<html>
<head>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<div class="moz-cite-prefix">LGTM.<br>
<br>
On 3/19/2014 6:38 PM, Rui Ueyama wrote:<br>
</div>
<blockquote
cite="mid:CAJENXguL7Q6p8XmzfvEUffKKUTFD7yNe4=9_JxU06oHbr0b9NQ@mail.gmail.com"
type="cite">
<div dir="ltr">Looks like we agreed that this should be enabled
only when some environment variable (maybe
LLD_ENABLE_ROUNDTRIP_TEST?) is set, ok?</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Wed, Mar 19, 2014 at 4:31 PM,
Shankar Easwaran <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:shankare@codeaurora.org" target="_blank">shankare@codeaurora.org</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="HOEnZb">
<div class="h5">On 3/19/2014 5:44 PM, Nick Kledzik wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
On Mar 19, 2014, at 3:38 PM, Rui Ueyama <<a
moz-do-not-send="true" href="mailto:ruiu@google.com"
target="_blank">ruiu@google.com</a>> wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
It is proved that RoundTripNative and RoundTripYAML
are good harnesses to guarantee there's no
information loss when an object is converted to/from
native/YAML formats. However, it makes LLD
*extremely* slow when linking non-toy programs.<br>
<br>
If RoundTrip tests are enabled, LLD takes about 10
*minutes* to link itself on my Linux box. My machine
is 3.5GHz Xeon. The result of gprof on LLD linking
llvm-tblegen shows that 77.8% of time was consumed
by RoundTripYAMLPass::perform() and 16.6% by
RoundTripNativePass::perform(). It means RoundTrip
tests are the dominant factor.<br>
<br>
I couldn't even run LLD linking LLD with profiling
enabled because it was too slow that I couldn't wait
it to finish.<br>
<br>
This is not an acceptable performance penalty even
for debug build. I think we should move the feature
behind a flag and enable it only for tests.<br>
<br>
Any objections?<br>
</blockquote>
Sounds good. But, how can we set it up so that all
tests (including tests added later) will get the round
trip passes by default? Is there some environment
variable that the LIT harness sets up that the driver
can detect and run those passes by default?<br>
</blockquote>
</div>
</div>
I like the environment variable idea too.
<div class="HOEnZb">
<div class="h5"><br>
<br>
--<br>
Qualcomm Innovation Center, Inc. is a member of Code
Aurora Forum, hosted by the Linux Foundation<br>
<br>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</blockquote>
<br>
<br>
<pre class="moz-signature" cols="72">--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by the Linux Foundation</pre>
</body>
</html>