13 research outputs found
A thread calculus with molecular dynamics
We present a theory of threads, interleaving of threads, and interaction
between threads and services with features of molecular dynamics, a model of
computation that bears on computations in which dynamic data structures are
involved. Threads can interact with services of which the states consist of
structured data objects and computations take place by means of actions which
may change the structure of the data objects. The features introduced include
restriction of the scope of names used in threads to refer to data objects.
Because that feature makes it troublesome to provide a model based on
structural operational semantics and bisimulation, we construct a projective
limit model for the theory.Comment: 47 pages; examples and results added, phrasing improved, references
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Multi-threaded microprocessors evolution or revolution
Abstract. Threading in microprocessors is not new, the earliest threaded processor design was implemented in the late 1970s and yet only now is it being used in mainstream microprocessor architecture. This paper reviews threaded microprocessors and explains why the more popular option of outof-order execution has a poor future and is not likely to provide a pathway for future microprocessor scalability. The first mainstream threaded architectures are beginning to emerge but unfortunately based on out-of-order execution. This paper will review the relevant trends in multi-threaded microprocessor design and look at one approach in detail, showing how wide instruction issue can be achieved and how it can provide excellent performance, latency tolerance and above all scalability with issue width. This model exploits ILP and loop level parallelism using a vector-like instruction set in a chip multiprocessor. 1 The Forces at Play in ISA Design There are two forces that determine the form and function of microprocessor architectur