<html>
<head>
<base href="https://bugs.llvm.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - After r348496, "Unable to predicate BX killed renamable $r0""
href="https://bugs.llvm.org/show_bug.cgi?id=41121">41121</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>After r348496, "Unable to predicate BX killed renamable $r0"
</td>
</tr>
<tr>
<th>Product</th>
<td>new-bugs
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Windows NT
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>new bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>dimitry@andric.com
</td>
</tr>
<tr>
<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>As described in <a href="https://bugs.freebsd.org/236567">https://bugs.freebsd.org/236567</a>, compiling the FreeBSD
lang/spidermonkey170 or lang/spidermonkey38 ports for armv7 or armv6 errors out
with (note the strange error formatting, this is verbatim):
Unable to predicate BX killed renamable $r0
!
UNREACHABLE executed at lib/CodeGen/IfConversion.cpp:2022!
Bisection shows this started occurring after <a href="https://reviews.llvm.org/rL348496">https://reviews.llvm.org/rL348496</a>
("[GVN] Don't perform scalar PRE on GEPs").
Minimized test case:
// clang -cc1 -triple armv7-- -S -O2 Unified_cpp_js_src10-min.cpp
template <typename> struct c;
template <typename b> struct j : c<b> {
j(int);
b *aa() { return d; }
b e() { return *d; }
b *d;
};
typedef struct {
struct {
union {
int f;
int *ab;
} g;
} h;
} i;
struct n {
int *k() { return ac.h.g.ab; }
int l() { return ac.h.g.f; }
i ac;
};
template <class m> struct p {
int ad();
int *k() {
n o = *static_cast<m *>(this)->ae();
return o.k();
}
};
template <> struct c<n> : p<j<n>> {
n *ae() { return static_cast<j<n> *>(this)->aa(); }
};
void fn1(bool *);
bool q;
int r;
void u() {
void *a[]{&&s, &&t};
t:
fn1(&q);
goto *a[r];
s:;
}
int v(j<n> w, j<n> x, bool *y) {
if (w.ad()) {
*y = w.k() == x.k();
return 0;
}
*y = w.e().l() == x.e().l();
return 0;
}
void fn1(bool *w) { v(0, 0, w); }</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>