On Mon, Jul 13, 2009 at 11:03, Roberto Bagnarabagnara@cs.unipr.it wrote:
Sebastian Pop wrote:
On Thu, Jul 9, 2009 at 07:12, Michael Classenmichael.classen@uni-passau.de wrote:
Maybe it could also be possible to use the Parma Watchdog Library (PWL) for providing a timeout for the precise method and falling back to the more conservative method once a certain timeout is reached?
Not in GCC. This would make the compiler non deterministic.
The new deterministic timeout facilities of the PPL and PWL (you need both) can be exploited (using the C language interface) by using the following functions:
Awesome! Thanks!
At the moment we cannot provide meaningful hints regarding the appropriate values to be given to these weight thresholds: they mainly depend on the particular application and on the particular problem instances considered. Some experimentation and tuning are unavoidable.
Please test and let us know how it goes. If you think you want this in time for GCC 4.5.0, please advise so that our release schedule matches the one of GCC.
We will play with PWL before integrating it in GCC.
I was thinking about starting the counter at the beginning of Graphite when we initialize PPL and reseting it after code generation is done. We may consider having the weight as a parameter of GCC with a default value set such that we don't increase more than 10-20% the compile time of SPEC Cpu2006 benchmarks.
Sebastian