WebSVN – QNX 8.QNX8 LLVM/Clang compiler suite – Blame – //llvm-build/x86_64/include/llvm/CodeGen/MachineJumpTableInfo.h

Rev	Author	Line No.	Line
14	pmbaty	1	//===-- CodeGen/MachineJumpTableInfo.h - Abstract Jump Tables --- 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	// The MachineJumpTableInfo class keeps track of jump tables referenced by
		10	// lowered switch instructions in the MachineFunction.
		11	//
		12	// Instructions reference the address of these jump tables through the use of
		13	// MO_JumpTableIndex values. When emitting assembly or machine code, these
		14	// virtual address references are converted to refer to the address of the
		15	// function jump tables.
		16	//
		17	//===----------------------------------------------------------------------===//
		18
		19	#ifndef LLVM_CODEGEN_MACHINEJUMPTABLEINFO_H
		20	#define LLVM_CODEGEN_MACHINEJUMPTABLEINFO_H
		21
		22	#include "llvm/Support/Printable.h"
		23	#include <cassert>
		24	#include <vector>
		25
		26	namespace llvm {
		27
		28	class MachineBasicBlock;
		29	class DataLayout;
		30	class raw_ostream;
		31
		32	/// MachineJumpTableEntry - One jump table in the jump table info.
		33	///
		34	struct MachineJumpTableEntry {
		35	/// MBBs - The vector of basic blocks from which to create the jump table.
		36	std::vector<MachineBasicBlock*> MBBs;
		37
		38	explicit MachineJumpTableEntry(const std::vector<MachineBasicBlock*> &M)
		39	: MBBs(M) {}
		40	};
		41
		42	class MachineJumpTableInfo {
		43	public:
		44	/// JTEntryKind - This enum indicates how each entry of the jump table is
		45	/// represented and emitted.
		46	enum JTEntryKind {
		47	/// EK_BlockAddress - Each entry is a plain address of block, e.g.:
		48	/// .word LBB123
		49	EK_BlockAddress,
		50
		51	/// EK_GPRel64BlockAddress - Each entry is an address of block, encoded
		52	/// with a relocation as gp-relative, e.g.:
		53	/// .gpdword LBB123
		54	EK_GPRel64BlockAddress,
		55
		56	/// EK_GPRel32BlockAddress - Each entry is an address of block, encoded
		57	/// with a relocation as gp-relative, e.g.:
		58	/// .gprel32 LBB123
		59	EK_GPRel32BlockAddress,
		60
		61	/// EK_LabelDifference32 - Each entry is the address of the block minus
		62	/// the address of the jump table. This is used for PIC jump tables where
		63	/// gprel32 is not supported. e.g.:
		64	/// .word LBB123 - LJTI1_2
		65	/// If the .set directive is supported, this is emitted as:
		66	/// .set L4_5_set_123, LBB123 - LJTI1_2
		67	/// .word L4_5_set_123
		68	EK_LabelDifference32,
		69
		70	/// EK_Inline - Jump table entries are emitted inline at their point of
		71	/// use. It is the responsibility of the target to emit the entries.
		72	EK_Inline,
		73
		74	/// EK_Custom32 - Each entry is a 32-bit value that is custom lowered by the
		75	/// TargetLowering::LowerCustomJumpTableEntry hook.
		76	EK_Custom32
		77	};
		78	private:
		79	JTEntryKind EntryKind;
		80	std::vector<MachineJumpTableEntry> JumpTables;
		81	public:
		82	explicit MachineJumpTableInfo(JTEntryKind Kind): EntryKind(Kind) {}
		83
		84	JTEntryKind getEntryKind() const { return EntryKind; }
		85
		86	/// getEntrySize - Return the size of each entry in the jump table.
		87	unsigned getEntrySize(const DataLayout &TD) const;
		88	/// getEntryAlignment - Return the alignment of each entry in the jump table.
		89	unsigned getEntryAlignment(const DataLayout &TD) const;
		90
		91	/// createJumpTableIndex - Create a new jump table.
		92	///
		93	unsigned createJumpTableIndex(const std::vector<MachineBasicBlock*> &DestBBs);
		94
		95	/// isEmpty - Return true if there are no jump tables.
		96	///
		97	bool isEmpty() const { return JumpTables.empty(); }
		98
		99	const std::vector<MachineJumpTableEntry> &getJumpTables() const {
		100	return JumpTables;
		101	}
		102
		103	/// RemoveJumpTable - Mark the specific index as being dead. This will
		104	/// prevent it from being emitted.
		105	void RemoveJumpTable(unsigned Idx) {
		106	JumpTables[Idx].MBBs.clear();
		107	}
		108
		109	/// RemoveMBBFromJumpTables - If MBB is present in any jump tables, remove it.
		110	bool RemoveMBBFromJumpTables(MachineBasicBlock *MBB);
		111
		112	/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
		113	/// the jump tables to branch to New instead.
		114	bool ReplaceMBBInJumpTables(MachineBasicBlock Old, MachineBasicBlock New);
		115
		116	/// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
		117	/// the jump table to branch to New instead.
		118	bool ReplaceMBBInJumpTable(unsigned Idx, MachineBasicBlock *Old,
		119	MachineBasicBlock *New);
		120
		121	/// print - Used by the MachineFunction printer to print information about
		122	/// jump tables. Implemented in MachineFunction.cpp
		123	///
		124	void print(raw_ostream &OS) const;
		125
		126	/// dump - Call to stderr.
		127	///
		128	void dump() const;
		129	};
		130
		131
		132	/// Prints a jump table entry reference.
		133	///
		134	/// The format is:
		135	/// %jump-table.5 - a jump table entry with index == 5.
		136	///
		137	/// Usage: OS << printJumpTableEntryReference(Idx) << '\n';
		138	Printable printJumpTableEntryReference(unsigned Idx);
		139
		140	} // End llvm namespace
		141
		142	#endif

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QNX 8.QNX8 LLVM/Clang compiler suite//llvm-build/x86_64/include/llvm/CodeGen/MachineJumpTableInfo.h – Rev 14