//===-- llvm/Target/TargetInstrInfo.h - Instruction Info --------*- C++ -*-===//
-//
+//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+//
//===----------------------------------------------------------------------===//
//
// This file describes the target machine instructions to the code generator.
#define LLVM_TARGET_TARGETINSTRINFO_H
#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/Support/DataTypes.h"
#include <vector>
#include <cassert>
class MachineInstr;
class TargetMachine;
-class Value;
-class Type;
-class Instruction;
-class Constant;
-class Function;
class MachineCodeForInstruction;
+class TargetRegisterClass;
+class LiveVariables;
//---------------------------------------------------------------------------
// Data types used to define information about a single machine instruction
//---------------------------------------------------------------------------
// struct TargetInstrDescriptor:
-// Predefined information about each machine instruction.
-// Designed to initialized statically.
+// Predefined information about each machine instruction.
+// Designed to initialized statically.
//
-const unsigned M_NOP_FLAG = 1 << 0;
-const unsigned M_BRANCH_FLAG = 1 << 1;
-const unsigned M_CALL_FLAG = 1 << 2;
-const unsigned M_RET_FLAG = 1 << 3;
-const unsigned M_BARRIER_FLAG = 1 << 4;
-const unsigned M_DELAY_SLOT_FLAG = 1 << 5;
-const unsigned M_CC_FLAG = 1 << 6;
-const unsigned M_LOAD_FLAG = 1 << 7;
-const unsigned M_STORE_FLAG = 1 << 8;
+const unsigned M_BRANCH_FLAG = 1 << 0;
+const unsigned M_CALL_FLAG = 1 << 1;
+const unsigned M_RET_FLAG = 1 << 2;
+const unsigned M_BARRIER_FLAG = 1 << 3;
+const unsigned M_DELAY_SLOT_FLAG = 1 << 4;
+const unsigned M_LOAD_FLAG = 1 << 5;
+const unsigned M_STORE_FLAG = 1 << 6;
-// M_2_ADDR_FLAG - 3-addr instructions which really work like 2-addr ones.
-const unsigned M_2_ADDR_FLAG = 1 << 9;
-
-// M_CONVERTIBLE_TO_3_ADDR - This is a M_2_ADDR_FLAG instruction which can be
+// M_CONVERTIBLE_TO_3_ADDR - This is a 2-address instruction which can be
// changed into a 3-address instruction if the first two operands cannot be
// assigned to the same register. The target must implement the
// TargetInstrInfo::convertToThreeAddress method for this instruction.
-const unsigned M_CONVERTIBLE_TO_3_ADDR = 1 << 10;
+const unsigned M_CONVERTIBLE_TO_3_ADDR = 1 << 7;
// This M_COMMUTABLE - is a 2- or 3-address instruction (of the form X = op Y,
// Z), which produces the same result if Y and Z are exchanged.
-const unsigned M_COMMUTABLE = 1 << 11;
+const unsigned M_COMMUTABLE = 1 << 8;
// M_TERMINATOR_FLAG - Is this instruction part of the terminator for a basic
// block? Typically this is things like return and branch instructions.
// Various passes use this to insert code into the bottom of a basic block, but
// before control flow occurs.
-const unsigned M_TERMINATOR_FLAG = 1 << 12;
+const unsigned M_TERMINATOR_FLAG = 1 << 9;
+
+// M_USES_CUSTOM_DAG_SCHED_INSERTION - Set if this instruction requires custom
+// insertion support when the DAG scheduler is inserting it into a machine basic
+// block.
+const unsigned M_USES_CUSTOM_DAG_SCHED_INSERTION = 1 << 10;
+
+// M_VARIABLE_OPS - Set if this instruction can have a variable number of extra
+// operands in addition to the minimum number operands specified.
+const unsigned M_VARIABLE_OPS = 1 << 11;
+
+// M_PREDICABLE - Set if this instruction has a predicate operand that
+// controls execution. It may be set to 'always'.
+const unsigned M_PREDICABLE = 1 << 12;
+
+// M_REMATERIALIZIBLE - Set if this instruction can be trivally re-materialized
+// at any time, e.g. constant generation, load from constant pool.
+const unsigned M_REMATERIALIZIBLE = 1 << 13;
+
+// M_CLOBBERS_PRED - Set if this instruction may clobbers the condition code
+// register and / or registers that are used to predicate instructions.
+const unsigned M_CLOBBERS_PRED = 1 << 14;
+
+// M_NOT_DUPLICABLE - Set if this instruction cannot be safely duplicated.
+// (e.g. instructions with unique labels attached).
+const unsigned M_NOT_DUPLICABLE = 1 << 15;
+
+// Machine operand flags
+// M_LOOK_UP_PTR_REG_CLASS - Set if this operand is a pointer value and it
+// requires a callback to look up its register class.
+const unsigned M_LOOK_UP_PTR_REG_CLASS = 1 << 0;
+
+/// M_PREDICATE_OPERAND - Set if this is one of the operands that made up of the
+/// predicate operand that controls an M_PREDICATED instruction.
+const unsigned M_PREDICATE_OPERAND = 1 << 1;
+
+namespace TOI {
+ // Operand constraints: only "tied_to" for now.
+ enum OperandConstraint {
+ TIED_TO = 0 // Must be allocated the same register as.
+ };
+}
+
+/// TargetOperandInfo - This holds information about one operand of a machine
+/// instruction, indicating the register class for register operands, etc.
+///
+class TargetOperandInfo {
+public:
+ /// RegClass - This specifies the register class enumeration of the operand
+ /// if the operand is a register. If not, this contains 0.
+ unsigned short RegClass;
+ unsigned short Flags;
+ /// Lower 16 bits are used to specify which constraints are set. The higher 16
+ /// bits are used to specify the value of constraints (4 bits each).
+ unsigned int Constraints;
+ /// Currently no other information.
+};
+
class TargetInstrDescriptor {
public:
+ MachineOpCode Opcode; // The opcode.
+ unsigned short numOperands; // Num of args (may be more if variable_ops).
const char * Name; // Assembly language mnemonic for the opcode.
- int numOperands; // Number of args; -1 if variable #args
- int resultPos; // Position of the result; -1 if no result
- unsigned maxImmedConst; // Largest +ve constant in IMMED field or 0.
- bool immedIsSignExtended; // Is IMMED field sign-extended? If so,
- // smallest -ve value is -(maxImmedConst+1).
- unsigned numDelaySlots; // Number of delay slots after instruction
- unsigned latency; // Latency in machine cycles
InstrSchedClass schedClass; // enum identifying instr sched class
unsigned Flags; // flags identifying machine instr class
unsigned TSFlags; // Target Specific Flag values
const unsigned *ImplicitUses; // Registers implicitly read by this instr
const unsigned *ImplicitDefs; // Registers implicitly defined by this instr
+ const TargetOperandInfo *OpInfo; // 'numOperands' entries about operands.
+
+ /// getOperandConstraint - Returns the value of the specific constraint if
+ /// it is set. Returns -1 if it is not set.
+ int getOperandConstraint(unsigned OpNum,
+ TOI::OperandConstraint Constraint) const {
+ assert((OpNum < numOperands || (Flags & M_VARIABLE_OPS)) &&
+ "Invalid operand # of TargetInstrInfo");
+ if (OpNum < numOperands &&
+ (OpInfo[OpNum].Constraints & (1 << Constraint))) {
+ unsigned Pos = 16 + Constraint * 4;
+ return (int)(OpInfo[OpNum].Constraints >> Pos) & 0xf;
+ }
+ return -1;
+ }
+
+ /// findTiedToSrcOperand - Returns the operand that is tied to the specified
+ /// dest operand. Returns -1 if there isn't one.
+ int findTiedToSrcOperand(unsigned OpNum) const;
};
//---------------------------------------------------------------------------
-///
+///
/// TargetInstrInfo - Interface to description of machine instructions
-///
+///
class TargetInstrInfo {
const TargetInstrDescriptor* desc; // raw array to allow static init'n
unsigned NumOpcodes; // number of entries in the desc array
unsigned numRealOpCodes; // number of non-dummy op codes
-
+
TargetInstrInfo(const TargetInstrInfo &); // DO NOT IMPLEMENT
void operator=(const TargetInstrInfo &); // DO NOT IMPLEMENT
public:
TargetInstrInfo(const TargetInstrDescriptor *desc, unsigned NumOpcodes);
virtual ~TargetInstrInfo();
- // Invariant: All instruction sets use opcode #0 as the PHI instruction
- enum { PHI = 0 };
-
+ // Invariant opcodes: All instruction sets have these as their low opcodes.
+ enum {
+ PHI = 0,
+ INLINEASM = 1,
+ LABEL = 2
+ };
+
unsigned getNumOpcodes() const { return NumOpcodes; }
-
+
/// get - Return the machine instruction descriptor that corresponds to the
/// specified instruction opcode.
///
const char *getName(MachineOpCode Opcode) const {
return get(Opcode).Name;
}
-
+
int getNumOperands(MachineOpCode Opcode) const {
return get(Opcode).numOperands;
}
-
InstrSchedClass getSchedClass(MachineOpCode Opcode) const {
return get(Opcode).schedClass;
}
//
// Query instruction class flags according to the machine-independent
// flags listed above.
- //
+ //
bool isReturn(MachineOpCode Opcode) const {
return get(Opcode).Flags & M_RET_FLAG;
}
- bool isTwoAddrInstr(MachineOpCode Opcode) const {
- return get(Opcode).Flags & M_2_ADDR_FLAG;
+ bool isCommutableInstr(MachineOpCode Opcode) const {
+ return get(Opcode).Flags & M_COMMUTABLE;
}
- bool isTerminatorInstr(unsigned Opcode) const {
+ bool isTerminatorInstr(MachineOpCode Opcode) const {
return get(Opcode).Flags & M_TERMINATOR_FLAG;
}
-
- /// Return true if the instruction is a register to register move
- /// and leave the source and dest operands in the passed parameters.
- virtual bool isMoveInstr(const MachineInstr& MI,
- unsigned& sourceReg,
- unsigned& destReg) const {
- return false;
- }
-
- /// convertToThreeAddress - This method must be implemented by targets that
- /// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target
- /// may be able to convert a two-address instruction into a true
- /// three-address instruction on demand. This allows the X86 target (for
- /// example) to convert ADD and SHL instructions into LEA instructions if they
- /// would require register copies due to two-addressness.
- ///
- /// This method returns a null pointer if the transformation cannot be
- /// performed, otherwise it returns the new instruction.
- ///
- virtual MachineInstr *convertToThreeAddress(MachineInstr *TA) const {
- return 0;
- }
-
- /// Insert a goto (unconditional branch) sequence to TMBB, at the
- /// end of MBB
- virtual void insertGoto(MachineBasicBlock& MBB,
- MachineBasicBlock& TMBB) const {
- assert(0 && "Target didn't implement insertGoto!");
- }
-
- /// Reverses the branch condition of the MachineInstr pointed by
- /// MI. The instruction is replaced and the new MI is returned.
- virtual MachineBasicBlock::iterator
- reverseBranchCondition(MachineBasicBlock::iterator MI) const {
- assert(0 && "Target didn't implement reverseBranchCondition!");
- abort();
- return MI;
- }
-
- //-------------------------------------------------------------------------
- // Code generation support for creating individual machine instructions
- //
- // WARNING: These methods are Sparc specific
- //
- // DO NOT USE ANY OF THESE METHODS THEY ARE DEPRECATED!
- //
- //-------------------------------------------------------------------------
-
- unsigned getNumDelaySlots(MachineOpCode Opcode) const {
- return get(Opcode).numDelaySlots;
- }
- bool isCCInstr(MachineOpCode Opcode) const {
- return get(Opcode).Flags & M_CC_FLAG;
- }
- bool isNop(MachineOpCode Opcode) const {
- return get(Opcode).Flags & M_NOP_FLAG;
- }
+
bool isBranch(MachineOpCode Opcode) const {
return get(Opcode).Flags & M_BRANCH_FLAG;
}
+
/// isBarrier - Returns true if the specified instruction stops control flow
/// from executing the instruction immediately following it. Examples include
/// unconditional branches and return instructions.
bool isBarrier(MachineOpCode Opcode) const {
return get(Opcode).Flags & M_BARRIER_FLAG;
}
-
+
bool isCall(MachineOpCode Opcode) const {
return get(Opcode).Flags & M_CALL_FLAG;
}
bool isStore(MachineOpCode Opcode) const {
return get(Opcode).Flags & M_STORE_FLAG;
}
-
+
/// hasDelaySlot - Returns true if the specified instruction has a delay slot
/// which must be filled by the code generator.
- bool hasDelaySlot(unsigned Opcode) const {
+ bool hasDelaySlot(MachineOpCode Opcode) const {
return get(Opcode).Flags & M_DELAY_SLOT_FLAG;
}
+
+ /// usesCustomDAGSchedInsertionHook - Return true if this instruction requires
+ /// custom insertion support when the DAG scheduler is inserting it into a
+ /// machine basic block.
+ bool usesCustomDAGSchedInsertionHook(MachineOpCode Opcode) const {
+ return get(Opcode).Flags & M_USES_CUSTOM_DAG_SCHED_INSERTION;
+ }
- virtual bool hasResultInterlock(MachineOpCode Opcode) const {
- return true;
+ bool hasVariableOperands(MachineOpCode Opcode) const {
+ return get(Opcode).Flags & M_VARIABLE_OPS;
}
- //
- // Latencies for individual instructions and instruction pairs
- //
- virtual int minLatency(MachineOpCode Opcode) const {
- return get(Opcode).latency;
+ bool isPredicable(MachineOpCode Opcode) const {
+ return get(Opcode).Flags & M_PREDICABLE;
+ }
+
+ bool isReMaterializable(MachineOpCode Opcode) const {
+ return get(Opcode).Flags & M_REMATERIALIZIBLE;
+ }
+
+ bool clobbersPredicate(MachineOpCode Opcode) const {
+ return get(Opcode).Flags & M_CLOBBERS_PRED;
+ }
+
+ bool isNotDuplicable(MachineOpCode Opcode) const {
+ return get(Opcode).Flags & M_NOT_DUPLICABLE;
+ }
+
+ /// getOperandConstraint - Returns the value of the specific constraint if
+ /// it is set. Returns -1 if it is not set.
+ int getOperandConstraint(MachineOpCode Opcode, unsigned OpNum,
+ TOI::OperandConstraint Constraint) const {
+ return get(Opcode).getOperandConstraint(OpNum, Constraint);
+ }
+
+ /// Return true if the instruction is a register to register move
+ /// and leave the source and dest operands in the passed parameters.
+ virtual bool isMoveInstr(const MachineInstr& MI,
+ unsigned& sourceReg,
+ unsigned& destReg) const {
+ return false;
+ }
+
+ /// isLoadFromStackSlot - If the specified machine instruction is a direct
+ /// load from a stack slot, return the virtual or physical register number of
+ /// the destination along with the FrameIndex of the loaded stack slot. If
+ /// not, return 0. This predicate must return 0 if the instruction has
+ /// any side effects other than loading from the stack slot.
+ virtual unsigned isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const{
+ return 0;
}
- virtual int maxLatency(MachineOpCode Opcode) const {
- return get(Opcode).latency;
+ /// isStoreToStackSlot - If the specified machine instruction is a direct
+ /// store to a stack slot, return the virtual or physical register number of
+ /// the source reg along with the FrameIndex of the loaded stack slot. If
+ /// not, return 0. This predicate must return 0 if the instruction has
+ /// any side effects other than storing to the stack slot.
+ virtual unsigned isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const {
+ return 0;
}
- //
- // Which operand holds an immediate constant? Returns -1 if none
- //
- virtual int getImmedConstantPos(MachineOpCode Opcode) const {
- return -1; // immediate position is machine specific, so say -1 == "none"
+ /// isOtherReMaterializableLoad - If the specified machine instruction is a
+ /// direct load that is trivially rematerializable, not counting loads from
+ /// stack slots, return true. If not, return false. This predicate must
+ /// return false if the instruction has any side effects other than
+ /// producing the value from the load, or if it requres any address
+ /// registers that are not always available.
+ virtual bool isOtherReMaterializableLoad(MachineInstr *MI) const {
+ return false;
+ }
+
+ /// convertToThreeAddress - This method must be implemented by targets that
+ /// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target
+ /// may be able to convert a two-address instruction into one or moretrue
+ /// three-address instructions on demand. This allows the X86 target (for
+ /// example) to convert ADD and SHL instructions into LEA instructions if they
+ /// would require register copies due to two-addressness.
+ ///
+ /// This method returns a null pointer if the transformation cannot be
+ /// performed, otherwise it returns the last new instruction.
+ ///
+ virtual MachineInstr *
+ convertToThreeAddress(MachineFunction::iterator &MFI,
+ MachineBasicBlock::iterator &MBBI, LiveVariables &LV) const {
+ return 0;
+ }
+
+ /// commuteInstruction - If a target has any instructions that are commutable,
+ /// but require converting to a different instruction or making non-trivial
+ /// changes to commute them, this method can overloaded to do this. The
+ /// default implementation of this method simply swaps the first two operands
+ /// of MI and returns it.
+ ///
+ /// If a target wants to make more aggressive changes, they can construct and
+ /// return a new machine instruction. If an instruction cannot commute, it
+ /// can also return null.
+ ///
+ virtual MachineInstr *commuteInstruction(MachineInstr *MI) const;
+
+ /// AnalyzeBranch - Analyze the branching code at the end of MBB, returning
+ /// true if it cannot be understood (e.g. it's a switch dispatch or isn't
+ /// implemented for a target). Upon success, this returns false and returns
+ /// with the following information in various cases:
+ ///
+ /// 1. If this block ends with no branches (it just falls through to its succ)
+ /// just return false, leaving TBB/FBB null.
+ /// 2. If this block ends with only an unconditional branch, it sets TBB to be
+ /// the destination block.
+ /// 3. If this block ends with an conditional branch and it falls through to
+ /// an successor block, it sets TBB to be the branch destination block and a
+ /// list of operands that evaluate the condition. These
+ /// operands can be passed to other TargetInstrInfo methods to create new
+ /// branches.
+ /// 4. If this block ends with an conditional branch and an unconditional
+ /// block, it returns the 'true' destination in TBB, the 'false' destination
+ /// in FBB, and a list of operands that evaluate the condition. These
+ /// operands can be passed to other TargetInstrInfo methods to create new
+ /// branches.
+ ///
+ /// Note that RemoveBranch and InsertBranch must be implemented to support
+ /// cases where this method returns success.
+ ///
+ virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
+ MachineBasicBlock *&FBB,
+ std::vector<MachineOperand> &Cond) const {
+ return true;
+ }
+
+ /// RemoveBranch - Remove the branching code at the end of the specific MBB.
+ /// this is only invoked in cases where AnalyzeBranch returns success. It
+ /// returns the number of instructions that were removed.
+ virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const {
+ assert(0 && "Target didn't implement TargetInstrInfo::RemoveBranch!");
+ return 0;
+ }
+
+ /// InsertBranch - Insert a branch into the end of the specified
+ /// MachineBasicBlock. This operands to this method are the same as those
+ /// returned by AnalyzeBranch. This is invoked in cases where AnalyzeBranch
+ /// returns success and when an unconditional branch (TBB is non-null, FBB is
+ /// null, Cond is empty) needs to be inserted. It returns the number of
+ /// instructions inserted.
+ virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
+ MachineBasicBlock *FBB,
+ const std::vector<MachineOperand> &Cond) const {
+ assert(0 && "Target didn't implement TargetInstrInfo::InsertBranch!");
+ return 0;
+ }
+
+ /// BlockHasNoFallThrough - Return true if the specified block does not
+ /// fall-through into its successor block. This is primarily used when a
+ /// branch is unanalyzable. It is useful for things like unconditional
+ /// indirect branches (jump tables).
+ virtual bool BlockHasNoFallThrough(MachineBasicBlock &MBB) const {
+ return false;
}
- // Check if the specified constant fits in the immediate field
- // of this machine instruction
- //
- virtual bool constantFitsInImmedField(MachineOpCode Opcode,
- int64_t intValue) const;
+ /// ReverseBranchCondition - Reverses the branch condition of the specified
+ /// condition list, returning false on success and true if it cannot be
+ /// reversed.
+ virtual bool ReverseBranchCondition(std::vector<MachineOperand> &Cond) const {
+ return true;
+ }
- // Return the largest positive constant that can be held in the IMMED field
- // of this machine instruction.
- // isSignExtended is set to true if the value is sign-extended before use
- // (this is true for all immediate fields in SPARC instructions).
- // Return 0 if the instruction has no IMMED field.
- //
- virtual uint64_t maxImmedConstant(MachineOpCode Opcode,
- bool &isSignExtended) const {
- isSignExtended = get(Opcode).immedIsSignExtended;
- return get(Opcode).maxImmedConst;
+ /// insertNoop - Insert a noop into the instruction stream at the specified
+ /// point.
+ virtual void insertNoop(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MI) const {
+ assert(0 && "Target didn't implement insertNoop!");
+ abort();
+ }
+
+ /// isPredicated - Returns true if the instruction is already predicated.
+ ///
+ virtual bool isPredicated(const MachineInstr *MI) const {
+ return false;
+ }
+
+ /// isUnpredicatedTerminator - Returns true if the instruction is a
+ /// terminator instruction that has not been predicated.
+ virtual bool isUnpredicatedTerminator(const MachineInstr *MI) const;
+
+ /// PredicateInstruction - Convert the instruction into a predicated
+ /// instruction. It returns true if the operation was successful.
+ virtual
+ bool PredicateInstruction(MachineInstr *MI,
+ const std::vector<MachineOperand> &Pred) const;
+
+ /// SubsumesPredicate - Returns true if the first specified predicate
+ /// subsumes the second, e.g. GE subsumes GT.
+ virtual
+ bool SubsumesPredicate(const std::vector<MachineOperand> &Pred1,
+ const std::vector<MachineOperand> &Pred2) const {
+ return false;
+ }
+
+ /// getPointerRegClass - Returns a TargetRegisterClass used for pointer
+ /// values.
+ virtual const TargetRegisterClass *getPointerRegClass() const {
+ assert(0 && "Target didn't implement getPointerRegClass!");
+ abort();
+ return 0; // Must return a value in order to compile with VS 2005
}
};