Reimplement BuildResultOperands to be in terms of the result instruction's

operand list instead of the operand list redundantly declared on the alias
or instruction.

With this change, we finally remove the ins/outs list on the alias.  Before:
  def : InstAlias<(outs GR16:$dst), (ins GR8 :$src),
                  "movsx $src, $dst",
                  (MOVSX16rr8W GR16:$dst, GR8:$src)>;
After:
  def : InstAlias<"movsx $src, $dst",
                  (MOVSX16rr8W GR16:$dst, GR8:$src)>;

This also makes the alias mechanism more general and powerful, which will
be exploited in subsequent patches.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118329 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/AsmMatcherEmitter.cpp

@@ -313,9 +313,11 @@ struct MatchableInfo {
   /// DefRec - This is the definition that it came from.
   PointerUnion<const CodeGenInstruction*, const CodeGenInstAlias*> DefRec;
   
-  // FIXME: REMOVE.
-  const CGIOperandList &TheOperandList;
-
+  const CodeGenInstruction *getResultInst() const {
+    if (DefRec.is<const CodeGenInstruction*>())
+      return DefRec.get<const CodeGenInstruction*>();
+    return DefRec.get<const CodeGenInstAlias*>()->ResultInst;
+  }
   
   /// ResOperands - This is the operand list that should be built for the result
   /// MCInst.
@@ -344,13 +346,11 @@ struct MatchableInfo {
   std::string ConversionFnKind;
   
   MatchableInfo(const CodeGenInstruction &CGI)
-    : TheDef(CGI.TheDef), DefRec(&CGI),
-      TheOperandList(CGI.Operands), AsmString(CGI.AsmString) {
+    : TheDef(CGI.TheDef), DefRec(&CGI), AsmString(CGI.AsmString) {
   }
 
   MatchableInfo(const CodeGenInstAlias *Alias)
-    : TheDef(Alias->TheDef), DefRec(Alias), TheOperandList(Alias->Operands),
-      AsmString(Alias->AsmString) {
+    : TheDef(Alias->TheDef), DefRec(Alias), AsmString(Alias->AsmString) {
   }
   
   void Initialize(const AsmMatcherInfo &Info,
@@ -1128,7 +1128,7 @@ BuildInstructionOperandReference(MatchableInfo *II,
   const CodeGenInstruction &CGI = *II->DefRec.get<const CodeGenInstruction*>();
   const CGIOperandList &Operands = CGI.Operands;
   
-  // Map this token to an operand. FIXME: Move elsewhere.
+  // Map this token to an operand.
   unsigned Idx;
   if (!Operands.hasOperandNamed(OperandName, Idx))
     throw TGError(II->TheDef->getLoc(), "error: unable to find operand: '" +
@@ -1171,6 +1171,8 @@ void AsmMatcherInfo::BuildAliasOperandReference(MatchableInfo *II,
   // Set up the operand class.
   for (unsigned i = 0, e = CGA.ResultOperands.size(); i != e; ++i)
     if (CGA.ResultOperands[i].Name == OperandName) {
+      // It's safe to go with the first one we find, because CodeGenInstAlias
+      // validates that all operands with the same name have the same record.
       Op.Class = getOperandClass(CGA.ResultInst->Operands[i]);
       Op.SrcOpName = OperandName;
       return;
@@ -1181,8 +1183,12 @@ void AsmMatcherInfo::BuildAliasOperandReference(MatchableInfo *II,
 }
 
 void MatchableInfo::BuildResultOperands() {
-  for (unsigned i = 0, e = TheOperandList.size(); i != e; ++i) {
-    const CGIOperandList::OperandInfo &OpInfo = TheOperandList[i];
+  const CodeGenInstruction *ResultInst = getResultInst();
+  
+  // Loop over all operands of the result instruction, determining how to
+  // populate them.
+  for (unsigned i = 0, e = ResultInst->Operands.size(); i != e; ++i) {
+    const CGIOperandList::OperandInfo &OpInfo = ResultInst->Operands[i];
 
     // If this is a tied operand, just copy from the previously handled operand.
     int TiedOp = OpInfo.getTiedRegister();
@@ -1794,15 +1800,9 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
     MatchableInfo &II = **it;
 
 
-    const CodeGenInstruction *ResultInst;
-    if (II.DefRec.is<const CodeGenInstruction*>())
-      ResultInst = II.DefRec.get<const CodeGenInstruction*>();
-    else
-      ResultInst = II.DefRec.get<const CodeGenInstAlias*>()->ResultInst;
-    
-    OS << "  { " << Target.getName() << "::" << ResultInst->TheDef->getName()
-    << ", \"" << II.Mnemonic << "\""
-    << ", " << II.ConversionFnKind << ", { ";
+    OS << "  { " << Target.getName() << "::"
+       << II.getResultInst()->TheDef->getName() << ", \"" << II.Mnemonic << "\""
+       << ", " << II.ConversionFnKind << ", { ";
     for (unsigned i = 0, e = II.AsmOperands.size(); i != e; ++i) {
       MatchableInfo::AsmOperand &Op = II.AsmOperands[i];
 

utils/TableGen/CodeGenInstruction.cpp

@@ -389,10 +389,8 @@ FlattenAsmStringVariants(StringRef Cur, unsigned Variant) {
 /// CodeGenInstAlias Implementation
 //===----------------------------------------------------------------------===//
 
-CodeGenInstAlias::CodeGenInstAlias(Record *R, CodeGenTarget &T)
-  : TheDef(R), Operands(R) {
+CodeGenInstAlias::CodeGenInstAlias(Record *R, CodeGenTarget &T) : TheDef(R) {
   AsmString = R->getValueAsString("AsmString");
-
   Result = R->getValueAsDag("ResultInst");
 
   // Verify that the root of the result is an instruction.

utils/TableGen/CodeGenInstruction.h

@@ -258,10 +258,6 @@ namespace llvm {
     /// instruction.
     std::string AsmString;
     
-    /// Operands - This is information about the (ins) and (outs) list specified
-    /// to the alias.
-    CGIOperandList Operands;
-    
     /// Result - The result instruction.
     DagInit *Result;