llvm-6502/lib/Target/Target.td
Dan Gohman e3b4c0e176 Mark IMPLICIT_DEF as being rematerializable and cheap-as-a-move.
It's already special-cased and treated as rematerializable within
LiveIntervals; this allows it to be handled by other passes
such as TwoAddressInstrctionPass.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55999 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-09 18:25:28 +00:00

500 lines
19 KiB
TableGen

//===- Target.td - Target Independent TableGen interface ---*- tablegen -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the target-independent interfaces which should be
// implemented by each target which is using a TableGen based code generator.
//
//===----------------------------------------------------------------------===//
// Include all information about LLVM intrinsics.
include "llvm/Intrinsics.td"
//===----------------------------------------------------------------------===//
// Register file description - These classes are used to fill in the target
// description classes.
class RegisterClass; // Forward def
// Register - You should define one instance of this class for each register
// in the target machine. String n will become the "name" of the register.
class Register<string n> {
string Namespace = "";
string AsmName = n;
// SpillSize - If this value is set to a non-zero value, it is the size in
// bits of the spill slot required to hold this register. If this value is
// set to zero, the information is inferred from any register classes the
// register belongs to.
int SpillSize = 0;
// SpillAlignment - This value is used to specify the alignment required for
// spilling the register. Like SpillSize, this should only be explicitly
// specified if the register is not in a register class.
int SpillAlignment = 0;
// Aliases - A list of registers that this register overlaps with. A read or
// modification of this register can potentially read or modify the aliased
// registers.
list<Register> Aliases = [];
// SubRegs - A list of registers that are parts of this register. Note these
// are "immediate" sub-registers and the registers within the list do not
// themselves overlap. e.g. For X86, EAX's SubRegs list contains only [AX],
// not [AX, AH, AL].
list<Register> SubRegs = [];
// DwarfNumbers - Numbers used internally by gcc/gdb to identify the register.
// These values can be determined by locating the <target>.h file in the
// directory llvmgcc/gcc/config/<target>/ and looking for REGISTER_NAMES. The
// order of these names correspond to the enumeration used by gcc. A value of
// -1 indicates that the gcc number is undefined and -2 that register number
// is invalid for this mode/flavour.
list<int> DwarfNumbers = [];
}
// RegisterWithSubRegs - This can be used to define instances of Register which
// need to specify sub-registers.
// List "subregs" specifies which registers are sub-registers to this one. This
// is used to populate the SubRegs and AliasSet fields of TargetRegisterDesc.
// This allows the code generator to be careful not to put two values with
// overlapping live ranges into registers which alias.
class RegisterWithSubRegs<string n, list<Register> subregs> : Register<n> {
let SubRegs = subregs;
}
// SubRegSet - This can be used to define a specific mapping of registers to
// indices, for use as named subregs of a particular physical register. Each
// register in 'subregs' becomes an addressable subregister at index 'n' of the
// corresponding register in 'regs'.
class SubRegSet<int n, list<Register> regs, list<Register> subregs> {
int index = n;
list<Register> From = regs;
list<Register> To = subregs;
}
// RegisterClass - Now that all of the registers are defined, and aliases
// between registers are defined, specify which registers belong to which
// register classes. This also defines the default allocation order of
// registers by register allocators.
//
class RegisterClass<string namespace, list<ValueType> regTypes, int alignment,
list<Register> regList> {
string Namespace = namespace;
// RegType - Specify the list ValueType of the registers in this register
// class. Note that all registers in a register class must have the same
// ValueTypes. This is a list because some targets permit storing different
// types in same register, for example vector values with 128-bit total size,
// but different count/size of items, like SSE on x86.
//
list<ValueType> RegTypes = regTypes;
// Size - Specify the spill size in bits of the registers. A default value of
// zero lets tablgen pick an appropriate size.
int Size = 0;
// Alignment - Specify the alignment required of the registers when they are
// stored or loaded to memory.
//
int Alignment = alignment;
// CopyCost - This value is used to specify the cost of copying a value
// between two registers in this register class. The default value is one
// meaning it takes a single instruction to perform the copying. A negative
// value means copying is extremely expensive or impossible.
int CopyCost = 1;
// MemberList - Specify which registers are in this class. If the
// allocation_order_* method are not specified, this also defines the order of
// allocation used by the register allocator.
//
list<Register> MemberList = regList;
// SubClassList - Specify which register classes correspond to subregisters
// of this class. The order should be by subregister set index.
list<RegisterClass> SubRegClassList = [];
// MethodProtos/MethodBodies - These members can be used to insert arbitrary
// code into a generated register class. The normal usage of this is to
// overload virtual methods.
code MethodProtos = [{}];
code MethodBodies = [{}];
}
//===----------------------------------------------------------------------===//
// DwarfRegNum - This class provides a mapping of the llvm register enumeration
// to the register numbering used by gcc and gdb. These values are used by a
// debug information writer (ex. DwarfWriter) to describe where values may be
// located during execution.
class DwarfRegNum<list<int> Numbers> {
// DwarfNumbers - Numbers used internally by gcc/gdb to identify the register.
// These values can be determined by locating the <target>.h file in the
// directory llvmgcc/gcc/config/<target>/ and looking for REGISTER_NAMES. The
// order of these names correspond to the enumeration used by gcc. A value of
// -1 indicates that the gcc number is undefined and -2 that register number is
// invalid for this mode/flavour.
list<int> DwarfNumbers = Numbers;
}
//===----------------------------------------------------------------------===//
// Pull in the common support for scheduling
//
include "TargetSchedule.td"
class Predicate; // Forward def
//===----------------------------------------------------------------------===//
// Instruction set description - These classes correspond to the C++ classes in
// the Target/TargetInstrInfo.h file.
//
class Instruction {
string Namespace = "";
dag OutOperandList; // An dag containing the MI def operand list.
dag InOperandList; // An dag containing the MI use operand list.
string AsmString = ""; // The .s format to print the instruction with.
// Pattern - Set to the DAG pattern for this instruction, if we know of one,
// otherwise, uninitialized.
list<dag> Pattern;
// The follow state will eventually be inferred automatically from the
// instruction pattern.
list<Register> Uses = []; // Default to using no non-operand registers
list<Register> Defs = []; // Default to modifying no non-operand registers
// Predicates - List of predicates which will be turned into isel matching
// code.
list<Predicate> Predicates = [];
// Code size.
int CodeSize = 0;
// Added complexity passed onto matching pattern.
int AddedComplexity = 0;
// These bits capture information about the high-level semantics of the
// instruction.
bit isReturn = 0; // Is this instruction a return instruction?
bit isBranch = 0; // Is this instruction a branch instruction?
bit isIndirectBranch = 0; // Is this instruction an indirect branch?
bit isBarrier = 0; // Can control flow fall through this instruction?
bit isCall = 0; // Is this instruction a call instruction?
bit isSimpleLoad = 0; // Is this just a load instruction?
bit mayLoad = 0; // Is it possible for this inst to read memory?
bit mayStore = 0; // Is it possible for this inst to write memory?
bit isTwoAddress = 0; // Is this a two address instruction?
bit isConvertibleToThreeAddress = 0; // Can this 2-addr instruction promote?
bit isCommutable = 0; // Is this 3 operand instruction commutable?
bit isTerminator = 0; // Is this part of the terminator for a basic block?
bit isReMaterializable = 0; // Is this instruction re-materializable?
bit isPredicable = 0; // Is this instruction predicable?
bit hasDelaySlot = 0; // Does this instruction have an delay slot?
bit usesCustomDAGSchedInserter = 0; // Pseudo instr needing special help.
bit hasCtrlDep = 0; // Does this instruction r/w ctrl-flow chains?
bit isNotDuplicable = 0; // Is it unsafe to duplicate this instruction?
bit isAsCheapAsAMove = 0; // As cheap (or cheaper) than a move instruction.
// Side effect flags - When set, the flags have these meanings:
//
// hasSideEffects - The instruction has side effects that are not
// captured by any operands of the instruction or other flags.
//
// mayHaveSideEffects - Some instances of the instruction can have side
// effects. The virtual method "isReallySideEffectFree" is called to
// determine this. Load instructions are an example of where this is
// useful. In general, loads always have side effects. However, loads from
// constant pools don't. Individual back ends make this determination.
//
// neverHasSideEffects - Set on an instruction with no pattern if it has no
// side effects.
bit hasSideEffects = 0;
bit mayHaveSideEffects = 0;
bit neverHasSideEffects = 0;
InstrItinClass Itinerary = NoItinerary;// Execution steps used for scheduling.
string Constraints = ""; // OperandConstraint, e.g. $src = $dst.
/// DisableEncoding - List of operand names (e.g. "$op1,$op2") that should not
/// be encoded into the output machineinstr.
string DisableEncoding = "";
}
/// Predicates - These are extra conditionals which are turned into instruction
/// selector matching code. Currently each predicate is just a string.
class Predicate<string cond> {
string CondString = cond;
}
/// NoHonorSignDependentRounding - This predicate is true if support for
/// sign-dependent-rounding is not enabled.
def NoHonorSignDependentRounding
: Predicate<"!HonorSignDependentRoundingFPMath()">;
class Requires<list<Predicate> preds> {
list<Predicate> Predicates = preds;
}
/// ops definition - This is just a simple marker used to identify the operands
/// list for an instruction. outs and ins are identical both syntatically and
/// semantically, they are used to define def operands and use operands to
/// improve readibility. This should be used like this:
/// (outs R32:$dst), (ins R32:$src1, R32:$src2) or something similar.
def ops;
def outs;
def ins;
/// variable_ops definition - Mark this instruction as taking a variable number
/// of operands.
def variable_ops;
/// ptr_rc definition - Mark this operand as being a pointer value whose
/// register class is resolved dynamically via a callback to TargetInstrInfo.
/// FIXME: We should probably change this to a class which contain a list of
/// flags. But currently we have but one flag.
def ptr_rc;
/// unknown definition - Mark this operand as being of unknown type, causing
/// it to be resolved by inference in the context it is used.
def unknown;
/// Operand Types - These provide the built-in operand types that may be used
/// by a target. Targets can optionally provide their own operand types as
/// needed, though this should not be needed for RISC targets.
class Operand<ValueType ty> {
ValueType Type = ty;
string PrintMethod = "printOperand";
dag MIOperandInfo = (ops);
}
def i1imm : Operand<i1>;
def i8imm : Operand<i8>;
def i16imm : Operand<i16>;
def i32imm : Operand<i32>;
def i64imm : Operand<i64>;
def f32imm : Operand<f32>;
def f64imm : Operand<f64>;
/// zero_reg definition - Special node to stand for the zero register.
///
def zero_reg;
/// PredicateOperand - This can be used to define a predicate operand for an
/// instruction. OpTypes specifies the MIOperandInfo for the operand, and
/// AlwaysVal specifies the value of this predicate when set to "always
/// execute".
class PredicateOperand<ValueType ty, dag OpTypes, dag AlwaysVal>
: Operand<ty> {
let MIOperandInfo = OpTypes;
dag DefaultOps = AlwaysVal;
}
/// OptionalDefOperand - This is used to define a optional definition operand
/// for an instruction. DefaultOps is the register the operand represents if none
/// is supplied, e.g. zero_reg.
class OptionalDefOperand<ValueType ty, dag OpTypes, dag defaultops>
: Operand<ty> {
let MIOperandInfo = OpTypes;
dag DefaultOps = defaultops;
}
// InstrInfo - This class should only be instantiated once to provide parameters
// which are global to the the target machine.
//
class InstrInfo {
// If the target wants to associate some target-specific information with each
// instruction, it should provide these two lists to indicate how to assemble
// the target specific information into the 32 bits available.
//
list<string> TSFlagsFields = [];
list<int> TSFlagsShifts = [];
// Target can specify its instructions in either big or little-endian formats.
// For instance, while both Sparc and PowerPC are big-endian platforms, the
// Sparc manual specifies its instructions in the format [31..0] (big), while
// PowerPC specifies them using the format [0..31] (little).
bit isLittleEndianEncoding = 0;
}
// Standard Instructions.
def PHI : Instruction {
let OutOperandList = (ops);
let InOperandList = (ops variable_ops);
let AsmString = "PHINODE";
let Namespace = "TargetInstrInfo";
}
def INLINEASM : Instruction {
let OutOperandList = (ops);
let InOperandList = (ops variable_ops);
let AsmString = "";
let Namespace = "TargetInstrInfo";
}
def DBG_LABEL : Instruction {
let OutOperandList = (ops);
let InOperandList = (ops i32imm:$id);
let AsmString = "";
let Namespace = "TargetInstrInfo";
let hasCtrlDep = 1;
}
def EH_LABEL : Instruction {
let OutOperandList = (ops);
let InOperandList = (ops i32imm:$id);
let AsmString = "";
let Namespace = "TargetInstrInfo";
let hasCtrlDep = 1;
}
def GC_LABEL : Instruction {
let OutOperandList = (ops);
let InOperandList = (ops i32imm:$id);
let AsmString = "";
let Namespace = "TargetInstrInfo";
let hasCtrlDep = 1;
}
def DECLARE : Instruction {
let OutOperandList = (ops);
let InOperandList = (ops variable_ops);
let AsmString = "";
let Namespace = "TargetInstrInfo";
let hasCtrlDep = 1;
}
def EXTRACT_SUBREG : Instruction {
let OutOperandList = (ops unknown:$dst);
let InOperandList = (ops unknown:$supersrc, i32imm:$subidx);
let AsmString = "";
let Namespace = "TargetInstrInfo";
let neverHasSideEffects = 1;
}
def INSERT_SUBREG : Instruction {
let OutOperandList = (ops unknown:$dst);
let InOperandList = (ops unknown:$supersrc, unknown:$subsrc, i32imm:$subidx);
let AsmString = "";
let Namespace = "TargetInstrInfo";
let neverHasSideEffects = 1;
let Constraints = "$supersrc = $dst";
}
def IMPLICIT_DEF : Instruction {
let OutOperandList = (ops unknown:$dst);
let InOperandList = (ops);
let AsmString = "";
let Namespace = "TargetInstrInfo";
let neverHasSideEffects = 1;
let isReMaterializable = 1;
let isAsCheapAsAMove = 1;
}
def SUBREG_TO_REG : Instruction {
let OutOperandList = (ops unknown:$dst);
let InOperandList = (ops unknown:$implsrc, unknown:$subsrc, i32imm:$subidx);
let AsmString = "";
let Namespace = "TargetInstrInfo";
let neverHasSideEffects = 1;
}
//===----------------------------------------------------------------------===//
// AsmWriter - This class can be implemented by targets that need to customize
// the format of the .s file writer.
//
// Subtargets can have multiple different asmwriters (e.g. AT&T vs Intel syntax
// on X86 for example).
//
class AsmWriter {
// AsmWriterClassName - This specifies the suffix to use for the asmwriter
// class. Generated AsmWriter classes are always prefixed with the target
// name.
string AsmWriterClassName = "AsmPrinter";
// InstFormatName - AsmWriters can specify the name of the format string to
// print instructions with.
string InstFormatName = "AsmString";
// Variant - AsmWriters can be of multiple different variants. Variants are
// used to support targets that need to emit assembly code in ways that are
// mostly the same for different targets, but have minor differences in
// syntax. If the asmstring contains {|} characters in them, this integer
// will specify which alternative to use. For example "{x|y|z}" with Variant
// == 1, will expand to "y".
int Variant = 0;
}
def DefaultAsmWriter : AsmWriter;
//===----------------------------------------------------------------------===//
// Target - This class contains the "global" target information
//
class Target {
// InstructionSet - Instruction set description for this target.
InstrInfo InstructionSet;
// AssemblyWriters - The AsmWriter instances available for this target.
list<AsmWriter> AssemblyWriters = [DefaultAsmWriter];
}
//===----------------------------------------------------------------------===//
// SubtargetFeature - A characteristic of the chip set.
//
class SubtargetFeature<string n, string a, string v, string d,
list<SubtargetFeature> i = []> {
// Name - Feature name. Used by command line (-mattr=) to determine the
// appropriate target chip.
//
string Name = n;
// Attribute - Attribute to be set by feature.
//
string Attribute = a;
// Value - Value the attribute to be set to by feature.
//
string Value = v;
// Desc - Feature description. Used by command line (-mattr=) to display help
// information.
//
string Desc = d;
// Implies - Features that this feature implies are present. If one of those
// features isn't set, then this one shouldn't be set either.
//
list<SubtargetFeature> Implies = i;
}
//===----------------------------------------------------------------------===//
// Processor chip sets - These values represent each of the chip sets supported
// by the scheduler. Each Processor definition requires corresponding
// instruction itineraries.
//
class Processor<string n, ProcessorItineraries pi, list<SubtargetFeature> f> {
// Name - Chip set name. Used by command line (-mcpu=) to determine the
// appropriate target chip.
//
string Name = n;
// ProcItin - The scheduling information for the target processor.
//
ProcessorItineraries ProcItin = pi;
// Features - list of
list<SubtargetFeature> Features = f;
}
//===----------------------------------------------------------------------===//
// Pull in the common support for calling conventions.
//
include "TargetCallingConv.td"
//===----------------------------------------------------------------------===//
// Pull in the common support for DAG isel generation.
//
include "TargetSelectionDAG.td"