<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<div class="moz-cite-prefix">On 5/25/2018 11:46 AM, JF Bastien
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:7A085E79-CC0C-4709-8405-2F2032DFDC3F@apple.com">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<br class="">
<div><br class="">
<blockquote type="cite" class="">
<div class="">On May 25, 2018, at 11:38 AM, Friedman, Eli <<a
href="mailto:efriedma@codeaurora.org" class=""
moz-do-not-send="true">efriedma@codeaurora.org</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<meta http-equiv="Content-Type" content="text/html;
charset=utf-8" class="">
<div text="#000000" bgcolor="#FFFFFF" class="">
<div class="moz-cite-prefix">On 5/25/2018 11:29 AM, JF
Bastien via cfe-dev wrote:<br class="">
</div>
<blockquote type="cite"
cite="mid:AC7AF159-592E-4EA7-9AA4-A8242D750526@apple.com"
class="">
<meta http-equiv="Content-Type" content="text/html;
charset=utf-8" class="">
<div class="">
<div class="">
<ol class="MailOutline">
<li class="">Teach the target infrastructure that
hardware interference size is something they can
specify (in tablegen files somewhere).</li>
<li class="">Allow overriding the value in
sub-targets using -march or -mcpu (the
sub-target defines the numeric value, and the
user gets the overriden one by using -march or
-mcpu).</li>
</ol>
</div>
</div>
</blockquote>
<br class="">
We can't change the value based on -mcpu. We generally
allow mixing code built with different values of -mcpu.
And any code which is linked together must use the same
value for hardware_destructive_interference_size, or else
we violate ODR.<br class="">
</div>
</div>
</blockquote>
<div><br class="">
</div>
<div>Interesting point. The case I’d like to cover is one where
the developer wants to get the exact right value for their
particular CPU, instead of a conservative answer with extra
padding. How do you think we should meet this use case?</div>
<br class="">
</div>
</blockquote>
<br>
Go back to the standards committee and ask for a function that isn't
constexpr? I can't think of any other reasonable solution.<br>
<br>
-Eli<br>
<pre class="moz-signature" cols="72">--
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project</pre>
</body>
</html>