DAGISelMatcherEmitter.cpp revision 3e22f2d489d6d1cff5123ae606cdea10d2c631f6 
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/// EmitMatcherOpcodes - Emit bytes for the specified matcher and return
131/// the number of bytes emitted.
132unsigned MatcherTableEmitter::
133EmitMatcher(const MatcherNode *N, unsigned Indent, formatted_raw_ostream &OS) {
134  OS.PadToColumn(Indent*2);
135
136  switch (N->getKind()) {
137  case MatcherNode::Push: assert(0 && "Should be handled by caller");
138  case MatcherNode::RecordNode:
139    OS << "OPC_RecordNode,";
140    OS.PadToColumn(CommentIndent) << "// "
141       << cast<RecordMatcherNode>(N)->getWhatFor() << '\n';
142    return 1;
143
144  case MatcherNode::RecordMemRef:
145    OS << "OPC_RecordMemRef,\n";
146    return 1;
147
148  case MatcherNode::CaptureFlagInput:
149    OS << "OPC_CaptureFlagInput,\n";
150    return 1;
151
152  case MatcherNode::MoveChild:
153    OS << "OPC_MoveChild, "
154       << cast<MoveChildMatcherNode>(N)->getChildNo() << ",\n";
155    return 2;
156
157  case MatcherNode::MoveParent:
158    OS << "OPC_MoveParent,\n";
159    return 1;
160
161  case MatcherNode::CheckSame:
162    OS << "OPC_CheckSame, "
163       << cast<CheckSameMatcherNode>(N)->getMatchNumber() << ",\n";
164    return 2;
165
166  case MatcherNode::CheckPatternPredicate: {
167    StringRef Pred = cast<CheckPatternPredicateMatcherNode>(N)->getPredicate();
168    OS << "OPC_CheckPatternPredicate, " << getPatternPredicate(Pred) << ',';
169    OS.PadToColumn(CommentIndent) << "// " << Pred << '\n';
170    return 2;
171  }
172  case MatcherNode::CheckPredicate: {
173    StringRef Pred = cast<CheckPredicateMatcherNode>(N)->getPredicateName();
174    OS << "OPC_CheckPredicate, " << getNodePredicate(Pred) << ',';
175    OS.PadToColumn(CommentIndent) << "// " << Pred << '\n';
176    return 2;
177  }
178
179  case MatcherNode::CheckOpcode:
180    OS << "OPC_CheckOpcode, "
181       << cast<CheckOpcodeMatcherNode>(N)->getOpcodeName() << ",\n";
182    return 2;
183
184  case MatcherNode::CheckMultiOpcode: {
185    const CheckMultiOpcodeMatcherNode *CMO=cast<CheckMultiOpcodeMatcherNode>(N);
186    OS << "OPC_CheckMultiOpcode, " << CMO->getNumOpcodeNames() << ", ";
187    for (unsigned i = 0, e = CMO->getNumOpcodeNames(); i != e; ++i)
188      OS << CMO->getOpcodeName(i) << ", ";
189    OS << '\n';
190    return 2 + CMO->getNumOpcodeNames();
191  }
192
193  case MatcherNode::CheckType:
194    OS << "OPC_CheckType, "
195       << getEnumName(cast<CheckTypeMatcherNode>(N)->getType()) << ",\n";
196    return 2;
197
198  case MatcherNode::CheckInteger: {
199    int64_t Val = cast<CheckIntegerMatcherNode>(N)->getValue();
200    OS << "OPC_CheckInteger" << ClassifyInt(Val) << ", ";
201    return EmitInt(Val, OS)+1;
202  }
203  case MatcherNode::CheckCondCode:
204    OS << "OPC_CheckCondCode, ISD::"
205       << cast<CheckCondCodeMatcherNode>(N)->getCondCodeName() << ",\n";
206    return 2;
207
208  case MatcherNode::CheckValueType:
209    OS << "OPC_CheckValueType, MVT::"
210       << cast<CheckValueTypeMatcherNode>(N)->getTypeName() << ",\n";
211    return 2;
212
213  case MatcherNode::CheckComplexPat: {
214    const ComplexPattern &Pattern =
215      cast<CheckComplexPatMatcherNode>(N)->getPattern();
216    OS << "OPC_CheckComplexPat, " << getComplexPat(Pattern) << ',';
217    OS.PadToColumn(CommentIndent) << "// " << Pattern.getSelectFunc();
218    OS << ": " << Pattern.getNumOperands() << " operands";
219    if (Pattern.hasProperty(SDNPHasChain))
220      OS << " + chain result and input";
221    OS << '\n';
222    return 2;
223  }
224
225  case MatcherNode::CheckAndImm: {
226    int64_t Val = cast<CheckAndImmMatcherNode>(N)->getValue();
227    OS << "OPC_CheckAndImm" << ClassifyInt(Val) << ", ";
228    return EmitInt(Val, OS)+1;
229  }
230
231  case MatcherNode::CheckOrImm: {
232    int64_t Val = cast<CheckOrImmMatcherNode>(N)->getValue();
233    OS << "OPC_CheckOrImm" << ClassifyInt(Val) << ", ";
234    return EmitInt(Val, OS)+1;
235  }
236  case MatcherNode::CheckFoldableChainNode:
237    OS << "OPC_CheckFoldableChainNode,\n";
238    return 1;
239  case MatcherNode::CheckChainCompatible:
240    OS << "OPC_CheckChainCompatible, "
241       << cast<CheckChainCompatibleMatcherNode>(N)->getPreviousOp() << ",\n";
242    return 2;
243
244  case MatcherNode::EmitInteger: {
245    int64_t Val = cast<EmitIntegerMatcherNode>(N)->getValue();
246    OS << "OPC_EmitInteger" << ClassifyInt(Val) << ", "
247       << getEnumName(cast<EmitIntegerMatcherNode>(N)->getVT()) << ", ";
248    return EmitInt(Val, OS)+2;
249  }
250  case MatcherNode::EmitStringInteger: {
251    const std::string &Val = cast<EmitStringIntegerMatcherNode>(N)->getValue();
252    // These should always fit into one byte.
253    OS << "OPC_EmitInteger1, "
254      << getEnumName(cast<EmitStringIntegerMatcherNode>(N)->getVT()) << ", "
255      << Val << ",\n";
256    return 3;
257  }
258
259  case MatcherNode::EmitRegister:
260    OS << "OPC_EmitRegister, "
261       << getEnumName(cast<EmitRegisterMatcherNode>(N)->getVT()) << ", ";
262    if (Record *R = cast<EmitRegisterMatcherNode>(N)->getReg())
263      OS << getQualifiedName(R) << ",\n";
264    else
265      OS << "0 /*zero_reg*/,\n";
266    return 3;
267
268  case MatcherNode::EmitConvertToTarget:
269    OS << "OPC_EmitConvertToTarget, "
270       << cast<EmitConvertToTargetMatcherNode>(N)->getSlot() << ",\n";
271    return 2;
272
273  case MatcherNode::EmitMergeInputChains: {
274    const EmitMergeInputChainsMatcherNode *MN =
275      cast<EmitMergeInputChainsMatcherNode>(N);
276    OS << "OPC_EmitMergeInputChains, " << MN->getNumNodes() << ", ";
277    for (unsigned i = 0, e = MN->getNumNodes(); i != e; ++i)
278      OS << MN->getNode(i) << ", ";
279    OS << '\n';
280    return 2+MN->getNumNodes();
281  }
282  case MatcherNode::EmitCopyToReg:
283    OS << "OPC_EmitCopyToReg, "
284       << cast<EmitCopyToRegMatcherNode>(N)->getSrcSlot() << ", "
285       << getQualifiedName(cast<EmitCopyToRegMatcherNode>(N)->getDestPhysReg())
286       << ",\n";
287    return 3;
288  case MatcherNode::EmitNodeXForm: {
289    const EmitNodeXFormMatcherNode *XF = cast<EmitNodeXFormMatcherNode>(N);
290    OS << "OPC_EmitNodeXForm, " << getNodeXFormID(XF->getNodeXForm()) << ", "
291       << XF->getSlot() << ',';
292    OS.PadToColumn(CommentIndent) << "// "<<XF->getNodeXForm()->getName()<<'\n';
293    return 3;
294  }
295
296  case MatcherNode::EmitNode: {
297    const EmitNodeMatcherNode *EN = cast<EmitNodeMatcherNode>(N);
298    OS << "OPC_EmitNode, TARGET_OPCODE(" << EN->getOpcodeName() << "), 0";
299
300    if (EN->hasChain())   OS << "|OPFL_Chain";
301    if (EN->hasFlag())    OS << "|OPFL_Flag";
302    if (EN->hasMemRefs()) OS << "|OPFL_MemRefs";
303    if (EN->getNumFixedArityOperands() != -1)
304      OS << "|OPFL_Variadic" << EN->getNumFixedArityOperands();
305    OS << ",\n";
306
307    OS.PadToColumn(Indent*2+4) << EN->getNumVTs() << "/*#VTs*/, ";
308    for (unsigned i = 0, e = EN->getNumVTs(); i != e; ++i)
309      OS << getEnumName(EN->getVT(i)) << ", ";
310
311    OS << EN->getNumOperands() << "/*#Ops*/, ";
312    for (unsigned i = 0, e = EN->getNumOperands(); i != e; ++i)
313      OS << EN->getOperand(i) << ", ";
314    OS << '\n';
315    return 6+EN->getNumVTs()+EN->getNumOperands();
316  }
317  case MatcherNode::CompleteMatch: {
318    const CompleteMatchMatcherNode *CM = cast<CompleteMatchMatcherNode>(N);
319    OS << "OPC_CompleteMatch, " << CM->getNumResults() << ", ";
320    for (unsigned i = 0, e = CM->getNumResults(); i != e; ++i)
321      OS << CM->getResult(i) << ", ";
322    OS << '\n';
323    OS.PadToColumn(Indent*2) << "// Src: "
324      << *CM->getPattern().getSrcPattern() << '\n';
325    OS.PadToColumn(Indent*2) << "// Dst: "
326      << *CM->getPattern().getDstPattern() << '\n';
327    return 2+CM->getNumResults();
328  }
329  }
330  assert(0 && "Unreachable");
331  return 0;
332}
333
334/// EmitMatcherList - Emit the bytes for the specified matcher subtree.
335unsigned MatcherTableEmitter::
336EmitMatcherList(const MatcherNode *N, unsigned Indent, unsigned CurrentIdx,
337                formatted_raw_ostream &OS) {
338  unsigned Size = 0;
339  while (N) {
340    // Push is a special case since it is binary.
341    if (const PushMatcherNode *PMN = dyn_cast<PushMatcherNode>(N)) {
342      // We need to encode the child and the offset of the failure code before
343      // emitting either of them.  Handle this by buffering the output into a
344      // string while we get the size.
345      SmallString<128> TmpBuf;
346      unsigned NextSize;
347      {
348        raw_svector_ostream OS(TmpBuf);
349        formatted_raw_ostream FOS(OS);
350        NextSize = EmitMatcherList(cast<PushMatcherNode>(N)->getNext(),
351                                   Indent+1, CurrentIdx+2, FOS);
352      }
353
354      // In the unlikely event that we have something too big to emit with a
355      // one byte offset, regenerate it with a two-byte one.
356      if (NextSize > 255) {
357        TmpBuf.clear();
358        raw_svector_ostream OS(TmpBuf);
359        formatted_raw_ostream FOS(OS);
360        NextSize = EmitMatcherList(cast<PushMatcherNode>(N)->getNext(),
361                                   Indent+1, CurrentIdx+3, FOS);
362        if (NextSize > 65535) {
363          errs() <<
364            "Tblgen internal error: can't handle pattern this complex yet\n";
365          exit(1);
366        }
367      }
368
369      OS << "/*" << CurrentIdx << "*/";
370      OS.PadToColumn(Indent*2);
371
372      if (NextSize < 256)
373        OS << "OPC_Push, " << NextSize << ",\n";
374      else
375        OS << "OPC_Push2, " << (NextSize&255) << ", " << (NextSize>>8) << ",\n";
376      OS << TmpBuf.str();
377
378      Size += 2+NextSize;
379      CurrentIdx += 2+NextSize;
380      N = PMN->getFailure();
381      continue;
382    }
383
384    OS << "/*" << CurrentIdx << "*/";
385    unsigned MatcherSize = EmitMatcher(N, Indent, OS);
386    Size += MatcherSize;
387    CurrentIdx += MatcherSize;
388
389    // If there are other nodes in this list, iterate to them, otherwise we're
390    // done.
391    N = N->getNext();
392  }
393  return Size;
394}
395
396void MatcherTableEmitter::EmitPredicateFunctions(formatted_raw_ostream &OS) {
397  // FIXME: Don't build off the DAGISelEmitter's predicates, emit them directly
398  // here into the case stmts.
399
400  // Emit pattern predicates.
401  OS << "bool CheckPatternPredicate(unsigned PredNo) const {\n";
402  OS << "  switch (PredNo) {\n";
403  OS << "  default: assert(0 && \"Invalid predicate in table?\");\n";
404  for (unsigned i = 0, e = PatternPredicates.size(); i != e; ++i)
405    OS << "  case " << i << ": return "  << PatternPredicates[i] << ";\n";
406  OS << "  }\n";
407  OS << "}\n\n";
408
409  // Emit Node predicates.
410  OS << "bool CheckNodePredicate(SDNode *N, unsigned PredNo) const {\n";
411  OS << "  switch (PredNo) {\n";
412  OS << "  default: assert(0 && \"Invalid predicate in table?\");\n";
413  for (unsigned i = 0, e = NodePredicates.size(); i != e; ++i)
414    OS << "  case " << i << ": return "  << NodePredicates[i] << "(N);\n";
415  OS << "  }\n";
416  OS << "}\n\n";
417
418  // Emit CompletePattern matchers.
419  // FIXME: This should be const.
420  OS << "bool CheckComplexPattern(SDNode *Root, SDValue N,\n";
421  OS << "      unsigned PatternNo, SmallVectorImpl<SDValue> &Result) {\n";
422  OS << "  switch (PatternNo) {\n";
423  OS << "  default: assert(0 && \"Invalid pattern # in table?\");\n";
424  for (unsigned i = 0, e = ComplexPatterns.size(); i != e; ++i) {
425    const ComplexPattern &P = *ComplexPatterns[i];
426    unsigned NumOps = P.getNumOperands();
427
428    if (P.hasProperty(SDNPHasChain))
429      ++NumOps;  // Get the chained node too.
430
431    OS << "  case " << i << ":\n";
432    OS << "    Result.resize(Result.size()+" << NumOps << ");\n";
433    OS << "    return "  << P.getSelectFunc();
434
435    // FIXME: Temporary hack until old isel dies.
436    if (P.hasProperty(SDNPHasChain))
437      OS << "XXX";
438
439    OS << "(Root, N";
440    for (unsigned i = 0; i != NumOps; ++i)
441      OS << ", Result[Result.size()-" << (NumOps-i) << ']';
442    OS << ");\n";
443  }
444  OS << "  }\n";
445  OS << "}\n\n";
446
447  // Emit SDNodeXForm handlers.
448  // FIXME: This should be const.
449  OS << "SDValue RunSDNodeXForm(SDValue V, unsigned XFormNo) {\n";
450  OS << "  switch (XFormNo) {\n";
451  OS << "  default: assert(0 && \"Invalid xform # in table?\");\n";
452
453  // FIXME: The node xform could take SDValue's instead of SDNode*'s.
454  for (unsigned i = 0, e = NodeXForms.size(); i != e; ++i)
455    OS << "  case " << i << ": return Transform_" << NodeXForms[i]->getName()
456       << "(V.getNode());\n";
457  OS << "  }\n";
458  OS << "}\n\n";
459}
460
461
462void llvm::EmitMatcherTable(const MatcherNode *Matcher, raw_ostream &O) {
463  formatted_raw_ostream OS(O);
464
465  OS << "// The main instruction selector code.\n";
466  OS << "SDNode *SelectCode2(SDNode *N) {\n";
467
468  MatcherTableEmitter MatcherEmitter;
469
470  OS << "  // Opcodes are emitted as 2 bytes, TARGET_OPCODE handles this.\n";
471  OS << "  #define TARGET_OPCODE(X) X & 255, unsigned(X) >> 8\n";
472  OS << "  static const unsigned char MatcherTable[] = {\n";
473  unsigned TotalSize = MatcherEmitter.EmitMatcherList(Matcher, 5, 0, OS);
474  OS << "    0\n  }; // Total Array size is " << (TotalSize+1) << " bytes\n\n";
475  OS << "  #undef TARGET_OPCODE\n";
476  OS << "  return SelectCodeCommon(N, MatcherTable,sizeof(MatcherTable));\n}\n";
477  OS << "\n";
478
479  // Next up, emit the function for node and pattern predicates:
480  MatcherEmitter.EmitPredicateFunctions(OS);
481}
482