Abstract
We introduce a new sequential model of computation, called the Logarithmic Pipelined Model (LPM), in which a RAM processor of fixed size has pipelined access to a memory ofm cells in time logm. Our motivation is that the usual assumption that a memory can be accessed in constant time becomes theoretically unacceptable asm increases, while an access time of logm is consistent with VLSI technologies. For a problem II of sizen, IT εP, we denote byS(n) the time required by the fastest known sequential algorithm, and byT(n) the time required by the fastest algorithm solving II in the LPM. LettingO(logn) =O(logm), we define several complexity classes; in particular, LP0 = {II εP:T(n) =O(S(n))}, the class of problems for which the LPM is as efficient as the standard model, and LP∞ =IIεP:T(n) =O(S(n) logn), where the problems are less adequately solved in the new model. We first study the relations between the LPM and other models of computation. Of particular relevance is comparison with the PRAM model. Then we discuss several problems and derive the relative upper and lower bounds in the LPM. Our results lead to a new organization of parallel algorithms for list-linked structures.
Similar content being viewed by others
References
A. Aggarwal, B. Alpern, A. K. Chandra, and M. Snir. A model for hierarchical memory.Proc. 19th ACM STOC, 1987, pp. 305–314.
A. Aggarwal, A. K. Chandra, and M. Snir. Hierarchical memory with block transfer.Proc. 28th IEEE FOCS, 1987, pp. 1–13.
A. Aggarwal, A. K. Chandra, and M. Snir. On communication latency in PRAM computation.Proc. 1st ACM SPAA, 1989, pp. 11–21.
A. Aho, J. Hopcroft, and J. Ullman.The Design and Analysis of Computer Algorithms. Addison-Wesley, Reading, MA, 1984.
B. Alpern, L. Carter, and E. Feig. Uniform memory hierarchies.Proc. 31st IEEE FOCS, 1990, pp. 600–608.
J. L. Bentley. A parallel algorithm for constructing minimum spanning trees.J. Algorithms,1 (1980), 51–59.
R. Cole. Parallel Merge-Sort.Proc. 27th IEEE FOCS, 1986, pp. 511–516.
R. Cole and U. Vishkin. Approximate and exact parallel scheduling with applications to list, tree and graph problems.Proc. 27th IEEE FOCS, 1986, pp. 478–491.
S. A. Cook. A taxonomy of problems with fast parallel algorithms.Inform, and Control,64 (1985), 2–22.
C. P. Kruskal. Searching, Merging, and Sorting in parallel computation.IEEE Trans. Comput.,32 (1983), 942–946.
F. Luccio and L. Pagli. Sequential computation based on pipelined access to memory.Proc. 27th Allerton Conference, 1989, pp. 702–711.
C. Mead and L. Conway.Introduction to VLSI Systems. Addison-Wesley, Reading, MA, 1980.
M. H. Nodine and J. F. Vitter. Large-scale sorting in parallel memories.Proc. 3rd ACM SPAA, 1991, pp. 29–39.
D. B. Skillicorn. A taxonomy for computer architectures.Computer,21 (1988), 46–57.
Author information
Authors and Affiliations
Additional information
This work was supported in part by M.U.R.S.T. of Italy under a research grant.
Rights and permissions
About this article
Cite this article
Luccio, F., Pagli, L. A model of sequential computation with Pipelined access to memory. Math. Systems Theory 26, 343–356 (1993). https://doi.org/10.1007/BF01189854
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF01189854