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    Hi Martin,<br>
    <br>
    This looks good to me. Coleen has also reviewed the change and given
    it the thumbs up. I'll let you get back to me regarding a test case
    before pushing the changes.<br>
    <br>
    JohnC<br>
    <br>
    <div class="moz-cite-prefix">On 4/16/2013 1:38 AM, Doerr, Martin
      wrote:<br>
    </div>
    <blockquote
cite="mid:7C9B87B351A4BA4AA9EC95BB4181165668F42BED@DEWDFEMB13A.global.corp.sap"
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        <p class="MsoNormal">Hi all,<o:p></o:p></p>
        <p class="MsoNormal"><o:p> </o:p></p>
        <p class="MsoNormal"><span lang="EN-US">we found a G1 bug i</span><span
            style="mso-fareast-language:DE" lang="EN-US">n the template
            interpreter on x86_64 and sparc with compressed Oops.<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US">“do_oop_store” performs a “</span><span
            style="color:black;background:silver;mso-highlight:silver"
            lang="EN-US">store_heap_oop</span><span style="color:black"
            lang="EN-US">” which compresses the input register.<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="color:black" lang="EN-US">This
            compressed Oop is passed to the succeeding
          </span><span style="mso-fareast-language:DE" lang="EN-US">g1_write_barrier_post,
            which is wrong.<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US">Correctly, g1_write_barrier_post needs the
            uncompressed Oop for the heap region crossing check.<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US">This fix preserves the uncompressed Oop in a
            register which gets passed to the g1_write_barrier_post:<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US"><a moz-do-not-send="true"
              href="http://cr.openjdk.java.net/%7Egoetz/webrevs/g1-cOops_bug/">http://cr.openjdk.java.net/~goetz/webrevs/g1-cOops_bug/</a><o:p></o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US">Please supply a bug id and review this change.<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US">Kind regards,<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US">Martin<o:p></o:p></span></p>
        <p class="MsoNormal"><span style="mso-fareast-language:DE"
            lang="EN-US"><o:p> </o:p></span></p>
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