Support primitive instantiations

[veripoolbot]

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Author Name: Alex Solomatnikov
Original Redmine Issue: 468 from https://www.veripool.org
Original Date: 2012-03-23

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Primitive definition:

primitive PRIM_DFFE (Q, ENA, D, CLK, CLRN, PRN, notifier);
    input D;   
    input CLRN;
    input PRN;
    input CLK;
    input ENA;
    input notifier;
    output Q; reg Q;
...

Primitive instantiation:

module dffe ( Q, CLK, ENA, D, CLRN, PRN );
    input D;
    input CLK;
    input CLRN;
    input PRN;
    input ENA;
    output Q;
    
    wire D_ipd;
    wire ENA_ipd;
    wire CLK_ipd;
    wire PRN_ipd;
    wire CLRN_ipd;
    
    buf (D_ipd, D);
    buf (ENA_ipd, ENA);
    buf (CLK_ipd, CLK);
    buf (PRN_ipd, PRN);
    buf (CLRN_ipd, CLRN);
    
    wire   legal;
    reg 	  viol_notifier;
    
    PRIM_DFFE ( Q, ENA_ipd, D_ipd, CLK_ipd, CLRN_ipd, PRN_ipd, viol_notifier );
...

error:

syntax error, unexpected '(', expecting IDENTIFIER

[veripoolbot]

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Original Redmine Comment
Author Name: Wilson Snyder (@wsnyder)
Original Date: 2012-03-23T02:20:10Z

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Primitives are not synthesizable and are very slow compared to writing good behavioral code and so are unlikely to be supported in the near term.

However if you want to undertake this, there is a bit of code I started on to support them a while ago before I decided it was too nasty for performance.

[veripoolbot]

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Original Redmine Comment
Author Name: Alex Solomatnikov
Original Date: 2012-04-24T18:09:29Z

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BTW, the problem with the code above is that verilator can not parse anonymous primitive instantiation.

If instance name is added, then at least verilator does not complain during parsing.

[veripoolbot]

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Original Redmine Comment
Author Name: Wilson Snyder (@wsnyder)
Original Date: 2012-04-25T00:43:21Z

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Added disabled test t_udp_noname. Anonymous UDPs will be a pain to support as removing the name results in a parser conflict, requiring a cascade of changes.