1//===- CodeGenMapTable.cpp - Instruction Mapping Table Generator ----------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8// CodeGenMapTable provides functionality for the TableGen to create
9// relation mapping between instructions. Relation models are defined using
10// InstrMapping as a base class. This file implements the functionality which
11// parses these definitions and generates relation maps using the information
12// specified there. These maps are emitted as tables in the XXXGenInstrInfo.inc
13// file along with the functions to query them.
14//
15// A relationship model to relate non-predicate instructions with their
16// predicated true/false forms can be defined as follows:
17//
18// def getPredOpcode : InstrMapping {
19// let FilterClass = "PredRel";
20// let RowFields = ["BaseOpcode"];
21// let ColFields = ["PredSense"];
22// let KeyCol = ["none"];
23// let ValueCols = [["true"], ["false"]]; }
24//
25// CodeGenMapTable parses this map and generates a table in XXXGenInstrInfo.inc
26// file that contains the instructions modeling this relationship. This table
27// is defined in the function
28// "int getPredOpcode(uint16_t Opcode, enum PredSense inPredSense)"
29// that can be used to retrieve the predicated form of the instruction by
30// passing its opcode value and the predicate sense (true/false) of the desired
31// instruction as arguments.
32//
33// Short description of the algorithm:
34//
35// 1) Iterate through all the records that derive from "InstrMapping" class.
36// 2) For each record, filter out instructions based on the FilterClass value.
37// 3) Iterate through this set of instructions and insert them into
38// RowInstrMap map based on their RowFields values. RowInstrMap is keyed by the
39// vector of RowFields values and contains vectors of Records (instructions) as
40// values. RowFields is a list of fields that are required to have the same
41// values for all the instructions appearing in the same row of the relation
42// table. All the instructions in a given row of the relation table have some
43// sort of relationship with the key instruction defined by the corresponding
44// relationship model.
45//
46// Ex: RowInstrMap(RowVal1, RowVal2, ...) -> [Instr1, Instr2, Instr3, ... ]
47// Here Instr1, Instr2, Instr3 have same values (RowVal1, RowVal2) for
48// RowFields. These groups of instructions are later matched against ValueCols
49// to determine the column they belong to, if any.
50//
51// While building the RowInstrMap map, collect all the key instructions in
52// KeyInstrVec. These are the instructions having the same values as KeyCol
53// for all the fields listed in ColFields.
54//
55// For Example:
56//
57// Relate non-predicate instructions with their predicated true/false forms.
58//
59// def getPredOpcode : InstrMapping {
60// let FilterClass = "PredRel";
61// let RowFields = ["BaseOpcode"];
62// let ColFields = ["PredSense"];
63// let KeyCol = ["none"];
64// let ValueCols = [["true"], ["false"]]; }
65//
66// Here, only instructions that have "none" as PredSense will be selected as key
67// instructions.
68//
69// 4) For each key instruction, get the group of instructions that share the
70// same key-value as the key instruction from RowInstrMap. Iterate over the list
71// of columns in ValueCols (it is defined as a list<list<string> >. Therefore,
72// it can specify multi-column relationships). For each column, find the
73// instruction from the group that matches all the values for the column.
74// Multiple matches are not allowed.
75//
76//===----------------------------------------------------------------------===//
77
78#include "Common/CodeGenInstruction.h"
79#include "Common/CodeGenTarget.h"
80#include "TableGenBackends.h"
81#include "llvm/ADT/SetVector.h"
82#include "llvm/ADT/StringExtras.h"
83#include "llvm/TableGen/CodeGenHelpers.h"
84#include "llvm/TableGen/Error.h"
85#include "llvm/TableGen/Record.h"
86
87using namespace llvm;
88using InstrRelMapTy = std::map<std::string, std::vector<const Record *>>;
89using RowInstrMapTy =
90 std::map<std::vector<const Init *>, std::vector<const Record *>>;
91
92namespace {
93
94//===----------------------------------------------------------------------===//
95// This class is used to represent InstrMapping class defined in Target.td file.
96class InstrMap {
97private:
98 std::string Name;
99 std::string FilterClass;
100 const ListInit *RowFields;
101 const ListInit *ColFields;
102 const ListInit *KeyCol;
103 std::vector<const ListInit *> ValueCols;
104
105public:
106 InstrMap(const Record *MapRec) {
107 Name = MapRec->getName().str();
108
109 // FilterClass - It's used to reduce the search space only to the
110 // instructions that define the kind of relationship modeled by
111 // this InstrMapping object/record.
112 const RecordVal *Filter = MapRec->getValue(Name: "FilterClass");
113 FilterClass = Filter->getValue()->getAsUnquotedString();
114
115 // List of fields/attributes that need to be same across all the
116 // instructions in a row of the relation table.
117 RowFields = MapRec->getValueAsListInit(FieldName: "RowFields");
118
119 // List of fields/attributes that are constant across all the instruction
120 // in a column of the relation table. Ex: ColFields = 'predSense'
121 ColFields = MapRec->getValueAsListInit(FieldName: "ColFields");
122
123 // Values for the fields/attributes listed in 'ColFields'.
124 // Ex: KeyCol = 'noPred' -- key instruction is non-predicated
125 KeyCol = MapRec->getValueAsListInit(FieldName: "KeyCol");
126
127 // List of values for the fields/attributes listed in 'ColFields', one for
128 // each column in the relation table.
129 //
130 // Ex: ValueCols = [['true'],['false']] -- it results two columns in the
131 // table. First column requires all the instructions to have predSense
132 // set to 'true' and second column requires it to be 'false'.
133 const ListInit *ColValList = MapRec->getValueAsListInit(FieldName: "ValueCols");
134
135 // Each instruction map must specify at least one column for it to be valid.
136 if (ColValList->empty())
137 PrintFatalError(ErrorLoc: MapRec->getLoc(), Msg: "InstrMapping record `" + Name +
138 "' has empty " +
139 "`ValueCols' field!");
140
141 for (const Init *I : ColValList->getElements()) {
142 const auto *ColI = cast<ListInit>(Val: I);
143
144 // Make sure that all the sub-lists in 'ValueCols' have same number of
145 // elements as the fields in 'ColFields'.
146 if (ColI->size() != ColFields->size())
147 PrintFatalError(ErrorLoc: MapRec->getLoc(),
148 Msg: "Record `" + Name +
149 "', field `ValueCols' entries don't match with " +
150 " the entries in 'ColFields'!");
151 ValueCols.push_back(x: ColI);
152 }
153 }
154
155 const std::string &getName() const { return Name; }
156 const std::string &getFilterClass() const { return FilterClass; }
157 const ListInit *getRowFields() const { return RowFields; }
158 const ListInit *getColFields() const { return ColFields; }
159 const ListInit *getKeyCol() const { return KeyCol; }
160 ArrayRef<const ListInit *> getValueCols() const { return ValueCols; }
161};
162
163//===----------------------------------------------------------------------===//
164// class MapTableEmitter : It builds the instruction relation maps using
165// the information provided in InstrMapping records. It outputs these
166// relationship maps as tables into XXXGenInstrInfo.inc file along with the
167// functions to query them.
168
169class MapTableEmitter {
170private:
171 // std::string TargetName;
172 const CodeGenTarget &Target;
173 // InstrMapDesc - InstrMapping record to be processed.
174 InstrMap InstrMapDesc;
175
176 // InstrDefs - list of instructions filtered using FilterClass defined
177 // in InstrMapDesc.
178 ArrayRef<const Record *> InstrDefs;
179
180 // RowInstrMap - maps RowFields values to the instructions. It's keyed by the
181 // values of the row fields and contains vector of records as values.
182 RowInstrMapTy RowInstrMap;
183
184 // KeyInstrVec - list of key instructions.
185 std::vector<const Record *> KeyInstrVec;
186 DenseMap<const Record *, std::vector<const Record *>> MapTable;
187
188public:
189 MapTableEmitter(const CodeGenTarget &Target, const RecordKeeper &Records,
190 const Record *IMRec)
191 : Target(Target), InstrMapDesc(IMRec) {
192 const std::string &FilterClass = InstrMapDesc.getFilterClass();
193 InstrDefs = Records.getAllDerivedDefinitions(ClassName: FilterClass);
194 }
195
196 void buildRowInstrMap();
197
198 // Returns true if an instruction is a key instruction, i.e., its ColFields
199 // have same values as KeyCol.
200 bool isKeyColInstr(const Record *CurInstr);
201
202 // Find column instruction corresponding to a key instruction based on the
203 // constraints for that column.
204 const Record *getInstrForColumn(const Record *KeyInstr,
205 const ListInit *CurValueCol);
206
207 // Find column instructions for each key instruction based
208 // on ValueCols and store them into MapTable.
209 void buildMapTable();
210
211 void emitBinSearch(raw_ostream &OS, unsigned TableSize);
212 void emitTablesWithFunc(raw_ostream &OS);
213 unsigned emitBinSearchTable(raw_ostream &OS);
214
215 // Lookup functions to query binary search tables.
216 void emitMapFuncBody(raw_ostream &OS, unsigned TableSize);
217};
218} // end anonymous namespace
219
220//===----------------------------------------------------------------------===//
221// Process all the instructions that model this relation (alreday present in
222// InstrDefs) and insert them into RowInstrMap which is keyed by the values of
223// the fields listed as RowFields. It stores vectors of records as values.
224// All the related instructions have the same values for the RowFields thus are
225// part of the same key-value pair.
226//===----------------------------------------------------------------------===//
227
228void MapTableEmitter::buildRowInstrMap() {
229 for (const Record *CurInstr : InstrDefs) {
230 std::vector<const Init *> KeyValue;
231 const ListInit *RowFields = InstrMapDesc.getRowFields();
232 for (const Init *RowField : RowFields->getElements()) {
233 const RecordVal *RecVal = CurInstr->getValue(Name: RowField);
234 if (RecVal == nullptr)
235 PrintFatalError(ErrorLoc: CurInstr->getLoc(),
236 Msg: "No value " + RowField->getAsString() + " found in \"" +
237 CurInstr->getName() +
238 "\" instruction description.");
239 const Init *CurInstrVal = RecVal->getValue();
240 KeyValue.push_back(x: CurInstrVal);
241 }
242
243 // Collect key instructions into KeyInstrVec. Later, these instructions are
244 // processed to assign column position to the instructions sharing
245 // their KeyValue in RowInstrMap.
246 if (isKeyColInstr(CurInstr))
247 KeyInstrVec.push_back(x: CurInstr);
248
249 RowInstrMap[KeyValue].push_back(x: CurInstr);
250 }
251}
252
253//===----------------------------------------------------------------------===//
254// Return true if an instruction is a KeyCol instruction.
255//===----------------------------------------------------------------------===//
256
257bool MapTableEmitter::isKeyColInstr(const Record *CurInstr) {
258 const ListInit *ColFields = InstrMapDesc.getColFields();
259 const ListInit *KeyCol = InstrMapDesc.getKeyCol();
260
261 // Check if the instruction is a KeyCol instruction.
262 bool MatchFound = true;
263 for (unsigned J = 0, EndCf = ColFields->size(); (J < EndCf) && MatchFound;
264 J++) {
265 const RecordVal *ColFieldName =
266 CurInstr->getValue(Name: ColFields->getElement(Idx: J));
267 std::string CurInstrVal = ColFieldName->getValue()->getAsUnquotedString();
268 std::string KeyColValue = KeyCol->getElement(Idx: J)->getAsUnquotedString();
269 MatchFound = CurInstrVal == KeyColValue;
270 }
271 return MatchFound;
272}
273
274//===----------------------------------------------------------------------===//
275// Build a map to link key instructions with the column instructions arranged
276// according to their column positions.
277//===----------------------------------------------------------------------===//
278
279void MapTableEmitter::buildMapTable() {
280 // Find column instructions for a given key based on the ColField
281 // constraints.
282 ArrayRef<const ListInit *> ValueCols = InstrMapDesc.getValueCols();
283 unsigned NumOfCols = ValueCols.size();
284 for (const Record *CurKeyInstr : KeyInstrVec) {
285 std::vector<const Record *> ColInstrVec(NumOfCols);
286
287 // Find the column instruction based on the constraints for the column.
288 for (unsigned ColIdx = 0; ColIdx < NumOfCols; ColIdx++) {
289 const ListInit *CurValueCol = ValueCols[ColIdx];
290 const Record *ColInstr = getInstrForColumn(KeyInstr: CurKeyInstr, CurValueCol);
291 ColInstrVec[ColIdx] = ColInstr;
292 }
293 MapTable[CurKeyInstr] = ColInstrVec;
294 }
295}
296
297//===----------------------------------------------------------------------===//
298// Find column instruction based on the constraints for that column.
299//===----------------------------------------------------------------------===//
300
301const Record *MapTableEmitter::getInstrForColumn(const Record *KeyInstr,
302 const ListInit *CurValueCol) {
303 const ListInit *RowFields = InstrMapDesc.getRowFields();
304 std::vector<const Init *> KeyValue;
305
306 // Construct KeyValue using KeyInstr's values for RowFields.
307 for (const Init *RowField : RowFields->getElements()) {
308 const Init *KeyInstrVal = KeyInstr->getValue(Name: RowField)->getValue();
309 KeyValue.push_back(x: KeyInstrVal);
310 }
311
312 // Get all the instructions that share the same KeyValue as the KeyInstr
313 // in RowInstrMap. We search through these instructions to find a match
314 // for the current column, i.e., the instruction which has the same values
315 // as CurValueCol for all the fields in ColFields.
316 ArrayRef<const Record *> RelatedInstrVec = RowInstrMap[KeyValue];
317
318 const ListInit *ColFields = InstrMapDesc.getColFields();
319 const Record *MatchInstr = nullptr;
320
321 for (const Record *CurInstr : RelatedInstrVec) {
322 bool MatchFound = true;
323 for (unsigned J = 0, EndCf = ColFields->size(); (J < EndCf) && MatchFound;
324 J++) {
325 const Init *ColFieldJ = ColFields->getElement(Idx: J);
326 const Init *CurInstrInit = CurInstr->getValue(Name: ColFieldJ)->getValue();
327 std::string CurInstrVal = CurInstrInit->getAsUnquotedString();
328 const Init *ColFieldJVallue = CurValueCol->getElement(Idx: J);
329 MatchFound = CurInstrVal == ColFieldJVallue->getAsUnquotedString();
330 }
331
332 if (MatchFound) {
333 if (MatchInstr) {
334 // Already had a match
335 // Error if multiple matches are found for a column.
336 std::string KeyValueStr;
337 for (const Init *Value : KeyValue) {
338 if (!KeyValueStr.empty())
339 KeyValueStr += ", ";
340 KeyValueStr += Value->getAsString();
341 }
342
343 PrintFatalError(Msg: "Multiple matches found for `" + KeyInstr->getName() +
344 "', for the relation `" + InstrMapDesc.getName() +
345 "', row fields [" + KeyValueStr + "], column `" +
346 CurValueCol->getAsString() + "'");
347 }
348 MatchInstr = CurInstr;
349 }
350 }
351 return MatchInstr;
352}
353
354//===----------------------------------------------------------------------===//
355// Emit one table per relation. Only instructions with a valid relation of a
356// given type are included in the table sorted by their enum values (opcodes).
357// Binary search is used for locating instructions in the table.
358//===----------------------------------------------------------------------===//
359
360unsigned MapTableEmitter::emitBinSearchTable(raw_ostream &OS) {
361 ArrayRef<const CodeGenInstruction *> NumberedInstructions =
362 Target.getInstructions();
363 StringRef Namespace = Target.getInstNamespace();
364 ArrayRef<const ListInit *> ValueCols = InstrMapDesc.getValueCols();
365 unsigned NumCol = ValueCols.size();
366 unsigned TableSize = 0;
367
368 OS << " using namespace " << Namespace << ";\n";
369 // Number of columns in the table are NumCol+1 because key instructions are
370 // emitted as first column.
371 for (const CodeGenInstruction *Inst : NumberedInstructions) {
372 const Record *CurInstr = Inst->TheDef;
373 ArrayRef<const Record *> ColInstrs = MapTable[CurInstr];
374 if (ColInstrs.empty())
375 continue;
376 std::string OutStr;
377 bool RelExists = false;
378 for (const Record *ColInstr : ColInstrs) {
379 if (ColInstr) {
380 RelExists = true;
381 OutStr += ", ";
382 OutStr += ColInstr->getName();
383 } else {
384 OutStr += ", (uint16_t)-1U";
385 }
386 }
387
388 if (RelExists) {
389 if (TableSize == 0)
390 OS << " static constexpr uint16_t Table[][" << NumCol + 1 << "] = {\n";
391 OS << " { " << CurInstr->getName() << OutStr << " },\n";
392 ++TableSize;
393 }
394 }
395
396 if (TableSize != 0)
397 OS << " }; // End of Table\n\n";
398 return TableSize;
399}
400
401//===----------------------------------------------------------------------===//
402// Emit binary search algorithm as part of the functions used to query
403// relation tables.
404//===----------------------------------------------------------------------===//
405
406void MapTableEmitter::emitBinSearch(raw_ostream &OS, unsigned TableSize) {
407 if (TableSize == 0) {
408 OS << " return -1;\n";
409 return;
410 }
411
412 OS << " unsigned mid;\n";
413 OS << " unsigned start = 0;\n";
414 OS << " unsigned end = " << TableSize << ";\n";
415 OS << " while (start < end) {\n";
416 OS << " mid = start + (end - start) / 2;\n";
417 OS << " if (Opcode == Table[mid][0]) \n";
418 OS << " break;\n";
419 OS << " if (Opcode < Table[mid][0])\n";
420 OS << " end = mid;\n";
421 OS << " else\n";
422 OS << " start = mid + 1;\n";
423 OS << " }\n";
424 OS << " if (start == end)\n";
425 OS << " return -1; // Instruction doesn't exist in this table.\n\n";
426}
427
428//===----------------------------------------------------------------------===//
429// Emit functions to query relation tables.
430//===----------------------------------------------------------------------===//
431
432void MapTableEmitter::emitMapFuncBody(raw_ostream &OS, unsigned TableSize) {
433 const ListInit *ColFields = InstrMapDesc.getColFields();
434 ArrayRef<const ListInit *> ValueCols = InstrMapDesc.getValueCols();
435
436 // Emit binary search algorithm to locate instructions in the
437 // relation table. If found, return opcode value from the appropriate column
438 // of the table.
439 emitBinSearch(OS, TableSize);
440 if (TableSize == 0)
441 return;
442
443 if (ValueCols.size() > 1) {
444 for (unsigned I = 0, E = ValueCols.size(); I < E; I++) {
445 const ListInit *ColumnI = ValueCols[I];
446 OS << " if (";
447 for (unsigned J = 0, ColSize = ColumnI->size(); J < ColSize; ++J) {
448 std::string ColName = ColFields->getElement(Idx: J)->getAsUnquotedString();
449 OS << "in" << ColName;
450 OS << " == ";
451 OS << ColName << "_" << ColumnI->getElement(Idx: J)->getAsUnquotedString();
452 if (J < ColumnI->size() - 1)
453 OS << " && ";
454 }
455 OS << ")\n";
456 OS << " return Table[mid][" << I + 1 << "];\n";
457 }
458 OS << " return -1;";
459 } else {
460 OS << " return Table[mid][1];\n";
461 }
462}
463
464//===----------------------------------------------------------------------===//
465// Emit relation tables and the functions to query them.
466//===----------------------------------------------------------------------===//
467
468void MapTableEmitter::emitTablesWithFunc(raw_ostream &OS) {
469 // Emit function name and the input parameters : mostly opcode value of the
470 // current instruction. However, if a table has multiple columns (more than 2
471 // since first column is used for the key instructions), then we also need
472 // to pass another input to indicate the column to be selected.
473
474 const ListInit *ColFields = InstrMapDesc.getColFields();
475 ArrayRef<const ListInit *> ValueCols = InstrMapDesc.getValueCols();
476 OS << "// " << InstrMapDesc.getName() << "\nLLVM_READONLY\n";
477 OS << "int " << InstrMapDesc.getName() << "(uint16_t Opcode";
478 if (ValueCols.size() > 1) {
479 for (const Init *CF : ColFields->getElements()) {
480 std::string ColName = CF->getAsUnquotedString();
481 OS << ", enum " << ColName << " in" << ColName;
482 }
483 }
484 OS << ") {\n";
485
486 // Emit map table.
487 unsigned TableSize = emitBinSearchTable(OS);
488
489 // Emit rest of the function body.
490 emitMapFuncBody(OS, TableSize);
491
492 OS << "}\n\n";
493}
494
495//===----------------------------------------------------------------------===//
496// Emit enums for the column fields across all the instruction maps.
497//===----------------------------------------------------------------------===//
498
499static void emitEnums(raw_ostream &OS, const RecordKeeper &Records) {
500 std::map<std::string, SetVector<const Init *>> ColFieldValueMap;
501
502 // Iterate over all InstrMapping records and create a map between column
503 // fields and their possible values across all records.
504 for (const Record *CurMap :
505 Records.getAllDerivedDefinitions(ClassName: "InstrMapping")) {
506 const ListInit *ColFields = CurMap->getValueAsListInit(FieldName: "ColFields");
507 const ListInit *List = CurMap->getValueAsListInit(FieldName: "ValueCols");
508 std::vector<const ListInit *> ValueCols;
509
510 for (const Init *Elem : *List) {
511 const auto *ListJ = cast<ListInit>(Val: Elem);
512
513 if (ListJ->size() != ColFields->size())
514 PrintFatalError(Msg: "Record `" + CurMap->getName() +
515 "', field "
516 "`ValueCols' entries don't match with the entries in "
517 "'ColFields' !");
518 ValueCols.push_back(x: ListJ);
519 }
520
521 for (unsigned J = 0, EndCf = ColFields->size(); J < EndCf; J++) {
522 std::string ColName = ColFields->getElement(Idx: J)->getAsUnquotedString();
523 auto &MapEntry = ColFieldValueMap[ColName];
524 for (const ListInit *List : ValueCols)
525 MapEntry.insert(X: List->getElement(Idx: J));
526 }
527 }
528
529 for (auto &[EnumName, FieldValues] : ColFieldValueMap) {
530 // Emit enumerated values for the column fields.
531 OS << "enum " << EnumName << " {\n";
532 ListSeparator LS(",\n");
533 for (const Init *Field : FieldValues)
534 OS << LS << " " << EnumName << "_" << Field->getAsUnquotedString();
535 OS << "\n};\n\n";
536 }
537}
538
539//===----------------------------------------------------------------------===//
540// Parse 'InstrMapping' records and use the information to form relationship
541// between instructions. These relations are emitted as tables along with the
542// functions to query them.
543//===----------------------------------------------------------------------===//
544void llvm::EmitMapTable(const RecordKeeper &Records, raw_ostream &OS) {
545 CodeGenTarget Target(Records);
546 StringRef NameSpace = Target.getInstNamespace();
547 ArrayRef<const Record *> InstrMapVec =
548 Records.getAllDerivedDefinitions(ClassName: "InstrMapping");
549
550 if (InstrMapVec.empty())
551 return;
552
553 IfDefEmitter IfDef(OS, "GET_INSTRMAP_INFO");
554 NamespaceEmitter NS(OS, ("llvm::" + NameSpace).str());
555
556 // Emit coulumn field names and their values as enums.
557 emitEnums(OS, Records);
558
559 // Iterate over all instruction mapping records and construct relationship
560 // maps based on the information specified there.
561 //
562 for (const Record *CurMap : InstrMapVec) {
563 MapTableEmitter IMap(Target, Records, CurMap);
564
565 // Build RowInstrMap to group instructions based on their values for
566 // RowFields. In the process, also collect key instructions into
567 // KeyInstrVec.
568 IMap.buildRowInstrMap();
569
570 // Build MapTable to map key instructions with the corresponding column
571 // instructions.
572 IMap.buildMapTable();
573
574 // Emit map tables and the functions to query them.
575 IMap.emitTablesWithFunc(OS);
576 }
577}
578