Browse Prior Art Database

Method to Dispatch Instructions Off a Target Buffer

IP.com Disclosure Number: IPCOM000103617D
Original Publication Date: 1993-Jan-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 1 page(s) / 59K

Publishing Venue

IBM

Related People

Barreh, JI: AUTHOR [+3]

Abstract

Disclosed is a strategy for allowing dispatch of instructions off a target buffer in order to improve the overall performance of a given system.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 55% of the total text.

Method to Dispatch Instructions Off a Target Buffer

       Disclosed is a strategy for allowing dispatch of
instructions off a target buffer in order to improve the overall
performance of a given system.

      The inability to dispatch instructions off a target buffer
limits the optimal performance of a system.  The system may be
considered to be made up of: 1) an icache-unit (ICU), 2) a
fixed-point unit (FXU), and 3) a floating-point unit (FPU).  The ICU
dispatches all FXU and FPU instructions and executes branches.
Branches can be considered to be either conditional or unconditional.
Conditional branches depend on a condition-register (CR) bit in order
to determine whether they are taken or not.  Conditional branches can
be either resolved or unresolved branches depending on whether the CR
is known at the time of the execution of the branch.  When the ICU
encounters an unresolved branch, it attempts to dispatch both the
conditional and target instruction streams of the branch.
Conditional instructions are those instructions dispatched past an
unresolved branch and within the same sequential stream of
instructions as the unresolved branch.  The target of the unresolved
branch produces the target stream of instructions.  Dispatching
instructions from the target buffers enables the ICU to provide the
target instruction stream to the FXU and the FPU in the vicinity of
an unresolved branch.  The ability to provide target instructions
significantly improves the...