Browse Prior Art Database

Method for dynamic optimization of programs

IP.com Disclosure Number: IPCOM000011546D
Original Publication Date: 2003-Mar-03
Included in the Prior Art Database: 2003-Mar-03
Document File: 1 page(s) / 31K

Publishing Venue

IBM

Abstract

Maintaining precise exceptions is an important aspect of achieving full compatibility with a legacy architecture. While asynchronous exceptions can be deferred to an appropriate boundary in the code, synchronous exceptions must be taken when they occur. This introduces uncertainty into liveness analysis since processor state that is otherwise dead may be exposed when an exception handler is invoked. Previous systems either had to sacrifice full compatibility to achieve more freedom to perform optimization, use less aggressive optimization or rely on hardware support. In this work, we demonstrate how aggressive optimization can be used in conjunction with dynamic compilation without the need for specialized hardware. The approach is based on maintaining enough state to recompute the processor state when an unpredicted event such as a synchronous exception may make otherwise dead processor state visible. The transformations necessary to preserve precise exception capability can be performed in linear time.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

THIS COPY WAS MADE FROM AN INTERNAL IBM DOCUMENT AND NOT FROM THE PUBLISHED BOOK

YOR820000508 Louis J Percello/Watson/IBM Michael Gschwind

Method for dynamic optimization of programs

This disclosure has been published as IBM Research Report

RC 21900 (98525) 5 December 2000 Computer Science "On Achieving Precise Exceptions Semantics in Dynamic Optimization"

Disclosed by International Business Machines Corporation

1