[TableGen][DecoderEmitter] Remove PredicateNamespace (NFC) (#155211)

There is no target named Thumb, so there is no need to make a special
case for it.

As part of this change, pass CodeGenTarget instead of DecoderEmitter
to FilterChooser to remove dependency between the latter two.

Author: s-barannikov

llvm/utils/TableGen/DecoderEmitter.cpp

@@ -340,7 +340,7 @@ class DecoderEmitter {
   SmallDenseMap<unsigned, std::vector<unsigned>> EncodingIDsByHwMode;
 
 public:
-  DecoderEmitter(const RecordKeeper &RK, StringRef PredicateNamespace);
+  explicit DecoderEmitter(const RecordKeeper &RK);
 
   const CodeGenTarget &getTarget() const { return Target; }
 
@@ -370,9 +370,6 @@ class DecoderEmitter {
                                   NamespacesHwModesMap &NamespacesWithHwModes);
 
   void parseInstructionEncodings();
-
-public:
-  StringRef PredicateNamespace;
 };
 
 } // end anonymous namespace
@@ -487,8 +484,7 @@ class FilterChooser {
   /// This field allows us to ignore the extra bits.
   unsigned MaxFilterWidth;
 
-  // Parent emitter
-  const DecoderEmitter *Emitter;
+  const CodeGenTarget &Target;
 
   /// If the selected filter matches multiple encodings, then this is the
   /// starting position and the width of the filtered range.
@@ -524,9 +520,9 @@ class FilterChooser {
   /// Constructs a top-level filter chooser.
   FilterChooser(ArrayRef<InstructionEncoding> Encodings,
                 ArrayRef<unsigned> EncodingIDs, unsigned MaxFilterWidth,
-                const DecoderEmitter *E)
+                const CodeGenTarget &Target)
       : Encodings(Encodings), EncodingIDs(EncodingIDs), Parent(nullptr),
-        MaxFilterWidth(MaxFilterWidth), Emitter(E) {
+        MaxFilterWidth(MaxFilterWidth), Target(Target) {
     // Sort encoding IDs once.
     stable_sort(this->EncodingIDs, LessEncodingIDByWidth(Encodings));
     // Filter width is the width of the smallest encoding.
@@ -542,7 +538,7 @@ class FilterChooser {
                 ArrayRef<unsigned> EncodingIDs, const KnownBits &FilterBits,
                 const FilterChooser &Parent)
       : Encodings(Encodings), EncodingIDs(EncodingIDs), Parent(&Parent),
-        MaxFilterWidth(Parent.MaxFilterWidth), Emitter(Parent.Emitter) {
+        MaxFilterWidth(Parent.MaxFilterWidth), Target(Parent.Target) {
     // Inferior filter choosers are created from sorted array of encoding IDs.
     assert(is_sorted(EncodingIDs, LessEncodingIDByWidth(Encodings)));
     assert(!FilterBits.hasConflict() && "Broken filter");
@@ -1155,8 +1151,7 @@ bool FilterChooser::emitPredicateMatchAux(const Init &Val, bool ParenIfBinOp,
   if (const auto *D = dyn_cast<DefInit>(&Val)) {
     if (!D->getDef()->isSubClassOf("SubtargetFeature"))
       return true;
-    OS << "Bits[" << Emitter->PredicateNamespace << "::" << D->getAsString()
-       << "]";
+    OS << "Bits[" << Target.getName() << "::" << D->getAsString() << "]";
     return false;
   }
   if (const auto *D = dyn_cast<DagInit>(&Val)) {
@@ -1350,7 +1345,7 @@ void FilterChooser::emitSingletonTableEntry(DecoderTableInfo &TableInfo,
                                      : MCD::OPC_TryDecode;
   TableInfo.Table.insertOpcode(DecoderOp);
   const Record *InstDef = Encodings[EncodingID].getInstruction()->TheDef;
-  TableInfo.Table.insertULEB128(Emitter->getTarget().getInstrIntValue(InstDef));
+  TableInfo.Table.insertULEB128(Target.getInstrIntValue(InstDef));
   TableInfo.Table.insertULEB128(DIdx);
 
   if (DecoderOp == MCD::OPC_TryDecode) {
@@ -2502,10 +2497,8 @@ void DecoderEmitter::parseInstructionEncodings() {
   NumEncodings = NumEncodingsSupported + NumEncodingsOmitted;
 }
 
-DecoderEmitter::DecoderEmitter(const RecordKeeper &RK,
-                               StringRef PredicateNamespace)
-    : RK(RK), Target(RK), CGH(Target.getHwModes()),
-      PredicateNamespace(PredicateNamespace) {
+DecoderEmitter::DecoderEmitter(const RecordKeeper &RK)
+    : RK(RK), Target(RK), CGH(Target.getHwModes()) {
   Target.reverseBitsForLittleEndianEncoding();
   parseInstructionEncodings();
 }
@@ -2560,7 +2553,7 @@ namespace {
     auto [DecoderNamespace, HwModeID, Size] = Key;
     const unsigned BitWidth = IsVarLenInst ? MaxInstLen : 8 * Size;
     // Emit the decoder for this (namespace, hwmode, width) combination.
-    FilterChooser FC(Encodings, EncodingIDs, BitWidth, this);
+    FilterChooser FC(Encodings, EncodingIDs, BitWidth, Target);
 
     // The decode table is cleared for each top level decoder function. The
     // predicates and decoders themselves, however, are shared across all
@@ -2603,7 +2596,6 @@ namespace {
   OS << "\n} // namespace\n";
 }
 
-void llvm::EmitDecoder(const RecordKeeper &RK, raw_ostream &OS,
-                       StringRef PredicateNamespace) {
-  DecoderEmitter(RK, PredicateNamespace).run(OS);
+void llvm::EmitDecoder(const RecordKeeper &RK, raw_ostream &OS) {
+  DecoderEmitter(RK).run(OS);
 }

llvm/utils/TableGen/DisassemblerEmitter.cpp

@@ -123,10 +123,7 @@ static void emitDisassembler(const RecordKeeper &Records, raw_ostream &OS) {
     return;
   }
 
-  StringRef PredicateNamespace = Target.getName();
-  if (PredicateNamespace == "Thumb")
-    PredicateNamespace = "ARM";
-  EmitDecoder(Records, OS, PredicateNamespace);
+  EmitDecoder(Records, OS);
 }
 
 cl::OptionCategory DisassemblerEmitterCat("Options for -gen-disassembler");

llvm/utils/TableGen/TableGenBackends.h

@@ -64,8 +64,7 @@ class RecordKeeper;
 void EmitMapTable(const RecordKeeper &RK, raw_ostream &OS);
 
 // Defined in DecoderEmitter.cpp
-void EmitDecoder(const RecordKeeper &RK, raw_ostream &OS,
-                 StringRef PredicateNamespace);
+void EmitDecoder(const RecordKeeper &RK, raw_ostream &OS);
 
 } // namespace llvm