Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Intenal Error of "Multiple root modules" happens if one of sub modules is not inlined when creating a protect lib. #1616

Closed
veripoolbot opened this issue Nov 29, 2019 · 6 comments
Closed

Intenal Error of "Multiple root modules" happens if one of sub modules is not inlined when creating a protect lib. #1616

veripoolbot opened this issue Nov 29, 2019 · 6 comments
Assignees
@toddstrader
Labels
resolution: fixed Closed; fixed

Comments

@veripoolbot
Copy link
Contributor

Author Name: Yutetsu TAKATSUKASA (@yTakatsukasa)
Original Redmine Issue: 1616 from https://www.veripool.org

Original Assignee: Todd Strader (@toddstrader)

First of all, thank you very much for maintaining and evolving the great software.

I am exploring --protect-lib to shorten the verilator runtime for a large design.
When I tried, I encountered Intenal Error of "Multiple root modules".
I can not share the actual design, so I made a tiny case to see the error.
The attached file is a small HDL to show the error.

I ran verilator as the following.

$ verilator --protect-lib tbp --top-module to_be_protected  --cc ./to_be_protected.sv

The error message is

%Error: Internal Error: to_be_protected.sv:10: ../V3ProtectLib.cpp:81: Multiple root modules
module to_be_protected  (input wire in, output wire out);
        ^~~~~~~~~~~~~~~
                         ... See the manual and https://verilator.org for more assistance.

As far as I tried, non-inlined module seems to cause the internal error because one of the following setting is necessary.

  • Adding /verilator no_inline_module/ comment
  • -O0 option

I tried the following versions and saw the error.
stable branch tag:verilator_4_022
master branch 3d6e8e9
@veripoolbot
Copy link
Contributor Author

Original Redmine Comment
Author Name: Todd Strader (@toddstrader)
Original Date: 2019-11-29T23:21:09Z

Thanks for the example. I'll take a look.

@veripoolbot
Copy link
Contributor Author

Original Redmine Comment
Author Name: Todd Strader (@toddstrader)
Original Date: 2019-11-30T16:37:07Z

That check was overly aggressive when inlining. Here's my proposed solution:
https://github.com/toddstrader/verilator-dev/tree/protect-inline

Wilson: I'm guessing this sort of fix doesn't require a Changes entry. But please let me know if it does. Also, please let me know if this needs any changes before pushing.

@veripoolbot
Copy link
Contributor Author

Original Redmine Comment
Author Name: Wilson Snyder (@wsnyder)
Original Date: 2019-12-01T10:58:10Z

Todd, thanks for fixing. Feel free to push, you just need to init m_foundTop = false in the constructor.

@veripoolbot
Copy link
Contributor Author

Original Redmine Comment
Author Name: Todd Strader (@toddstrader)
Original Date: 2019-12-01T13:02:22Z

m_foundTop is already in the constructor initializer list. Is it fine there or should I move it to the constructor's implementation?

@veripoolbot
Copy link
Contributor Author

Original Redmine Comment
Author Name: Wilson Snyder (@wsnyder)
Original Date: 2019-12-01T16:01:44Z

Sorry, missed that, looks fine.

@veripoolbot
Copy link
Contributor Author

Original Redmine Comment
Author Name: Todd Strader (@toddstrader)
Original Date: 2019-12-02T13:35:24Z

Fixed in git towards 4.024.

@veripoolbot veripoolbot added the resolution: fixed Closed; fixed label Dec 22, 2019
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees

@toddstrader toddstrader

Labels
resolution: fixed Closed; fixed
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
2 participants
@toddstrader @veripoolbot