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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - load-store-vectorizer cannot assume that offset calculated from add nuw is safe"
href="https://bugs.llvm.org/show_bug.cgi?id=46591">46591</a>
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<th>Summary</th>
<td>load-store-vectorizer cannot assume that offset calculated from add nuw is safe
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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>All
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>normal
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>Scalar Optimizations
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>juneyoung.lee@sf.snu.ac.kr
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<th>CC</th>
<td>llvm-bugs@lists.llvm.org
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<div>
<pre>Created <span class=""><a href="attachment.cgi?id=23680" name="attach_23680" title="Input & output">attachment 23680</a> <a href="attachment.cgi?id=23680&action=edit" title="Input & output">[details]</a></span>
Input & output
test/Transforms/LoadStoreVectorizer/X86/vectorize-i8-nested-add.ll 's
ld_v4i8_add_nuw vectorizes a sequence of loads, which is illegal.
<a href="https://godbolt.org/z/NzK5oY">https://godbolt.org/z/NzK5oY</a>
(the attached file contains this input/output)
Counter example: if v0 and v1 is 0, nuw is never triggered, but the offsets
aren't still consecutive.
<a href="https://alive2.llvm.org/ce/z/4nZKBs">https://alive2.llvm.org/ce/z/4nZKBs</a>
This can happen when a program has an allocation larger than 4G.</pre>
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