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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [X86] Failure to use sqrtsd destination operand to optimize out movsd"
href="https://bugs.llvm.org/show_bug.cgi?id=45752">45752</a>
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<th>Summary</th>
<td>[X86] Failure to use sqrtsd destination operand to optimize out movsd
</td>
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<th>Product</th>
<td>libraries
</td>
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<th>Version</th>
<td>trunk
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>Backend: X86
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>gabravier@gmail.com
</td>
</tr>
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<th>CC</th>
<td>craig.topper@gmail.com, llvm-bugs@lists.llvm.org, llvm-dev@redking.me.uk, spatel+llvm@rotateright.com
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<p>
<div>
<pre>typedef double v2df __attribute__((vector_size(16)));
v2df _mm_sqrt_sd(v2df a, v2df b)
{
v2df c = __builtin_ia32_sqrtpd((v2df){b[0], b[1]});
return (v2df){c[0], a[1]};
}
GCC -O3 outputs this :
_mm_sqrt_sd(double __vector(2), double __vector(2)):
sqrtsd xmm0, xmm1
ret
LLVM outputs this :
_mm_sqrt_sd(double __vector(2), double __vector(2)):
sqrtpd xmm1, xmm1
movsd xmm0, xmm1 # xmm0 = xmm1[0],xmm0[1]
ret</pre>
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