[PTLsim-devel] validate option

Thu Oct 11 20:21:35 EDT 2007

On Thursday 11 October 2007 18:29, Komal Jothi wrote:
> Hi,
>
> Can you please give me the details on how to use the 'validate' option in
> PTLsim?
>
> My understanding is that, if a benchmark is run with the -validate option,
> PTLsim would compare the ooo core results with the seq core results, during
> run time.
>
> Is there a log file that would clearly indicate the results being committed
> by each core?
>
> I could not find much documentation on the -validate parameter in the
> manual.
>

This feature isn't implemented in the open source version of PTLsim. We use it 
with one of our internally developed core models - it probably shouldn't have 
even been included since it isn't actually used anywhere.

You could try to implement this feature for ooocore if you'd like to use it. 
The seqcore model has an execute_sequential function like this:

int execute_sequential(Context& ctx, CommitRecord* cmtrec,
  W64 bbcount, W64 insncount)

The CommitRecord structure records the register state and list of stores that 
would be committed if the sequential core was allowed to write to the 
architectural state. When the OOO core commits each x86 instruction in the 
commit stage, you could call execute_sequential for exactly one instruction, 
then allow the OOO commit to occur, then compare the architectural state 
against execute_sequential's output. This should be fairly easy to add.

- Matt

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 Matt T. Yourst                    yourst at peptidal.com
 Peptidal Research Inc., Co-Founder and Lead Architect
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