Search

Filter

  • Advanced Filters:

  • to
  • Specific Data Sources:

    All Edit

    Select All  |  Select None

Reset filters

We present a new algorithm for eliminating null pointer checks from programs written in Java™. Our new algorithm is split into two phases. In the first phase, it moves null checks backward, and it is iterated for a few times with other optimizations to eliminate redundant null checks and maximize the effectiveness of other optimizations. In the second phase, it moves null checks forward and converts many null checks to hardware traps in order to minimize the execution cost of the remaining null checks. As a result, it eliminates many null checks effectively and exploits the maximum use of hardware traps. This algorithm has been implemented in the IBM cross-platform Java Just-in-Time (JIT) compiler. Our experimental results show that our approach improves performance by up to 71% for jBYTEmark and up to 10% for SPECjvm98 over the previously known best algorithm. They also show that it increases JIT compilation time by only 2.3%. Although we implemented our algorithm for Java, it is also applicable for other languages requiring null checking.

Effective null pointer check elimination utilizing hardware trap


Effective Null Pointer Check Elimination Utilizing Hardware Trap Motohiro Kawahito Hideaki Komatsu Toshio Nakatani IBM Tokyo Research Laboratory 1623-14, Shimotsuruma, Yamato, Kanagawa, 242-8502, Japan { jl25131, komatsu, nakatani }@jp.ibm.com ABSTRACT We present a new algorithm for eliminating null pointer checks from programs written in Java™. Our new algorithm is split into two phases. In the first phase, it moves null checks backward, and it is iterated for a few times with other optimizations to eliminate redundant null checks and maximize the effectiveness of other optimizations. In the second phase, it moves null checks forward and converts many null checks to hardware traps in order to minimize the execution cost of the remaining null checks. As a result, it eliminates many null checks effectively and exploits the maximum use of hardware traps. This algorithm has been implemented in the IBM cross-platform Java Just-in-Time (JIT) compiler. Our experimental results show that our approach improves performance by up to 71% for jBYTEmark and up to 10% for SPECjvm98 over the previously known best algorithm. They also show that it increases JIT compilation time by only 2.3%. Although we implemented our algorithm for Java, it is also applicable for other languages requiring null checking. ond is that all the null checks cannot necessarily rely on the hardware support mechanism. For example, some operating systems do not generate an interrupt when the offset of the address is larger than a certain size. As another example, AIX does not generate an interrupt for reading from the first page at the address zero. A more subtle example is that when devirtualization [1, 3, 6, 7, 13] is applied, an explicit null check instruction must be generated for an object access to the method table, since this object access will be eliminated by transforming the dynamic (virtual) call to a static (non-virtual) call or inlining its method body. Here, the execution...

End of preview. To view the full-text, please rent this article to continue.

/lp/association-for-computing-machinery/effective-null-pointer-check-elimination-utilizing-hardware-trap-9a7uk80jJO
Welcome to DeepDyve! Rent Premier Research Articles and Save Up to 90%

Learn more

Bookmark

Effective null pointer check elimination utilizing hardware trap

Kawahito, Motohiro; Komatsu, Hideaki; Nakatani, Toshio
ACM SIGARCH Computer Architecture News , Volume 28 (5)
Association for Computing MachineryDec 1, 2000

More Info

More Like This Article

View All dataSource[]=actageo&dataSource[]=aspet&dataSource[]=aaos&dataSource[]=aacc&dataSource[]=aacr&dataSource[]=aea&dataSource[]=aip&dataSource[]=ajnr&dataSource[]=ams&dataSource[]=aps_physical&dataSource[]=appi_book&dataSource[]=appi_journal&dataSource[]=apha&dataSource[]=asip&dataSource[]=asm&dataSource[]=asn&dataSource[]=aspb&dataSource[]=avs&dataSource[]=annual_reviews&dataSource[]=arxiv&dataSource[]=acm&dataSource[]=berghahn&dataSource[]=cabi&dataSource[]=clinical_trials&dataSource[]=dailymed&dataSource[]=degruyter&dataSource[]=du_press&dataSource[]=esa&dataSource[]=eu_press&dataSource[]=elsevier&dataSource[]=emerald&dataSource[]=ejtr&dataSource[]=emea&dataSource[]=epo&dataSource[]=faseb&dataSource[]=gsa&dataSource[]=health_affairs&dataSource[]=hindawi&dataSource[]=imanager&dataSource[]=imedpub&dataSource[]=informa_healthcare&dataSource[]=informs&dataSource[]=iop&dataSource[]=iucr&dataSource[]=iospress&dataSource[]=jbjs&dataSource[]=leftcoast&dataSource[]=lu_press&dataSource[]=mesharpe&dataSource[]=mary_ann_liebert&dataSource[]=medline&dataSource[]=mit_press&dataSource[]=nature&dataSource[]=oxford&dataSource[]=pier_professional&dataSource[]=pnas&dataSource[]=portlandpress&dataSource[]=psyc_articles&dataSource[]=psyc_books&dataSource[]=psyc_critiques&dataSource[]=plos_journal&dataSource[]=pubmed_central&dataSource[]=rsna&dataSource[]=rockefeller&dataSource[]=rcn&dataSource[]=ria&dataSource[]=rsc&dataSource[]=sage&dataSource[]=spie&dataSource[]=springer_journal&dataSource[]=springer&dataSource[]=taylor_francis&dataSource[]=aps&dataSource[]=the_scientist&dataSource[]=uc_press&dataSource[]=uspto_abstract&dataSource[]=wiley&dataSource[]=pct

Browse: Subject Areas | Journals | Publishers

Sign Up for a DeepDyve Account

Bookmark an Article

To bookmark an article, please log in first, or sign up for a DeepDyve account if you don't already have one.

OK

Subscribe to Journal Email Alerts

To subscribe to email alerts, please log in first, or sign up for a DeepDyve account if you don't already have one.

OK

Thank you for renting with DeepDyve

Your PayPal account has been charged $2.99. You now have access to the full text of this article. A rental receipt has also been sent to your email address.

Your credit card has been charged $2.99. You now have access to the full text of this article. A rental receipt has also been sent to your email address.

OK

New! You can now keep track of new articles from ACM SIGARCH Computer Architecture News on your personalized homepage! Learn more

PDF Download — Not Available

Thanks for your interest in purchasing the PDF. Your request has been noted and we will work with our publisher partner to discuss enabling this feature.

In the meantime, you can get the PDF by visiting the publisher site.

Thank you for purchasing with DeepDyve

Your PayPal account has been charged $.

Your credit card has been charged $.

You can now download this article. A purchase receipt has also been sent to your email address.

Download This Article or I'm done with my download

Print Page — Not Available

Thanks for your interest in printing individual pages. Your request has been noted and we will work with our publisher partner to discuss enabling this feature.

In the meantime, you can get the PDF by visiting the publisher site.

Thank you for printing with DeepDyve

Your PayPal account has been charged $0.

Your credit card has been charged $0.

You can now print this article. A purchase receipt has also been sent to your email address.

Print the Selected Pages or I'm done with my printing

Please refresh to generate a new download link

Your article download link has expired. Please refresh this page to obtain a new download link and try again.

Follow a Journal

To get new article updates from a journal on your personalized homepage, please log in first, or sign up for a DeepDyve account if you don't already have one.

OK