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Multisequencing a Single Instruction Stream Meta High-End Machine - The Role of the Dealer

IP.com Disclosure Number: IPCOM000104347D
Original Publication Date: 1993-Apr-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 4 page(s) / 180K

Publishing Venue

IBM

Related People

Ekanadham, K: AUTHOR [+3]

Abstract

Multisequencing a Single Instruction Stream (MSIS) is a uniprocessor organization in which a set of processing elements (PE) 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.

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Multisequencing a Single Instruction Stream

Meta

High-End Machine - The Role of the Dealer

      Multisequencing a Single Instruction Stream (MSIS) is a
uniprocessor organization in which a set of processing elements (PE)
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 a PE sees 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 and the
THREAD is the smallest unit of aggregation of instructions from a
SEGMENT.

      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 deactivates the THREADS and alternate THREADS are
decoded.

      At the conclusion of a Z-SEGMENT or at the point of a Branch
Wrong Guess, the register state of the processor is distributed among
the register files  that  constitute  the results of THREAD
processing.  To determine the machine state a ZZT is employed.  The
ZZT is a two dimensional structure which is accessed by both
architected register name and level of conditionality.  The level of
conditionality of an instruction is assigned to instructions during
the  E-MODE and corresponds to the number of: branch instruc...