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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [X86] Investigate vectorization of the overflow add/sub nodes to PADD+PADDS+PCMPEQ etc."
href="https://bugs.llvm.org/show_bug.cgi?id=37763">37763</a>
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<th>Summary</th>
<td>[X86] Investigate vectorization of the overflow add/sub nodes to PADD+PADDS+PCMPEQ etc.
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<th>Product</th>
<td>libraries
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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>Windows NT
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>Backend: X86
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>llvm-dev@redking.me.uk
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<th>CC</th>
<td>craig.topper@gmail.com, deadalnix@gmail.com, lebedev.ri@gmail.com, llvm-bugs@lists.llvm.org, spatel+llvm@rotateright.com
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<pre>We may be able to efficiently vectorize some SADDO/UADDO (etc.) nodes (vXi8 and
vXi16) by performing both a PADDW and PADDSW (etc.) and comparing the results.
e.g.
#include <x86intrin.h>
struct Res {
__v8hi value;
__v8hi overflow;
};
struct Res saddo16(__v8hi x, __v8hi y) {
struct Res r;
r.value = _mm_add_epi16(x, y);
r.overflow = (r.value != (__v8hi)_mm_adds_epi16(x, y));
return r;
}
<a href="https://godbolt.org/g/4xkauv">https://godbolt.org/g/4xkauv</a></pre>
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