1//===- DAGISelMatcherGen.cpp - Matcher generator --------------------------===//
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#include "DAGISelMatcher.h"
11#include "CodeGenDAGPatterns.h"
12#include "CodeGenRegisters.h"
13#include "llvm/ADT/DenseMap.h"
14#include "llvm/ADT/SmallVector.h"
15#include "llvm/ADT/StringMap.h"
16#include "llvm/TableGen/Error.h"
17#include "llvm/TableGen/Record.h"
18#include <utility>
19using namespace llvm;
20
21
22/// getRegisterValueType - Look up and return the ValueType of the specified
23/// register. If the register is a member of multiple register classes which
24/// have different associated types, return MVT::Other.
25static MVT::SimpleValueType getRegisterValueType(Record *R,
26                                                 const CodeGenTarget &T) {
27  bool FoundRC = false;
28  MVT::SimpleValueType VT = MVT::Other;
29  const CodeGenRegister *Reg = T.getRegBank().getReg(R);
30  ArrayRef<CodeGenRegisterClass*> RCs = T.getRegBank().getRegClasses();
31
32  for (unsigned rc = 0, e = RCs.size(); rc != e; ++rc) {
33    const CodeGenRegisterClass &RC = *RCs[rc];
34    if (!RC.contains(Reg))
35      continue;
36
37    if (!FoundRC) {
38      FoundRC = true;
39      VT = RC.getValueTypeNum(0);
40      continue;
41    }
42
43    // If this occurs in multiple register classes, they all have to agree.
44    assert(VT == RC.getValueTypeNum(0));
45  }
46  return VT;
47}
48
49
50namespace {
51  class MatcherGen {
52    const PatternToMatch &Pattern;
53    const CodeGenDAGPatterns &CGP;
54
55    /// PatWithNoTypes - This is a clone of Pattern.getSrcPattern() that starts
56    /// out with all of the types removed.  This allows us to insert type checks
57    /// as we scan the tree.
58    TreePatternNode *PatWithNoTypes;
59
60    /// VariableMap - A map from variable names ('$dst') to the recorded operand
61    /// number that they were captured as.  These are biased by 1 to make
62    /// insertion easier.
63    StringMap<unsigned> VariableMap;
64
65    /// NextRecordedOperandNo - As we emit opcodes to record matched values in
66    /// the RecordedNodes array, this keeps track of which slot will be next to
67    /// record into.
68    unsigned NextRecordedOperandNo;
69
70    /// MatchedChainNodes - This maintains the position in the recorded nodes
71    /// array of all of the recorded input nodes that have chains.
72    SmallVector<unsigned, 2> MatchedChainNodes;
73
74    /// MatchedGlueResultNodes - This maintains the position in the recorded
75    /// nodes array of all of the recorded input nodes that have glue results.
76    SmallVector<unsigned, 2> MatchedGlueResultNodes;
77
78    /// MatchedComplexPatterns - This maintains a list of all of the
79    /// ComplexPatterns that we need to check.  The patterns are known to have
80    /// names which were recorded.  The second element of each pair is the first
81    /// slot number that the OPC_CheckComplexPat opcode drops the matched
82    /// results into.
83    SmallVector<std::pair<const TreePatternNode*,
84                          unsigned>, 2> MatchedComplexPatterns;
85
86    /// PhysRegInputs - List list has an entry for each explicitly specified
87    /// physreg input to the pattern.  The first elt is the Register node, the
88    /// second is the recorded slot number the input pattern match saved it in.
89    SmallVector<std::pair<Record*, unsigned>, 2> PhysRegInputs;
90
91    /// Matcher - This is the top level of the generated matcher, the result.
92    Matcher *TheMatcher;
93
94    /// CurPredicate - As we emit matcher nodes, this points to the latest check
95    /// which should have future checks stuck into its Next position.
96    Matcher *CurPredicate;
97  public:
98    MatcherGen(const PatternToMatch &pattern, const CodeGenDAGPatterns &cgp);
99
100    ~MatcherGen() {
101      delete PatWithNoTypes;
102    }
103
104    bool EmitMatcherCode(unsigned Variant);
105    void EmitResultCode();
106
107    Matcher *GetMatcher() const { return TheMatcher; }
108  private:
109    void AddMatcher(Matcher *NewNode);
110    void InferPossibleTypes();
111
112    // Matcher Generation.
113    void EmitMatchCode(const TreePatternNode *N, TreePatternNode *NodeNoTypes);
114    void EmitLeafMatchCode(const TreePatternNode *N);
115    void EmitOperatorMatchCode(const TreePatternNode *N,
116                               TreePatternNode *NodeNoTypes);
117
118    // Result Code Generation.
119    unsigned getNamedArgumentSlot(StringRef Name) {
120      unsigned VarMapEntry = VariableMap[Name];
121      assert(VarMapEntry != 0 &&
122             "Variable referenced but not defined and not caught earlier!");
123      return VarMapEntry-1;
124    }
125
126    /// GetInstPatternNode - Get the pattern for an instruction.
127    const TreePatternNode *GetInstPatternNode(const DAGInstruction &Ins,
128                                              const TreePatternNode *N);
129
130    void EmitResultOperand(const TreePatternNode *N,
131                           SmallVectorImpl<unsigned> &ResultOps);
132    void EmitResultOfNamedOperand(const TreePatternNode *N,
133                                  SmallVectorImpl<unsigned> &ResultOps);
134    void EmitResultLeafAsOperand(const TreePatternNode *N,
135                                 SmallVectorImpl<unsigned> &ResultOps);
136    void EmitResultInstructionAsOperand(const TreePatternNode *N,
137                                        SmallVectorImpl<unsigned> &ResultOps);
138    void EmitResultSDNodeXFormAsOperand(const TreePatternNode *N,
139                                        SmallVectorImpl<unsigned> &ResultOps);
140    };
141
142} // end anon namespace.
143
144MatcherGen::MatcherGen(const PatternToMatch &pattern,
145                       const CodeGenDAGPatterns &cgp)
146: Pattern(pattern), CGP(cgp), NextRecordedOperandNo(0),
147  TheMatcher(0), CurPredicate(0) {
148  // We need to produce the matcher tree for the patterns source pattern.  To do
149  // this we need to match the structure as well as the types.  To do the type
150  // matching, we want to figure out the fewest number of type checks we need to
151  // emit.  For example, if there is only one integer type supported by a
152  // target, there should be no type comparisons at all for integer patterns!
153  //
154  // To figure out the fewest number of type checks needed, clone the pattern,
155  // remove the types, then perform type inference on the pattern as a whole.
156  // If there are unresolved types, emit an explicit check for those types,
157  // apply the type to the tree, then rerun type inference.  Iterate until all
158  // types are resolved.
159  //
160  PatWithNoTypes = Pattern.getSrcPattern()->clone();
161  PatWithNoTypes->RemoveAllTypes();
162
163  // If there are types that are manifestly known, infer them.
164  InferPossibleTypes();
165}
166
167/// InferPossibleTypes - As we emit the pattern, we end up generating type
168/// checks and applying them to the 'PatWithNoTypes' tree.  As we do this, we
169/// want to propagate implied types as far throughout the tree as possible so
170/// that we avoid doing redundant type checks.  This does the type propagation.
171void MatcherGen::InferPossibleTypes() {
172  // TP - Get *SOME* tree pattern, we don't care which.  It is only used for
173  // diagnostics, which we know are impossible at this point.
174  TreePattern &TP = *CGP.pf_begin()->second;
175
176  bool MadeChange = true;
177  while (MadeChange)
178    MadeChange = PatWithNoTypes->ApplyTypeConstraints(TP,
179                                              true/*Ignore reg constraints*/);
180}
181
182
183/// AddMatcher - Add a matcher node to the current graph we're building.
184void MatcherGen::AddMatcher(Matcher *NewNode) {
185  if (CurPredicate != 0)
186    CurPredicate->setNext(NewNode);
187  else
188    TheMatcher = NewNode;
189  CurPredicate = NewNode;
190}
191
192
193//===----------------------------------------------------------------------===//
194// Pattern Match Generation
195//===----------------------------------------------------------------------===//
196
197/// EmitLeafMatchCode - Generate matching code for leaf nodes.
198void MatcherGen::EmitLeafMatchCode(const TreePatternNode *N) {
199  assert(N->isLeaf() && "Not a leaf?");
200
201  // Direct match against an integer constant.
202  if (IntInit *II = dyn_cast<IntInit>(N->getLeafValue())) {
203    // If this is the root of the dag we're matching, we emit a redundant opcode
204    // check to ensure that this gets folded into the normal top-level
205    // OpcodeSwitch.
206    if (N == Pattern.getSrcPattern()) {
207      const SDNodeInfo &NI = CGP.getSDNodeInfo(CGP.getSDNodeNamed("imm"));
208      AddMatcher(new CheckOpcodeMatcher(NI));
209    }
210
211    return AddMatcher(new CheckIntegerMatcher(II->getValue()));
212  }
213
214  // An UnsetInit represents a named node without any constraints.
215  if (N->getLeafValue() == UnsetInit::get()) {
216    assert(N->hasName() && "Unnamed ? leaf");
217    return;
218  }
219
220  DefInit *DI = dyn_cast<DefInit>(N->getLeafValue());
221  if (DI == 0) {
222    errs() << "Unknown leaf kind: " << *N << "\n";
223    abort();
224  }
225
226  Record *LeafRec = DI->getDef();
227
228  // A ValueType leaf node can represent a register when named, or itself when
229  // unnamed.
230  if (LeafRec->isSubClassOf("ValueType")) {
231    // A named ValueType leaf always matches: (add i32:$a, i32:$b).
232    if (N->hasName())
233      return;
234    // An unnamed ValueType as in (sext_inreg GPR:$foo, i8).
235    return AddMatcher(new CheckValueTypeMatcher(LeafRec->getName()));
236  }
237
238  if (// Handle register references.  Nothing to do here, they always match.
239      LeafRec->isSubClassOf("RegisterClass") ||
240      LeafRec->isSubClassOf("RegisterOperand") ||
241      LeafRec->isSubClassOf("PointerLikeRegClass") ||
242      LeafRec->isSubClassOf("SubRegIndex") ||
243      // Place holder for SRCVALUE nodes. Nothing to do here.
244      LeafRec->getName() == "srcvalue")
245    return;
246
247  // If we have a physreg reference like (mul gpr:$src, EAX) then we need to
248  // record the register
249  if (LeafRec->isSubClassOf("Register")) {
250    AddMatcher(new RecordMatcher("physreg input "+LeafRec->getName(),
251                                 NextRecordedOperandNo));
252    PhysRegInputs.push_back(std::make_pair(LeafRec, NextRecordedOperandNo++));
253    return;
254  }
255
256  if (LeafRec->isSubClassOf("CondCode"))
257    return AddMatcher(new CheckCondCodeMatcher(LeafRec->getName()));
258
259  if (LeafRec->isSubClassOf("ComplexPattern")) {
260    // We can't model ComplexPattern uses that don't have their name taken yet.
261    // The OPC_CheckComplexPattern operation implicitly records the results.
262    if (N->getName().empty()) {
263      errs() << "We expect complex pattern uses to have names: " << *N << "\n";
264      exit(1);
265    }
266
267    // Remember this ComplexPattern so that we can emit it after all the other
268    // structural matches are done.
269    MatchedComplexPatterns.push_back(std::make_pair(N, 0));
270    return;
271  }
272
273  errs() << "Unknown leaf kind: " << *N << "\n";
274  abort();
275}
276
277void MatcherGen::EmitOperatorMatchCode(const TreePatternNode *N,
278                                       TreePatternNode *NodeNoTypes) {
279  assert(!N->isLeaf() && "Not an operator?");
280  const SDNodeInfo &CInfo = CGP.getSDNodeInfo(N->getOperator());
281
282  // If this is an 'and R, 1234' where the operation is AND/OR and the RHS is
283  // a constant without a predicate fn that has more that one bit set, handle
284  // this as a special case.  This is usually for targets that have special
285  // handling of certain large constants (e.g. alpha with it's 8/16/32-bit
286  // handling stuff).  Using these instructions is often far more efficient
287  // than materializing the constant.  Unfortunately, both the instcombiner
288  // and the dag combiner can often infer that bits are dead, and thus drop
289  // them from the mask in the dag.  For example, it might turn 'AND X, 255'
290  // into 'AND X, 254' if it knows the low bit is set.  Emit code that checks
291  // to handle this.
292  if ((N->getOperator()->getName() == "and" ||
293       N->getOperator()->getName() == "or") &&
294      N->getChild(1)->isLeaf() && N->getChild(1)->getPredicateFns().empty() &&
295      N->getPredicateFns().empty()) {
296    if (IntInit *II = dyn_cast<IntInit>(N->getChild(1)->getLeafValue())) {
297      if (!isPowerOf2_32(II->getValue())) {  // Don't bother with single bits.
298        // If this is at the root of the pattern, we emit a redundant
299        // CheckOpcode so that the following checks get factored properly under
300        // a single opcode check.
301        if (N == Pattern.getSrcPattern())
302          AddMatcher(new CheckOpcodeMatcher(CInfo));
303
304        // Emit the CheckAndImm/CheckOrImm node.
305        if (N->getOperator()->getName() == "and")
306          AddMatcher(new CheckAndImmMatcher(II->getValue()));
307        else
308          AddMatcher(new CheckOrImmMatcher(II->getValue()));
309
310        // Match the LHS of the AND as appropriate.
311        AddMatcher(new MoveChildMatcher(0));
312        EmitMatchCode(N->getChild(0), NodeNoTypes->getChild(0));
313        AddMatcher(new MoveParentMatcher());
314        return;
315      }
316    }
317  }
318
319  // Check that the current opcode lines up.
320  AddMatcher(new CheckOpcodeMatcher(CInfo));
321
322  // If this node has memory references (i.e. is a load or store), tell the
323  // interpreter to capture them in the memref array.
324  if (N->NodeHasProperty(SDNPMemOperand, CGP))
325    AddMatcher(new RecordMemRefMatcher());
326
327  // If this node has a chain, then the chain is operand #0 is the SDNode, and
328  // the child numbers of the node are all offset by one.
329  unsigned OpNo = 0;
330  if (N->NodeHasProperty(SDNPHasChain, CGP)) {
331    // Record the node and remember it in our chained nodes list.
332    AddMatcher(new RecordMatcher("'" + N->getOperator()->getName() +
333                                         "' chained node",
334                                 NextRecordedOperandNo));
335    // Remember all of the input chains our pattern will match.
336    MatchedChainNodes.push_back(NextRecordedOperandNo++);
337
338    // Don't look at the input chain when matching the tree pattern to the
339    // SDNode.
340    OpNo = 1;
341
342    // If this node is not the root and the subtree underneath it produces a
343    // chain, then the result of matching the node is also produce a chain.
344    // Beyond that, this means that we're also folding (at least) the root node
345    // into the node that produce the chain (for example, matching
346    // "(add reg, (load ptr))" as a add_with_memory on X86).  This is
347    // problematic, if the 'reg' node also uses the load (say, its chain).
348    // Graphically:
349    //
350    //         [LD]
351    //         ^  ^
352    //         |  \                              DAG's like cheese.
353    //        /    |
354    //       /    [YY]
355    //       |     ^
356    //      [XX]--/
357    //
358    // It would be invalid to fold XX and LD.  In this case, folding the two
359    // nodes together would induce a cycle in the DAG, making it a 'cyclic DAG'
360    // To prevent this, we emit a dynamic check for legality before allowing
361    // this to be folded.
362    //
363    const TreePatternNode *Root = Pattern.getSrcPattern();
364    if (N != Root) {                             // Not the root of the pattern.
365      // If there is a node between the root and this node, then we definitely
366      // need to emit the check.
367      bool NeedCheck = !Root->hasChild(N);
368
369      // If it *is* an immediate child of the root, we can still need a check if
370      // the root SDNode has multiple inputs.  For us, this means that it is an
371      // intrinsic, has multiple operands, or has other inputs like chain or
372      // glue).
373      if (!NeedCheck) {
374        const SDNodeInfo &PInfo = CGP.getSDNodeInfo(Root->getOperator());
375        NeedCheck =
376          Root->getOperator() == CGP.get_intrinsic_void_sdnode() ||
377          Root->getOperator() == CGP.get_intrinsic_w_chain_sdnode() ||
378          Root->getOperator() == CGP.get_intrinsic_wo_chain_sdnode() ||
379          PInfo.getNumOperands() > 1 ||
380          PInfo.hasProperty(SDNPHasChain) ||
381          PInfo.hasProperty(SDNPInGlue) ||
382          PInfo.hasProperty(SDNPOptInGlue);
383      }
384
385      if (NeedCheck)
386        AddMatcher(new CheckFoldableChainNodeMatcher());
387    }
388  }
389
390  // If this node has an output glue and isn't the root, remember it.
391  if (N->NodeHasProperty(SDNPOutGlue, CGP) &&
392      N != Pattern.getSrcPattern()) {
393    // TODO: This redundantly records nodes with both glues and chains.
394
395    // Record the node and remember it in our chained nodes list.
396    AddMatcher(new RecordMatcher("'" + N->getOperator()->getName() +
397                                         "' glue output node",
398                                 NextRecordedOperandNo));
399    // Remember all of the nodes with output glue our pattern will match.
400    MatchedGlueResultNodes.push_back(NextRecordedOperandNo++);
401  }
402
403  // If this node is known to have an input glue or if it *might* have an input
404  // glue, capture it as the glue input of the pattern.
405  if (N->NodeHasProperty(SDNPOptInGlue, CGP) ||
406      N->NodeHasProperty(SDNPInGlue, CGP))
407    AddMatcher(new CaptureGlueInputMatcher());
408
409  for (unsigned i = 0, e = N->getNumChildren(); i != e; ++i, ++OpNo) {
410    // Get the code suitable for matching this child.  Move to the child, check
411    // it then move back to the parent.
412    AddMatcher(new MoveChildMatcher(OpNo));
413    EmitMatchCode(N->getChild(i), NodeNoTypes->getChild(i));
414    AddMatcher(new MoveParentMatcher());
415  }
416}
417
418
419void MatcherGen::EmitMatchCode(const TreePatternNode *N,
420                               TreePatternNode *NodeNoTypes) {
421  // If N and NodeNoTypes don't agree on a type, then this is a case where we
422  // need to do a type check.  Emit the check, apply the tyep to NodeNoTypes and
423  // reinfer any correlated types.
424  SmallVector<unsigned, 2> ResultsToTypeCheck;
425
426  for (unsigned i = 0, e = NodeNoTypes->getNumTypes(); i != e; ++i) {
427    if (NodeNoTypes->getExtType(i) == N->getExtType(i)) continue;
428    NodeNoTypes->setType(i, N->getExtType(i));
429    InferPossibleTypes();
430    ResultsToTypeCheck.push_back(i);
431  }
432
433  // If this node has a name associated with it, capture it in VariableMap. If
434  // we already saw this in the pattern, emit code to verify dagness.
435  if (!N->getName().empty()) {
436    unsigned &VarMapEntry = VariableMap[N->getName()];
437    if (VarMapEntry == 0) {
438      // If it is a named node, we must emit a 'Record' opcode.
439      AddMatcher(new RecordMatcher("$" + N->getName(), NextRecordedOperandNo));
440      VarMapEntry = ++NextRecordedOperandNo;
441    } else {
442      // If we get here, this is a second reference to a specific name.  Since
443      // we already have checked that the first reference is valid, we don't
444      // have to recursively match it, just check that it's the same as the
445      // previously named thing.
446      AddMatcher(new CheckSameMatcher(VarMapEntry-1));
447      return;
448    }
449  }
450
451  if (N->isLeaf())
452    EmitLeafMatchCode(N);
453  else
454    EmitOperatorMatchCode(N, NodeNoTypes);
455
456  // If there are node predicates for this node, generate their checks.
457  for (unsigned i = 0, e = N->getPredicateFns().size(); i != e; ++i)
458    AddMatcher(new CheckPredicateMatcher(N->getPredicateFns()[i]));
459
460  for (unsigned i = 0, e = ResultsToTypeCheck.size(); i != e; ++i)
461    AddMatcher(new CheckTypeMatcher(N->getType(ResultsToTypeCheck[i]),
462                                    ResultsToTypeCheck[i]));
463}
464
465/// EmitMatcherCode - Generate the code that matches the predicate of this
466/// pattern for the specified Variant.  If the variant is invalid this returns
467/// true and does not generate code, if it is valid, it returns false.
468bool MatcherGen::EmitMatcherCode(unsigned Variant) {
469  // If the root of the pattern is a ComplexPattern and if it is specified to
470  // match some number of root opcodes, these are considered to be our variants.
471  // Depending on which variant we're generating code for, emit the root opcode
472  // check.
473  if (const ComplexPattern *CP =
474                   Pattern.getSrcPattern()->getComplexPatternInfo(CGP)) {
475    const std::vector<Record*> &OpNodes = CP->getRootNodes();
476    assert(!OpNodes.empty() &&"Complex Pattern must specify what it can match");
477    if (Variant >= OpNodes.size()) return true;
478
479    AddMatcher(new CheckOpcodeMatcher(CGP.getSDNodeInfo(OpNodes[Variant])));
480  } else {
481    if (Variant != 0) return true;
482  }
483
484  // Emit the matcher for the pattern structure and types.
485  EmitMatchCode(Pattern.getSrcPattern(), PatWithNoTypes);
486
487  // If the pattern has a predicate on it (e.g. only enabled when a subtarget
488  // feature is around, do the check).
489  if (!Pattern.getPredicateCheck().empty())
490    AddMatcher(new CheckPatternPredicateMatcher(Pattern.getPredicateCheck()));
491
492  // Now that we've completed the structural type match, emit any ComplexPattern
493  // checks (e.g. addrmode matches).  We emit this after the structural match
494  // because they are generally more expensive to evaluate and more difficult to
495  // factor.
496  for (unsigned i = 0, e = MatchedComplexPatterns.size(); i != e; ++i) {
497    const TreePatternNode *N = MatchedComplexPatterns[i].first;
498
499    // Remember where the results of this match get stuck.
500    MatchedComplexPatterns[i].second = NextRecordedOperandNo;
501
502    // Get the slot we recorded the value in from the name on the node.
503    unsigned RecNodeEntry = VariableMap[N->getName()];
504    assert(!N->getName().empty() && RecNodeEntry &&
505           "Complex pattern should have a name and slot");
506    --RecNodeEntry;  // Entries in VariableMap are biased.
507
508    const ComplexPattern &CP =
509      CGP.getComplexPattern(((DefInit*)N->getLeafValue())->getDef());
510
511    // Emit a CheckComplexPat operation, which does the match (aborting if it
512    // fails) and pushes the matched operands onto the recorded nodes list.
513    AddMatcher(new CheckComplexPatMatcher(CP, RecNodeEntry,
514                                          N->getName(), NextRecordedOperandNo));
515
516    // Record the right number of operands.
517    NextRecordedOperandNo += CP.getNumOperands();
518    if (CP.hasProperty(SDNPHasChain)) {
519      // If the complex pattern has a chain, then we need to keep track of the
520      // fact that we just recorded a chain input.  The chain input will be
521      // matched as the last operand of the predicate if it was successful.
522      ++NextRecordedOperandNo; // Chained node operand.
523
524      // It is the last operand recorded.
525      assert(NextRecordedOperandNo > 1 &&
526             "Should have recorded input/result chains at least!");
527      MatchedChainNodes.push_back(NextRecordedOperandNo-1);
528    }
529
530    // TODO: Complex patterns can't have output glues, if they did, we'd want
531    // to record them.
532  }
533
534  return false;
535}
536
537
538//===----------------------------------------------------------------------===//
539// Node Result Generation
540//===----------------------------------------------------------------------===//
541
542void MatcherGen::EmitResultOfNamedOperand(const TreePatternNode *N,
543                                          SmallVectorImpl<unsigned> &ResultOps){
544  assert(!N->getName().empty() && "Operand not named!");
545
546  // A reference to a complex pattern gets all of the results of the complex
547  // pattern's match.
548  if (const ComplexPattern *CP = N->getComplexPatternInfo(CGP)) {
549    unsigned SlotNo = 0;
550    for (unsigned i = 0, e = MatchedComplexPatterns.size(); i != e; ++i)
551      if (MatchedComplexPatterns[i].first->getName() == N->getName()) {
552        SlotNo = MatchedComplexPatterns[i].second;
553        break;
554      }
555    assert(SlotNo != 0 && "Didn't get a slot number assigned?");
556
557    // The first slot entry is the node itself, the subsequent entries are the
558    // matched values.
559    for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
560      ResultOps.push_back(SlotNo+i);
561    return;
562  }
563
564  unsigned SlotNo = getNamedArgumentSlot(N->getName());
565
566  // If this is an 'imm' or 'fpimm' node, make sure to convert it to the target
567  // version of the immediate so that it doesn't get selected due to some other
568  // node use.
569  if (!N->isLeaf()) {
570    StringRef OperatorName = N->getOperator()->getName();
571    if (OperatorName == "imm" || OperatorName == "fpimm") {
572      AddMatcher(new EmitConvertToTargetMatcher(SlotNo));
573      ResultOps.push_back(NextRecordedOperandNo++);
574      return;
575    }
576  }
577
578  ResultOps.push_back(SlotNo);
579}
580
581void MatcherGen::EmitResultLeafAsOperand(const TreePatternNode *N,
582                                         SmallVectorImpl<unsigned> &ResultOps) {
583  assert(N->isLeaf() && "Must be a leaf");
584
585  if (IntInit *II = dyn_cast<IntInit>(N->getLeafValue())) {
586    AddMatcher(new EmitIntegerMatcher(II->getValue(), N->getType(0)));
587    ResultOps.push_back(NextRecordedOperandNo++);
588    return;
589  }
590
591  // If this is an explicit register reference, handle it.
592  if (DefInit *DI = dyn_cast<DefInit>(N->getLeafValue())) {
593    Record *Def = DI->getDef();
594    if (Def->isSubClassOf("Register")) {
595      const CodeGenRegister *Reg =
596        CGP.getTargetInfo().getRegBank().getReg(Def);
597      AddMatcher(new EmitRegisterMatcher(Reg, N->getType(0)));
598      ResultOps.push_back(NextRecordedOperandNo++);
599      return;
600    }
601
602    if (Def->getName() == "zero_reg") {
603      AddMatcher(new EmitRegisterMatcher(0, N->getType(0)));
604      ResultOps.push_back(NextRecordedOperandNo++);
605      return;
606    }
607
608    // Handle a reference to a register class. This is used
609    // in COPY_TO_SUBREG instructions.
610    if (Def->isSubClassOf("RegisterOperand"))
611      Def = Def->getValueAsDef("RegClass");
612    if (Def->isSubClassOf("RegisterClass")) {
613      std::string Value = getQualifiedName(Def) + "RegClassID";
614      AddMatcher(new EmitStringIntegerMatcher(Value, MVT::i32));
615      ResultOps.push_back(NextRecordedOperandNo++);
616      return;
617    }
618
619    // Handle a subregister index. This is used for INSERT_SUBREG etc.
620    if (Def->isSubClassOf("SubRegIndex")) {
621      std::string Value = getQualifiedName(Def);
622      AddMatcher(new EmitStringIntegerMatcher(Value, MVT::i32));
623      ResultOps.push_back(NextRecordedOperandNo++);
624      return;
625    }
626  }
627
628  errs() << "unhandled leaf node: \n";
629  N->dump();
630}
631
632/// GetInstPatternNode - Get the pattern for an instruction.
633///
634const TreePatternNode *MatcherGen::
635GetInstPatternNode(const DAGInstruction &Inst, const TreePatternNode *N) {
636  const TreePattern *InstPat = Inst.getPattern();
637
638  // FIXME2?: Assume actual pattern comes before "implicit".
639  TreePatternNode *InstPatNode;
640  if (InstPat)
641    InstPatNode = InstPat->getTree(0);
642  else if (/*isRoot*/ N == Pattern.getDstPattern())
643    InstPatNode = Pattern.getSrcPattern();
644  else
645    return 0;
646
647  if (InstPatNode && !InstPatNode->isLeaf() &&
648      InstPatNode->getOperator()->getName() == "set")
649    InstPatNode = InstPatNode->getChild(InstPatNode->getNumChildren()-1);
650
651  return InstPatNode;
652}
653
654static bool
655mayInstNodeLoadOrStore(const TreePatternNode *N,
656                       const CodeGenDAGPatterns &CGP) {
657  Record *Op = N->getOperator();
658  const CodeGenTarget &CGT = CGP.getTargetInfo();
659  CodeGenInstruction &II = CGT.getInstruction(Op);
660  return II.mayLoad || II.mayStore;
661}
662
663static unsigned
664numNodesThatMayLoadOrStore(const TreePatternNode *N,
665                           const CodeGenDAGPatterns &CGP) {
666  if (N->isLeaf())
667    return 0;
668
669  Record *OpRec = N->getOperator();
670  if (!OpRec->isSubClassOf("Instruction"))
671    return 0;
672
673  unsigned Count = 0;
674  if (mayInstNodeLoadOrStore(N, CGP))
675    ++Count;
676
677  for (unsigned i = 0, e = N->getNumChildren(); i != e; ++i)
678    Count += numNodesThatMayLoadOrStore(N->getChild(i), CGP);
679
680  return Count;
681}
682
683void MatcherGen::
684EmitResultInstructionAsOperand(const TreePatternNode *N,
685                               SmallVectorImpl<unsigned> &OutputOps) {
686  Record *Op = N->getOperator();
687  const CodeGenTarget &CGT = CGP.getTargetInfo();
688  CodeGenInstruction &II = CGT.getInstruction(Op);
689  const DAGInstruction &Inst = CGP.getInstruction(Op);
690
691  // If we can, get the pattern for the instruction we're generating.  We derive
692  // a variety of information from this pattern, such as whether it has a chain.
693  //
694  // FIXME2: This is extremely dubious for several reasons, not the least of
695  // which it gives special status to instructions with patterns that Pat<>
696  // nodes can't duplicate.
697  const TreePatternNode *InstPatNode = GetInstPatternNode(Inst, N);
698
699  // NodeHasChain - Whether the instruction node we're creating takes chains.
700  bool NodeHasChain = InstPatNode &&
701                      InstPatNode->TreeHasProperty(SDNPHasChain, CGP);
702
703  // Instructions which load and store from memory should have a chain,
704  // regardless of whether they happen to have an internal pattern saying so.
705  if (Pattern.getSrcPattern()->TreeHasProperty(SDNPHasChain, CGP)
706      && (II.hasCtrlDep || II.mayLoad || II.mayStore || II.canFoldAsLoad ||
707          II.hasSideEffects))
708      NodeHasChain = true;
709
710  bool isRoot = N == Pattern.getDstPattern();
711
712  // TreeHasOutGlue - True if this tree has glue.
713  bool TreeHasInGlue = false, TreeHasOutGlue = false;
714  if (isRoot) {
715    const TreePatternNode *SrcPat = Pattern.getSrcPattern();
716    TreeHasInGlue = SrcPat->TreeHasProperty(SDNPOptInGlue, CGP) ||
717                    SrcPat->TreeHasProperty(SDNPInGlue, CGP);
718
719    // FIXME2: this is checking the entire pattern, not just the node in
720    // question, doing this just for the root seems like a total hack.
721    TreeHasOutGlue = SrcPat->TreeHasProperty(SDNPOutGlue, CGP);
722  }
723
724  // NumResults - This is the number of results produced by the instruction in
725  // the "outs" list.
726  unsigned NumResults = Inst.getNumResults();
727
728  // Loop over all of the operands of the instruction pattern, emitting code
729  // to fill them all in.  The node 'N' usually has number children equal to
730  // the number of input operands of the instruction.  However, in cases
731  // where there are predicate operands for an instruction, we need to fill
732  // in the 'execute always' values.  Match up the node operands to the
733  // instruction operands to do this.
734  SmallVector<unsigned, 8> InstOps;
735  for (unsigned ChildNo = 0, InstOpNo = NumResults, e = II.Operands.size();
736       InstOpNo != e; ++InstOpNo) {
737
738    // Determine what to emit for this operand.
739    Record *OperandNode = II.Operands[InstOpNo].Rec;
740    if (OperandNode->isSubClassOf("OperandWithDefaultOps") &&
741        !CGP.getDefaultOperand(OperandNode).DefaultOps.empty()) {
742      // This is a predicate or optional def operand; emit the
743      // 'default ops' operands.
744      const DAGDefaultOperand &DefaultOp
745        = CGP.getDefaultOperand(OperandNode);
746      for (unsigned i = 0, e = DefaultOp.DefaultOps.size(); i != e; ++i)
747        EmitResultOperand(DefaultOp.DefaultOps[i], InstOps);
748      continue;
749    }
750
751    // Otherwise this is a normal operand or a predicate operand without
752    // 'execute always'; emit it.
753
754    // For operands with multiple sub-operands we may need to emit
755    // multiple child patterns to cover them all.  However, ComplexPattern
756    // children may themselves emit multiple MI operands.
757    unsigned NumSubOps = 1;
758    if (OperandNode->isSubClassOf("Operand")) {
759      DagInit *MIOpInfo = OperandNode->getValueAsDag("MIOperandInfo");
760      if (unsigned NumArgs = MIOpInfo->getNumArgs())
761        NumSubOps = NumArgs;
762    }
763
764    unsigned FinalNumOps = InstOps.size() + NumSubOps;
765    while (InstOps.size() < FinalNumOps) {
766      const TreePatternNode *Child = N->getChild(ChildNo);
767      unsigned BeforeAddingNumOps = InstOps.size();
768      EmitResultOperand(Child, InstOps);
769      assert(InstOps.size() > BeforeAddingNumOps && "Didn't add any operands");
770
771      // If the operand is an instruction and it produced multiple results, just
772      // take the first one.
773      if (!Child->isLeaf() && Child->getOperator()->isSubClassOf("Instruction"))
774        InstOps.resize(BeforeAddingNumOps+1);
775
776      ++ChildNo;
777    }
778  }
779
780  // If this node has input glue or explicitly specified input physregs, we
781  // need to add chained and glued copyfromreg nodes and materialize the glue
782  // input.
783  if (isRoot && !PhysRegInputs.empty()) {
784    // Emit all of the CopyToReg nodes for the input physical registers.  These
785    // occur in patterns like (mul:i8 AL:i8, GR8:i8:$src).
786    for (unsigned i = 0, e = PhysRegInputs.size(); i != e; ++i)
787      AddMatcher(new EmitCopyToRegMatcher(PhysRegInputs[i].second,
788                                          PhysRegInputs[i].first));
789    // Even if the node has no other glue inputs, the resultant node must be
790    // glued to the CopyFromReg nodes we just generated.
791    TreeHasInGlue = true;
792  }
793
794  // Result order: node results, chain, glue
795
796  // Determine the result types.
797  SmallVector<MVT::SimpleValueType, 4> ResultVTs;
798  for (unsigned i = 0, e = N->getNumTypes(); i != e; ++i)
799    ResultVTs.push_back(N->getType(i));
800
801  // If this is the root instruction of a pattern that has physical registers in
802  // its result pattern, add output VTs for them.  For example, X86 has:
803  //   (set AL, (mul ...))
804  // This also handles implicit results like:
805  //   (implicit EFLAGS)
806  if (isRoot && !Pattern.getDstRegs().empty()) {
807    // If the root came from an implicit def in the instruction handling stuff,
808    // don't re-add it.
809    Record *HandledReg = 0;
810    if (II.HasOneImplicitDefWithKnownVT(CGT) != MVT::Other)
811      HandledReg = II.ImplicitDefs[0];
812
813    for (unsigned i = 0; i != Pattern.getDstRegs().size(); ++i) {
814      Record *Reg = Pattern.getDstRegs()[i];
815      if (!Reg->isSubClassOf("Register") || Reg == HandledReg) continue;
816      ResultVTs.push_back(getRegisterValueType(Reg, CGT));
817    }
818  }
819
820  // If this is the root of the pattern and the pattern we're matching includes
821  // a node that is variadic, mark the generated node as variadic so that it
822  // gets the excess operands from the input DAG.
823  int NumFixedArityOperands = -1;
824  if (isRoot &&
825      (Pattern.getSrcPattern()->NodeHasProperty(SDNPVariadic, CGP)))
826    NumFixedArityOperands = Pattern.getSrcPattern()->getNumChildren();
827
828  // If this is the root node and multiple matched nodes in the input pattern
829  // have MemRefs in them, have the interpreter collect them and plop them onto
830  // this node. If there is just one node with MemRefs, leave them on that node
831  // even if it is not the root.
832  //
833  // FIXME3: This is actively incorrect for result patterns with multiple
834  // memory-referencing instructions.
835  bool PatternHasMemOperands =
836    Pattern.getSrcPattern()->TreeHasProperty(SDNPMemOperand, CGP);
837
838  bool NodeHasMemRefs = false;
839  if (PatternHasMemOperands) {
840    unsigned NumNodesThatLoadOrStore =
841      numNodesThatMayLoadOrStore(Pattern.getDstPattern(), CGP);
842    bool NodeIsUniqueLoadOrStore = mayInstNodeLoadOrStore(N, CGP) &&
843                                   NumNodesThatLoadOrStore == 1;
844    NodeHasMemRefs =
845      NodeIsUniqueLoadOrStore || (isRoot && (mayInstNodeLoadOrStore(N, CGP) ||
846                                             NumNodesThatLoadOrStore != 1));
847  }
848
849  assert((!ResultVTs.empty() || TreeHasOutGlue || NodeHasChain) &&
850         "Node has no result");
851
852  AddMatcher(new EmitNodeMatcher(II.Namespace+"::"+II.TheDef->getName(),
853                                 ResultVTs.data(), ResultVTs.size(),
854                                 InstOps.data(), InstOps.size(),
855                                 NodeHasChain, TreeHasInGlue, TreeHasOutGlue,
856                                 NodeHasMemRefs, NumFixedArityOperands,
857                                 NextRecordedOperandNo));
858
859  // The non-chain and non-glue results of the newly emitted node get recorded.
860  for (unsigned i = 0, e = ResultVTs.size(); i != e; ++i) {
861    if (ResultVTs[i] == MVT::Other || ResultVTs[i] == MVT::Glue) break;
862    OutputOps.push_back(NextRecordedOperandNo++);
863  }
864}
865
866void MatcherGen::
867EmitResultSDNodeXFormAsOperand(const TreePatternNode *N,
868                               SmallVectorImpl<unsigned> &ResultOps) {
869  assert(N->getOperator()->isSubClassOf("SDNodeXForm") && "Not SDNodeXForm?");
870
871  // Emit the operand.
872  SmallVector<unsigned, 8> InputOps;
873
874  // FIXME2: Could easily generalize this to support multiple inputs and outputs
875  // to the SDNodeXForm.  For now we just support one input and one output like
876  // the old instruction selector.
877  assert(N->getNumChildren() == 1);
878  EmitResultOperand(N->getChild(0), InputOps);
879
880  // The input currently must have produced exactly one result.
881  assert(InputOps.size() == 1 && "Unexpected input to SDNodeXForm");
882
883  AddMatcher(new EmitNodeXFormMatcher(InputOps[0], N->getOperator()));
884  ResultOps.push_back(NextRecordedOperandNo++);
885}
886
887void MatcherGen::EmitResultOperand(const TreePatternNode *N,
888                                   SmallVectorImpl<unsigned> &ResultOps) {
889  // This is something selected from the pattern we matched.
890  if (!N->getName().empty())
891    return EmitResultOfNamedOperand(N, ResultOps);
892
893  if (N->isLeaf())
894    return EmitResultLeafAsOperand(N, ResultOps);
895
896  Record *OpRec = N->getOperator();
897  if (OpRec->isSubClassOf("Instruction"))
898    return EmitResultInstructionAsOperand(N, ResultOps);
899  if (OpRec->isSubClassOf("SDNodeXForm"))
900    return EmitResultSDNodeXFormAsOperand(N, ResultOps);
901  errs() << "Unknown result node to emit code for: " << *N << '\n';
902  PrintFatalError("Unknown node in result pattern!");
903}
904
905void MatcherGen::EmitResultCode() {
906  // Patterns that match nodes with (potentially multiple) chain inputs have to
907  // merge them together into a token factor.  This informs the generated code
908  // what all the chained nodes are.
909  if (!MatchedChainNodes.empty())
910    AddMatcher(new EmitMergeInputChainsMatcher
911               (MatchedChainNodes.data(), MatchedChainNodes.size()));
912
913  // Codegen the root of the result pattern, capturing the resulting values.
914  SmallVector<unsigned, 8> Ops;
915  EmitResultOperand(Pattern.getDstPattern(), Ops);
916
917  // At this point, we have however many values the result pattern produces.
918  // However, the input pattern might not need all of these.  If there are
919  // excess values at the end (such as implicit defs of condition codes etc)
920  // just lop them off.  This doesn't need to worry about glue or chains, just
921  // explicit results.
922  //
923  unsigned NumSrcResults = Pattern.getSrcPattern()->getNumTypes();
924
925  // If the pattern also has (implicit) results, count them as well.
926  if (!Pattern.getDstRegs().empty()) {
927    // If the root came from an implicit def in the instruction handling stuff,
928    // don't re-add it.
929    Record *HandledReg = 0;
930    const TreePatternNode *DstPat = Pattern.getDstPattern();
931    if (!DstPat->isLeaf() &&DstPat->getOperator()->isSubClassOf("Instruction")){
932      const CodeGenTarget &CGT = CGP.getTargetInfo();
933      CodeGenInstruction &II = CGT.getInstruction(DstPat->getOperator());
934
935      if (II.HasOneImplicitDefWithKnownVT(CGT) != MVT::Other)
936        HandledReg = II.ImplicitDefs[0];
937    }
938
939    for (unsigned i = 0; i != Pattern.getDstRegs().size(); ++i) {
940      Record *Reg = Pattern.getDstRegs()[i];
941      if (!Reg->isSubClassOf("Register") || Reg == HandledReg) continue;
942      ++NumSrcResults;
943    }
944  }
945
946  assert(Ops.size() >= NumSrcResults && "Didn't provide enough results");
947  Ops.resize(NumSrcResults);
948
949  // If the matched pattern covers nodes which define a glue result, emit a node
950  // that tells the matcher about them so that it can update their results.
951  if (!MatchedGlueResultNodes.empty())
952    AddMatcher(new MarkGlueResultsMatcher(MatchedGlueResultNodes.data(),
953                                          MatchedGlueResultNodes.size()));
954
955  AddMatcher(new CompleteMatchMatcher(Ops.data(), Ops.size(), Pattern));
956}
957
958
959/// ConvertPatternToMatcher - Create the matcher for the specified pattern with
960/// the specified variant.  If the variant number is invalid, this returns null.
961Matcher *llvm::ConvertPatternToMatcher(const PatternToMatch &Pattern,
962                                       unsigned Variant,
963                                       const CodeGenDAGPatterns &CGP) {
964  MatcherGen Gen(Pattern, CGP);
965
966  // Generate the code for the matcher.
967  if (Gen.EmitMatcherCode(Variant))
968    return 0;
969
970  // FIXME2: Kill extra MoveParent commands at the end of the matcher sequence.
971  // FIXME2: Split result code out to another table, and make the matcher end
972  // with an "Emit <index>" command.  This allows result generation stuff to be
973  // shared and factored?
974
975  // If the match succeeds, then we generate Pattern.
976  Gen.EmitResultCode();
977
978  // Unconditional match.
979  return Gen.GetMatcher();
980}
981