//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Nate Begeman and is distributed under the
-// University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// The MachineJumpTableInfo class keeps track of jump tables referenced by
// lowered switch instructions in the MachineFunction.
//
-// Instructions reference the address of these jump tables through the use of
-// MO_JumpTableIndex values. When emitting assembly or machine code, these
-// virtual address references are converted to refer to the address of the
+// Instructions reference the address of these jump tables through the use of
+// MO_JumpTableIndex values. When emitting assembly or machine code, these
+// virtual address references are converted to refer to the address of the
// function jump tables.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_MACHINEJUMPTABLEINFO_H
#define LLVM_CODEGEN_MACHINEJUMPTABLEINFO_H
+#include <cassert>
#include <vector>
-#include <iosfwd>
namespace llvm {
class MachineBasicBlock;
-class TargetData;
+class DataLayout;
+class raw_ostream;
/// MachineJumpTableEntry - One jump table in the jump table info.
///
struct MachineJumpTableEntry {
/// MBBs - The vector of basic blocks from which to create the jump table.
std::vector<MachineBasicBlock*> MBBs;
-
- MachineJumpTableEntry(std::vector<MachineBasicBlock*> &M) : MBBs(M) {}
+
+ explicit MachineJumpTableEntry(const std::vector<MachineBasicBlock*> &M)
+ : MBBs(M) {}
};
-
+
class MachineJumpTableInfo {
- const TargetData *TD;
+public:
+ /// JTEntryKind - This enum indicates how each entry of the jump table is
+ /// represented and emitted.
+ enum JTEntryKind {
+ /// EK_BlockAddress - Each entry is a plain address of block, e.g.:
+ /// .word LBB123
+ EK_BlockAddress,
+
+ /// EK_GPRel64BlockAddress - Each entry is an address of block, encoded
+ /// with a relocation as gp-relative, e.g.:
+ /// .gpdword LBB123
+ EK_GPRel64BlockAddress,
+
+ /// EK_GPRel32BlockAddress - Each entry is an address of block, encoded
+ /// with a relocation as gp-relative, e.g.:
+ /// .gprel32 LBB123
+ EK_GPRel32BlockAddress,
+
+ /// EK_LabelDifference32 - Each entry is the address of the block minus
+ /// the address of the jump table. This is used for PIC jump tables where
+ /// gprel32 is not supported. e.g.:
+ /// .word LBB123 - LJTI1_2
+ /// If the .set directive is supported, this is emitted as:
+ /// .set L4_5_set_123, LBB123 - LJTI1_2
+ /// .word L4_5_set_123
+ EK_LabelDifference32,
+
+ /// EK_Inline - Jump table entries are emitted inline at their point of
+ /// use. It is the responsibility of the target to emit the entries.
+ EK_Inline,
+
+ /// EK_Custom32 - Each entry is a 32-bit value that is custom lowered by the
+ /// TargetLowering::LowerCustomJumpTableEntry hook.
+ EK_Custom32
+ };
+private:
+ JTEntryKind EntryKind;
std::vector<MachineJumpTableEntry> JumpTables;
public:
- MachineJumpTableInfo(const TargetData *td) : TD(td) {}
-
- /// getJumpTableIndex - Create a new jump table or return an existing one.
+ explicit MachineJumpTableInfo(JTEntryKind Kind): EntryKind(Kind) {}
+
+ JTEntryKind getEntryKind() const { return EntryKind; }
+
+ /// getEntrySize - Return the size of each entry in the jump table.
+ unsigned getEntrySize(const DataLayout &TD) const;
+ /// getEntryAlignment - Return the alignment of each entry in the jump table.
+ unsigned getEntryAlignment(const DataLayout &TD) const;
+
+ /// createJumpTableIndex - Create a new jump table.
///
- unsigned getJumpTableIndex(std::vector<MachineBasicBlock*> &DestBBs);
-
+ unsigned createJumpTableIndex(const std::vector<MachineBasicBlock*> &DestBBs);
+
/// isEmpty - Return true if there are no jump tables.
///
bool isEmpty() const { return JumpTables.empty(); }
const std::vector<MachineJumpTableEntry> &getJumpTables() const {
return JumpTables;
}
-
+
+ /// RemoveJumpTable - Mark the specific index as being dead. This will
+ /// prevent it from being emitted.
+ void RemoveJumpTable(unsigned Idx) {
+ JumpTables[Idx].MBBs.clear();
+ }
+
/// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
/// the jump tables to branch to New instead.
- void ReplaceMBBInJumpTables(MachineBasicBlock *Old, MachineBasicBlock *New) {
- for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
- MachineJumpTableEntry &JTE = JumpTables[i];
- for (unsigned j = 0, e = JTE.MBBs.size(); j != e; ++j)
- if (JTE.MBBs[j] == Old)
- JTE.MBBs[j] = New;
- }
- }
-
- /// getEntrySize - returns the size of an individual field in a jump table
- unsigned getEntrySize() const;
-
- /// getAlignment - returns the target's preferred alignment for jump tables
- unsigned getAlignment() const;
-
+ bool ReplaceMBBInJumpTables(MachineBasicBlock *Old, MachineBasicBlock *New);
+
+ /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
+ /// the jump table to branch to New instead.
+ bool ReplaceMBBInJumpTable(unsigned Idx, MachineBasicBlock *Old,
+ MachineBasicBlock *New);
+
/// print - Used by the MachineFunction printer to print information about
/// jump tables. Implemented in MachineFunction.cpp
///
- void print(std::ostream &OS) const;
+ void print(raw_ostream &OS) const;
- /// dump - Call print(std::cerr) to be called from the debugger.
+ /// dump - Call to stderr.
///
void dump() const;
};
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