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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Dead call to std::terminate when using noexcept"
href="https://bugs.llvm.org/show_bug.cgi?id=46690">46690</a>
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<th>Summary</th>
<td>Dead call to std::terminate when using noexcept
</td>
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<th>Product</th>
<td>clang
</td>
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<th>Version</th>
<td>10.0
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
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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>C++
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>federico.kircheis@gmail.com
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<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<pre>Hello, it seems that clang does not optimize some dead code paths when
exceptions are involved.
I know this is common, but since at least GCC is able to optimize this case, I
thought it might have been valuable reporting it.
----
int bar_ex_noexcept(int i)
noexcept
{
struct foo{};
try {
if (i <0){
throw foo();
}
return i;
} catch(...) {
return -1;
}
}
----
GCC output <a href="https://godbolt.org/z/5E3jbx">https://godbolt.org/z/5E3jbx</a> (note missing terminate even without
optimizations), and clangs output with -O3: <a href="https://godbolt.org/z/1ozsGP">https://godbolt.org/z/1ozsGP</a>
I'm not very good at reading assembly, but strangely removing "noexcept", seem
to produce better code.</pre>
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