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<base href="https://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - [InstSimplify] missing vector icmp with constant edge case patterns"
href="https://llvm.org/bugs/show_bug.cgi?id=27734">27734</a>
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<tr>
<th>Summary</th>
<td>[InstSimplify] missing vector icmp with constant edge case patterns
</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>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Scalar Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>spatel+llvm@rotateright.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>This was noted in <a href="http://reviews.llvm.org/D17859">http://reviews.llvm.org/D17859</a> where we semi-canonicalized
vector integer LE/GE comparisons: we're missing 3 out 4 of the vector
transforms when doing an icmp against an edge case constant:
define i1 @scalar_uge_true(i4 %x) {
%cmp = icmp uge i4 %x, 0
ret i1 %cmp
}
define i1 @scalar_ule_true(i4 %x) {
%cmp = icmp ule i4 %x, 15
ret i1 %cmp
}
define i1 @scalar_sge_true(i4 %x) {
%cmp = icmp sge i4 %x, -8
ret i1 %cmp
}
define i1 @scalar_sle_true(i4 %x) {
%cmp = icmp sle i4 %x, 7
ret i1 %cmp
}
define <4 x i1> @vector_uge_true(<4 x i4> %x) {
%cmp = icmp uge <4 x i4> %x, zeroinitializer
ret <4 x i1> %cmp
}
define <4 x i1> @vector_ule_true(<4 x i4> %x) {
%cmp = icmp ule <4 x i4> %x, <i4 15, i4 15, i4 15, i4 15>
ret <4 x i1> %cmp
}
define <4 x i1> @vector_sge_true(<4 x i4> %x) {
%cmp = icmp sge <4 x i4> %x, <i4 -8, i4 -8, i4 -8, i4 -8>
ret <4 x i1> %cmp
}
define <4 x i1> @vector_sle_true(<4 x i4> %x) {
%cmp = icmp sle <4 x i4> %x, <i4 7, i4 7, i4 7, i4 7>
ret <4 x i1> %cmp
}
------------------------------------------------------------------------
$ ./opt -instsimplify vec_icmp.ll -S
...
define i1 @scalar_uge_true(i4 %x) {
ret i1 true
}
define i1 @scalar_ule_true(i4 %x) {
ret i1 true
}
define i1 @scalar_sge_true(i4 %x) {
ret i1 true
}
define i1 @scalar_sle_true(i4 %x) {
ret i1 true
}
define <4 x i1> @vector_uge_true(<4 x i4> %x) {
ret <4 x i1> <i1 true, i1 true, i1 true, i1 true>
}
define <4 x i1> @vector_ule_true(<4 x i4> %x) {
%cmp = icmp ule <4 x i4> %x, <i4 -1, i4 -1, i4 -1, i4 -1>
ret <4 x i1> %cmp
}
define <4 x i1> @vector_sge_true(<4 x i4> %x) {
%cmp = icmp sge <4 x i4> %x, <i4 -8, i4 -8, i4 -8, i4 -8>
ret <4 x i1> %cmp
}
define <4 x i1> @vector_sle_true(<4 x i4> %x) {
%cmp = icmp sle <4 x i4> %x, <i4 7, i4 7, i4 7, i4 7>
ret <4 x i1> %cmp
}</pre>
</div>
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