/// TargetInstrInfo - Interface to description of machine instruction set
///
class TargetInstrInfo : public MCInstrInfo {
- TargetInstrInfo(const TargetInstrInfo &); // DO NOT IMPLEMENT
- void operator=(const TargetInstrInfo &); // DO NOT IMPLEMENT
+ TargetInstrInfo(const TargetInstrInfo &) LLVM_DELETED_FUNCTION;
+ void operator=(const TargetInstrInfo &) LLVM_DELETED_FUNCTION;
public:
TargetInstrInfo(int CFSetupOpcode = -1, int CFDestroyOpcode = -1)
: CallFrameSetupOpcode(CFSetupOpcode),
llvm_unreachable("Target didn't implement TargetInstrInfo::insertSelect!");
}
+ /// analyzeSelect - Analyze the given select instruction, returning true if
+ /// it cannot be understood. It is assumed that MI->isSelect() is true.
+ ///
+ /// When successful, return the controlling condition and the operands that
+ /// determine the true and false result values.
+ ///
+ /// Result = SELECT Cond, TrueOp, FalseOp
+ ///
+ /// Some targets can optimize select instructions, for example by predicating
+ /// the instruction defining one of the operands. Such targets should set
+ /// Optimizable.
+ ///
+ /// @param MI Select instruction to analyze.
+ /// @param Cond Condition controlling the select.
+ /// @param TrueOp Operand number of the value selected when Cond is true.
+ /// @param FalseOp Operand number of the value selected when Cond is false.
+ /// @param Optimizable Returned as true if MI is optimizable.
+ /// @returns False on success.
+ virtual bool analyzeSelect(const MachineInstr *MI,
+ SmallVectorImpl<MachineOperand> &Cond,
+ unsigned &TrueOp, unsigned &FalseOp,
+ bool &Optimizable) const {
+ assert(MI && MI->isSelect() && "MI must be a select instruction");
+ return true;
+ }
+
+ /// optimizeSelect - Given a select instruction that was understood by
+ /// analyzeSelect and returned Optimizable = true, attempt to optimize MI by
+ /// merging it with one of its operands. Returns NULL on failure.
+ ///
+ /// When successful, returns the new select instruction. The client is
+ /// responsible for deleting MI.
+ ///
+ /// If both sides of the select can be optimized, PreferFalse is used to pick
+ /// a side.
+ ///
+ /// @param MI Optimizable select instruction.
+ /// @param PreferFalse Try to optimize FalseOp instead of TrueOp.
+ /// @returns Optimized instruction or NULL.
+ virtual MachineInstr *optimizeSelect(MachineInstr *MI,
+ bool PreferFalse = false) const {
+ // This function must be implemented if Optimizable is ever set.
+ llvm_unreachable("Target must implement TargetInstrInfo::optimizeSelect!");
+ }
+
/// copyPhysReg - Emit instructions to copy a pair of physical registers.
+ ///
+ /// This function should support copies within any legal register class as
+ /// well as any cross-class copies created during instruction selection.
+ ///
+ /// The source and destination registers may overlap, which may require a
+ /// careful implementation when multiple copy instructions are required for
+ /// large registers. See for example the ARM target.
virtual void copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI, DebugLoc DL,
unsigned DestReg, unsigned SrcReg,
const MachineInstr *UseMI, unsigned UseIdx,
bool FindMin = false) const;
- /// computeOperandLatency - Compute and return the latency of the given data
- /// dependent def and use. DefMI must be a valid def. UseMI may be NULL for
- /// an unknown use. If the subtarget allows, this may or may not need to call
- /// getOperandLatency().
- ///
- /// FindMin may be set to get the minimum vs. expected latency. Minimum
- /// latency is used for scheduling groups, while expected latency is for
- /// instruction cost and critical path.
- unsigned computeOperandLatency(const InstrItineraryData *ItinData,
- const TargetRegisterInfo *TRI,
- const MachineInstr *DefMI,
- const MachineInstr *UseMI,
- unsigned Reg, bool FindMin) const;
-
- /// getOutputLatency - Compute and return the output dependency latency of a
- /// a given pair of defs which both target the same register. This is usually
- /// one.
- virtual unsigned getOutputLatency(const InstrItineraryData *ItinData,
- const MachineInstr *DefMI, unsigned DefIdx,
- const MachineInstr *DepMI) const {
- return 1;
- }
-
/// getInstrLatency - Compute the instruction latency of a given instruction.
/// If the instruction has higher cost when predicated, it's returned via
/// PredCost.
unsigned defaultDefLatency(const MCSchedModel *SchedModel,
const MachineInstr *DefMI) const;
+ int computeDefOperandLatency(const InstrItineraryData *ItinData,
+ const MachineInstr *DefMI, bool FindMin) const;
+
/// isHighLatencyDef - Return true if this opcode has high latency to its
/// result.
virtual bool isHighLatencyDef(int opc) const { return false; }