[SV][ExportVerilog] Add sv.func, sv.func.call{.procedural}, sv.func.dpi.import

include/circt/Conversion/ExportVerilog.h

@@ -17,6 +17,9 @@
 #include "mlir/Pass/Pass.h"
 
 namespace circt {
+namespace hw {
+class HWModuleLike;
+} // namespace hw
 
 std::unique_ptr<mlir::Pass>
 createTestApplyLoweringOptionPass(llvm::StringRef options);

include/circt/Conversion/Passes.td

@@ -118,8 +118,8 @@ def HWLowerInstanceChoices : Pass<"hw-lower-instance-choices",
   ];
 }
 
-def PrepareForEmission : Pass<"prepare-for-emission",
-                              "hw::HWModuleOp"> {
+def PrepareForEmission : InterfacePass<"prepare-for-emission",
+                              "hw::HWModuleLike"> {
   let summary = "Prepare IR for ExportVerilog";
   let description = [{
     This pass runs only PrepareForEmission.

include/circt/Dialect/HW/ModuleImplementation.h

@@ -18,6 +18,7 @@
 #include "circt/Dialect/HW/HWTypes.h"
 #include "circt/Support/LLVM.h"
 #include "mlir/IR/DialectImplementation.h"
+#include "mlir/IR/OpImplementation.h"
 
 namespace circt {
 namespace hw {
@@ -50,7 +51,16 @@ void printModuleSignature(OpAsmPrinter &p, Operation *op,
 ParseResult parseModuleSignature(OpAsmParser &parser,
                                  SmallVectorImpl<PortParse> &args,
                                  TypeAttr &modType);
+
+void printModuleSignatureNew(OpAsmPrinter &p, Region &body,
+                             hw::ModuleType modType,
+                             ArrayRef<Attribute> portAttrs,
+                             ArrayRef<Location> locAttrs);
 void printModuleSignatureNew(OpAsmPrinter &p, HWModuleLike op);
+void getAsmBlockArgumentNamesImpl(mlir::Region &region,
+                                  OpAsmSetValueNameFn setNameFn);
+
+SmallVector<Location> getAllPortLocsImpl(hw::ModuleType modType);
 
 } // namespace module_like_impl
 } // namespace hw

include/circt/Dialect/SV/SVDialect.td

@@ -22,7 +22,7 @@ def SVDialect : Dialect {
     This dialect defines the `sv` dialect, which represents various
     SystemVerilog-specific constructs in an AST-like representation.
   }];
-  let dependentDialects = ["circt::comb::CombDialect"];
+  let dependentDialects = ["circt::comb::CombDialect", "circt::hw::HWDialect"];
 
   let useDefaultTypePrinterParser = 1;
   let useDefaultAttributePrinterParser = 1;

include/circt/Dialect/SV/SVStatements.td

@@ -12,6 +12,9 @@
 
 include "mlir/IR/EnumAttr.td"
 include "mlir/IR/OpAsmInterface.td"
+include "mlir/Interfaces/FunctionInterfaces.td"
+include "mlir/Interfaces/ControlFlowInterfaces.td"
+include "circt/Dialect/Emit/EmitOpInterfaces.td"
 
 //===----------------------------------------------------------------------===//
 // Control flow like-operations
@@ -879,3 +882,178 @@ def MacroDefOp : SVOp<"macro.def",
     MacroDeclOp getReferencedMacro(const hw::HWSymbolCache *cache);
   }];
 }
+
+
+//===----------------------------------------------------------------------===//
+// Function/Call
+//===----------------------------------------------------------------------===//
+
+def FuncDPIImportOp: SVOp<"func.dpi.import", 
+  [DeclareOpInterfaceMethods<SymbolUserOpInterface>]> {
+  let summary = "Emit a dpi import statement. See SV spec 35.4";
+
+  let arguments = (ins FlatSymbolRefAttr:$callee,
+                       OptionalAttr<StrAttr>: $linkage_name);
+  let results = (outs);
+
+  let assemblyFormat = "(`linkage` $linkage_name^)? $callee attr-dict";
+}
+
+def FuncOp : SVOp<"func", 
+     [IsolatedFromAbove, Symbol, OpAsmOpInterface, ProceduralRegion,
+      DeclareOpInterfaceMethods<HWModuleLike>,
+      DeclareOpInterfaceMethods<PortList>,
+      FunctionOpInterface, HasParent<"mlir::ModuleOp">]> {
+  let summary = "A System Verilog function";
+  let description = [{
+    `sv.func` reresents System Verilog function in SV spec 13.4.
+    Similar to HW module, it's allowed to mix the order of input
+    and output arguments. `sv.func` can be used for both function
+    declaration and definition, i.e. a function without a body
+    region is a declaration.
+
+    In SV there are two representations for function results,
+    "output argument" and "return value". Currently an output argument
+    is considered as as a return value if it's is the last argument
+    and has a special attribute `sv.func.explicitly_returned`.
+  }];
+
+  let arguments = (ins 
+    SymbolNameAttr:$sym_name,
+    TypeAttrOf<ModuleType>:$module_type,
+    OptionalAttr<DictArrayAttr>:$per_argument_attrs,
+    OptionalAttr<LocationArrayAttr>:$input_locs, // Null for actual definition.
+    OptionalAttr<LocationArrayAttr>:$result_locs,
+    OptionalAttr<StrAttr>:$verilogName
+  );
+
+  let results = (outs);
+  let regions = (region AnyRegion:$body);
+
+  let hasCustomAssemblyFormat = 1;
+  let extraClassDeclaration = [{
+    static mlir::StringRef getExplicitlyReturnedAttrName() {
+      return "sv.func.explicitly_returned";
+    }
+
+    mlir::FunctionType getFunctionType() {
+      return getModuleType().getFuncType();
+    }
+
+    void setFunctionTypeAttr(mlir::TypeAttr mlirType) {
+      setModuleType(cast<hw::ModuleType>(mlirType.getValue()));
+    }
+
+    /// Returns the argument types of this function.
+    ArrayRef<Type> getArgumentTypes() { return getFunctionType().getInputs(); }
+
+    /// Returns the result types of this function.
+    ArrayRef<Type> getResultTypes() { return getFunctionType().getResults(); }
+
+    Type getExplicitlyReturnedType();
+
+    size_t getNumOutputs() {
+      return getResultTypes().size();
+    }
+
+    size_t getNumInputs() {
+      return getArgumentTypes().size();
+    }
+
+    ::mlir::Region *getCallableRegion() { return isExternal() ? nullptr : &getBody(); }
+    bool isDeclaration() { return isExternal(); }
+
+    /// OpAsmInterface
+    void getAsmBlockArgumentNames(mlir::Region &region,
+                                          mlir::OpAsmSetValueNameFn setNameFn);
+    SmallVector<hw::PortInfo> getPortList(bool excludeExplicitReturn);
+  }];
+  let extraClassDefinition = [{
+    hw::ModuleType $cppClass::getHWModuleType() {
+      return getModuleType();
+    }
+    void $cppClass::setHWModuleType(hw::ModuleType type) {
+      return setModuleType(type);
+    }
+    void $cppClass::setAllPortNames(llvm::ArrayRef<mlir::Attribute>) {
+    }
+
+    size_t $cppClass::getNumPorts() {
+      auto modty = getHWModuleType();
+      return modty.getNumPorts();
+    }
+
+    size_t $cppClass::getNumInputPorts() {
+      auto modty = getHWModuleType();
+      return modty.getNumInputs();
+    }
+
+    size_t $cppClass::getNumOutputPorts() {
+      auto modty = getHWModuleType();
+      return modty.getNumOutputs();
+    }
+
+    size_t $cppClass::getPortIdForInputId(size_t idx) {
+      auto modty = getHWModuleType();
+      return modty.getPortIdForInputId(idx);
+    }
+
+    size_t $cppClass::getPortIdForOutputId(size_t idx) {
+      auto modty = getHWModuleType();
+      return modty.getPortIdForOutputId(idx);
+    }
+  }];
+}
+
+class SVFuncCallBase<string mnemonic, list<Trait> traits = []>: SVOp<mnemonic, 
+  traits # [CallOpInterface, DeclareOpInterfaceMethods<SymbolUserOpInterface>]> {
+
+  let arguments = (ins FlatSymbolRefAttr:$callee, Variadic<AnyType>:$inputs);
+  let results = (outs Variadic<AnyType>);
+
+  let assemblyFormat = 
+      "$callee `(` $inputs `)` attr-dict `:` functional-type($inputs, results)";
+
+  let extraClassDeclaration = [{
+    Value getExplicitlyReturnedValue(sv::FuncOp op);
+
+    operand_range getArgOperands() {
+      return getInputs();
+    }
+    MutableOperandRange getArgOperandsMutable() {
+      return getInputsMutable();
+    }
+    mlir::CallInterfaceCallable getCallableForCallee() {
+      return (*this)->getAttrOfType<mlir::SymbolRefAttr>("callee");
+    }
+
+    /// Set the callee for this operation.
+    void setCalleeFromCallable(mlir::CallInterfaceCallable callee) {
+      (*this)->setAttr(getCalleeAttrName(), callee.get<mlir::SymbolRefAttr>());
+    }
+  }];
+}
+
+def FuncCallProceduralOp : SVFuncCallBase<"func.call.procedural", [ProceduralOp]> {
+  let summary = "Function call in a procedural region";
+}
+
+def FuncCallOp : SVFuncCallBase<"func.call", [NonProceduralOp]> {
+  let summary = "Function call in a non-procedural region";
+  let description = [{
+    This op represents a function call in a non-procedural region.
+    A function call in a non-procedural region must have a return
+    value and no output argument.
+  }];
+}
+
+def ReturnOp : SVOp<"return",
+                   [Pure, ReturnLike, Terminator, HasParent<"FuncOp">]> {
+  let summary = "Function return operation";
+
+  let arguments = (ins Variadic<AnyType>:$operands);
+
+  let hasCustomAssemblyFormat = 1;
+  let assemblyFormat = "attr-dict ($operands^ `:` type($operands))?";
+  let hasVerifier = 1;
+}

include/circt/Dialect/SV/SVVisitors.h

@@ -39,11 +39,13 @@ class Visitor {
             AlwaysCombOp, AlwaysFFOp, InitialOp, CaseOp,
             // Other Statements.
             AssignOp, BPAssignOp, PAssignOp, ForceOp, ReleaseOp, AliasOp,
-            FWriteOp, SystemFunctionOp, VerbatimOp,
+            FWriteOp, SystemFunctionOp, VerbatimOp, FuncCallOp,
+            FuncCallProceduralOp, ReturnOp,
             // Type declarations.
             InterfaceOp, InterfaceSignalOp, InterfaceModportOp,
             InterfaceInstanceOp, GetModportOp, AssignInterfaceSignalOp,
-            ReadInterfaceSignalOp, MacroDeclOp, MacroDefOp,
+            ReadInterfaceSignalOp, MacroDeclOp, MacroDefOp, FuncDPIImportOp,
+            FuncOp,
             // Verification statements.
             AssertOp, AssumeOp, CoverOp, AssertConcurrentOp, AssumeConcurrentOp,
             CoverConcurrentOp,
@@ -127,6 +129,9 @@ class Visitor {
   HANDLE(AliasOp, Unhandled);
   HANDLE(FWriteOp, Unhandled);
   HANDLE(SystemFunctionOp, Unhandled);
+  HANDLE(FuncCallProceduralOp, Unhandled);
+  HANDLE(FuncCallOp, Unhandled);
+  HANDLE(ReturnOp, Unhandled);
   HANDLE(VerbatimOp, Unhandled);
 
   // Type declarations.
@@ -139,6 +144,8 @@ class Visitor {
   HANDLE(ReadInterfaceSignalOp, Unhandled);
   HANDLE(MacroDefOp, Unhandled);
   HANDLE(MacroDeclOp, Unhandled);
+  HANDLE(FuncDPIImportOp, Unhandled);
+  HANDLE(FuncOp, Unhandled);
 
   // Verification statements.
   HANDLE(AssertOp, Unhandled);