<html>
<head>
<base href="http://llvm.org/bugs/" />
</head>
<body><span class="vcard"><a class="email" href="mailto:hfinkel@anl.gov" title="Hal Finkel <hfinkel@anl.gov>"> <span class="fn">Hal Finkel</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - DSE miscompile"
href="http://llvm.org/bugs/show_bug.cgi?id=17405">bug 17405</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">Status</td>
<td>NEW
</td>
<td>RESOLVED
</td>
</tr>
<tr>
<td style="text-align:right;">Resolution</td>
<td>---
</td>
<td>INVALID
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - DSE miscompile"
href="http://llvm.org/bugs/show_bug.cgi?id=17405#c3">Comment # 3</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED INVALID - DSE miscompile"
href="http://llvm.org/bugs/show_bug.cgi?id=17405">bug 17405</a>
from <span class="vcard"><a class="email" href="mailto:hfinkel@anl.gov" title="Hal Finkel <hfinkel@anl.gov>"> <span class="fn">Hal Finkel</span></a>
</span></b>
<pre>I'm closing this bug; the problem seems to be that the input IR is subtly
invalid. The call instruction:
%call5.1 = tail call signext i8 @toggle_value(%struct.Toggle* %1) #4
is marked as a tail call, and according to BasicAA cannot modify its
stack-allocated argument (although it actually does):
lib/Analysis/BasicAliasAnalysis.cpp:
// If this is a tail call and Loc.Ptr points to a stack location, we know
that
// the tail call cannot access or modify the local stack.
// We cannot exclude byval arguments here; these belong to the caller of
// the current function not to the current function, and a tail callee
// may reference them.
if (isa<AllocaInst>(Object))
if (const CallInst *CI = dyn_cast<CallInst>(CS.getInstruction()))
if (CI->isTailCall())
return NoModRef;</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>