+ return ContractNodes(MatcherPtr, CGP);
+ }
+
+ // 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.release();
+ 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, Operands,
+ EN->hasChain(), EN->hasInFlag(),
+ EN->hasOutFlag(),
+ EN->hasMemRefs(),
+ EN->getNumFixedArityOperands(),
+ Pattern));
+ return;
+ }
+
+ // FIXME2: Kill off all the SelectionDAG::SelectNodeTo and getMachineNode
+ // variants.