Prevent unnecessary CopyToReg when the same HW register appears in two spots
in the pattern.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25437 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/DAGISelEmitter.cpp b/utils/TableGen/DAGISelEmitter.cpp
index daf63a8..cd05277 100644
--- a/utils/TableGen/DAGISelEmitter.cpp
+++ b/utils/TableGen/DAGISelEmitter.cpp
@@ -1835,6 +1835,7 @@
std::map<std::string, Record*> OperatorMap;
// Names of all the folded nodes which produce chains.
std::vector<std::pair<std::string, unsigned> > FoldedChains;
+ std::set<std::string> Duplicates;
unsigned TmpNo;
public:
@@ -1952,6 +1953,7 @@
// previously named thing.
OS << " if (" << VarMapEntry << " != " << RootName << OpNo
<< ") goto P" << PatternNo << "Fail;\n";
+ Duplicates.insert(RootName + utostr(OpNo));
continue;
}
}
@@ -2351,6 +2353,13 @@
EmitCopyToRegs(Child, RootName + utostr(OpNo), ChainEmitted);
} else {
if (DefInit *DI = dynamic_cast<DefInit*>(Child->getLeafValue())) {
+ if (!Child->getName().empty()) {
+ std::string Name = RootName + utostr(OpNo);
+ if (Duplicates.find(Name) != Duplicates.end())
+ // A duplicate! Do not emit a copy for this node.
+ continue;
+ }
+
Record *RR = DI->getDef();
if (RR->isSubClassOf("Register")) {
MVT::ValueType RVT = getRegisterValueType(RR, T);