https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107767
Bug ID: 107767
Summary: GCC has some problems in optimizer of trivial case
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: regression
Assignee: unassigned at gcc dot gnu.org
Reporter: socketpair at gmail dot com
Target Milestone: ---
See https://godbolt.org/z/rTfTondfP
```
#include <stdint.h>
int firewall(const uint8_t *restrict data) {
const uint8_t ip_proto = *data;
const uint16_t dst_port = *((const uint16_t *)data + 32);
if (ip_proto == 17 && dst_port == 15) return 1;
if (ip_proto == 17 && dst_port == 23) return 1;
if (ip_proto == 17 && dst_port == 47) return 1;
if (ip_proto == 17 && dst_port == 45) return 1;
if (ip_proto == 17 && dst_port == 42) return 1;
if (ip_proto == 17 && dst_port == 1) return 1;
if (ip_proto == 17 && dst_port == 2) return 1;
if (ip_proto == 17 && dst_port == 3) return 1;
return 0;
}
int firewall2(const uint8_t *restrict data) {
const uint16_t dst_port = *((const uint16_t *)data + 32);
if (dst_port == 15) return 1;
if (dst_port == 23) return 1;
if (dst_port == 47) return 1;
if (dst_port == 45) return 1;
if (dst_port == 42) return 1;
if (dst_port == 1) return 1;
if (dst_port == 2) return 1;
if (dst_port == 3) return 1;
return 0;
}
```
Compile with -Os.
Second function IS NOT minimal, obviously. It's a bug. GCC 12.2 does not have
it.
