Abstract
A traditional approach to solving the problem of local compaction of a horizontal microcode is described. In accordance with this approach any linear segment of the source microcode is made to correspond to a unique data dependence graph. A notion of the data exchange between the microoperations is introduced. Based on this notion, a model is developed that demonstrates that a given linear segment is, generally, associated with a set of semantically equivalent data dependence graphs, which differ from one another by the order of the execution of the exchanges on shared static resources. An optimization combinatorial problem on the permutation of the exchanges of a linear segment is formulated. Conditions for the existence of an admissible solution are studied, and a method for finding it is developed. A new space of solutions for the local compaction problem is obtained through the use of a new data dependence graph, which is, in a sense, better than the original one.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
REFERENCES
Davidson, S., Landskov, D., Shriver, B., and Mallet, P.W., Some Experiments in Local Microcode Compaction for Horizontal Machines, IEEE Trans. Comput., 1981, vol. 30,no. 7, pp. 460–477.
Landskov, D., Davidson, S., Shriver, B., and Mallet, P.W., Local Microcode Compaction Techniques, ACM Comput. Surveys, 1980, vol. 12,no. 3, pp. 261–294.
Fisher, J.A., Trace Scheduling: A Technique for Global Microcode Compaction, IEEE Trans. Comput., 1981, vol. C-30,no. 7, pp. 478–490.
Tokoro, M., Tamura, E., and Takizuka, T., Optimization of Microprograms, IEEE Trans. Comput., 1981, vol. C-30,no. 7, pp. 491–504.
Dasgupta, S. and Tartar, J., The Identification of Maximal Parallelism in Straight-line Microprograms, IEEE Trans. Comput., 1976, vol. C-25,no. 10, pp. 986–992.
Mezzalama, M. and Prinetto, P., A Machine-Independent to Microprogram Synthesis, Software Pract. & Exper, 1982, vol. 12,no. 11, pp. 985–1010.
Mezzalama, M. and Prinetto, P., Microprogram Simulation Using a Structured Microcode Model, Microprocess. Microprogram, 1984, vol. 13,no. 5, pp. 299–314.
Ramamoorthy, C.V. and Tsuchiya, M., A High Level Language for Horizontal Microprogramming, IEEE Trans. Comput., 1974, vol. C-23,no. 8, pp. 791–801.
Tokoro, M., Takizuka, T., Tamura, E., and Yamaura, I., An Approach to Microprogram Optimization Considering Resource Occupancy and Instruction Formats, Proc. of 10th Annu. Workshop on Microprogramming, 1977, pp. 92–108.
Tsuchiya, M. and Gonzalez, M.J., Toward Optimization of Horizontal Microprogrammings, IEEE Trans. Comput., 1976, vol. C-25,no. 10, pp. 992–999.
Conway, R.W., Maxwell, W.L., and Miller, L.W., Theory of Scheduling, Reading, Mass.,: Addison-Wesley, 1967. Translated under the title Teoriya raspisanii, Moscow: Nauka, 1975.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Malykh, O.N., Shakhnovskii, Y.S. Optimization of a Data Dependence Graph for the Local Microcode Compaction Problem. Part 1: Problem Statement. Programming and Computer Software 30, 34–46 (2004). https://doi.org/10.1023/B:PACS.0000013439.23101.14
Issue Date:
DOI: https://doi.org/10.1023/B:PACS.0000013439.23101.14