<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Issue</th>
<td>
<a href=https://github.com/llvm/llvm-project/issues/139883>139883</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>
Large compilation time with -O2 for a small file on x86_64-linux-gnu
</td>
</tr>
<tr>
<th>Labels</th>
<td>
new issue
</td>
</tr>
<tr>
<th>Assignees</th>
<td>
</td>
</tr>
<tr>
<th>Reporter</th>
<td>
KavyaChopra04
</td>
</tr>
</table>
<pre>
```
kchopra@ast-epyc4:~$ clang -v
clang version 21.0.0git (https://github.com/llvm/llvm-project.git 165d47ef704ae6e93b0b31991efe8feed1f68a09)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /local/home/kchopra/compilers/bin
Build config: +assertions
Found candidate GCC installation: /local/home/kchopra/compilers/bin/../lib/gcc/x86_64-pc-linux-gnu/15.0.1
Selected GCC installation: /local/home/kchopra/compilers/bin/../lib/gcc/x86_64-pc-linux-gnu/15.0.1
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
kchopra@ast-epyc4:~$ time clang -O2 clang_bug/clang_long.c
clang_bug/clang_long.c:97:1: warning: label at end of compound statement is a C23 extension [-Wc23-extensions]
97 | }
| ^
1 warning generated.
real 0m5.079s
user 0m5.056s
sys 0m0.014s
kchopra@ast-epyc4:~$ cat clang_bug/clang_long.c
int a, b = 4, c, d, e, f, g, i, j, k, l, m, n, o;
static int h;
int main() {
h = a;
if (d * o * b >= 0)
goto p;
q:
if (j >= 0)
goto r;
goto s;
p:
if (j >= 0)
goto r;
t:
f = j;
goto u;
v:
if (d >= 0)
goto w;
r:
if (b)
goto x;
y:
if (b * e >= 0)
goto z;
goto aa;
ab:
b = (i << 6) + 0532;
if (o >= 0)
goto ac;
goto ad;
u:
a = 6;
if (m)
goto ae;
af:
if (o >= 0)
goto ag;
s:
if (b >= 0)
goto ah;
ai:
if (l)
goto af;
goto v;
ac:
aa:
if (g)
goto aj;
ag:
if (h >= 0)
goto ai;
goto q;
ak:
d = c;
if (j)
goto ah;
z:
m = h;
if (o)
goto al;
am:
m = a * o;
if (d)
goto an;
ah:
h = (d << 6) - 1;
if (h * b >= 0)
goto an;
goto ab;
aj:
if (a * h * j)
goto an;
goto ai;
ao:
c = n + 5;
if (e)
goto ak;
an:
goto q;
ad:
if (a)
goto ao;
ae:
if (o)
o = 6;
if (k)
goto am;
if (b)
w:
if (b * j)
goto t;
al:
k = b;
goto y;
x:
}
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzEVkGv4yYQ_jXkgmJhbMfxIQcnb11VrdRDK_W4wnhsk2DIGpz33h762yvA3o3Tza72VOlpHuDvmxk-BjLMGNEpgAPKjih72bDJ9no8_MZu7-zU6-vISLqpdfN-QDsy_5Hywv0nlBJm7Bau7zxFSfkPoinmkqkOb2-IlGF4g9EIrTCNIxKRTliM6L639mpQUiJaIVp1wvZTHXE9IFpJeVv-ba-jPgO3kWPFu6xJc2hzkjLYQZHUpE7iooihhX0L0MTtbs9IgWiBSPkXGzuwKCnx2373cZduJ3VR-lVtpVDT27ZTkwP1I7AGD7oB6aBXbcQbIuWvylgmJTQvYnTrLh3NmUS06vUAiFaLALTiergKCaNBtKqFQqQ8TkI2mGvVii6wj8wYGK3QyiBSVnpSDeZMNaJhFvAvpxMWISJzmJ-NSKsocnhROyk5R7Sa93zld9ulVZxFJIoRKf8ECdxC8z-EPn3Z9jBJKxwzKXGEkiNKybBLn0ISOmMSer-Dp16-U6JWDLDU6R80jD7WU-c26MdSqy7iSwV_61NSFjlKytiFfWWjEsoftWQ1SMwsBtVg3WKnlz9tY5mFAZTFwmCGTzTB8GZB-ZuBsuP2b06T7Zclg7IXREqMcZFjlJ8wyuc5xmGefUCkjJfYuAMFI7PQRIiUiJQjMIlIQYYsInnhqm4yMC4r2c6tmHfjF0hE4tT84FYz-z2dhLKYIXrCNUbJC07dkDvTOAPOtM50zghnzs5cnJHODM4oZ7Q7RFI6wQTHznEfVtxwYK7o9ogWGOVHr0jvI7KAwVi07nlpMKIl1t66lD44DAkvg5Ow01bja-B8cs_QV-r5GXxcQviZCbPrz5HtAm991ueVyynMbmuXzTOXrwE-ruH1jPKQtwB5f4B4WeCZ38-rpNisLKsXJ-GIEd0LjJITSk5458-DHjHJwi39Gks_i8L4OkwTptMShfkou7W34X5zDObM2vX2nofs5tL6jxxP8HPhMbEmyEdcu9rKbWbxwHIC3rO7R_ZcBC67e1z_NC2xCvdppl8WeuOV42vlzivl5o19XiiDp_QPR_cYV86RhjWNhbv2cAEfyWom9wu5X8qoWZXRFsdrT_33L_HieJnWc5zzWs2QZPB1_oGLWV-mFxfcp6p8iWfr7ODR12Umq4W8OqTmIatH9qyiK-3y20ehv3UvLo9-hvX35VFwb4b3e_8Q3Mkx0-2chVyyuPig9Uqm9zB7C5jw--T-li5x0xySpkgKtoFDnKc5pUmSkU1_2BU1jds8ywHimHBo4zTjeV6nJG7jLC424kAJzUgWp3GcFjGJUqB0n6dxDrzhTQ0oJTAwISPXI0Z67DbCmAkOcVLs98nG_wgb39BSquAV-6-IUtffjgffWNZTZ1BKpDDWfHVjhZVw-N21jji0Or4rCg3Dq7C97xdaPWKGzcCkxK2QgLVamswvLc9mGuXh55pcRCufqOut5p3cDvTfAAAA__8RQTU8">