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Verilator won't inline modules that contain interfaces #1018

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veripoolbot opened this issue Dec 23, 2015 · 5 comments
Closed

Verilator won't inline modules that contain interfaces #1018

veripoolbot opened this issue Dec 23, 2015 · 5 comments
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resolution: fixed Closed; fixed type: feature-IEEE Request to add new feature, described in IEEE 1800

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Author Name: Johan Bjork
Original Redmine Issue: 1018 from https://www.veripool.org
Original Date: 2015-12-22
Original Assignee: Johan Bjork

From V3Inline.cpp

     virtual void visit(AstVar* nodep, AstNUser*) {
	// Can't look at AstIfaceRefDType directly as it is no longer underneath the module
	if (nodep->isIfaceRef()) {
	    // Unsupported: Inlining of modules with ifaces (see AstIface comment above)
	    if (m_modp) cantInline("Interfaced",true);
	}
	nodep->iterateChildren(*this);
     }

Ideally verilator should support inlining modules that contain interfaces to improve both verilation/compilation time as well as runtime.
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Original Redmine Comment
Author Name: Johan Bjork
Original Date: 2015-12-25T05:28:31Z

I started working on this. Some tricky required to handle AstVarXRef's but nothing too terrible. patch draft here: https://github.com/phb/verilator-dev/tree/issue1018

Happy holidays everyone!

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Original Redmine Comment
Author Name: Wilson Snyder (@wsnyder)
Original Date: 2016-01-07T02:03:30Z

Surprisingly less code than I expected.

I think you need to m_renameInterfaces.clear() on each visit AstModule.

Also, for testing, for each of the exsting interface test .pl files please make a new _noinl.pl test file similar to e.g. t_inst_slice_noinl.pl. Otherwise we'll only be verifying the inliner version, and when the non-inline code drifts we'll soon get bug reports of large designs breaking because they didn't get inlined.

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Original Redmine Comment
Author Name: Johan Bjork
Original Date: 2016-01-21T04:19:48Z

Updated patch. From the first patch the main changes are

  1. Added noinl tests
  2. Ensure to clone the AstIfaceRefDType when needed, as it contains a link to the cell which now is cloned.

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Original Redmine Comment
Author Name: Wilson Snyder (@wsnyder)
Original Date: 2016-01-22T00:14:09Z

Great, fixed in git towards 3.881.

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Original Redmine Comment
Author Name: Wilson Snyder (@wsnyder)
Original Date: 2016-03-02T00:15:42Z

In 3.882.

@veripoolbot veripoolbot added resolution: fixed Closed; fixed type: feature-IEEE Request to add new feature, described in IEEE 1800 labels Dec 22, 2019
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resolution: fixed Closed; fixed type: feature-IEEE Request to add new feature, described in IEEE 1800
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