Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Ekanadham, K: AUTHOR [+2]
Metaparallelism is a process that determines the form of parallelism that is to be used in a specific application. Metaparallelism has two interfaces:
Metaparallelism is a process that determines the form of
parallelism that is to be used in a specific application.
Metaparallelism has two interfaces:
derived from prior executions.
o Explicit statements made in the program or compiler output that
bear on the form of parallelism.
Metaparallelism uses aspects of program behavior as it
relates to the
capabilities of the Metaparallel Processor to cope with this behavior
to determine the type of parallelism that is to be pursued.
Metaparallelism employes speculation, that is, allocation of
resources to computations without a guarantee that these computations
are required, in order to complete the application in the faster
The choice of parallelisms that metaparallelism can select from are:
forms of parallelism.
o Path-oriented forms of parallelism with speculation.
o Computation-oriented parallelism with bifurcation at branches.
o A set of independent paths that intercommunicate by sending
messages to each other.
o A combination of the above.
Metaparallelism employs means at its disposal to alter
the form of
parallelism specified by the programmer/compiler at the source level
and to notify the programmer about significant aspects that interfere
with the parallelization of the application.
MSIS is a
uniprocessor organization in which a set of
processing elements (PEs) working in concert execute Segments of the
instruction stream. The Segments are either P-Segments, normal
uniprocessor instruction stream portions, that are processed in the
E-MODE of MSIS and produce Z-Segments, or the Z-Segments that are
processed in Z-MODE by MSIS. The main difference between E-MODE and
Z-MODE is that during E-MODE each PE sees all instructions in the
Segment and executes the ones that are assigned to it, but during
Z-MODE a PE only sees the instructions assigned to it.
As all PEs
see all instructions in E-MODE, each PE can create
the Z-CODE it will require to re-execute the Segment as a Z-Segment,
the Z-CODE being stored in the Z-CACHE, and associated with
instructions in the Z-CODE are S-LISTS and D-LISTS as, appropriate.
An S-LIST instructs the PE, in the Z-MODE, that one or more of the
source registers in an instruction assigned to it is set by another
instruction that is executed on another PE; an S-LIST is a receiving
obligation. The D-LIST instructs the PE in the Z-MODE as to the
names of PEs that require the values of the register(s) that are
being set by an instruction that is assigned to it. A D-LIST entry
is a sending obligation.
The set of
instructions assigned to a single PE can be further
delineated as THREADS. A THREAD is a sequence of instructions in the
original conceptual order, and a Thread is associated with a register
file which is either real or virtual. There are no sending or
receiving obligations between instructions within a THREAD, a...