BU/CLA CS-551
Parallel Computing: Models, Languages, and Architectures
Compound Vector Processing [problem 8.11 in textbook]
The following sequence of CVF is to be executed on a Cray X-MP vector
processor:
A(I) = B(I) + s * C(I)
D(I) = s * B(I) * C(I)
E(I) = C(I) * C(I) - B(I)
where B(I) and C(I) are each 64-element vectors originally stored in
memory. The resulting vectors A(I), D(I), and E(I) must be stored back
into memory after the computation.
- Write 11 vector instructions in proper order to execute the above
CVF on a Cray X-MP processro with 2 vector-load pipes and 1
vector-store pipe which can be used simultaneously with the remaining
functional pipelines.
- Show a space-time diagram (similar to fig. 8.19) for achieving
maximally chained vector operations for executing the above CVFs in
minimum time.
- What is the potential speedup of the above vector chaining
operations over the chaining operations on the Cray 1 (which has only
one memory-access pipe).
This document has been prepared by Professor Azer Bestavros
<best@cs.bu.edu> as the WWW Home Page for
CS-551, which is
part of the NSF-funded
undergraduate curriculum on parallel
computing at BU.
Date of last update: November 22, 1994.