Browse Prior Art Database

Automatic Creation of Fastpaths in Existing and New Code with Minimal or No Programmer Intervention

IP.com Disclosure Number: IPCOM000106036D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Parikh, SN: AUTHOR

Abstract

An automated way is needed to bypass repeated execution of same code with same results each time.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Automatic Creation of Fastpaths in Existing and New Code with Minimal or No Programmer Intervention

      An automated way is needed to bypass repeated execution of same
code with same results each time.

      The problem is more complex and almost intractable for the
existing code and in deployment for years (and even decades).  The
understanding and modification of such code is often impossible.

      This invention describes a method of inserting fast paths in
code with minimal programmer intervention.  In fact, this method can
achieve integration of FastPaths by merely recompilation of the
program in question.

     The 'FastPath' is a way to bypass a piece of code which is
typically executed repeatedly.  Additionally, for the purpose of this
invention, has one additional, nevertheless fairly easy condition:
on each execution of this code, the results of the execution of the
section of the code (which needs to be bypassed by means of the
FastPath) are same for SAME set of input, i.e. the code achieves same
values of the output parameters.  Or stated differently, the results
of the execution for the same set of input parameters do not change
over time.  As an example, one may consider the computation of
mathematical functions ( f(x) = (1-x3)tan(x)**2 ).

      The programmer on identifying such pieces of code may want to
insert the code to add a FastPath.  However, this modification will
need a good understanding of the code.  Often the programmer,
performing the maintenance of the code, is quite unfamiliar with the
working of the code and therefore is unwilling to hazard a change.
To compound the problem, for fairly old systems in production mode,
such an understanding is lost for ever.

      To improve the performance of code of this nature with
technique of FastPat...