<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 - Missing line information after EarlyCSE and InstCombine pass at Og"
href="https://bugs.llvm.org/show_bug.cgi?id=50475">50475</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Missing line information after EarlyCSE and InstCombine pass at Og
</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>Linux
</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>DebugInfo
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>cristianassaiante@outlook.com
</td>
</tr>
<tr>
<th>CC</th>
<td>jdevlieghere@apple.com, keith.walker@arm.com, llvm-bugs@lists.llvm.org, paul_robinson@playstation.sony.com
</td>
</tr></table>
<p>
<div>
<pre>The last assignment to a variable passed to an external function is not reached
in debugging. If we put a breakpoint on line 14, after a next command we end up
in line 17 thus skipping lines 15 and 16 where the last assignment to v_0 and
v_1 is done. From opt-bisect, the pass after which line 15 is not reached
anymore is EarlyCSEPass and the pass after which line 16 is not reached anymore
is InstCombinePass.
$ cat a.c
int test_in();
void test_out(int v_0, int v_1, int v_2, int v_3);
int main (void)
{
int v_0, v_1, v_2, v_3;
v_0 = test_in();
v_1 = test_in();
v_2 = test_in();
v_3 = test_in();
v_1 = (!v_1 > (v_2 - (v_3 <= v_0)));
v_0 = (v_1 < (~v_2 <= (v_3 >= v_0)));
v_3 = ((v_2 + v_3) >= v_0);
v_0 = (v_2 | (!(v_3 * v_0) < v_1));
v_1 = (v_3 % !(~!v_0 >= (v_2 + v_1)));
test_out(v_0, v_1, v_2, v_3);
return 0;
}
$ cat lib/test.c
#include <stdio.h>
int ctr = 0;
int test_in() {
return ctr++;
}
void test_out(int v_0, int v_1, int v_2, int v_3) {
printf("%d%d%d%d", v_0, v_1, v_2, v_3);
}
$ clang -v
clang version 13.0.0
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /usr/local/bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Candidate multilib: .;@m64
Selected multilib: .;@m64
$ lldb -v
lldb version 13.0.0
clang revision c2c977ce50597b0e5186afc342c5784bd0aa6973
lldb revision c2c977ce50597b0e5186afc342c5784bd0aa6973
$ clang -g -Og -o opt lib/test.c a.c
$ lldb opt
(lldb) target create "opt"
Current executable set to '/home/stepping/test/opt' (x86_64).
(lldb) b 14
Breakpoint 1: where = opt`main + 83 at a.c:14:14, address = 0x0000000000400553
(lldb) r
Process 155 launched: '/home/stepping/test/opt' (x86_64)
Process 155 stopped
* thread #1, name = 'opt', stop reason = breakpoint 1.1
frame #0: 0x0000000000400553 opt`main at a.c:14:14
11 v_1 = (!v_1 > (v_2 - (v_3 <= v_0)));
12 v_0 = (v_1 < (~v_2 <= (v_3 >= v_0)));
13
-> 14 v_3 = ((v_2 + v_3) >= v_0);
15 v_0 = (v_2 | (!(v_3 * v_0) < v_1));
16 v_1 = (v_3 % !(~!v_0 >= (v_2 + v_1)));
17 test_out(v_0, v_1, v_2, v_3);
(lldb) next
Process 155 stopped
* thread #1, name = 'opt', stop reason = step over
frame #0: 0x000000000040055c opt`main at a.c:17:2
14 v_3 = ((v_2 + v_3) >= v_0);
15 v_0 = (v_2 | (!(v_3 * v_0) < v_1));
16 v_1 = (v_3 % !(~!v_0 >= (v_2 + v_1)));
-> 17 test_out(v_0, v_1, v_2, v_3);
18 return 0;
19 }</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>