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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [llvm-mca] Optionally add code comments to llvm-mca reports"
href="https://bugs.llvm.org/show_bug.cgi?id=51132">51132</a>
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<th>Summary</th>
<td>[llvm-mca] Optionally add code comments to llvm-mca reports
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<th>Product</th>
<td>tools
</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>Windows NT
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>llvm-mca
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>llvm-dev@redking.me.uk
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</tr>
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<th>CC</th>
<td>andrea.dibiagio@gmail.com, llvm-bugs@lists.llvm.org, matthew.davis@sony.com
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<pre><a href="https://llvm.godbolt.org/z/8Po4eeccq">https://llvm.godbolt.org/z/8Po4eeccq</a>
Under some circumstances it'd be useful if llvm-mca could annotate standard
assembly code comments to the report. We can see these from clang asm output
(although they then get stripped by llvm-mca), but when we're analyzing raw asm
or gcc/msvc code then not everyone can perform shuffle decodes in their
heads.....
Shuffle decodes are the most useful to me, but I see no reason why they
shouldn't work with all comments. But it should be an opt-in feature as in many
cases it's just extra noise.
Not sure about json output - should the comment be put in a separate field?
Instruction Info:
[1]: #uOps
[2]: Latency
[3]: RThroughput
[4]: MayLoad
[5]: MayStore
[6]: HasSideEffects (U)
[1] [2] [3] [4] [5] [6] Instructions:
1 1 0.50 pshufd $0, %xmm0, %xmm0 ##
xmm0[0,0,0,0]
Resource pressure by instruction:
[0] [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
[11] [12] [13] Instructions:
- - - - - 0.50 0.50 - - - -
0.50 0.50 - pshufd $0, %xmm0, %xmm0 ## xmm0[0,0,0,0]</pre>
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