I ran some more debugging sessions and found that using -O0 is painfully
slow (atleast twice slower compared to O1). I think which should keep both
the options with the default being -O (as it is currently).
On a similar note, GCC 4.8 has introduced -Og for superior debugging
experience. (http://gcc.gnu.org/gcc-4.8/changes.html). Anyone have an idea
of how good it is. If it's good, then we could modify the script to check
for gcc version and use -Og if we use gcc 4.8 or higher.

- Bhushan


On Fri, Feb 1, 2013 at 11:17 AM, Stephan Diestelhorst <
[email protected]> wrote:

> Vidyabhushan Mohan wrote on Wednesday 30 January 2013, 17:39:47:
> > Hi,
> > I have been using Marss to simulate parsec/spec workloads and so far
> things
> > have been great. I was debugging one of my simulation runs in debug mode
> > (scons debug=1 core=8) but I found out that most of the local variables
> and
> > some of the function arguments were optimized out and I had to resort to
> > debugging the assembly. When I checked the script in ptlsim/SConstruct, I
> > see this piece of code (lines 33-38):
> >
> >
> > if int(debug):
> >     env.Append(CCFLAGS = '-g')
> >
> >     # If debugging level is 1 then do optimize
> >
> >     if int(debug) == 1:
> >         env.Append(CCFLAGS = '-O')
> >
> >
> > Was it intentional to *enable* optimization when debug =1 is specified?
> > Since I do not want any optimizations enabled in the *debug* build, I
> could
> > sidestep this by specifying, for example debug =2. But I still wanted to
> > confirm if enabling optimization (for debug=1) was intentional. If not,
> > perhaps we could change it to -O0.
>
> Personally I find that -O0 code is a pain to look at, but I do rely on
> the assertions and extra printouts.  Furthermore, I am  almost always
> looking at the assembly directly...
>
> So maybe having both options (explicitly) would be good?
>
> Stephan
>
>
>
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