llvm-6502/include/llvm/Target/Target.td
Chris Lattner a33b93f7f1 sketch out the planned instruction alias mechanism, add some comments about
how the push/pop mnemonic aliases are wrong.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117857 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-31 18:43:46 +00:00

698 lines
27 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
// SubRegIndex - Use instances of SubRegIndex to identify subregisters.
class SubRegIndex {
string Namespace = "";
}
// 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 = [];
// SubRegIndices - For each register in SubRegs, specify the SubRegIndex used
// to address it. Sub-sub-register indices are automatically inherited from
// SubRegs.
list<SubRegIndex> SubRegIndices = [];
// CompositeIndices - Specify subreg indices that don't correspond directly to
// a register in SubRegs and are not inherited. The following formats are
// supported:
//
// (a) Identity - Reg:a == Reg
// (a b) Alias - Reg:a == Reg:b
// (a b,c) Composite - Reg:a == (Reg:b):c
//
// This can be used to disambiguate a sub-sub-register that exists in more
// than one subregister and other weird stuff.
list<dag> CompositeIndices = [];
// 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;
}
// 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;
// SubRegClasses - Specify the register class of subregisters as a list of
// dags: (RegClass SubRegIndex, SubRegindex, ...)
list<dag> SubRegClasses = [];
// 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 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 "llvm/Target/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 isCompare = 0; // Is this instruction a comparison instruction?
bit isBarrier = 0; // Can control flow fall through this instruction?
bit isCall = 0; // Is this instruction a call instruction?
bit canFoldAsLoad = 0; // Can this be folded as a simple memory operand?
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 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 usesCustomInserter = 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.
bit hasExtraSrcRegAllocReq = 0; // Sources have special regalloc requirement?
bit hasExtraDefRegAllocReq = 0; // Defs have special regalloc requirement?
// 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.
//
// neverHasSideEffects - Set on an instruction with no pattern if it has no
// side effects.
bit hasSideEffects = 0;
bit neverHasSideEffects = 0;
// Is this instruction a "real" instruction (with a distinct machine
// encoding), or is it a pseudo instruction used for codegen modeling
// purposes.
bit isCodeGenOnly = 0;
// Is this instruction a pseudo instruction for use by the assembler parser.
bit isAsmParserOnly = 0;
InstrItinClass Itinerary = NoItinerary;// Execution steps used for scheduling.
string Constraints = ""; // OperandConstraint, e.g. $src = $dst.
/// DisableEncoding - List of operand names (e.g. "$op1,$op2") that should not
/// be encoded into the output machineinstr.
string DisableEncoding = "";
/// Target-specific flags. This becomes the TSFlags field in TargetInstrDesc.
bits<64> TSFlags = 0;
}
/// Predicates - These are extra conditionals which are turned into instruction
/// selector matching code. Currently each predicate is just a string.
class Predicate<string cond> {
string CondString = cond;
/// AssemblerMatcherPredicate - If this feature can be used by the assembler
/// matcher, this is true. Targets should set this by inheriting their
/// feature from the AssemblerPredicate class in addition to Predicate.
bit AssemblerMatcherPredicate = 0;
}
/// NoHonorSignDependentRounding - This predicate is true if support for
/// sign-dependent-rounding is not enabled.
def NoHonorSignDependentRounding
: Predicate<"!HonorSignDependentRoundingFPMath()">;
class Requires<list<Predicate> preds> {
list<Predicate> Predicates = preds;
}
/// ops definition - This is just a simple marker used to identify the operands
/// list for an instruction. outs and ins are identical both syntatically and
/// semantically, they are used to define def operands and use operands to
/// improve readibility. This should be used like this:
/// (outs R32:$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;
/// PointerLikeRegClass - Values that are designed to have pointer width are
/// derived from this. TableGen treats the register class as having a symbolic
/// type that it doesn't know, and resolves the actual regclass to use by using
/// the TargetRegisterInfo::getPointerRegClass() hook at codegen time.
class PointerLikeRegClass<int Kind> {
int RegClassKind = Kind;
}
/// 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 : PointerLikeRegClass<0>;
/// 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;
/// AsmOperandClass - Representation for the kinds of operands which the target
/// specific parser can create and the assembly matcher may need to distinguish.
///
/// Operand classes are used to define the order in which instructions are
/// matched, to ensure that the instruction which gets matched for any
/// particular list of operands is deterministic.
///
/// The target specific parser must be able to classify a parsed operand into a
/// unique class which does not partially overlap with any other classes. It can
/// match a subset of some other class, in which case the super class field
/// should be defined.
class AsmOperandClass {
/// The name to use for this class, which should be usable as an enum value.
string Name = ?;
/// The super classes of this operand.
list<AsmOperandClass> SuperClasses = [];
/// The name of the method on the target specific operand to call to test
/// whether the operand is an instance of this class. If not set, this will
/// default to "isFoo", where Foo is the AsmOperandClass name. The method
/// signature should be:
/// bool isFoo() const;
string PredicateMethod = ?;
/// The name of the method on the target specific operand to call to add the
/// target specific operand to an MCInst. If not set, this will default to
/// "addFooOperands", where Foo is the AsmOperandClass name. The method
/// signature should be:
/// void addFooOperands(MCInst &Inst, unsigned N) const;
string RenderMethod = ?;
}
def ImmAsmOperand : AsmOperandClass {
let Name = "Imm";
}
/// 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";
string AsmOperandLowerMethod = ?;
dag MIOperandInfo = (ops);
// ParserMatchClass - The "match class" that operands of this type fit
// in. Match classes are used to define the order in which instructions are
// match, to ensure that which instructions gets matched is deterministic.
//
// The target specific parser must be able to classify an parsed operand into
// a unique class, which does not partially overlap with any other classes. It
// can match a subset of some other class, in which case the AsmOperandClass
// should declare the other operand as one of its super classes.
AsmOperandClass ParserMatchClass = ImmAsmOperand;
}
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 target machine.
//
class InstrInfo {
// 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 Pseudo Instructions.
// This list must match TargetOpcodes.h and CodeGenTarget.cpp.
// Only these instructions are allowed in the TargetOpcode namespace.
let isCodeGenOnly = 1, Namespace = "TargetOpcode" in {
def PHI : Instruction {
let OutOperandList = (outs);
let InOperandList = (ins variable_ops);
let AsmString = "PHINODE";
}
def INLINEASM : Instruction {
let OutOperandList = (outs);
let InOperandList = (ins variable_ops);
let AsmString = "";
}
def PROLOG_LABEL : Instruction {
let OutOperandList = (outs);
let InOperandList = (ins i32imm:$id);
let AsmString = "";
let hasCtrlDep = 1;
let isNotDuplicable = 1;
}
def EH_LABEL : Instruction {
let OutOperandList = (outs);
let InOperandList = (ins i32imm:$id);
let AsmString = "";
let hasCtrlDep = 1;
let isNotDuplicable = 1;
}
def GC_LABEL : Instruction {
let OutOperandList = (outs);
let InOperandList = (ins i32imm:$id);
let AsmString = "";
let hasCtrlDep = 1;
let isNotDuplicable = 1;
}
def KILL : Instruction {
let OutOperandList = (outs);
let InOperandList = (ins variable_ops);
let AsmString = "";
let neverHasSideEffects = 1;
}
def EXTRACT_SUBREG : Instruction {
let OutOperandList = (outs unknown:$dst);
let InOperandList = (ins unknown:$supersrc, i32imm:$subidx);
let AsmString = "";
let neverHasSideEffects = 1;
}
def INSERT_SUBREG : Instruction {
let OutOperandList = (outs unknown:$dst);
let InOperandList = (ins unknown:$supersrc, unknown:$subsrc, i32imm:$subidx);
let AsmString = "";
let neverHasSideEffects = 1;
let Constraints = "$supersrc = $dst";
}
def IMPLICIT_DEF : Instruction {
let OutOperandList = (outs unknown:$dst);
let InOperandList = (ins);
let AsmString = "";
let neverHasSideEffects = 1;
let isReMaterializable = 1;
let isAsCheapAsAMove = 1;
}
def SUBREG_TO_REG : Instruction {
let OutOperandList = (outs unknown:$dst);
let InOperandList = (ins unknown:$implsrc, unknown:$subsrc, i32imm:$subidx);
let AsmString = "";
let neverHasSideEffects = 1;
}
def COPY_TO_REGCLASS : Instruction {
let OutOperandList = (outs unknown:$dst);
let InOperandList = (ins unknown:$src, i32imm:$regclass);
let AsmString = "";
let neverHasSideEffects = 1;
let isAsCheapAsAMove = 1;
}
def DBG_VALUE : Instruction {
let OutOperandList = (outs);
let InOperandList = (ins variable_ops);
let AsmString = "DBG_VALUE";
let isAsCheapAsAMove = 1;
}
def REG_SEQUENCE : Instruction {
let OutOperandList = (outs unknown:$dst);
let InOperandList = (ins variable_ops);
let AsmString = "";
let neverHasSideEffects = 1;
let isAsCheapAsAMove = 1;
}
def COPY : Instruction {
let OutOperandList = (outs unknown:$dst);
let InOperandList = (ins unknown:$src);
let AsmString = "";
let neverHasSideEffects = 1;
let isAsCheapAsAMove = 1;
}
}
//===----------------------------------------------------------------------===//
// AsmParser - This class can be implemented by targets that wish to implement
// .s file parsing.
//
// Subtargets can have multiple different assembly parsers (e.g. AT&T vs Intel
// syntax on X86 for example).
//
class AsmParser {
// AsmParserClassName - This specifies the suffix to use for the asmparser
// class. Generated AsmParser classes are always prefixed with the target
// name.
string AsmParserClassName = "AsmParser";
// AsmParserInstCleanup - If non-empty, this is the name of a custom member
// function of the AsmParser class to call on every matched instruction.
// This can be used to perform target specific instruction post-processing.
string AsmParserInstCleanup = "";
// Variant - AsmParsers can be of multiple different variants. Variants are
// used to support targets that need to parser multiple formats for the
// assembly language.
int Variant = 0;
// CommentDelimiter - If given, the delimiter string used to recognize
// comments which are hard coded in the .td assembler strings for individual
// instructions.
string CommentDelimiter = "";
// RegisterPrefix - If given, the token prefix which indicates a register
// token. This is used by the matcher to automatically recognize hard coded
// register tokens as constrained registers, instead of tokens, for the
// purposes of matching.
string RegisterPrefix = "";
}
def DefaultAsmParser : AsmParser;
/// AssemblerPredicate - This is a Predicate that can be used when the assembler
/// matches instructions and aliases.
class AssemblerPredicate {
bit AssemblerMatcherPredicate = 1;
}
/// MnemonicAlias - This class allows targets to define assembler mnemonic
/// aliases. This should be used when all forms of one mnemonic are accepted
/// with a different mnemonic. For example, X86 allows:
/// sal %al, 1 -> shl %al, 1
/// sal %ax, %cl -> shl %ax, %cl
/// sal %eax, %cl -> shl %eax, %cl
/// etc. Though "sal" is accepted with many forms, all of them are directly
/// translated to a shl, so it can be handled with (in the case of X86, it
/// actually has one for each suffix as well):
/// def : MnemonicAlias<"sal", "shl">;
///
/// Mnemonic aliases are mapped before any other translation in the match phase,
/// and do allow Requires predicates, e.g.:
///
/// def : MnemonicAlias<"pushf", "pushfq">, Requires<[In64BitMode]>;
/// def : MnemonicAlias<"pushf", "pushfl">, Requires<[In32BitMode]>;
///
class MnemonicAlias<string From, string To> {
string FromMnemonic = From;
string ToMnemonic = To;
// Predicates - Predicates that must be true for this remapping to happen.
list<Predicate> Predicates = [];
}
/// InstAlias - This defines an alternate assembly syntax that is allowed to
/// match an instruction that has a different (more canonical) assembly
/// representation.
class InstAlias<dag Outs, dag Ins, string Asm, dag Result> {
dag OutOperandList = Outs; // An dag containing the MI def operand list.
dag InOperandList = Ins; // An dag containing the MI use operand list.
string AsmString = Asm; // The .s format to match the instruction with.
dag ResultInst = Result; // The MCInst to generate.
// Predicates - Predicates that must be true for this to match.
list<Predicate> Predicates = [];
}
//===----------------------------------------------------------------------===//
// 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;
// FirstOperandColumn/OperandSpacing - If the assembler syntax uses a columnar
// layout, the asmwriter can actually generate output in this columns (in
// verbose-asm mode). These two values indicate the width of the first column
// (the "opcode" area) and the width to reserve for subsequent operands. When
// verbose asm mode is enabled, operands will be indented to respect this.
int FirstOperandColumn = -1;
// OperandSpacing - Space between operand columns.
int OperandSpacing = -1;
// isMCAsmWriter - Is this assembly writer for an MC emitter? This controls
// generation of the printInstruction() method. For MC printers, it takes
// an MCInstr* operand, otherwise it takes a MachineInstr*.
bit isMCAsmWriter = 0;
}
def DefaultAsmWriter : AsmWriter;
//===----------------------------------------------------------------------===//
// Target - This class contains the "global" target information
//
class Target {
// InstructionSet - Instruction set description for this target.
InstrInfo InstructionSet;
// AssemblyParsers - The AsmParser instances available for this target.
list<AsmParser> AssemblyParsers = [DefaultAsmParser];
// 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 "llvm/Target/TargetCallingConv.td"
//===----------------------------------------------------------------------===//
// Pull in the common support for DAG isel generation.
//
include "llvm/Target/TargetSelectionDAG.td"