Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Debug Support for Trace Directed Program Restructuring

IP.com Disclosure Number: IPCOM000113367D
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Heisch, RR: AUTHOR [+2]

Abstract

This disclosure presents a method for supporting program debugging for programs which have been reordered using Trace Directed Program Restructuring. TDPR is a method for reorganizing the instructions in a program, based on an address trace or execution profile for the actual execution of that program, so as to improve the utilization of the instruction cache (which typically results in improved performance) and the utilization of real memory (which typically results in a reduction in real memory requirements).

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 81% of the total text.

Debug Support for Trace Directed Program Restructuring

      This disclosure presents a method for supporting program
debugging for programs which have been reordered using Trace Directed
Program Restructuring.  TDPR is a method for reorganizing the
instructions in a program, based on an address trace or execution
profile for the actual execution of that program, so as to improve
the utilization of the instruction cache (which typically results in
improved performance) and the utilization of real memory (which
typically results in a reduction in real memory requirements).

      A prototype implementation of TDPR for AIX* executables on the
RS/6000* has resulted in program speedups of up to 73% and reductions
in real memory requirements of up to 61%.

      One major problem with reordering an AIX executable is the
inability to effectively debug a reordered program.  Reordering a
program both invalidates much of the address dependent debug
information in the executable as well as disassociates the traceback
entries from the reordered code.  A lack of debug support severely
limits the appeal of TDPR and may be viewed as an unacceptable
tradeoff for performance by many customers.

      The solution to this debug problem for reordered code is to
provide a cross reference table for the debugger which contains a
mapping of reordered addresses to original addresses.  This cross
reference table is provided as an additional AIX XCOFF section in the
program exec...