[llvm] [TableGen] More generically handle tied source operands in CompressInstEmitter. (PR #146183)

[Rahul Joshi via llvm-commits]

================
@@ -331,60 +348,29 @@ static bool verifyDagOpCount(const CodeGenInstruction &Inst, const DagInit *Dag,
   return true;
 }
 
-static bool validateArgsTypes(const Init *Arg1, const Init *Arg2) {
-  return cast<DefInit>(Arg1)->getDef() == cast<DefInit>(Arg2)->getDef();
-}
-
-// Creates a mapping between the operand name in the Dag (e.g. $rs1) and
-// its index in the list of Dag operands and checks that operands with the same
-// name have the same types. For example in 'C_ADD $rs1, $rs2' we generate the
-// mapping $rs1 --> 0, $rs2 ---> 1. If the operand appears twice in the (tied)
-// same Dag we use the last occurrence for indexing.
-void CompressInstEmitter::createDagOperandMapping(
-    const Record *Rec, StringMap<unsigned> &SourceOperands,
-    StringMap<unsigned> &DestOperands, const DagInit *SourceDag,
-    const DagInit *DestDag, IndexedMap<OpData> &SourceOperandMap,
-    bool HasSourceTiedOp) {
-  for (unsigned I = 0; I < DestDag->getNumArgs(); ++I) {
-    // Skip fixed immediates and registers, they were handled in
-    // addDagOperandMapping.
-    if ("" == DestDag->getArgNameStr(I))
-      continue;
-    DestOperands[DestDag->getArgNameStr(I)] = I;
-  }
+// Check that all names in the source DAG appear in the destionation DAG.
+void CompressInstEmitter::checkDagOperandMapping(
+    const Record *Rec,
+    const StringMap<std::pair<unsigned, unsigned>> &DestOperands,
+    const DagInit *SourceDag, const DagInit *DestDag) {
 
   for (unsigned I = 0; I < SourceDag->getNumArgs(); ++I) {
     // Skip fixed immediates and registers, they were handled in
     // addDagOperandMapping.
-    if ("" == SourceDag->getArgNameStr(I))
+    if (SourceDag->getArgNameStr(I).empty())
       continue;
 
-    StringMap<unsigned>::iterator It =
-        SourceOperands.find(SourceDag->getArgNameStr(I));
-    if (It != SourceOperands.end()) {
-      // Operand sharing the same name in the Dag should be mapped as tied.
-      if (HasSourceTiedOp)
-        SourceOperandMap[I + 1].TiedOpIdx = It->getValue() + 1;
-      else
-        SourceOperandMap[I].TiedOpIdx = It->getValue();
-      if (!validateArgsTypes(SourceDag->getArg(It->getValue()),
-                             SourceDag->getArg(I)))
-        PrintFatalError(Rec->getLoc(),
-                        "Input Operand '" + SourceDag->getArgNameStr(I) +
-                            "' has a mismatched tied operand!\n");
-    }
-    It = DestOperands.find(SourceDag->getArgNameStr(I));
+    auto It = DestOperands.find(SourceDag->getArgNameStr(I));
----------------
jurahul wrote:

extract SourceDag->getArgNameStr(I) into a local variable?

https://github.com/llvm/llvm-project/pull/146183