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<base href="https://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Live range for register DBG_VALUEs extends across register mask clobbers"
href="https://llvm.org/bugs/show_bug.cgi?id=26589">26589</a>
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<th>Summary</th>
<td>Live range for register DBG_VALUEs extends across register mask clobbers
</td>
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<th>Product</th>
<td>libraries
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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
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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>Common Code Generator Code
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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<th>Reporter</th>
<td>rnk@google.com
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<th>CC</th>
<td>aprantl@apple.com, llvm-bugs@lists.llvm.org
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<th>Classification</th>
<td>Unclassified
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<p>
<div>
<pre>Consider:
void __attribute__((noinline)) clobber() { asm volatile("xor %edi, %edi"); }
int main(int argc, char **argv) { clobber(); }
Clang emits dwarf that shows that argc is in EDI and it is live across the
entire body of main. This is not true, it is clobbered by the call to clobber.
Our current code only stops live ranges on direct register definitions, not
call register masks.
Iterating over register mask clobbers should be enough to fix this.</pre>
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