+
+ // Turn EmitNode->MarkFlagResults->CompleteMatch into
+ // MarkFlagResults->EmitNode->CompleteMatch when we can to encourage
+ // MorphNodeTo formation. This is safe because MarkFlagResults never refers
+ // to the root of the pattern.
+ if (isa<EmitNodeMatcher>(N) && isa<MarkGlueResultsMatcher>(N->getNext()) &&
+ isa<CompleteMatchMatcher>(N->getNext()->getNext())) {
+ // Unlink the two nodes from the list.
+ Matcher *EmitNode = MatcherPtr.take();
+ Matcher *MFR = EmitNode->takeNext();
+ Matcher *Tail = MFR->takeNext();
+
+ // Relink them.
+ MatcherPtr.reset(MFR);
+ MFR->setNext(EmitNode);
+ EmitNode->setNext(Tail);
+ return ContractNodes(MatcherPtr, CGP);
+ }
+
+ // Turn EmitNode->CompleteMatch into MorphNodeTo if we can.
+ if (EmitNodeMatcher *EN = dyn_cast<EmitNodeMatcher>(N))
+ if (CompleteMatchMatcher *CM =
+ dyn_cast<CompleteMatchMatcher>(EN->getNext())) {
+ // We can only use MorphNodeTo if the result values match up.
+ unsigned RootResultFirst = EN->getFirstResultSlot();
+ bool ResultsMatch = true;
+ for (unsigned i = 0, e = CM->getNumResults(); i != e; ++i)
+ if (CM->getResult(i) != RootResultFirst+i)
+ ResultsMatch = false;
+
+ // If the selected node defines a subset of the glue/chain results, we
+ // can't use MorphNodeTo. For example, we can't use MorphNodeTo if the
+ // matched pattern has a chain but the root node doesn't.
+ const PatternToMatch &Pattern = CM->getPattern();
+
+ if (!EN->hasChain() &&
+ Pattern.getSrcPattern()->NodeHasProperty(SDNPHasChain, CGP))
+ ResultsMatch = false;
+
+ // If the matched node has glue and the output root doesn't, we can't
+ // use MorphNodeTo.
+ //
+ // NOTE: Strictly speaking, we don't have to check for glue here
+ // because the code in the pattern generator doesn't handle it right. We
+ // do it anyway for thoroughness.
+ if (!EN->hasOutFlag() &&
+ Pattern.getSrcPattern()->NodeHasProperty(SDNPOutGlue, CGP))
+ ResultsMatch = false;
+
+
+ // If the root result node defines more results than the source root node
+ // *and* has a chain or glue input, then we can't match it because it
+ // would end up replacing the extra result with the chain/glue.
+#if 0
+ if ((EN->hasGlue() || EN->hasChain()) &&
+ EN->getNumNonChainGlueVTs() > ... need to get no results reliably ...)
+ ResultMatch = false;
+#endif
+
+ if (ResultsMatch) {
+ const SmallVectorImpl<MVT::SimpleValueType> &VTs = EN->getVTList();
+ const SmallVectorImpl<unsigned> &Operands = EN->getOperandList();
+ MatcherPtr.reset(new MorphNodeToMatcher(EN->getOpcodeName(),
+ VTs.data(), VTs.size(),
+ Operands.data(),Operands.size(),
+ EN->hasChain(), EN->hasInFlag(),
+ EN->hasOutFlag(),
+ EN->hasMemRefs(),
+ EN->getNumFixedArityOperands(),
+ Pattern));
+ return;
+ }
+
+ // FIXME2: Kill off all the SelectionDAG::SelectNodeTo and getMachineNode
+ // variants.
+ }
+
+ ContractNodes(N->getNextPtr(), CGP);
+
+
+ // If we have a CheckType/CheckChildType/Record node followed by a
+ // CheckOpcode, invert the two nodes. We prefer to do structural checks
+ // before type checks, as this opens opportunities for factoring on targets
+ // like X86 where many operations are valid on multiple types.
+ if ((isa<CheckTypeMatcher>(N) || isa<CheckChildTypeMatcher>(N) ||
+ isa<RecordMatcher>(N)) &&
+ isa<CheckOpcodeMatcher>(N->getNext())) {
+ // Unlink the two nodes from the list.
+ Matcher *CheckType = MatcherPtr.take();
+ Matcher *CheckOpcode = CheckType->takeNext();
+ Matcher *Tail = CheckOpcode->takeNext();
+
+ // Relink them.
+ MatcherPtr.reset(CheckOpcode);
+ CheckOpcode->setNext(CheckType);
+ CheckType->setNext(Tail);
+ return ContractNodes(MatcherPtr, CGP);
+ }
+}
+
+/// SinkPatternPredicates - Pattern predicates can be checked at any level of
+/// the matching tree. The generator dumps them at the top level of the pattern
+/// though, which prevents factoring from being able to see past them. This
+/// optimization sinks them as far down into the pattern as possible.
+///
+/// Conceptually, we'd like to sink these predicates all the way to the last
+/// matcher predicate in the series. However, it turns out that some
+/// ComplexPatterns have side effects on the graph, so we really don't want to
+/// run a the complex pattern if the pattern predicate will fail. For this
+/// reason, we refuse to sink the pattern predicate past a ComplexPattern.
+///
+static void SinkPatternPredicates(OwningPtr<Matcher> &MatcherPtr) {
+ // Recursively scan for a PatternPredicate.
+ // If we reached the end of the chain, we're done.
+ Matcher *N = MatcherPtr.get();
+ if (N == 0) return;
+
+ // Walk down all members of a scope node.
+ if (ScopeMatcher *Scope = dyn_cast<ScopeMatcher>(N)) {
+ for (unsigned i = 0, e = Scope->getNumChildren(); i != e; ++i) {
+ OwningPtr<Matcher> Child(Scope->takeChild(i));
+ SinkPatternPredicates(Child);
+ Scope->resetChild(i, Child.take());
+ }
+ return;
+ }