Circuit Placement w/ Multi-core Processors

1. Circuit Placement w/ Multi-core Processors Design Presentation May 10-02 Mike Drob Grant Furgiuele Ben Winters Advisor: Dr. Chris Chu Client: IBM

2. Project Overview • Circuit Placement problem is bottleneck of physical design • Currently only single-core – no threads • Will attempt to parallelize some functions of the FastPlace algorithm using the linux pthreads library. • Will implement RQL idea into FastPlace

3. Design Considerations • Paralellize certain CPU and time heavy functions • Profiled existing algorithm using gprof in Linux • Analyze ease of parallelizing parts of the algorithm • Spring potential energy calculation • Global Placesment (Matrix Problem) • Local refinement optimizations

4. Design Considerations (cont.) • Cores v. Threads • Speedup only continues with more cores if there are more threads • Specify number of cores at compilation time or at run time? • RQL concept • Nullify the spreading forces on a small portion of the modules with highest force • Leaves these modules at their quadratically optimal location

5. Paralellization Priorities • Using the ISPD2005 Benchmarks Global Placement Detailed Placement

6. Desired Performance Gains Unit Time Taken by Top 10 Most Time Consuming Functions vs. All Other Functions

7. Prototyping • Program which looped 10,000,000 times. • Took ~6.5 seconds on single core • With two threads on dual core, took ~3.5 seconds • With four threads on quad core, took ~2 seconds • Results not quite halved / fourthed due to overhead. • Thread creation overhead • System overhead

8. Testing Considerations • Frequent Testing • On a per method basis • Will use Valgrind to profile performance • Gprof doesn’t work with threaded programs • Testing done on a variety of systems • Test for consistant performance levels in comparable systems • Test for increased performance in more capable systems

9. Schedule

10. Personnel Effort Estimates

11. Cost Estimates

12. Questions?