[ImportVerilog][MooreToCore]Lower moore.namedConstant to hw.constant & hw.wire

[mingzheTerapines]

Refer to #7083
For [ImportVerilog] this PR changed value to attribute for builder of moore.named_constant. Because for lower pass case it is hard to transform an value to an attribute.
For [MooreToCore] this PR learned how moore.constant and hw.param.value build and have this lowering method.
String attribute will be supported later.

[mingzheTerapines]

Because following varifying, mooretocore is stopped. When blocking this code will success.

LogicalResult ParamValueOp::verify() {
  // Check that the attribute expression is valid in this module.
  return checkParameterInContext(
      getValue(), (*this)->getParentOfType<hw::HWModuleOp>(), *this);
}

[mingzheTerapines]

@fabianschuiki Hailong and I were wondering why hw.param.value has traits constant like and pure.
Also I found name information missed when lowering to hw.param.value, is that acceptable?
Test failed because I changed param.value varifying the parent module type.

[fabianschuiki]

Sorry for taking so long to look at this!

I think the hw.param.* are designed to work with parameters defined on the hw.module. These would then be emitted in Verilog as module Foo #(<params>) .... If I'm not mistaken, hw.param.value is used to take one of those module parameters (which is an attribute) and make it available as an SSA value. So this might not do what you need 🤔.

Have you tried lowering the named constants to an hw.wire? If you give the wire an inner symbol name, it will not be deleted. For example:

%p1 = moore.named_constant parameter 1 : !moore.i32
// lower to
%0 = hw.constant 1 : i32
%p1 = hw.wire %0 sym @someUniqueSymbolName : i32

[mingzheTerapines]

Sorry for taking so long to look at this!

I think the hw.param.* are designed to work with parameters defined on the hw.module. These would then be emitted in Verilog as module Foo #(<params>) .... If I'm not mistaken, hw.param.value is used to take one of those module parameters (which is an attribute) and make it available as an SSA value. So this might not do what you need 🤔.

Have you tried lowering the named constants to an hw.wire? If you give the wire an inner symbol name, it will not be deleted. For example:

%p1 = moore.named_constant parameter 1 : !moore.i32
// lower to
%0 = hw.constant 1 : i32
%p1 = hw.wire %0 sym @someUniqueSymbolName : i32

Thanks for your advice. In specialize pass in hw, hw.param.value with integer will be automatically replaced hw.constant. So it is the same for integer case. What's more, parameter in IEEE standard can accept more than integer attribute, so I think translate sv.parameter to hw.param.value is Okay. But other attribute type case this time will not be supported. Because we focus on basic need.
And as your concern of hw.module, new patch by @cepheus69 will solve this problem to ensure hw.param.value in every hw.moduleop region.

I have updeted some codes and test, please have a look and thanks for your patient.

[mingzheTerapines]

@fabianschuiki Thanks @cepheus69 , module to core has been available now.
And I checked json below string will be implictly transformed to an integer in value. Any attribute could be handled in namedconstant.

{
              "name": "p",
              "kind": "Parameter",
              "addr": 2797836494528,
              "type": "logic[23:0]",
              "initializer": {
                "kind": "Conversion",
                "type": "logic[23:0]",
                "operand": {
                  "kind": "StringLiteral",
                  "type": "bit[23:0]",
                  "literal": "str",
                  "constant": "24'd7566450"
                },
                "constant": "24'd7566450"
              },
              "value": "24'd7566450",
              "isLocal": false,
              "isPort": false,
              "isBody": true
            }

[fabianschuiki]

Really nice!