Re: [myhdl-list] newb question

[Jan D. <ja...@ja...>]

Jan Decaluwe wrote:
> Christopher L. Felton wrote:
> 
> 
>>For this test, most people would not simulate this design this way.   
>>The design has a simple state machine
>>that controls the inputs to a bank of pwm's (controls the duty  
>>cycle).  But the state machine goes to the next
>>state on the order of 100ms real-time.  But since the simulation has  
>>little logic and the logic switches minimally
>>it seemed like a good test to profile the MyHDL simulation execution
>>(most the time spent in the simulation code and not the logic code).
> 
> 
> This seems to imply that more "typical" code (e.g. with more logic
> inside generators) could have a relatively larger intbv overhead,
> and therefore more to gain from intbv optimization.
> 
> I'll see if I can do a profiling check on my recent designs.

Below you find a profiling output of a recent test plan. I believe this
is quite representative for the code I tend to write.

I used Python 2.5, cProfile, ordered by time (first 20 items).

I use intbv slicing a lot, and you see this takes a considerable amount
of time.

It seems that optimizing intbv would help significantly, but the Simulation
(including Signal) overhead being what it is, we can't expect miracles.

(Until the py.py team delivers a Python that is 10 times faster :-))

Jan

----

Wed Feb 13 18:36:07 2008    runprof

          536613094 function calls (523280085 primitive calls) in 2643.025 CPU seconds

    Ordered by: internal time

    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
  19119681  257.504    0.000  461.618    0.000 _intbv.py:148(__setitem__)
        12  244.692   20.391 2623.724  218.644 _Simulation.py:95(run)
  27579102  222.675    0.000  390.886    0.000 _Signal.py:180(_set_next)
   2092116  144.248    0.000  937.835    0.000 _Waiter.py:184(next)
  89188746  139.018    0.000  139.018    0.000 {isinstance}
  25572768  126.633    0.000  126.633    0.000 _intbv.py:80(_checkBounds)
   4748554  108.021    0.000 1078.335    0.000 _Waiter.py:152(next)
  19675183  105.021    0.000  105.021    0.000 _Signal.py:46(purge)
41201947/30501215   94.226    0.000  168.693    0.000 {cmp}
27633083/26039251   93.698    0.000  248.657    0.000 _Signal.py:426(__cmp__)
  10615743   93.432    0.000  140.551    0.000 _intbv.py:121(__getitem__)
  28024120   84.658    0.000  107.350    0.000 _Signal.py:151(_update)
    668592   76.952    0.000  447.660    0.001 xxx.py:131(xxx)
13568864/13268586   75.899    0.000  127.541    0.000 _intbv.py:428(__cmp__)
  63303336   75.171    0.000   75.171    0.000 {method 'append' of 'list' objects}
  25711177   61.852    0.000   61.852    0.000 _Signal.py:224(_setNextBool)
   8153851   43.938    0.000  122.899    0.000 _Signal.py:284(__getitem__)
  33114023   38.130    0.000   38.130    0.000 {id}
  29873445   33.188    0.000   33.188    0.000 {method 'extend' of 'list' objects}
   3053592   31.259    0.000   50.400    0.000 _intbv.py:39(__init__)


-- 
Jan Decaluwe - Resources bvba - http://www.jandecaluwe.com
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