Add support for visiting op classes

Op classes are sets of ops, providing a common base class in the op class hierarchy,
which can be used to group sets of ops with a common property.

Before this patch, op class only support `isa<>` checks, but not visiting.

This was because visiting relies on `OpDescription::get<OpT>`, which is only supported
for concrete ops, but not op classes.

This patch changes that by introducing a new `OpDescription::getAll<OpT>` template
which returns an `ArrayRef` of OpDescriptions. The existing `get<OpT>` template
is implemented in terms of the new `getAll` template.

Visitor code is changed to use `getAll` instead, and handle non-trivial array refs
(representing op classes) accordingly, using the already existing mechanism for op sets.

Author: jasilvanus

include/llvm-dialects/Dialect/OpDescription.h

@@ -65,8 +65,14 @@ class OpDescription {
     return m_kind == Kind::Dialect || m_kind == Kind::DialectWithOverloads;
   }
 
+  // Only supported for concrete ops, not for op classes.
   template <typename OpT> static const OpDescription &get();
 
+  // For concrete ops, returns a 1-element array containing the result of get().
+  // For op classes, returns an array containing the descriptions of all
+  // concrete ops that belong to this op class.
+  template <typename OpT> static llvm::ArrayRef<OpDescription> getAll();
+
   Kind getKind() const { return m_kind; }
 
   unsigned getOpcode() const;

include/llvm-dialects/Dialect/Visitor.h

@@ -120,9 +120,18 @@ class VisitorKey {
   friend class VisitorTemplate;
 
 public:
+  // OpT may be a concrete dialect op, or an op class.
   template <typename OpT> static VisitorKey op() {
-    VisitorKey key{Kind::OpDescription};
-    key.m_description = &OpDescription::get<OpT>();
+    auto const descriptions = OpDescription::getAll<OpT>();
+    if (descriptions.size() == 1) {
+      VisitorKey key{Kind::OpDescription};
+      key.m_description = &descriptions[0];
+      return key;
+    }
+    // OpT is an op class. Resolve it by all concrete sub ops.
+    static const OpSet set = OpSet::fromOpDescriptions(descriptions);
+    VisitorKey key{Kind::OpSet};
+    key.m_set = &set;
     return key;
   }
 

lib/Dialect/OpDescription.cpp

@@ -112,6 +112,10 @@ template <> const OpDescription &OpDescription::get<UnaryInstruction>() {
   return desc;
 }
 
+template <> ArrayRef<OpDescription> OpDescription::getAll<UnaryInstruction>() {
+  return get<UnaryInstruction>();
+}
+
 template <> const OpDescription &OpDescription::get<BinaryOperator>() {
   static unsigned opcodes[] = {
 #define HANDLE_BINARY_INST(num, opcode, Class) Instruction::opcode,
@@ -121,6 +125,10 @@ template <> const OpDescription &OpDescription::get<BinaryOperator>() {
   return desc;
 }
 
+template <> ArrayRef<OpDescription> OpDescription::getAll<BinaryOperator>() {
+  return get<BinaryOperator>();
+}
+
 // Generate OpDescription for all dedicate instruction classes.
 #define HANDLE_USER_INST(...)
 #define HANDLE_UNARY_INST(...)
@@ -129,19 +137,28 @@ template <> const OpDescription &OpDescription::get<BinaryOperator>() {
   template <> const OpDescription &OpDescription::get<Class>() {               \
     static const OpDescription desc{Kind::Core, Instruction::opcode};          \
     return desc;                                                               \
+  }                                                                            \
+  template <> ArrayRef<OpDescription> OpDescription::getAll<Class>() {         \
+    return get<Class>();                                                       \
   }
 #include "llvm/IR/Instruction.def"
 
 #define HANDLE_INTRINSIC_DESC(Class, opcode)                                   \
   template <> const OpDescription &OpDescription::get<Class>() {               \
     static const OpDescription desc{Kind::Intrinsic, Intrinsic::opcode};       \
     return desc;                                                               \
+  }                                                                            \
+  template <> ArrayRef<OpDescription> OpDescription::getAll<Class>() {         \
+    return get<Class>();                                                       \
   }
 #define HANDLE_INTRINSIC_DESC_OPCODE_SET(Class, ...)                           \
   template <> const OpDescription &OpDescription::get<Class>() {               \
     static unsigned opcodes[] = {__VA_ARGS__};                                 \
     static const OpDescription desc{Kind::Intrinsic, opcodes};                 \
     return desc;                                                               \
+  }                                                                            \
+  template <> ArrayRef<OpDescription> OpDescription::getAll<Class>() {         \
+    return get<Class>();                                                       \
   }
 
 // ============================================================================

lib/TableGen/GenDialect.cpp

@@ -271,6 +271,7 @@ void llvm_dialects::genDialectDefs(raw_ostream &out, RecordKeeperTy &records) {
 
   out << R"(
 #include "llvm/Support/raw_ostream.h"
+#include <array>
 #endif // GET_INCLUDES
 
 #ifdef GET_DIALECT_DEFS
@@ -326,10 +327,10 @@ void llvm_dialects::genDialectDefs(raw_ostream &out, RecordKeeperTy &records) {
     }
 
     bool $Dialect::isDialectOp(::llvm::CallInst& op) {
-      ::llvm::Function *calledFunc = op.getCalledFunction(); 
+      ::llvm::Function *calledFunc = op.getCalledFunction();
       if (!calledFunc)
         return false;
-      
+
       return isDialectOp(calledFunc->getName());
     }
 
@@ -448,14 +449,18 @@ void llvm_dialects::genDialectDefs(raw_ostream &out, RecordKeeperTy &records) {
   if (!dialect->cppNamespace.empty())
     out << tgfmt("} // namespace $namespace\n", &fmt);
 
-  // Define specializations of OpDescription::get for reflection
+  // Define specializations of OpDescription::{get, getAll} for reflection
   for (const auto &opPtr : dialect->operations) {
     Operation &op = *opPtr;
 
     FmtContextScope scope{fmt};
     fmt.withOp(op.name);
     fmt.addSubst("mnemonic", op.mnemonic);
 
+    // We'd prefer fully qualifying the llvm_dialects namespace below in getAll
+    // with leading "::", but this is parsed as oart of the preceding ArrayRef
+    // type as there are just spaces in between. (gcc/clang/MSVC reject this)
+    // The get() variant does not have this problem due to the `&` token.
     out << tgfmt(R"(
       template <>
       const ::llvm_dialects::OpDescription &
@@ -464,10 +469,48 @@ void llvm_dialects::genDialectDefs(raw_ostream &out, RecordKeeperTy &records) {
         return desc;
       }
 
+      template <>
+      ::llvm::ArrayRef<::llvm_dialects::OpDescription>
+      llvm_dialects::OpDescription::getAll<$namespace::$_op>() {
+        return get<$namespace::$_op>();
+      }
+
     )",
                  &fmt, op.haveResultOverloads() ? "true" : "false");
   }
 
+  // Define specializations of OpDescription::getAll for op classes
+  for (const auto &opClassPtr : dialect->opClasses) {
+    OpClass &opClass = *opClassPtr;
+
+    FmtContextScope scope{fmt};
+    fmt.withOp(opClass.name);
+
+    // We'd prefer fully qualifying the llvm_dialects namespace below with
+    // leading "::", but gcc/clang/MSVC reject this as they interpret the
+    // ::llvm_dialects identifier than within the preceding ArrayRef type. The
+    // get() variant does not have this problem as the `&` token separates the
+    // two.
+    out << tgfmt(R"(
+      template <>
+      ::llvm::ArrayRef<::llvm_dialects::OpDescription>
+      llvm_dialects::OpDescription::getAll<$namespace::$_op>() {
+        static const std::array<::llvm_dialects::OpDescription, $0> desc{)",
+                 &fmt, opClass.operations.size());
+    for (const auto &op : opClass.operations) {
+      fmt.addSubst("mnemonic", op->mnemonic);
+      out << tgfmt(R"(
+          ::llvm_dialects::OpDescription{$0, "$dialect.$mnemonic"},)",
+                   &fmt, op->haveResultOverloads() ? "true" : "false");
+    }
+    out << tgfmt(R"(
+        };
+        return desc;
+      }
+    )",
+                 &fmt, opClass.operations.size());
+  }
+
   out << R"(
 #endif // GET_DIALECT_DEFS
 )";