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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - LLD generates duplicate .pdata chunks"
href="https://bugs.llvm.org/show_bug.cgi?id=45950">45950</a>
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<th>Summary</th>
<td>LLD generates duplicate .pdata chunks
</td>
</tr>
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<th>Product</th>
<td>lld
</td>
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Windows NT
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
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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>COFF
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
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<th>Reporter</th>
<td>alexandre.ganea@ubisoft.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org, peter@pcc.me.uk, rnk@google.com
</td>
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<p>
<div>
<pre>We stumped on a case where LLD generates two identical RUNTIME_FUNCTION for the
same function, but with different UNWIND_INFO. This looks like an error, for
the same .OBJs, link.exe does not generate duplicates.
Function Table
Begin End Info Function Name
0049D0DC 0554E9D0 0554E9F7 06ACBCE8
Unwind version: 1
Unwind flags: EHANDLER UHANDLER
Size of prologue: 0x0A
Count of codes: 2
Unwind codes:
0A: ALLOC_SMALL, size=0x30
06: PUSH_NONVOL, register=rbp
Handler: 05503340
0049D0E8 0554E9D0 0554E9F7 06ACB0E8
Unwind version: 1
Unwind flags: EHANDLER UHANDLER
Size of prologue: 0x0A
Count of codes: 2
Unwind codes:
0A: ALLOC_SMALL, size=0x30
06: PUSH_NONVOL, register=rbp
Handler: 05503340
Here, we get two RUNTIME_FUNCTION for function 0554E9D0, but two different
Info/UNWIND_INFO.
Interestingly, for the same inputs, we get a different number of entries
between different linkers:
VS2019 16.5.4 link.exe : Function Table (316955)
LLD 8.0: Function Table (316888)
LLD 10.0: Function Table (316959)
Any idea of what could be going on here? I was under the impression that we
need more than xxHash64 folding for .pdata chunks? Maybe a specific step after
ICF? I will dig next week.</pre>
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