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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [ARM][load / store optimization pass] Missed optimization: coalesce pre-increment"
href="https://bugs.llvm.org/show_bug.cgi?id=44467">44467</a>
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<th>Summary</th>
<td>[ARM][load / store optimization pass] Missed optimization: coalesce pre-increment
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<th>Product</th>
<td>new-bugs
</td>
</tr>
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<th>Version</th>
<td>trunk
</td>
</tr>
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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>
</tr>
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<th>Keywords</th>
<td>missing-feature
</td>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>new bugs
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
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<th>Reporter</th>
<td>diogo.sampaio@arm.com
</td>
</tr>
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<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org
</td>
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<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=22991" name="attach_22991" title="Minimal MIR case">attachment 22991</a> <a href="attachment.cgi?id=22991&action=edit" title="Minimal MIR case">[details]</a></span>
Minimal MIR case
Missed optimization:
When running
llc --print-before-all --start-before=arm-ldst-opt missed.mir -o -
we obtain:
push.w {r4, r5, r6, r7, r8, r10, r11, lr}
sub sp, #8
strd r0, r1, [sp] @ 8-byte Folded Spill
@ InlineAsm Start
@ InlineAsm End
ldrd r0, r1, [sp], #8 @ 8-byte Folded Reload
pop.w {r4, r5, r6, r7, r8, r10, r11, pc}
I would expect the strd to be pre-incremented, as:
push.w {r4, r5, r6, r7, r8, r10, r11, lr}
strd r0, r1, [sp, #-8]!
@ InlineAsm Start
@ InlineAsm End
ldrd r0, r1, [sp], #8
pop.w {r4, r5, r6, r7, r8, r10, r11, pc}</pre>
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