1 //===- Target.td - Target Independent TableGen interface ---*- tablegen -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the target-independent interfaces which should be
11 // implemented by each target which is using a TableGen based code generator.
13 //===----------------------------------------------------------------------===//
15 // Include all information about LLVM intrinsics.
16 include "llvm/Intrinsics.td"
18 //===----------------------------------------------------------------------===//
19 // Register file description - These classes are used to fill in the target
20 // description classes.
22 class RegisterClass; // Forward def
24 // Register - You should define one instance of this class for each register
25 // in the target machine. String n will become the "name" of the register.
26 class Register<string n> {
27 string Namespace = "";
30 // SpillSize - If this value is set to a non-zero value, it is the size in
31 // bits of the spill slot required to hold this register. If this value is
32 // set to zero, the information is inferred from any register classes the
33 // register belongs to.
36 // SpillAlignment - This value is used to specify the alignment required for
37 // spilling the register. Like SpillSize, this should only be explicitly
38 // specified if the register is not in a register class.
39 int SpillAlignment = 0;
41 // Aliases - A list of registers that this register overlaps with. A read or
42 // modification of this register can potentially read or modify the aliased
44 list<Register> Aliases = [];
46 // SubRegs - A list of registers that are parts of this register. Note these
47 // are "immediate" sub-registers and the registers within the list do not
48 // themselves overlap. e.g. For X86, EAX's SubRegs list contains only [AX],
50 list<Register> SubRegs = [];
52 // DwarfNumbers - Numbers used internally by gcc/gdb to identify the register.
53 // These values can be determined by locating the <target>.h file in the
54 // directory llvmgcc/gcc/config/<target>/ and looking for REGISTER_NAMES. The
55 // order of these names correspond to the enumeration used by gcc. A value of
56 // -1 indicates that the gcc number is undefined and -2 that register number
57 // is invalid for this mode/flavour.
58 list<int> DwarfNumbers = [];
61 // RegisterWithSubRegs - This can be used to define instances of Register which
62 // need to specify sub-registers.
63 // List "subregs" specifies which registers are sub-registers to this one. This
64 // is used to populate the SubRegs and AliasSet fields of TargetRegisterDesc.
65 // This allows the code generator to be careful not to put two values with
66 // overlapping live ranges into registers which alias.
67 class RegisterWithSubRegs<string n, list<Register> subregs> : Register<n> {
68 let SubRegs = subregs;
71 // SubRegSet - This can be used to define a specific mapping of registers to
72 // indices, for use as named subregs of a particular physical register. Each
73 // register in 'subregs' becomes an addressable subregister at index 'n' of the
74 // corresponding register in 'regs'.
75 class SubRegSet<int n, list<Register> regs, list<Register> subregs> {
78 list<Register> From = regs;
79 list<Register> To = subregs;
82 // RegisterClass - Now that all of the registers are defined, and aliases
83 // between registers are defined, specify which registers belong to which
84 // register classes. This also defines the default allocation order of
85 // registers by register allocators.
87 class RegisterClass<string namespace, list<ValueType> regTypes, int alignment,
88 list<Register> regList> {
89 string Namespace = namespace;
91 // RegType - Specify the list ValueType of the registers in this register
92 // class. Note that all registers in a register class must have the same
93 // ValueTypes. This is a list because some targets permit storing different
94 // types in same register, for example vector values with 128-bit total size,
95 // but different count/size of items, like SSE on x86.
97 list<ValueType> RegTypes = regTypes;
99 // Size - Specify the spill size in bits of the registers. A default value of
100 // zero lets tablgen pick an appropriate size.
103 // Alignment - Specify the alignment required of the registers when they are
104 // stored or loaded to memory.
106 int Alignment = alignment;
108 // CopyCost - This value is used to specify the cost of copying a value
109 // between two registers in this register class. The default value is one
110 // meaning it takes a single instruction to perform the copying. A negative
111 // value means copying is extremely expensive or impossible.
114 // MemberList - Specify which registers are in this class. If the
115 // allocation_order_* method are not specified, this also defines the order of
116 // allocation used by the register allocator.
118 list<Register> MemberList = regList;
120 // SubClassList - Specify which register classes correspond to subregisters
121 // of this class. The order should be by subregister set index.
122 list<RegisterClass> SubRegClassList = [];
124 // MethodProtos/MethodBodies - These members can be used to insert arbitrary
125 // code into a generated register class. The normal usage of this is to
126 // overload virtual methods.
127 code MethodProtos = [{}];
128 code MethodBodies = [{}];
132 //===----------------------------------------------------------------------===//
133 // DwarfRegNum - This class provides a mapping of the llvm register enumeration
134 // to the register numbering used by gcc and gdb. These values are used by a
135 // debug information writer (ex. DwarfWriter) to describe where values may be
136 // located during execution.
137 class DwarfRegNum<list<int> Numbers> {
138 // DwarfNumbers - Numbers used internally by gcc/gdb to identify the register.
139 // These values can be determined by locating the <target>.h file in the
140 // directory llvmgcc/gcc/config/<target>/ and looking for REGISTER_NAMES. The
141 // order of these names correspond to the enumeration used by gcc. A value of
142 // -1 indicates that the gcc number is undefined and -2 that register number is
143 // invalid for this mode/flavour.
144 list<int> DwarfNumbers = Numbers;
147 //===----------------------------------------------------------------------===//
148 // Pull in the common support for scheduling
150 include "TargetSchedule.td"
152 class Predicate; // Forward def
154 //===----------------------------------------------------------------------===//
155 // Instruction set description - These classes correspond to the C++ classes in
156 // the Target/TargetInstrInfo.h file.
159 string Namespace = "";
161 dag OutOperandList; // An dag containing the MI def operand list.
162 dag InOperandList; // An dag containing the MI use operand list.
163 string AsmString = ""; // The .s format to print the instruction with.
165 // Pattern - Set to the DAG pattern for this instruction, if we know of one,
166 // otherwise, uninitialized.
169 // The follow state will eventually be inferred automatically from the
170 // instruction pattern.
172 list<Register> Uses = []; // Default to using no non-operand registers
173 list<Register> Defs = []; // Default to modifying no non-operand registers
175 // Predicates - List of predicates which will be turned into isel matching
177 list<Predicate> Predicates = [];
182 // Added complexity passed onto matching pattern.
183 int AddedComplexity = 0;
185 // These bits capture information about the high-level semantics of the
187 bit isReturn = 0; // Is this instruction a return instruction?
188 bit isBranch = 0; // Is this instruction a branch instruction?
189 bit isIndirectBranch = 0; // Is this instruction an indirect branch?
190 bit isBarrier = 0; // Can control flow fall through this instruction?
191 bit isCall = 0; // Is this instruction a call instruction?
192 bit isSimpleLoad = 0; // Is this just a load instruction?
193 bit mayStore = 0; // Can this instruction modify memory?
194 bit isImplicitDef = 0; // Is this instruction an implicit def instruction?
195 bit isTwoAddress = 0; // Is this a two address instruction?
196 bit isConvertibleToThreeAddress = 0; // Can this 2-addr instruction promote?
197 bit isCommutable = 0; // Is this 3 operand instruction commutable?
198 bit isTerminator = 0; // Is this part of the terminator for a basic block?
199 bit isReMaterializable = 0; // Is this instruction re-materializable?
200 bit isPredicable = 0; // Is this instruction predicable?
201 bit hasDelaySlot = 0; // Does this instruction have an delay slot?
202 bit usesCustomDAGSchedInserter = 0; // Pseudo instr needing special help.
203 bit hasCtrlDep = 0; // Does this instruction r/w ctrl-flow chains?
204 bit isNotDuplicable = 0; // Is it unsafe to duplicate this instruction?
206 // Side effect flags - If neither of these flags is set, then the instruction
207 // *always* has side effects. When set, the flags have these meanings:
209 // neverHasSideEffects - The instruction has no side effects that are not
210 // captured by any operands of the instruction or other flags, and when
211 // *all* instances of the instruction of that opcode have no side effects.
212 // mayHaveSideEffects - Some instances of the instruction can have side
213 // effects. The virtual method "isReallySideEffectFree" is called to
214 // determine this. Load instructions are an example of where this is
215 // useful. In general, loads always have side effects. However, loads from
216 // constant pools don't. Individual back ends make this determination.
217 bit neverHasSideEffects = 0;
218 bit mayHaveSideEffects = 0;
220 InstrItinClass Itinerary = NoItinerary;// Execution steps used for scheduling.
222 string Constraints = ""; // OperandConstraint, e.g. $src = $dst.
224 /// DisableEncoding - List of operand names (e.g. "$op1,$op2") that should not
225 /// be encoded into the output machineinstr.
226 string DisableEncoding = "";
229 /// Predicates - These are extra conditionals which are turned into instruction
230 /// selector matching code. Currently each predicate is just a string.
231 class Predicate<string cond> {
232 string CondString = cond;
235 /// NoHonorSignDependentRounding - This predicate is true if support for
236 /// sign-dependent-rounding is not enabled.
237 def NoHonorSignDependentRounding
238 : Predicate<"!HonorSignDependentRoundingFPMath()">;
240 class Requires<list<Predicate> preds> {
241 list<Predicate> Predicates = preds;
244 /// ops definition - This is just a simple marker used to identify the operands
245 /// list for an instruction. outs and ins are identical both syntatically and
246 /// semantically, they are used to define def operands and use operands to
247 /// improve readibility. This should be used like this:
248 /// (outs R32:$dst), (ins R32:$src1, R32:$src2) or something similar.
253 /// variable_ops definition - Mark this instruction as taking a variable number
257 /// ptr_rc definition - Mark this operand as being a pointer value whose
258 /// register class is resolved dynamically via a callback to TargetInstrInfo.
259 /// FIXME: We should probably change this to a class which contain a list of
260 /// flags. But currently we have but one flag.
263 /// Operand Types - These provide the built-in operand types that may be used
264 /// by a target. Targets can optionally provide their own operand types as
265 /// needed, though this should not be needed for RISC targets.
266 class Operand<ValueType ty> {
268 string PrintMethod = "printOperand";
269 dag MIOperandInfo = (ops);
272 def i1imm : Operand<i1>;
273 def i8imm : Operand<i8>;
274 def i16imm : Operand<i16>;
275 def i32imm : Operand<i32>;
276 def i64imm : Operand<i64>;
278 /// zero_reg definition - Special node to stand for the zero register.
282 /// PredicateOperand - This can be used to define a predicate operand for an
283 /// instruction. OpTypes specifies the MIOperandInfo for the operand, and
284 /// AlwaysVal specifies the value of this predicate when set to "always
286 class PredicateOperand<ValueType ty, dag OpTypes, dag AlwaysVal>
288 let MIOperandInfo = OpTypes;
289 dag DefaultOps = AlwaysVal;
292 /// OptionalDefOperand - This is used to define a optional definition operand
293 /// for an instruction. DefaultOps is the register the operand represents if none
294 /// is supplied, e.g. zero_reg.
295 class OptionalDefOperand<ValueType ty, dag OpTypes, dag defaultops>
297 let MIOperandInfo = OpTypes;
298 dag DefaultOps = defaultops;
302 // InstrInfo - This class should only be instantiated once to provide parameters
303 // which are global to the the target machine.
306 // If the target wants to associate some target-specific information with each
307 // instruction, it should provide these two lists to indicate how to assemble
308 // the target specific information into the 32 bits available.
310 list<string> TSFlagsFields = [];
311 list<int> TSFlagsShifts = [];
313 // Target can specify its instructions in either big or little-endian formats.
314 // For instance, while both Sparc and PowerPC are big-endian platforms, the
315 // Sparc manual specifies its instructions in the format [31..0] (big), while
316 // PowerPC specifies them using the format [0..31] (little).
317 bit isLittleEndianEncoding = 0;
320 // Standard Instructions.
321 def PHI : Instruction {
322 let OutOperandList = (ops);
323 let InOperandList = (ops variable_ops);
324 let AsmString = "PHINODE";
325 let Namespace = "TargetInstrInfo";
327 def INLINEASM : Instruction {
328 let OutOperandList = (ops);
329 let InOperandList = (ops variable_ops);
331 let Namespace = "TargetInstrInfo";
333 def LABEL : Instruction {
334 let OutOperandList = (ops);
335 let InOperandList = (ops i32imm:$id);
337 let Namespace = "TargetInstrInfo";
340 def EXTRACT_SUBREG : Instruction {
341 let OutOperandList = (ops variable_ops);
342 let InOperandList = (ops variable_ops);
344 let Namespace = "TargetInstrInfo";
346 def INSERT_SUBREG : Instruction {
347 let OutOperandList = (ops variable_ops);
348 let InOperandList = (ops variable_ops);
350 let Namespace = "TargetInstrInfo";
353 //===----------------------------------------------------------------------===//
354 // AsmWriter - This class can be implemented by targets that need to customize
355 // the format of the .s file writer.
357 // Subtargets can have multiple different asmwriters (e.g. AT&T vs Intel syntax
358 // on X86 for example).
361 // AsmWriterClassName - This specifies the suffix to use for the asmwriter
362 // class. Generated AsmWriter classes are always prefixed with the target
364 string AsmWriterClassName = "AsmPrinter";
366 // InstFormatName - AsmWriters can specify the name of the format string to
367 // print instructions with.
368 string InstFormatName = "AsmString";
370 // Variant - AsmWriters can be of multiple different variants. Variants are
371 // used to support targets that need to emit assembly code in ways that are
372 // mostly the same for different targets, but have minor differences in
373 // syntax. If the asmstring contains {|} characters in them, this integer
374 // will specify which alternative to use. For example "{x|y|z}" with Variant
375 // == 1, will expand to "y".
378 def DefaultAsmWriter : AsmWriter;
381 //===----------------------------------------------------------------------===//
382 // Target - This class contains the "global" target information
385 // InstructionSet - Instruction set description for this target.
386 InstrInfo InstructionSet;
388 // AssemblyWriters - The AsmWriter instances available for this target.
389 list<AsmWriter> AssemblyWriters = [DefaultAsmWriter];
392 //===----------------------------------------------------------------------===//
393 // SubtargetFeature - A characteristic of the chip set.
395 class SubtargetFeature<string n, string a, string v, string d,
396 list<SubtargetFeature> i = []> {
397 // Name - Feature name. Used by command line (-mattr=) to determine the
398 // appropriate target chip.
402 // Attribute - Attribute to be set by feature.
404 string Attribute = a;
406 // Value - Value the attribute to be set to by feature.
410 // Desc - Feature description. Used by command line (-mattr=) to display help
415 // Implies - Features that this feature implies are present. If one of those
416 // features isn't set, then this one shouldn't be set either.
418 list<SubtargetFeature> Implies = i;
421 //===----------------------------------------------------------------------===//
422 // Processor chip sets - These values represent each of the chip sets supported
423 // by the scheduler. Each Processor definition requires corresponding
424 // instruction itineraries.
426 class Processor<string n, ProcessorItineraries pi, list<SubtargetFeature> f> {
427 // Name - Chip set name. Used by command line (-mcpu=) to determine the
428 // appropriate target chip.
432 // ProcItin - The scheduling information for the target processor.
434 ProcessorItineraries ProcItin = pi;
436 // Features - list of
437 list<SubtargetFeature> Features = f;
440 //===----------------------------------------------------------------------===//
441 // Pull in the common support for calling conventions.
443 include "TargetCallingConv.td"
445 //===----------------------------------------------------------------------===//
446 // Pull in the common support for DAG isel generation.
448 include "TargetSelectionDAG.td"