OS) const;
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  /// dump - Call to stderr.
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  ///
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  void dump() const;
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};
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/// Prints a jump table entry reference.
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///
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/// The format is:
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///   %jump-table.5       - a jump table entry with index == 5.
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///
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/// Usage: OS << printJumpTableEntryReference(Idx) << '\n';
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Printable printJumpTableEntryReference(unsigned Idx);
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} // End llvm namespace
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#endif