[ImportVerilog][Moore] Support union type (#7084)

* [ImportVerilog]Support union types.

* [ImportVerilog]Rename structMember with structLikeMember

* [ImportVerilog] check the type of new Expressions.

* [ImportVerilog]Add value check for new Expressions.

* clang-format modify recommand

* [importVerilog]Remove useless inlcludes

* [ImportVerilog]Add union size and domain

* [ImportVerilog]Give more specefic errors

include/circt/Dialect/Moore/MooreOps.td

@@ -790,7 +790,7 @@ def ExtractOp : MooreOp<"extract"> {
     $input `from` $lowBit attr-dict `:`
     type($input) `,` type($lowBit) `->` type($result)
   }];
-} 
+}
 
 def StructCreateOp : MooreOp<"struct_create", [SameOperandsAndResultType]> {
   let summary = "Struct Create operation";
@@ -817,11 +817,11 @@ def StructCreateOp : MooreOp<"struct_create", [SameOperandsAndResultType]> {
     ```
     See IEEE 1800-2017 § 7.2. "Structures".
   }];
-  let arguments = (ins UnpackedType:$structName);
+  let arguments = (ins UnpackedType:$input);
   let results = (outs UnpackedType:$result);
   let hasCustomAssemblyFormat = 1;
   let assemblyFormat = [{
-    $structName attr-dict `:` type($structName)
+  $input attr-dict `:` type($input)
   }];
 }
 
@@ -853,11 +853,12 @@ def StructExtractOp : MooreOp<"struct_extract"> {
     ```
     See IEEE 1800-2017 § 7.2.1 "Assigning to structures".
   }];
-  let arguments = (ins StrAttr:$memberName, UnpackedType:$structName);
+  let arguments = (ins StrAttr:$memberName, UnpackedType:$input);
   let results = (outs UnpackedType:$result);
   let assemblyFormat = [{
-    $structName `,`   $memberName  attr-dict `:`
-    type($structName) `->` type($result)
+  $input `,`   $memberName  attr-dict `:`
+  type($input) `->`
+  type($result)
   }];
 }
 
@@ -894,4 +895,67 @@ def StructInjectOp : MooreOp<"struct_inject"> {
   }];
 }
 
+def UnionCreateOp : MooreOp<"union_create"> {
+  let summary = "Union Create operation";
+  let description = [{
+  A union is a data type that represents a single piece
+  of storage that can be accessed using one of
+  the named member data types. Only one of the
+  data types in the union can be used at a time.
+  By default, a union is unpacked, meaning there
+  is no required representation for how members
+  of the union are stored. Dynamic types and chandle
+  types can only be used in tagged unions.
+  See IEEE 1800-2017 § 7.3 "Unions"
+
+  Example:
+  ```
+  typedef union { int i; shortreal f; } num; // named union type
+  num n;
+  n.f = 0.0; // set n in floating point format
+  typedef struct {
+  bit isfloat;
+  union { int i; shortreal f; } n;           // anonymous union type
+  } tagged_st;                               // named structure
+  ```
+  See IEEE 1800-2017 § 7.3 "Unions"
+  }];
+  let arguments = (ins StrAttr:$unionName, UnpackedType:$input);
+  let results = (outs UnpackedType:$result);
+  let assemblyFormat = [{
+  $unionName `,` $input attr-dict `:`
+  type($input) `->` type($result)
+  }];
+ }
+
+ def UnionExtractOp : MooreOp<"union_extract"> {
+  let summary = "Union Extract operation";
+  let description = [{
+  With packed unions, writing one member and reading another is
+  independent of the byte ordering of the machine,
+  unlike an unpacked union of unpacked structures,
+  which are C-compatible and have members in ascending address order.
+  See IEEE 1800-2017 § 7.3.1 "Packed unions"
+
+  Example:
+  ```
+  typedef union packed { // default unsigned
+  s_atmcell acell;
+  bit [423:0] bit_slice;
+  bit [52:0][7:0] byte_slice;
+  } u_atmcell;
+  u_atmcell u1;
+  byte b; bit [3:0] nib;
+  b = u1.bit_slice[415:408]; // same as b = u1.byte_slice[51];
+  nib = u1.bit_slice [423:420];
+  ```
+  See IEEE 1800-2017 § 7.3.1 "Packed unions"
+  }];
+  let arguments = (ins StrAttr:$memberName, UnpackedType:$input);
+  let results = (outs UnpackedType:$result);
+  let assemblyFormat = [{
+  $input `,`   $memberName  attr-dict `:`
+  type($input) `->` type($result)
+  }];
+ }
 #endif // CIRCT_DIALECT_MOORE_MOOREOPS

include/circt/Dialect/Moore/MooreTypes.h

@@ -35,9 +35,11 @@ class QueueType;
 class RealType;
 class StringType;
 class StructType;
+class UnionType;
 class UnpackedType;
 class UnpackedArrayType;
 class UnpackedStructType;
+class UnpackedUnionType;
 class VoidType;
 
 /// The number of values each bit of a type can assume.
@@ -81,7 +83,7 @@ public:
   static bool classof(Type type) {
     return llvm::isa<PackedType, StringType, ChandleType, EventType, RealType,
                      UnpackedArrayType, OpenUnpackedArrayType, AssocArrayType,
-                     QueueType, UnpackedStructType>(type);
+                     QueueType, UnpackedStructType, UnpackedUnionType>(type);
   }
 
   /// Get the value domain of this type.
@@ -130,8 +132,8 @@ protected:
 class PackedType : public UnpackedType {
 public:
   static bool classof(Type type) {
-    return llvm::isa<VoidType, IntType, ArrayType, OpenArrayType, StructType>(
-        type);
+    return llvm::isa<VoidType, IntType, ArrayType, OpenArrayType, StructType,
+                     UnionType>(type);
   }
 
   /// Get the value domain of this type.
@@ -151,19 +153,19 @@ protected:
 //===----------------------------------------------------------------------===//
 
 /// A member of a struct.
-struct StructMember {
+struct StructLikeMember {
   /// The name of this member.
   StringAttr name;
   /// The type of this member.
   UnpackedType type;
 
-  bool operator==(const StructMember &other) const {
+  bool operator==(const StructLikeMember &other) const {
     return name == other.name && type == other.type;
   }
 };
 
 // NOLINTNEXTLINE(readability-identifier-naming)
-inline llvm::hash_code hash_value(const StructMember &x) {
+inline llvm::hash_code hash_value(const StructLikeMember &x) {
   return llvm::hash_combine(x.name, x.type);
 }
 

include/circt/Dialect/Moore/MooreTypes.td

@@ -280,7 +280,7 @@ def QueueType : MooreTypeDef<"Queue", [], "moore::UnpackedType"> {
 class StructLikeType<
   string name, list<Trait> traits = [], string baseCppClass = "::mlir::Type"
 > : MooreTypeDef<name, traits, baseCppClass> {
-  let parameters = (ins ArrayRefParameter<"StructMember">:$members);
+  let parameters = (ins ArrayRefParameter<"StructLikeMember">:$members);
   let assemblyFormat = [{
     `<` custom<Members>($members) `>`
   }];
@@ -305,6 +305,25 @@ def UnpackedStructType : StructLikeType<
   }];
 }
 
+def UnionType : StructLikeType<"Union", [], "moore::PackedType"> {
+  let mnemonic = "union";
+  let summary = "a packed union type";
+  let description = [{
+    A packed union. All members are guaranteed to be packed as well.
+  }];
+  let genVerifyDecl = 1;
+}
+
+
+def UnpackedUnionType : StructLikeType<
+  "UnpackedUnion", [], "moore::UnpackedType"
+> {
+  let mnemonic = "uunion";
+  let summary = "an unpacked union type";
+  let description = [{
+    An unpacked union.
+  }];
+}
 
 //===----------------------------------------------------------------------===//
 // Constraints

lib/Conversion/ImportVerilog/Expressions.cpp

@@ -429,10 +429,20 @@ struct ExprVisitor {
   }
 
   Value visit(const slang::ast::MemberAccessExpression &expr) {
-    return builder.create<moore::StructExtractOp>(
-        loc, context.convertType(*expr.type),
-        builder.getStringAttr(expr.member.name),
-        context.convertExpression(expr.value()));
+    auto type = context.convertType(*expr.type);
+    auto valueType = expr.value().type;
+    auto value = context.convertExpression(expr.value());
+    if (!type || !value)
+      return {};
+    if (valueType->isStruct()) {
+      return builder.create<moore::StructExtractOp>(
+          loc, type, builder.getStringAttr(expr.member.name), value);
+    }
+    if (valueType->isPackedUnion() || valueType->isUnpackedUnion()) {
+      return builder.create<moore::UnionExtractOp>(
+          loc, type, builder.getStringAttr(expr.member.name), value);
+    }
+    llvm_unreachable("unsupported symbol kind");
   }
 
   // Handle set membership operator.

lib/Conversion/ImportVerilog/Types.cpp

@@ -101,8 +101,9 @@ struct TypeVisitor {
   }
 
   // Collect the members in a struct or union.
-  LogicalResult collectMembers(const slang::ast::Scope &structType,
-                               SmallVectorImpl<moore::StructMember> &members) {
+  LogicalResult
+  collectMembers(const slang::ast::Scope &structType,
+                 SmallVectorImpl<moore::StructLikeMember> &members) {
     for (auto &field : structType.membersOfType<slang::ast::FieldSymbol>()) {
       auto name = StringAttr::get(context.getContext(), field.name);
       auto innerType = context.convertType(*field.getDeclaredType());
@@ -115,19 +116,33 @@ struct TypeVisitor {
 
   // Handle packed and unpacked structs.
   Type visit(const slang::ast::PackedStructType &type) {
-    SmallVector<moore::StructMember> members;
+    SmallVector<moore::StructLikeMember> members;
     if (failed(collectMembers(type, members)))
       return {};
     return moore::StructType::get(context.getContext(), members);
   }
 
   Type visit(const slang::ast::UnpackedStructType &type) {
-    SmallVector<moore::StructMember> members;
+    SmallVector<moore::StructLikeMember> members;
     if (failed(collectMembers(type, members)))
       return {};
     return moore::UnpackedStructType::get(context.getContext(), members);
   }
 
+  Type visit(const slang::ast::PackedUnionType &type) {
+    SmallVector<moore::StructLikeMember> members;
+    if (failed(collectMembers(type, members)))
+      return {};
+    return moore::UnionType::get(context.getContext(), members);
+  }
+
+  Type visit(const slang::ast::UnpackedUnionType &type) {
+    SmallVector<moore::StructLikeMember> members;
+    if (failed(collectMembers(type, members)))
+      return {};
+    return moore::UnpackedUnionType::get(context.getContext(), members);
+  }
+
   /// Emit an error for all other types.
   template <typename T>
   Type visit(T &&node) {

lib/Dialect/Moore/MooreTypes.cpp

@@ -22,8 +22,9 @@ using mlir::AsmParser;
 using mlir::AsmPrinter;
 
 static LogicalResult parseMembers(AsmParser &parser,
-                                  SmallVector<StructMember> &members);
-static void printMembers(AsmPrinter &printer, ArrayRef<StructMember> members);
+                                  SmallVector<StructLikeMember> &members);
+static void printMembers(AsmPrinter &printer,
+                         ArrayRef<StructLikeMember> members);
 
 static ParseResult parseMooreType(AsmParser &parser, Type &type);
 static void printMooreType(Type type, AsmPrinter &printer);
@@ -38,7 +39,7 @@ Domain UnpackedType::getDomain() const {
       .Case<UnpackedArrayType, OpenUnpackedArrayType, AssocArrayType,
             QueueType>(
           [&](auto type) { return type.getElementType().getDomain(); })
-      .Case<UnpackedStructType>([](auto type) {
+      .Case<UnpackedStructType, UnpackedUnionType>([](auto type) {
         for (const auto &member : type.getMembers())
           if (member.type.getDomain() == Domain::FourValued)
             return Domain::FourValued;
@@ -67,6 +68,17 @@ std::optional<unsigned> UnpackedType::getBitSize() const {
         }
         return size;
       })
+      .Case<UnpackedUnionType>([](auto type) -> std::optional<unsigned> {
+        unsigned size = 0;
+        for (const auto &member : type.getMembers()) {
+          if (auto memberSize = member.type.getBitSize()) {
+            size = (*memberSize > size) ? *memberSize : size;
+          } else {
+            return std::nullopt;
+          }
+        }
+        return size;
+      })
       .Default([](auto) { return std::nullopt; });
 }
 
@@ -91,7 +103,7 @@ Domain PackedType::getDomain() const {
       .Case<IntType>([&](auto type) { return type.getDomain(); })
       .Case<ArrayType, OpenArrayType>(
           [&](auto type) { return type.getElementType().getDomain(); })
-      .Case<StructType>([](auto type) {
+      .Case<StructType, UnionType>([](auto type) {
         for (const auto &member : type.getMembers())
           if (member.type.getDomain() == Domain::FourValued)
             return Domain::FourValued;
@@ -119,7 +131,19 @@ std::optional<unsigned> PackedType::getBitSize() const {
           }
         }
         return size;
-      });
+      })
+      .Case<UnionType>([](auto type) -> std::optional<unsigned> {
+        unsigned size = 0;
+        for (const auto &member : type.getMembers()) {
+          if (auto memberSize = member.type.getBitSize()) {
+            size = (*memberSize > size) ? *memberSize : size;
+          } else {
+            return std::nullopt;
+          }
+        }
+        return size;
+      })
+      .Default([](auto) { return std::nullopt; });
 }
 
 //===----------------------------------------------------------------------===//
@@ -128,7 +152,7 @@ std::optional<unsigned> PackedType::getBitSize() const {
 
 /// Parse a list of struct members.
 static LogicalResult parseMembers(AsmParser &parser,
-                                  SmallVector<StructMember> &members) {
+                                  SmallVector<StructLikeMember> &members) {
   return parser.parseCommaSeparatedList(AsmParser::Delimiter::Braces, [&]() {
     std::string name;
     UnpackedType type;
@@ -142,10 +166,11 @@ static LogicalResult parseMembers(AsmParser &parser,
 }
 
 /// Print a list of struct members.
-static void printMembers(AsmPrinter &printer, ArrayRef<StructMember> members) {
+static void printMembers(AsmPrinter &printer,
+                         ArrayRef<StructLikeMember> members) {
   printer << "{";
   llvm::interleaveComma(members, printer.getStream(),
-                        [&](const StructMember &member) {
+                        [&](const StructLikeMember &member) {
                           printer.printKeywordOrString(member.name);
                           printer << ": ";
                           printer.printStrippedAttrOrType(member.type);
@@ -153,15 +178,26 @@ static void printMembers(AsmPrinter &printer, ArrayRef<StructMember> members) {
   printer << "}";
 }
 
-LogicalResult StructType::verify(function_ref<InFlightDiagnostic()> emitError,
-                                 ArrayRef<StructMember> members) {
+static LogicalResult
+verifyAllMembersPacked(function_ref<InFlightDiagnostic()> emitError,
+                       ArrayRef<StructLikeMember> members) {
   if (!llvm::all_of(members, [](const auto &member) {
         return llvm::isa<PackedType>(member.type);
       }))
-    return emitError() << "StructType members must be packed types";
+    return emitError() << "StructType/UnionType members must be packed types";
   return success();
 }
 
+LogicalResult StructType::verify(function_ref<InFlightDiagnostic()> emitError,
+                                 ArrayRef<StructLikeMember> members) {
+  return verifyAllMembersPacked(emitError, members);
+}
+
+LogicalResult UnionType::verify(function_ref<InFlightDiagnostic()> emitError,
+                                ArrayRef<StructLikeMember> members) {
+  return verifyAllMembersPacked(emitError, members);
+}
+
 //===----------------------------------------------------------------------===//
 // Generated logic
 //===----------------------------------------------------------------------===//

test/Conversion/ImportVerilog/basic.sv

@@ -122,7 +122,7 @@ module Statements;
     automatic int a;
     // CHECK moore.blocking_assign %i, %a : i32
     i = a;
-    
+
     //===------------------------------------------------------------------===//
     // Conditional statements
 
@@ -321,6 +321,16 @@ module Expressions;
       int a, b;
     } c, d;
   } struct1;
+  // CHECK: %union0 = moore.variable : union<{a: i32, b: i32}>
+  union packed {
+    int a, b;
+  } union0;
+  // CHECK: %union1 = moore.variable : union<{c: union<{a: i32, b: i32}>, d: union<{a: i32, b: i32}>}>
+  union packed {
+    union packed {
+      int a, b;
+    } c, d;
+  } union1;
 
   initial begin
     // CHECK: moore.constant 0 : i32
@@ -660,6 +670,24 @@ module Expressions;
     // CHECK: [[TMP2:%.+]] = moore.struct_extract [[TMP1]], "b" : struct<{a: i32, b: i32}> -> i32
     // CHECK: moore.blocking_assign %b, [[TMP2]] : i32
     b = struct1.d.b;
+
+    // CHECK: [[TMP:%.+]] = moore.union_extract %union0, "a" : union<{a: i32, b: i32}> -> i32
+    // CHECK: moore.blocking_assign [[TMP]], %a : i32
+    union0.a = a;
+
+    // CHECK: [[TMP:%.+]]  = moore.union_extract %union0, "b" : union<{a: i32, b: i32}> -> i32
+    // CHECK: moore.blocking_assign %b, [[TMP]] : i32
+    b = union0.b;
+
+    // CHECK: [[TMP1:%.+]] = moore.union_extract %union1, "c" : union<{c: union<{a: i32, b: i32}>, d: union<{a: i32, b: i32}>}> -> union<{a: i32, b: i32}>
+    // CHECK: [[TMP2:%.+]] = moore.union_extract [[TMP1]], "a" : union<{a: i32, b: i32}> -> i32
+    // CHECK: moore.blocking_assign [[TMP2]], %a : i32
+    union1.c.a = a;
+
+    // CHECK: [[TMP1:%.+]] = moore.union_extract %union1, "d" : union<{c: union<{a: i32, b: i32}>, d: union<{a: i32, b: i32}>}> -> union<{a: i32, b: i32}>
+    // CHECK: [[TMP2:%.+]] = moore.union_extract [[TMP1]], "b" : union<{a: i32, b: i32}> -> i32
+    // CHECK: moore.blocking_assign %b, [[TMP2]] : i32
+    b = union1.d.b;
   end
 endmodule
 

test/Conversion/ImportVerilog/types-errors.sv

@@ -7,5 +7,5 @@
 module Foo;
   // expected-error @below {{unsupported type}}
   // expected-note @below {{}}
-  union { bit a; logic b; } x;
+  event notDone;
 endmodule

test/Dialect/Moore/types-errors.mlir

@@ -11,5 +11,9 @@ unrealized_conversion_cast to !moore.array<4 x string>
 unrealized_conversion_cast to !moore.open_array<string>
 
 // -----
-// expected-error @below {{StructType members must be packed types}}
+// expected-error @below {{StructType/UnionType members must be packed types}}
 unrealized_conversion_cast to !moore.struct<{foo: string}>
+
+// -----
+// expected-error @below {{StructType/UnionType members must be packed types}}
+unrealized_conversion_cast to !moore.union<{foo: string}>

unittests/Dialect/Moore/TypesTest.cpp

@@ -131,14 +131,14 @@ TEST(TypesTest, Structs) {
   auto bit8Type = IntType::getInt(&context, 8);
   auto bitDynArrayType = OpenUnpackedArrayType::get(bitType);
 
-  auto s0 = StructType::get(&context, {StructMember{foo, bitType}});
-  auto s1 = StructType::get(
-      &context, {StructMember{foo, bitType}, StructMember{bar, bit8Type}});
-  auto s2 = StructType::get(
-      &context, {StructMember{foo, bitType}, StructMember{bar, logicType}});
-  auto s3 =
-      UnpackedStructType::get(&context, {StructMember{foo, bitType},
-                                         StructMember{bar, bitDynArrayType}});
+  auto s0 = StructType::get(&context, {StructLikeMember{foo, bitType}});
+  auto s1 = StructType::get(&context, {StructLikeMember{foo, bitType},
+                                       StructLikeMember{bar, bit8Type}});
+  auto s2 = StructType::get(&context, {StructLikeMember{foo, bitType},
+                                       StructLikeMember{bar, logicType}});
+  auto s3 = UnpackedStructType::get(
+      &context,
+      {StructLikeMember{foo, bitType}, StructLikeMember{bar, bitDynArrayType}});
 
   // Value domain
   ASSERT_EQ(s0.getDomain(), Domain::TwoValued);
@@ -151,6 +151,27 @@ TEST(TypesTest, Structs) {
   ASSERT_EQ(s1.getBitSize(), 9u);
   ASSERT_EQ(s2.getBitSize(), 2u);
   ASSERT_EQ(s3.getBitSize(), std::nullopt);
+
+  auto u0 = UnionType::get(&context, {StructLikeMember{foo, bitType}});
+  auto u1 = UnionType::get(&context, {StructLikeMember{foo, bitType},
+                                      StructLikeMember{bar, bit8Type}});
+  auto u2 = UnionType::get(&context, {StructLikeMember{foo, bitType},
+                                      StructLikeMember{bar, logicType}});
+  auto u3 = UnpackedUnionType::get(
+      &context,
+      {StructLikeMember{foo, bitType}, StructLikeMember{bar, bitDynArrayType}});
+
+  // Value domain
+  ASSERT_EQ(u0.getDomain(), Domain::TwoValued);
+  ASSERT_EQ(u1.getDomain(), Domain::TwoValued);
+  ASSERT_EQ(u2.getDomain(), Domain::FourValued);
+  ASSERT_EQ(u3.getDomain(), Domain::TwoValued);
+
+  // Bit size
+  ASSERT_EQ(u0.getBitSize(), 1u);
+  ASSERT_EQ(u1.getBitSize(), 8u);
+  ASSERT_EQ(u2.getBitSize(), 1u);
+  ASSERT_EQ(u3.getBitSize(), std::nullopt);
 }
 
 } // namespace