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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Missed store elimination on conditional change"
href="https://bugs.llvm.org/show_bug.cgi?id=48115">48115</a>
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<th>Summary</th>
<td>Missed store elimination on conditional change
</td>
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<th>Product</th>
<td>libraries
</td>
</tr>
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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>All
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
</tr>
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<th>Priority</th>
<td>P
</td>
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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>daan@dsprenkels.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, pengfei.wang@intel.com, spatel+llvm@rotateright.com
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<p>
<div>
<pre>The following IR:
```
target datalayout =
"e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
define void @cmov(i64* nocapture align 8 dereferenceable(8) %a, i64 %b, i1
zeroext %cond) unnamed_addr #0 {
%_9 = load i64, i64* %a, align 8
%1 = select i1 %cond, i64 %b, i64 %_9
store i64 %1, i64* %a, align 8
ret void
}
```
is compiled to the following X86:
```
cmov: # @cmov
test edx, edx
jne .LBB0_2
mov rsi, qword ptr [rdi]
.LBB0_2:
mov qword ptr [rdi], rsi # (*) could be eliminated
ret
```
This assembly snippet has a store that could be eliminated.
Godbolt: <a href="https://godbolt.org/z/Yz64eh">https://godbolt.org/z/Yz64eh</a></pre>
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