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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 --- - X86: MachineBasicBlock::getFirstTerminator returns end() in llvm::getFuncletMembership"
href="https://llvm.org/bugs/show_bug.cgi?id=28938">28938</a>
</td>
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<tr>
<th>Summary</th>
<td>X86: MachineBasicBlock::getFirstTerminator returns end() in llvm::getFuncletMembership
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Backend: X86
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>dexonsmith@apple.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>If you add an assertion after the call to MachineBasicBlock::getFirstTerminator
in llvm::getFuncletMembership that it's not the end() iterator, 48 X86
testcases fail. IIUC, every MachineBasicBlock should end with a terminator, so
this seems like a bug in X86.
I'm about to commit a patch that papers over this by checking for end() (to
avoid dereferencing it) to unblock my work on <a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED --- - static_cast() of sentinel value in LLVM intrusive lists is Undefined Behavior"
href="show_bug.cgi?id=26753">bug 26753</a>.
Here are the tests that fail locally for me if you use an assertion instead:
--
Failing Tests (48):
LLVM :: CodeGen/WinEH/wineh-nested-unwind.ll
LLVM :: CodeGen/WinEH/wineh-noret-cleanup.ll
LLVM :: CodeGen/X86/branchfolding-catchpads.ll
LLVM :: CodeGen/X86/catchpad-dynamic-alloca.ll
LLVM :: CodeGen/X86/catchpad-lifetime.ll
LLVM :: CodeGen/X86/catchpad-realign-savexmm.ll
LLVM :: CodeGen/X86/catchpad-regmask.ll
LLVM :: CodeGen/X86/catchpad-weight.ll
LLVM :: CodeGen/X86/catchret-empty-fallthrough.ll
LLVM :: CodeGen/X86/catchret-fallthrough.ll
LLVM :: CodeGen/X86/catchret-regmask.ll
LLVM :: CodeGen/X86/cleanuppad-inalloca.ll
LLVM :: CodeGen/X86/cleanuppad-large-codemodel.ll
LLVM :: CodeGen/X86/cleanuppad-realign.ll
LLVM :: CodeGen/X86/deopt-bundles.ll
LLVM :: CodeGen/X86/funclet-layout.ll
LLVM :: CodeGen/X86/late-address-taken.ll
LLVM :: CodeGen/X86/pr26757.ll
LLVM :: CodeGen/X86/pr27501.ll
LLVM :: CodeGen/X86/regalloc-spill-at-ehpad.ll
LLVM :: CodeGen/X86/seh-catch-all-win32.ll
LLVM :: CodeGen/X86/seh-catch-all.ll
LLVM :: CodeGen/X86/seh-catchpad.ll
LLVM :: CodeGen/X86/seh-except-finally.ll
LLVM :: CodeGen/X86/seh-exception-code.ll
LLVM :: CodeGen/X86/seh-finally.ll
LLVM :: CodeGen/X86/seh-safe-div-win32.ll
LLVM :: CodeGen/X86/seh-safe-div.ll
LLVM :: CodeGen/X86/seh-stack-realign.ll
LLVM :: CodeGen/X86/tail-dup-catchret.ll
LLVM :: CodeGen/X86/tail-merge-wineh.ll
LLVM :: CodeGen/X86/win-catchpad-csrs.ll
LLVM :: CodeGen/X86/win-catchpad-nested-cxx.ll
LLVM :: CodeGen/X86/win-catchpad-nested.ll
LLVM :: CodeGen/X86/win-catchpad-varargs.ll
LLVM :: CodeGen/X86/win-catchpad.ll
LLVM :: CodeGen/X86/win-cleanuppad.ll
LLVM :: CodeGen/X86/win-funclet-cfi.ll
LLVM :: CodeGen/X86/win-mixed-ehpersonality.ll
LLVM :: CodeGen/X86/win32-eh-states.ll
LLVM :: CodeGen/X86/win32-eh.ll
LLVM :: CodeGen/X86/win32-seh-catchpad-realign.ll
LLVM :: CodeGen/X86/win32-seh-catchpad.ll
LLVM :: CodeGen/X86/win32-seh-nested-finally.ll
LLVM :: CodeGen/X86/wineh-coreclr.ll
LLVM :: CodeGen/X86/wineh-exceptionpointer.ll
LLVM :: DebugInfo/COFF/comdat.ll
LLVM :: Transforms/IndVarSimplify/iv-widen-elim-ext.ll
--</pre>
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