[Bug c++/14563] octave built under Cygwin very slow

[paulthomas2 at wanadoo dot fr]

------- Additional Comments From paulthomas2 at wanadoo dot fr  2004-03-24 16:38 -------
Subject: Re:  octave built under Cygwin very slow

bangerth at dealii dot org wrote:

>------- Additional Comments From bangerth at dealii dot org  2004-03-24 15:57 -------
>First, thanks for you efforts! 
> 
>The Unwind_SjLj_* functions have to do with exceptions. Danny, I CC: 
>you because here's a cygwin question: is sjlj the default on windows, 
>and are you aware of any significant changes in this area that could 
>affect this? 
> 
>Paul&Ben: even if the problem is in this function, am I correct with 
>my math that these functions only account for at most about 1/4 of 
>the run-time? If that is the case, then they can't make up for a 
>six-fold increase in run-time... 
> 
>W. 
>
>  
>
This is why I am questioning the calibration of the profiling - none of 
the times add up.  Is it reasonable that the faster of the two builds be 
bumped up from 20 to 90s runtime with profiling?  If so, should I expect 
to see the total profile time add up to the original 20s?  In fact, the 
total that I can find in the profiling is about 12seconds, including 
octave start-up.  Even if the latter is negligible, I am missing 40% of 
the unprofiled execution time and 80% or so of the wall-clock time.

Am I right in thinking that setting -fno-exceptions will suppress sjlj 
if it is the default?  Perhaps we should try that as an experiment?

Paul T



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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14563