[Bug ipa/100994] New: wrong code with "-O1 -finline-small-functions -fipa-cp"

[suochenyao at 163 dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100994

            Bug ID: 100994
           Summary: wrong code with "-O1 -finline-small-functions
                    -fipa-cp"
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: suochenyao at 163 dot com
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---

*******************************************************************************
OS and Platform:
CentOS Linux release 7.8.2003 (Core), x86_64 GNU/Linux
*******************************************************************************
Program:
struct a {
  unsigned b : 4;
  unsigned c : 9;
} const d;
int e, f, g;
char h;
short i;
static int(j)() { return 0; }
static int k(const struct a l) {
  for (; g; j() & l.c)
    ;
  e = 1;
  i = e + 6;
  for (; e != 7; e = i)
    h = f || l.b;
  int m = l.c;
  return 0;
}
void main() { k(d); }
*******************************************************************************
gcc version:
$ gcc -v
Using built-in specs.
COLLECT_GCC=/data/bin/gcc-dev/bin/gcc
COLLECT_LTO_WRAPPER=/data/bin/gcc-dev/libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../configure --prefix=/data/bin/gcc-dev --disable-multilib
--enable-languages=c,c++
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.0 20210608 (experimental) (GCC)

git version: 1afa4facb9348cac0349ff9c30066aa25a3608f7
*******************************************************************************
Command Lines:
$ gcc -O1 -finline-small-functions -fipa-cp -Wall -Wextra -fno-strict-aliasing
-fwrapv a.c -o a1.out
a.c: In function ‘k’:
a.c:10:17: warning: value computed is not used [-Wunused-value]
   10 |   for (; g; j() & l.c)
      |             ~~~~^~~~~
a.c:16:7: warning: unused variable ‘m’ [-Wunused-variable]
   16 |   int m = l.c;
      |       ^
a.c: At top level:
a.c:19:6: warning: return type of ‘main’ is not ‘int’ [-Wmain]
   19 | void main() { k(d); }
      |      ^~~~
$ /data/bin/gcc-dev/bin/gcc a.c -o a2.out
$ ./a1.out
Segmentation fault (core dumped)
$ ./a2.out
$