[globalisel][tablegen] Generate TypeObject table. NFC

[dsanders]

Summary

Generate the type table from the types used by a target rather than hard-coding
the union of types used by all targets.

Depends on D36084

[rovka]

You should add checks for the GILLT enum in GlobalISelEmitter.td, since now it won't be the same enum for all targets.

utils/TableGen/GlobalISelEmitter.cpp

116

This is going to fall all the way to the unreachable if both types are invalid - you should check that case explicitly.

123

I think you can get rid of this check. If Ty.isVector, you check NumElements, and if that doesn't settle it then you can unconditionally look at the SizeInBits and it will be relevant for both scalars and vectors.

[dsanders]

utils/TableGen/GlobalISelEmitter.cpp

116

Well spotted.

123

I agree.

[dsanders]

Fixed the priority sort-order nits:

• Returns false if both sides are invalid instead of aborting.
• Avoid checking size-in-bits on separate code-paths and handle it in one place.
• Also order pointers and pointer address spaces since there's no longer an unreachable for them to fall into.

[rovka]

LGTM now.

[dsanders]

This was reverted in order to revert D36084. Investigating the problem with D36084

utils/TableGen/GlobalISelEmitter.cpp

if (Ty.isVector()) {
       return;
     }
     llvm_unreachable("Unhandled LLT");
   }
 
   const LLT &get() const { return Ty; }
 
   /// This ordering is used for std::unique() and std::sort(). There's no
-  /// particular logic behind the order.
+  /// particular logic behind the order but either A < B or B < A must be
+  /// true if A != B.
   bool operator<(const LLTCodeGen &Other) const {
-    if (!Ty.isValid())
-      return Other.Ty.isValid();
-    if (Ty.isScalar()) {
-      if (!Other.Ty.isValid())
-        return false;
-      if (Other.Ty.isScalar())
-        return Ty.getSizeInBits() < Other.Ty.getSizeInBits();
-      return false;
-    }
+    if (Ty.isValid() != Other.Ty.isValid())
+      return Ty.isValid() < Other.Ty.isValid();
+    if (Ty.isVector() != Other.Ty.isVector())
+      return Ty.isVector() < Other.Ty.isVector();
+    if (Ty.isScalar() != Other.Ty.isScalar())
+      return Ty.isScalar() < Other.Ty.isScalar();
+
+    if (Ty.isScalar())
+
     if (Ty.isVector()) {
-      if (!Other.Ty.isValid() || Other.Ty.isScalar())
-        return false;
-      if (Other.Ty.isVector()) {
-        if (Ty.getNumElements() < Other.Ty.getNumElements())
-          return true;
-        if (Ty.getNumElements() > Other.Ty.getNumElements())
-          return false;
-        return Ty.getSizeInBits() < Other.Ty.getSizeInBits();
-      }
-      return false;
-    }
+      if (Ty.getNumElements() != Other.Ty.getNumElements())
+        return Ty.getNumElements() < Other.Ty.getNumElements();
     llvm_unreachable("Unhandled LLT");
   }
 };
 
 class InstructionMatcher;
 /// Convert an MVT to an equivalent LLT if possible, or the invalid LLT() for
 /// MVTs that don't map cleanly to an LLT (e.g., iPTR, *any, ...).
 static Optional<LLTCodeGen> MVTToLLT(MVT::SimpleValueType SVT) {

 };
 
 /// Generates code to check that an operand is a particular LLT.
 class LLTOperandMatcher : public OperandPredicateMatcher {
 protected:
   LLTCodeGen Ty;
 
 public:
+  static std::set<LLTCodeGen> KnownTypes;
+
   LLTOperandMatcher(const LLTCodeGen &Ty)
-      : OperandPredicateMatcher(OPM_LLT), Ty(Ty) {}
+      : OperandPredicateMatcher(OPM_LLT), Ty(Ty) {
+    KnownTypes.insert(Ty);
+  }
 
   static bool classof(const OperandPredicateMatcher *P) {
     return P->getKind() == OPM_LLT;
   }
 
   void emitPredicateOpcodes(MatchTable &Table, RuleMatcher &Rule,
                             unsigned InsnVarID, unsigned OpIdx) const override {
     Table << MatchTable::Opcode("GIM_CheckType") << MatchTable::Comment("MI")
           << MatchTable::IntValue(InsnVarID) << MatchTable::Comment("Op")
           << MatchTable::IntValue(OpIdx) << MatchTable::Comment("Type")
           << MatchTable::NamedValue(Ty.getCxxEnumValue())
           << MatchTable::LineBreak;
   }
 };
 
+std::set<LLTCodeGen> LLTOperandMatcher::KnownTypes;
+
 /// Generates code to check that an operand is a particular target constant.
 class ComplexPatternOperandMatcher : public OperandPredicateMatcher {
 protected:
   const OperandMatcher &Operand;
   const Record &TheDef;
 
   unsigned getAllocatedTemporariesBaseID() const;
 
SubtargetFeatureInfo::emitComputeAvailableFeatures(
       ModuleFeatures, OS);
   SubtargetFeatureInfo::emitComputeAvailableFeatures(
       Target.getName(), "InstructionSelector",
       "computeAvailableFunctionFeatures", FunctionFeatures, OS,
       "const MachineFunction *MF");
 
   // Emit a table containing the LLT objects needed by the matcher and an enum
   // for the matcher to reference them with.
-  std::vector<LLTCodeGen> TypeObjects = {
-      LLT::scalar(8),      LLT::scalar(16),     LLT::scalar(32),
-      LLT::scalar(64),     LLT::scalar(80),     LLT::scalar(128),
-      LLT::vector(8, 1),   LLT::vector(16, 1),  LLT::vector(32, 1),
-      LLT::vector(64, 1),  LLT::vector(8, 8),   LLT::vector(16, 8),
-      LLT::vector(32, 8),  LLT::vector(64, 8),  LLT::vector(4, 16),
-      LLT::vector(8, 16),  LLT::vector(16, 16), LLT::vector(32, 16),
-      LLT::vector(2, 32),  LLT::vector(4, 32),  LLT::vector(8, 32),
-      LLT::vector(16, 32), LLT::vector(2, 64),  LLT::vector(4, 64),
-      LLT::vector(8, 64),
-  };
+  std::vector<LLTCodeGen> TypeObjects;
+  for (const auto &Ty : LLTOperandMatcher::KnownTypes)
+    TypeObjects.push_back(Ty);
   std::sort(TypeObjects.begin(), TypeObjects.end());
   OS << "enum {\n";
   for (const auto &TypeObject : TypeObjects) {
     OS << "  ";
     TypeObject.emitCxxEnumValue(OS);
     OS << ",\n";
   }
   OS << "};\n"