Dealer Instruction Processing Unit Governor - Continuous Operation
Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2005-Mar-19
Publishing Venue
IBM
Related People
Ekanadham, K: AUTHOR [+3]
Abstract
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.
Dealer Instruction Processing Unit Governor - Continuous Operation
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
instruction 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, and the
THREAD is the smallest unit of
aggregation of instructions from a SEGMENT.
Individual
instructions, while executing, carry an
indication
as to
which SEGMENT, DECODER,
and THREAD they belong. The
information concerning the DECODER
and THREAD is derived
from
the Z-CODE itself.
The SEGMENT index is assigned
sequentially at
each SEGMENT SWITCH.
Segment switches occur at
points in the
code where the Z-SEGMENT terminates or where a Branch Wrong Guess has
been detected.
MSIS HEM
is a High End Machine design that uses multiple
decoders within a single processor in the place of separate
processor elements (PEs).
A single Instruction Processing Unit
(IPU) executes all instructions in
MSIS HEM albeit through a
multiplicity of register
files that are associated with the
THREADS. MSIS META HEM is
a Multiple Execution Thread
Architecture that separates the THREADS from the next higher
aggregate of instructions, the
DECODER. Thus the
action of S-LIST
and/or D-LIST entries within the Z-CODE activates and...