<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Mar 21, 2012, at 11:53 AM, Kostya Serebryany wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><blockquote class="gmail_quote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex; "><div class="im">> The gcc Ada front-end does this too, in quite a range of situations. For<br>> example multiple threads racily initialize a pointer variable, but they all<br>> initialize to the same value. The various valgrind based race detection<br>> tools all complain about this, which makes them much less useful than they<br>> might be for Ada.<br><br></div>FWIW, after thinking about this for awhile, I realize that we already have the tools to handle this: TBAA.<br><br>It would be general goodness for clang to emit VTable loads and stores in their with their own TBAA type class (one that does not even alias "char*").</blockquote><div><br></div><div>Indeed, sounds very nice.</div><div>I'll try to make a patch that adds TBAA metadata to VTable loads (unless someone else knows how to do it off the top of his head). </div></span><br class="Apple-interchange-newline"></blockquote></div><br><div>Sounds great, thanks Kostya,</div><div><br></div><div>-Chris</div></body></html>