1. Efficient Sharing Analysis Xuan Li, Andy King and Lunjin Lu Oakland University, U.S.A & University of Kent, U.K.

2. The motivations Sharing analysis is one of the most important analysis in logic program analysis Classical Sharing analysis is exponential In abstract interpretation, you can mimic computation in a simpler abstract domain instead of complex concrete domain space. We attack this problem by doing computation in an abstract domain, which will avoid exponential operator.

3. Classical Solution The domain is set of sets of variables. If there is n variables, there are 2^(2^n-1) sharings in domain, which is very large. There is an exponential operator in least fixed point computation. Moreover, it is executed very often. The classical solution is slow because of these reasons.

4. Our Solution Create abstract domain that can remember which groups will do closure under union. Modify the operation in abstract domain and avoid exponential operator. Only execute closure on demand after least fixed point computation.

5. How good is it Improve efficiency more than100 times compared with classical solution. We avoid the exponential operator. However, the domain space is still very large. Although this algorithm is more efficient than classical algorithm, the performance is still not good when the input is large. Note we are dealing with 2^(2^n-1) sharings for n variables,.

6. Implementation Support both Windows and Linux. Use C++. Implement our own framework which itself is worthy to mention. Top-down framework.

7. Performance ProgramXSSH/secondSSH/second Treesort.pl01 Ga.pl11 Qsort.pl04 Merge.pl16 Kalah.pl183 Peep.pl1400 Sdda.pl11173 Disj_r.pl7>3600 Read.pl11>3600

8. Future work Encoding using Boolean formula. Backward analysis. Improve precision. Do not do cross union.

9. Conclusion We provide a new analysis for Sharing analysis. This new analysis is much efficient than classical analysis