DAGISelMatcherEmitter.cpp revision c84edb7bdd345db280c908583d55bdf4e670a225 
1//===- DAGISelMatcherEmitter.cpp - Matcher Emitter ------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains code to generate C++ code a matcher.
11//
12//===----------------------------------------------------------------------===//
13
14#include "DAGISelMatcher.h"
15#include "CodeGenDAGPatterns.h"
16#include "Record.h"
17#include "llvm/ADT/DenseMap.h"
18#include "llvm/ADT/SmallString.h"
19#include "llvm/ADT/StringMap.h"
20#include "llvm/Support/FormattedStream.h"
21using namespace llvm;
22
23namespace {
24enum {
25  CommentIndent = 30
26};
27}
28
29/// ClassifyInt - Classify an integer by size, return '1','2','4','8' if this
30/// fits in 1, 2, 4, or 8 sign extended bytes.
31static char ClassifyInt(int64_t Val) {
32  if (Val == int8_t(Val))  return '1';
33  if (Val == int16_t(Val)) return '2';
34  if (Val == int32_t(Val)) return '4';
35  return '8';
36}
37
38/// EmitInt - Emit the specified integer, returning the number of bytes emitted.
39static unsigned EmitInt(int64_t Val, formatted_raw_ostream &OS) {
40  unsigned BytesEmitted = 1;
41  OS << (int)(unsigned char)Val << ", ";
42  if (Val == int8_t(Val)) {
43    OS << '\n';
44    return BytesEmitted;
45  }
46
47  OS << (int)(unsigned char)(Val >> 8) << ", ";
48  ++BytesEmitted;
49
50  if (Val != int16_t(Val)) {
51    OS << (int)(unsigned char)(Val >> 16) << ", "
52       << (int)(unsigned char)(Val >> 24) << ", ";
53    BytesEmitted += 2;
54
55    if (Val != int32_t(Val)) {
56      OS << (int)(unsigned char)(Val >> 32) << ", "
57         << (int)(unsigned char)(Val >> 40) << ", "
58         << (int)(unsigned char)(Val >> 48) << ", "
59         << (int)(unsigned char)(Val >> 56) << ", ";
60      BytesEmitted += 4;
61    }
62  }
63
64  OS.PadToColumn(CommentIndent) << "// " << Val << " aka 0x";
65  OS.write_hex(Val) << '\n';
66  return BytesEmitted;
67}
68
69namespace {
70class MatcherTableEmitter {
71  StringMap<unsigned> NodePredicateMap, PatternPredicateMap;
72  std::vector<std::string> NodePredicates, PatternPredicates;
73
74  DenseMap<const ComplexPattern*, unsigned> ComplexPatternMap;
75  std::vector<const ComplexPattern*> ComplexPatterns;
76
77
78  DenseMap<Record*, unsigned> NodeXFormMap;
79  std::vector<const Record*> NodeXForms;
80
81public:
82  MatcherTableEmitter() {}
83
84  unsigned EmitMatcherList(const MatcherNode *N, unsigned Indent,
85                           unsigned StartIdx, formatted_raw_ostream &OS);
86
87  void EmitPredicateFunctions(formatted_raw_ostream &OS);
88private:
89  unsigned EmitMatcher(const MatcherNode *N, unsigned Indent,
90                       formatted_raw_ostream &OS);
91
92  unsigned getNodePredicate(StringRef PredName) {
93    unsigned &Entry = NodePredicateMap[PredName];
94    if (Entry == 0) {
95      NodePredicates.push_back(PredName.str());
96      Entry = NodePredicates.size();
97    }
98    return Entry-1;
99  }
100  unsigned getPatternPredicate(StringRef PredName) {
101    unsigned &Entry = PatternPredicateMap[PredName];
102    if (Entry == 0) {
103      PatternPredicates.push_back(PredName.str());
104      Entry = PatternPredicates.size();
105    }
106    return Entry-1;
107  }
108
109  unsigned getComplexPat(const ComplexPattern &P) {
110    unsigned &Entry = ComplexPatternMap[&P];
111    if (Entry == 0) {
112      ComplexPatterns.push_back(&P);
113      Entry = ComplexPatterns.size();
114    }
115    return Entry-1;
116  }
117
118  unsigned getNodeXFormID(Record *Rec) {
119    unsigned &Entry = NodeXFormMap[Rec];
120    if (Entry == 0) {
121      NodeXForms.push_back(Rec);
122      Entry = NodeXForms.size();
123    }
124    return Entry-1;
125  }
126
127};
128} // end anonymous namespace.
129
130/// EmitVBRValue - Emit the specified value as a VBR, returning the number of
131/// bytes emitted.
132static unsigned EmitVBRValue(unsigned Val, raw_ostream &OS) {
133  if (Val <= 127) {
134    OS << Val << ", ";
135    return 1;
136  }
137
138  unsigned InVal = Val;
139  unsigned NumBytes = 0;
140  while (Val >= 128) {
141    OS << (Val&127) << "|128,";
142    Val >>= 7;
143    ++NumBytes;
144  }
145  OS << Val << "/*" << InVal << "*/, ";
146  return NumBytes+1;
147}
148
149/// EmitMatcherOpcodes - Emit bytes for the specified matcher and return
150/// the number of bytes emitted.
151unsigned MatcherTableEmitter::
152EmitMatcher(const MatcherNode *N, unsigned Indent, formatted_raw_ostream &OS) {
153  OS.PadToColumn(Indent*2);
154
155  switch (N->getKind()) {
156  case MatcherNode::Push: assert(0 && "Should be handled by caller");
157  case MatcherNode::RecordNode:
158    OS << "OPC_RecordNode,";
159    OS.PadToColumn(CommentIndent) << "// "
160       << cast<RecordMatcherNode>(N)->getWhatFor() << '\n';
161    return 1;
162
163  case MatcherNode::RecordChild:
164    OS << "OPC_RecordChild" << cast<RecordChildMatcherNode>(N)->getChildNo()
165       << ',';
166    OS.PadToColumn(CommentIndent) << "// "
167      << cast<RecordChildMatcherNode>(N)->getWhatFor() << '\n';
168    return 1;
169
170  case MatcherNode::RecordMemRef:
171    OS << "OPC_RecordMemRef,\n";
172    return 1;
173
174  case MatcherNode::CaptureFlagInput:
175    OS << "OPC_CaptureFlagInput,\n";
176    return 1;
177
178  case MatcherNode::MoveChild:
179    OS << "OPC_MoveChild, "
180       << cast<MoveChildMatcherNode>(N)->getChildNo() << ",\n";
181    return 2;
182
183  case MatcherNode::MoveParent:
184    OS << "OPC_MoveParent,\n";
185    return 1;
186
187  case MatcherNode::CheckSame:
188    OS << "OPC_CheckSame, "
189       << cast<CheckSameMatcherNode>(N)->getMatchNumber() << ",\n";
190    return 2;
191
192  case MatcherNode::CheckPatternPredicate: {
193    StringRef Pred = cast<CheckPatternPredicateMatcherNode>(N)->getPredicate();
194    OS << "OPC_CheckPatternPredicate, " << getPatternPredicate(Pred) << ',';
195    OS.PadToColumn(CommentIndent) << "// " << Pred << '\n';
196    return 2;
197  }
198  case MatcherNode::CheckPredicate: {
199    StringRef Pred = cast<CheckPredicateMatcherNode>(N)->getPredicateName();
200    OS << "OPC_CheckPredicate, " << getNodePredicate(Pred) << ',';
201    OS.PadToColumn(CommentIndent) << "// " << Pred << '\n';
202    return 2;
203  }
204
205  case MatcherNode::CheckOpcode:
206    OS << "OPC_CheckOpcode, "
207       << cast<CheckOpcodeMatcherNode>(N)->getOpcodeName() << ",\n";
208    return 2;
209
210  case MatcherNode::CheckMultiOpcode: {
211    const CheckMultiOpcodeMatcherNode *CMO=cast<CheckMultiOpcodeMatcherNode>(N);
212    OS << "OPC_CheckMultiOpcode, " << CMO->getNumOpcodeNames() << ", ";
213    for (unsigned i = 0, e = CMO->getNumOpcodeNames(); i != e; ++i)
214      OS << CMO->getOpcodeName(i) << ", ";
215    OS << '\n';
216    return 2 + CMO->getNumOpcodeNames();
217  }
218
219  case MatcherNode::CheckType:
220    OS << "OPC_CheckType, "
221       << getEnumName(cast<CheckTypeMatcherNode>(N)->getType()) << ",\n";
222    return 2;
223
224  case MatcherNode::CheckInteger: {
225    int64_t Val = cast<CheckIntegerMatcherNode>(N)->getValue();
226    OS << "OPC_CheckInteger" << ClassifyInt(Val) << ", ";
227    return EmitInt(Val, OS)+1;
228  }
229  case MatcherNode::CheckCondCode:
230    OS << "OPC_CheckCondCode, ISD::"
231       << cast<CheckCondCodeMatcherNode>(N)->getCondCodeName() << ",\n";
232    return 2;
233
234  case MatcherNode::CheckValueType:
235    OS << "OPC_CheckValueType, MVT::"
236       << cast<CheckValueTypeMatcherNode>(N)->getTypeName() << ",\n";
237    return 2;
238
239  case MatcherNode::CheckComplexPat: {
240    const ComplexPattern &Pattern =
241      cast<CheckComplexPatMatcherNode>(N)->getPattern();
242    OS << "OPC_CheckComplexPat, " << getComplexPat(Pattern) << ',';
243    OS.PadToColumn(CommentIndent) << "// " << Pattern.getSelectFunc();
244    OS << ": " << Pattern.getNumOperands() << " operands";
245    if (Pattern.hasProperty(SDNPHasChain))
246      OS << " + chain result and input";
247    OS << '\n';
248    return 2;
249  }
250
251  case MatcherNode::CheckAndImm: {
252    int64_t Val = cast<CheckAndImmMatcherNode>(N)->getValue();
253    OS << "OPC_CheckAndImm" << ClassifyInt(Val) << ", ";
254    return EmitInt(Val, OS)+1;
255  }
256
257  case MatcherNode::CheckOrImm: {
258    int64_t Val = cast<CheckOrImmMatcherNode>(N)->getValue();
259    OS << "OPC_CheckOrImm" << ClassifyInt(Val) << ", ";
260    return EmitInt(Val, OS)+1;
261  }
262  case MatcherNode::CheckFoldableChainNode:
263    OS << "OPC_CheckFoldableChainNode,\n";
264    return 1;
265  case MatcherNode::CheckChainCompatible:
266    OS << "OPC_CheckChainCompatible, "
267       << cast<CheckChainCompatibleMatcherNode>(N)->getPreviousOp() << ",\n";
268    return 2;
269
270  case MatcherNode::EmitInteger: {
271    int64_t Val = cast<EmitIntegerMatcherNode>(N)->getValue();
272    OS << "OPC_EmitInteger" << ClassifyInt(Val) << ", "
273       << getEnumName(cast<EmitIntegerMatcherNode>(N)->getVT()) << ", ";
274    return EmitInt(Val, OS)+2;
275  }
276  case MatcherNode::EmitStringInteger: {
277    const std::string &Val = cast<EmitStringIntegerMatcherNode>(N)->getValue();
278    // These should always fit into one byte.
279    OS << "OPC_EmitInteger1, "
280      << getEnumName(cast<EmitStringIntegerMatcherNode>(N)->getVT()) << ", "
281      << Val << ",\n";
282    return 3;
283  }
284
285  case MatcherNode::EmitRegister:
286    OS << "OPC_EmitRegister, "
287       << getEnumName(cast<EmitRegisterMatcherNode>(N)->getVT()) << ", ";
288    if (Record *R = cast<EmitRegisterMatcherNode>(N)->getReg())
289      OS << getQualifiedName(R) << ",\n";
290    else
291      OS << "0 /*zero_reg*/,\n";
292    return 3;
293
294  case MatcherNode::EmitConvertToTarget:
295    OS << "OPC_EmitConvertToTarget, "
296       << cast<EmitConvertToTargetMatcherNode>(N)->getSlot() << ",\n";
297    return 2;
298
299  case MatcherNode::EmitMergeInputChains: {
300    const EmitMergeInputChainsMatcherNode *MN =
301      cast<EmitMergeInputChainsMatcherNode>(N);
302    OS << "OPC_EmitMergeInputChains, " << MN->getNumNodes() << ", ";
303    for (unsigned i = 0, e = MN->getNumNodes(); i != e; ++i)
304      OS << MN->getNode(i) << ", ";
305    OS << '\n';
306    return 2+MN->getNumNodes();
307  }
308  case MatcherNode::EmitCopyToReg:
309    OS << "OPC_EmitCopyToReg, "
310       << cast<EmitCopyToRegMatcherNode>(N)->getSrcSlot() << ", "
311       << getQualifiedName(cast<EmitCopyToRegMatcherNode>(N)->getDestPhysReg())
312       << ",\n";
313    return 3;
314  case MatcherNode::EmitNodeXForm: {
315    const EmitNodeXFormMatcherNode *XF = cast<EmitNodeXFormMatcherNode>(N);
316    OS << "OPC_EmitNodeXForm, " << getNodeXFormID(XF->getNodeXForm()) << ", "
317       << XF->getSlot() << ',';
318    OS.PadToColumn(CommentIndent) << "// "<<XF->getNodeXForm()->getName()<<'\n';
319    return 3;
320  }
321
322  case MatcherNode::EmitNode: {
323    const EmitNodeMatcherNode *EN = cast<EmitNodeMatcherNode>(N);
324    OS << "OPC_EmitNode, TARGET_OPCODE(" << EN->getOpcodeName() << "), 0";
325
326    if (EN->hasChain())   OS << "|OPFL_Chain";
327    if (EN->hasFlag())    OS << "|OPFL_Flag";
328    if (EN->hasMemRefs()) OS << "|OPFL_MemRefs";
329    if (EN->getNumFixedArityOperands() != -1)
330      OS << "|OPFL_Variadic" << EN->getNumFixedArityOperands();
331    OS << ",\n";
332
333    OS.PadToColumn(Indent*2+4) << EN->getNumVTs() << "/*#VTs*/, ";
334    for (unsigned i = 0, e = EN->getNumVTs(); i != e; ++i)
335      OS << getEnumName(EN->getVT(i)) << ", ";
336
337    OS << EN->getNumOperands() << "/*#Ops*/, ";
338    unsigned NumOperandBytes = 0;
339    for (unsigned i = 0, e = EN->getNumOperands(); i != e; ++i) {
340      // We emit the operand numbers in VBR encoded format, in case the number
341      // is too large to represent with a byte.
342      NumOperandBytes += EmitVBRValue(EN->getOperand(i), OS);
343    }
344    OS << '\n';
345    return 6+EN->getNumVTs()+NumOperandBytes;
346  }
347  case MatcherNode::MarkFlagResults: {
348    const MarkFlagResultsMatcherNode *CFR = cast<MarkFlagResultsMatcherNode>(N);
349    OS << "OPC_MarkFlagResults, " << CFR->getNumNodes() << ", ";
350    unsigned NumOperandBytes = 0;
351    for (unsigned i = 0, e = CFR->getNumNodes(); i != e; ++i)
352      NumOperandBytes += EmitVBRValue(CFR->getNode(i), OS);
353    OS << '\n';
354    return 2+NumOperandBytes;
355  }
356  case MatcherNode::CompleteMatch: {
357    const CompleteMatchMatcherNode *CM = cast<CompleteMatchMatcherNode>(N);
358    OS << "OPC_CompleteMatch, " << CM->getNumResults() << ", ";
359    unsigned NumResultBytes = 0;
360    for (unsigned i = 0, e = CM->getNumResults(); i != e; ++i)
361      NumResultBytes += EmitVBRValue(CM->getResult(i), OS);
362    OS << '\n';
363    OS.PadToColumn(Indent*2) << "// Src: "
364      << *CM->getPattern().getSrcPattern() << '\n';
365    OS.PadToColumn(Indent*2) << "// Dst: "
366      << *CM->getPattern().getDstPattern() << '\n';
367    return 2 + NumResultBytes;
368  }
369  }
370  assert(0 && "Unreachable");
371  return 0;
372}
373
374/// EmitMatcherList - Emit the bytes for the specified matcher subtree.
375unsigned MatcherTableEmitter::
376EmitMatcherList(const MatcherNode *N, unsigned Indent, unsigned CurrentIdx,
377                formatted_raw_ostream &OS) {
378  unsigned Size = 0;
379  while (N) {
380    // Push is a special case since it is binary.
381    if (const PushMatcherNode *PMN = dyn_cast<PushMatcherNode>(N)) {
382      // We need to encode the child and the offset of the failure code before
383      // emitting either of them.  Handle this by buffering the output into a
384      // string while we get the size.
385      SmallString<128> TmpBuf;
386      unsigned NextSize;
387      {
388        raw_svector_ostream OS(TmpBuf);
389        formatted_raw_ostream FOS(OS);
390        NextSize = EmitMatcherList(cast<PushMatcherNode>(N)->getNext(),
391                                   Indent+1, CurrentIdx+2, FOS);
392      }
393
394      // In the unlikely event that we have something too big to emit with a
395      // one byte offset, regenerate it with a two-byte one.
396      if (NextSize > 255) {
397        TmpBuf.clear();
398        raw_svector_ostream OS(TmpBuf);
399        formatted_raw_ostream FOS(OS);
400        NextSize = EmitMatcherList(cast<PushMatcherNode>(N)->getNext(),
401                                   Indent+1, CurrentIdx+3, FOS);
402        if (NextSize > 65535) {
403          errs() <<
404            "Tblgen internal error: can't handle pattern this complex yet\n";
405          exit(1);
406        }
407      }
408
409      OS << "/*" << CurrentIdx << "*/";
410      OS.PadToColumn(Indent*2);
411
412      if (NextSize < 256)
413        OS << "OPC_Push, " << NextSize << ",\n";
414      else
415        OS << "OPC_Push2, " << (NextSize&255) << ", " << (NextSize>>8) << ",\n";
416      OS << TmpBuf.str();
417
418      Size += 2+NextSize;
419      CurrentIdx += 2+NextSize;
420      N = PMN->getFailure();
421      continue;
422    }
423
424    OS << "/*" << CurrentIdx << "*/";
425    unsigned MatcherSize = EmitMatcher(N, Indent, OS);
426    Size += MatcherSize;
427    CurrentIdx += MatcherSize;
428
429    // If there are other nodes in this list, iterate to them, otherwise we're
430    // done.
431    N = N->getNext();
432  }
433  return Size;
434}
435
436void MatcherTableEmitter::EmitPredicateFunctions(formatted_raw_ostream &OS) {
437  // FIXME: Don't build off the DAGISelEmitter's predicates, emit them directly
438  // here into the case stmts.
439
440  // Emit pattern predicates.
441  OS << "bool CheckPatternPredicate(unsigned PredNo) const {\n";
442  OS << "  switch (PredNo) {\n";
443  OS << "  default: assert(0 && \"Invalid predicate in table?\");\n";
444  for (unsigned i = 0, e = PatternPredicates.size(); i != e; ++i)
445    OS << "  case " << i << ": return "  << PatternPredicates[i] << ";\n";
446  OS << "  }\n";
447  OS << "}\n\n";
448
449  // Emit Node predicates.
450  OS << "bool CheckNodePredicate(SDNode *N, unsigned PredNo) const {\n";
451  OS << "  switch (PredNo) {\n";
452  OS << "  default: assert(0 && \"Invalid predicate in table?\");\n";
453  for (unsigned i = 0, e = NodePredicates.size(); i != e; ++i)
454    OS << "  case " << i << ": return "  << NodePredicates[i] << "(N);\n";
455  OS << "  }\n";
456  OS << "}\n\n";
457
458  // Emit CompletePattern matchers.
459  // FIXME: This should be const.
460  OS << "bool CheckComplexPattern(SDNode *Root, SDValue N,\n";
461  OS << "      unsigned PatternNo, SmallVectorImpl<SDValue> &Result) {\n";
462  OS << "  switch (PatternNo) {\n";
463  OS << "  default: assert(0 && \"Invalid pattern # in table?\");\n";
464  for (unsigned i = 0, e = ComplexPatterns.size(); i != e; ++i) {
465    const ComplexPattern &P = *ComplexPatterns[i];
466    unsigned NumOps = P.getNumOperands();
467
468    if (P.hasProperty(SDNPHasChain))
469      ++NumOps;  // Get the chained node too.
470
471    OS << "  case " << i << ":\n";
472    OS << "    Result.resize(Result.size()+" << NumOps << ");\n";
473    OS << "    return "  << P.getSelectFunc();
474
475    // FIXME: Temporary hack until old isel dies.
476    if (P.hasProperty(SDNPHasChain))
477      OS << "XXX";
478
479    OS << "(Root, N";
480    for (unsigned i = 0; i != NumOps; ++i)
481      OS << ", Result[Result.size()-" << (NumOps-i) << ']';
482    OS << ");\n";
483  }
484  OS << "  }\n";
485  OS << "}\n\n";
486
487  // Emit SDNodeXForm handlers.
488  // FIXME: This should be const.
489  OS << "SDValue RunSDNodeXForm(SDValue V, unsigned XFormNo) {\n";
490  OS << "  switch (XFormNo) {\n";
491  OS << "  default: assert(0 && \"Invalid xform # in table?\");\n";
492
493  // FIXME: The node xform could take SDValue's instead of SDNode*'s.
494  for (unsigned i = 0, e = NodeXForms.size(); i != e; ++i)
495    OS << "  case " << i << ": return Transform_" << NodeXForms[i]->getName()
496       << "(V.getNode());\n";
497  OS << "  }\n";
498  OS << "}\n\n";
499}
500
501
502void llvm::EmitMatcherTable(const MatcherNode *Matcher, raw_ostream &O) {
503  formatted_raw_ostream OS(O);
504
505  OS << "// The main instruction selector code.\n";
506  OS << "SDNode *SelectCode(SDNode *N) {\n";
507
508  MatcherTableEmitter MatcherEmitter;
509
510  OS << "  // Opcodes are emitted as 2 bytes, TARGET_OPCODE handles this.\n";
511  OS << "  #define TARGET_OPCODE(X) X & 255, unsigned(X) >> 8\n";
512  OS << "  static const unsigned char MatcherTable[] = {\n";
513  unsigned TotalSize = MatcherEmitter.EmitMatcherList(Matcher, 5, 0, OS);
514  OS << "    0\n  }; // Total Array size is " << (TotalSize+1) << " bytes\n\n";
515  OS << "  #undef TARGET_OPCODE\n";
516  OS << "  return SelectCodeCommon(N, MatcherTable,sizeof(MatcherTable));\n}\n";
517  OS << "\n";
518
519  // Next up, emit the function for node and pattern predicates:
520  MatcherEmitter.EmitPredicateFunctions(OS);
521}
522