<html>
<head>
<base href="https://bugs.llvm.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [X86][SSE] Failure to merge 2 x float stores to <2 x float> store"
href="https://bugs.llvm.org/show_bug.cgi?id=41892">41892</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[X86][SSE] Failure to merge 2 x float stores to <2 x float> store
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Windows NT
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Backend: X86
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>llvm-dev@redking.me.uk
</td>
</tr>
<tr>
<th>CC</th>
<td>craig.topper@gmail.com, llvm-bugs@lists.llvm.org, llvm-dev@redking.me.uk, spatel+llvm@rotateright.com
</td>
</tr></table>
<p>
<div>
<pre><a href="https://godbolt.org/z/InfZZK">https://godbolt.org/z/InfZZK</a>
#include <x86intrin.h>
void sum_pairs_128(__m128 f, float *p) {
p[0] = f[0] + f[1];
p[1] = f[2] + f[3];
}
clang -O3 -march=btver2
_Z13sum_pairs_128Dv4_fPf: # @_Z13sum_pairs_128Dv4_fPf
vhaddps %xmm0, %xmm0, %xmm0
vmovss %xmm0, (%rdi)
vextractps $1, %xmm0, 4(%rdi)
retq
would be better if we managed to merge to:
_Z13sum_pairs_128Dv4_fPf: # @_Z13sum_pairs_128Dv4_fPf
vhaddps %xmm0, %xmm0, %xmm0
vmovsd %xmm0, (%rdi)
retq</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>