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From: McCormack, M. <Mic...@si...> - 2012-03-04 22:00:27
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Hi Julian, Thanks for the feedback. The bug number is: https://bugs.kde.org/show_bug.cgi?id=251569 You are right, it should set ECX too. Thanks, Mike -----Original Message----- From: Julian Seward [mailto:js...@ac...] Sent: Friday, 2 March 2012 11:28 PM To: val...@li... Cc: McCormack, Michael; Dennison, Paul; Patterson, Eliot; Forster, Duncan Subject: Re: [Valgrind-developers] [PATCH] Handle RDTSCP instruction on x86-64 (Bug 251569) > Valgrind 3.7.0 crashes on my x86-64 machine when it encouters the RDTSCP > instruction. The attached patch (against 3.7.0) fixes the problem. Added > to the currently opened bug also: What's the bug number? > https://bugs.kde.org/attachment.cgi?id=69198 Thanks for the patch. I would ask though, is this really right? According to my reading of the Intel docs, RDTSC writes EDX and EAX, and RDTSCP also writes ECX. Whereas your patch appears to not modify ECX, if I read it right. We could just route rdtscp through to rdtscp on the host, as is done with rdtsc at present. The real difficulty with that is that we don't have a way to return more than 64 bits from a helper call right now (iow, it's a code generation problem in the JIT). J ________________________________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses. |