DAGISelMatcherEmitter.cpp revision 984e18823e863f2232ccf63f7e84b878dbd55b6f 
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                           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::CheckType:
185    OS << "OPC_CheckType, "
186       << getEnumName(cast<CheckTypeMatcherNode>(N)->getType()) << ",\n";
187    return 2;
188
189  case MatcherNode::CheckInteger: {
190    int64_t Val = cast<CheckIntegerMatcherNode>(N)->getValue();
191    OS << "OPC_CheckInteger" << ClassifyInt(Val) << ", ";
192    return EmitInt(Val, OS)+1;
193  }
194  case MatcherNode::CheckCondCode:
195    OS << "OPC_CheckCondCode, ISD::"
196       << cast<CheckCondCodeMatcherNode>(N)->getCondCodeName() << ",\n";
197    return 2;
198
199  case MatcherNode::CheckValueType:
200    OS << "OPC_CheckValueType, MVT::"
201       << cast<CheckValueTypeMatcherNode>(N)->getTypeName() << ",\n";
202    return 2;
203
204  case MatcherNode::CheckComplexPat: {
205    const ComplexPattern &Pattern =
206      cast<CheckComplexPatMatcherNode>(N)->getPattern();
207    OS << "OPC_CheckComplexPat, " << getComplexPat(Pattern) << ',';
208    OS.PadToColumn(CommentIndent) << "// " << Pattern.getSelectFunc();
209    OS << ": " << Pattern.getNumOperands() << " operands";
210    if (Pattern.hasProperty(SDNPHasChain))
211      OS << " + chain result and input";
212    OS << '\n';
213    return 2;
214  }
215
216  case MatcherNode::CheckAndImm: {
217    int64_t Val = cast<CheckAndImmMatcherNode>(N)->getValue();
218    OS << "OPC_CheckAndImm" << ClassifyInt(Val) << ", ";
219    return EmitInt(Val, OS)+1;
220  }
221
222  case MatcherNode::CheckOrImm: {
223    int64_t Val = cast<CheckOrImmMatcherNode>(N)->getValue();
224    OS << "OPC_CheckOrImm" << ClassifyInt(Val) << ", ";
225    return EmitInt(Val, OS)+1;
226  }
227  case MatcherNode::CheckFoldableChainNode:
228    OS << "OPC_CheckFoldableChainNode,\n";
229    return 1;
230  case MatcherNode::CheckChainCompatible:
231    OS << "OPC_CheckChainCompatible, "
232       << cast<CheckChainCompatibleMatcherNode>(N)->getPreviousOp() << ",\n";
233    return 2;
234
235  case MatcherNode::EmitInteger: {
236    int64_t Val = cast<EmitIntegerMatcherNode>(N)->getValue();
237    OS << "OPC_EmitInteger" << ClassifyInt(Val) << ", "
238       << getEnumName(cast<EmitIntegerMatcherNode>(N)->getVT()) << ", ";
239    return EmitInt(Val, OS)+2;
240  }
241  case MatcherNode::EmitStringInteger: {
242    const std::string &Val = cast<EmitStringIntegerMatcherNode>(N)->getValue();
243    // These should always fit into one byte.
244    OS << "OPC_EmitInteger1, "
245      << getEnumName(cast<EmitStringIntegerMatcherNode>(N)->getVT()) << ", "
246      << Val << ",\n";
247    return 3;
248  }
249
250  case MatcherNode::EmitRegister:
251    OS << "OPC_EmitRegister, "
252       << getEnumName(cast<EmitRegisterMatcherNode>(N)->getVT()) << ", ";
253    if (Record *R = cast<EmitRegisterMatcherNode>(N)->getReg())
254      OS << getQualifiedName(R) << ",\n";
255    else
256      OS << "0 /*zero_reg*/,\n";
257    return 3;
258
259  case MatcherNode::EmitConvertToTarget:
260    OS << "OPC_EmitConvertToTarget, "
261       << cast<EmitConvertToTargetMatcherNode>(N)->getSlot() << ",\n";
262    return 2;
263
264  case MatcherNode::EmitMergeInputChains: {
265    const EmitMergeInputChainsMatcherNode *MN =
266      cast<EmitMergeInputChainsMatcherNode>(N);
267    OS << "OPC_EmitMergeInputChains, " << MN->getNumNodes() << ", ";
268    for (unsigned i = 0, e = MN->getNumNodes(); i != e; ++i)
269      OS << MN->getNode(i) << ", ";
270    OS << '\n';
271    return 2+MN->getNumNodes();
272  }
273  case MatcherNode::EmitCopyToReg:
274    OS << "OPC_EmitCopyToReg, "
275       << cast<EmitCopyToRegMatcherNode>(N)->getSrcSlot() << ", "
276       << getQualifiedName(cast<EmitCopyToRegMatcherNode>(N)->getDestPhysReg())
277       << ",\n";
278    return 3;
279  case MatcherNode::EmitNodeXForm: {
280    const EmitNodeXFormMatcherNode *XF = cast<EmitNodeXFormMatcherNode>(N);
281    OS << "OPC_EmitNodeXForm, " << getNodeXFormID(XF->getNodeXForm()) << ", "
282       << XF->getSlot() << ',';
283    OS.PadToColumn(CommentIndent) << "// "<<XF->getNodeXForm()->getName()<<'\n';
284    return 3;
285  }
286
287  case MatcherNode::EmitNode: {
288    const EmitNodeMatcherNode *EN = cast<EmitNodeMatcherNode>(N);
289    OS << "OPC_EmitNode, TARGET_OPCODE(" << EN->getOpcodeName() << "), 0";
290
291    if (EN->hasChain())   OS << "|OPFL_Chain";
292    if (EN->hasFlag())    OS << "|OPFL_Flag";
293    if (EN->hasMemRefs()) OS << "|OPFL_MemRefs";
294    if (EN->getNumFixedArityOperands() != -1)
295      OS << "|OPFL_Variadic" << EN->getNumFixedArityOperands();
296    OS << ",\n";
297
298    OS.PadToColumn(Indent*2+4) << EN->getNumVTs() << "/*#VTs*/, ";
299    for (unsigned i = 0, e = EN->getNumVTs(); i != e; ++i)
300      OS << getEnumName(EN->getVT(i)) << ", ";
301
302    OS << EN->getNumOperands() << "/*#Ops*/, ";
303    for (unsigned i = 0, e = EN->getNumOperands(); i != e; ++i)
304      OS << EN->getOperand(i) << ", ";
305    OS << '\n';
306    return 5+EN->getNumVTs()+EN->getNumOperands();
307  }
308  case MatcherNode::CompleteMatch: {
309    const CompleteMatchMatcherNode *CM = cast<CompleteMatchMatcherNode>(N);
310    OS << "OPC_CompleteMatch, " << CM->getNumResults() << ", ";
311    for (unsigned i = 0, e = CM->getNumResults(); i != e; ++i)
312      OS << CM->getResult(i) << ", ";
313    OS << '\n';
314    OS.PadToColumn(Indent*2) << "// Src: "
315      << *CM->getPattern().getSrcPattern() << '\n';
316    OS.PadToColumn(Indent*2) << "// Dst: "
317      << *CM->getPattern().getDstPattern() << '\n';
318    return 2+CM->getNumResults();
319  }
320  }
321  assert(0 && "Unreachable");
322  return 0;
323}
324
325/// EmitMatcherList - Emit the bytes for the specified matcher subtree.
326unsigned MatcherTableEmitter::
327EmitMatcherList(const MatcherNode *N, unsigned Indent,
328                formatted_raw_ostream &OS) {
329  unsigned Size = 0;
330  while (N) {
331    // Push is a special case since it is binary.
332    if (const PushMatcherNode *PMN = dyn_cast<PushMatcherNode>(N)) {
333      // We need to encode the child and the offset of the failure code before
334      // emitting either of them.  Handle this by buffering the output into a
335      // string while we get the size.
336      SmallString<128> TmpBuf;
337      unsigned NextSize;
338      {
339        raw_svector_ostream OS(TmpBuf);
340        formatted_raw_ostream FOS(OS);
341        NextSize = EmitMatcherList(cast<PushMatcherNode>(N)->getNext(),
342                                   Indent+1, FOS);
343      }
344
345      if (NextSize > 255) {
346        errs() <<
347          "Tblgen internal error: can't handle predicate this complex yet\n";
348        // FIXME: exit(1);
349      }
350
351      OS.PadToColumn(Indent*2);
352      OS << "OPC_Push, " << NextSize << ",\n";
353      OS << TmpBuf.str();
354
355      Size += 2 + NextSize;
356
357      N = PMN->getFailure();
358      continue;
359    }
360
361    Size += EmitMatcher(N, Indent, OS);
362
363    // If there are other nodes in this list, iterate to them, otherwise we're
364    // done.
365    N = N->getNext();
366  }
367  return Size;
368}
369
370void MatcherTableEmitter::EmitPredicateFunctions(formatted_raw_ostream &OS) {
371  // FIXME: Don't build off the DAGISelEmitter's predicates, emit them directly
372  // here into the case stmts.
373
374  // Emit pattern predicates.
375  OS << "bool CheckPatternPredicate(unsigned PredNo) const {\n";
376  OS << "  switch (PredNo) {\n";
377  OS << "  default: assert(0 && \"Invalid predicate in table?\");\n";
378  for (unsigned i = 0, e = PatternPredicates.size(); i != e; ++i)
379    OS << "  case " << i << ": return "  << PatternPredicates[i] << ";\n";
380  OS << "  }\n";
381  OS << "}\n\n";
382
383  // Emit Node predicates.
384  OS << "bool CheckNodePredicate(SDNode *N, unsigned PredNo) const {\n";
385  OS << "  switch (PredNo) {\n";
386  OS << "  default: assert(0 && \"Invalid predicate in table?\");\n";
387  for (unsigned i = 0, e = NodePredicates.size(); i != e; ++i)
388    OS << "  case " << i << ": return "  << NodePredicates[i] << "(N);\n";
389  OS << "  }\n";
390  OS << "}\n\n";
391
392  // Emit CompletePattern matchers.
393  // FIXME: This should be const.
394  OS << "bool CheckComplexPattern(SDNode *Root, SDValue N,\n";
395  OS << "      unsigned PatternNo, SmallVectorImpl<SDValue> &Result) {\n";
396  OS << "  switch (PatternNo) {\n";
397  OS << "  default: assert(0 && \"Invalid pattern # in table?\");\n";
398  for (unsigned i = 0, e = ComplexPatterns.size(); i != e; ++i) {
399    const ComplexPattern &P = *ComplexPatterns[i];
400    unsigned NumOps = P.getNumOperands();
401
402    if (P.hasProperty(SDNPHasChain))
403      ++NumOps;  // Get the chained node too.
404
405    OS << "  case " << i << ":\n";
406    OS << "    Result.resize(Result.size()+" << NumOps << ");\n";
407    OS << "    return "  << P.getSelectFunc();
408
409    // FIXME: Temporary hack until old isel dies.
410    if (P.hasProperty(SDNPHasChain))
411      OS << "XXX";
412
413    OS << "(Root, N";
414    for (unsigned i = 0; i != NumOps; ++i)
415      OS << ", Result[Result.size()-" << (NumOps-i) << ']';
416    OS << ");\n";
417  }
418  OS << "  }\n";
419  OS << "}\n\n";
420
421  // Emit SDNodeXForm handlers.
422  // FIXME: This should be const.
423  OS << "SDValue RunSDNodeXForm(SDValue V, unsigned XFormNo) {\n";
424  OS << "  switch (XFormNo) {\n";
425  OS << "  default: assert(0 && \"Invalid xform # in table?\");\n";
426
427  // FIXME: The node xform could take SDValue's instead of SDNode*'s.
428  for (unsigned i = 0, e = NodeXForms.size(); i != e; ++i)
429    OS << "  case " << i << ": return Transform_" << NodeXForms[i]->getName()
430       << "(V.getNode());\n";
431  OS << "  }\n";
432  OS << "}\n\n";
433}
434
435
436void llvm::EmitMatcherTable(const MatcherNode *Matcher, raw_ostream &O) {
437  formatted_raw_ostream OS(O);
438
439  OS << "// The main instruction selector code.\n";
440  OS << "SDNode *SelectCode2(SDNode *N) {\n";
441
442  MatcherTableEmitter MatcherEmitter;
443
444  OS << "  // Opcodes are emitted as 2 bytes, TARGET_OPCODE handles this.\n";
445  OS << "  #define TARGET_OPCODE(X) X & 255, unsigned(X) >> 8\n";
446  OS << "  static const unsigned char MatcherTable[] = {\n";
447  unsigned TotalSize = MatcherEmitter.EmitMatcherList(Matcher, 2, OS);
448  OS << "    0\n  }; // Total Array size is " << (TotalSize+1) << " bytes\n\n";
449  OS << "  #undef TARGET_OPCODE\n";
450  OS << "  return SelectCodeCommon(N, MatcherTable,sizeof(MatcherTable));\n}\n";
451  OS << "\n";
452
453  // Next up, emit the function for node and pattern predicates:
454  MatcherEmitter.EmitPredicateFunctions(OS);
455}
456