<html>
<head>
<base href="https://llvm.org/bugs/" />
</head>
<body><span class="vcard"><a class="email" href="mailto:kkhoo@perfwizard.com" title="Kay Tiong Khoo <kkhoo@perfwizard.com>"> <span class="fn">Kay Tiong Khoo</span></a>
</span> changed
<a class="bz_bug_link
bz_status_REOPENED "
title="REOPENED --- - x86 FMA could choose different instruction to avoid move"
href="https://llvm.org/bugs/show_bug.cgi?id=17229">bug 17229</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">Status</td>
<td>RESOLVED
</td>
<td>REOPENED
</td>
</tr>
<tr>
<td style="text-align:right;">Resolution</td>
<td>FIXED
</td>
<td>---
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_REOPENED "
title="REOPENED --- - x86 FMA could choose different instruction to avoid move"
href="https://llvm.org/bugs/show_bug.cgi?id=17229#c9">Comment # 9</a>
on <a class="bz_bug_link
bz_status_REOPENED "
title="REOPENED --- - x86 FMA could choose different instruction to avoid move"
href="https://llvm.org/bugs/show_bug.cgi?id=17229">bug 17229</a>
from <span class="vcard"><a class="email" href="mailto:kkhoo@perfwizard.com" title="Kay Tiong Khoo <kkhoo@perfwizard.com>"> <span class="fn">Kay Tiong Khoo</span></a>
</span></b>
<pre>Reopening: -ffast-math shouldn't be necessary.
Testing with clang built from r254421, the test case in <a href="show_bug.cgi?id=17229#c2">comment 2</a> looks good,
but the original test case has not changed:
$ cat 17229.c
#pragma STDC FP_CONTRACT ON
double foo(double x, double y, double z) {
return y*z + x;
}
double foo2(double x, double *y, double z) {
return (*y)*z + x;
}
$ ./clang -S -O1 -fomit-frame-pointer -march=haswell -o - 17229.c |grep xmm
vfmadd213sd %xmm0, %xmm2, %xmm1
vmovaps %xmm1, %xmm0
vfmadd231sd (%rdi), %xmm1, %xmm0
Note that FP_CONTRACT ON was made the clang default in:
<a href="http://llvm.org/viewvc/llvm-project?view=revision&revision=253269">http://llvm.org/viewvc/llvm-project?view=revision&revision=253269</a>
but reverted in:
<a href="http://llvm.org/viewvc/llvm-project?view=revision&revision=253337">http://llvm.org/viewvc/llvm-project?view=revision&revision=253337</a></pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>