[Bug tree-optimization/101009] New: wrong code with "-O3 -fno-tree-sra"

["suochenyao at 163 dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101009

            Bug ID: 101009
           Summary: wrong code with "-O3 -fno-tree-sra"
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: suochenyao at 163 dot com
  Target Milestone: ---

*******************************************************************************
OS and Platform:
CentOS Linux release 7.8.2003 (Core), x86_64 GNU/Linux
*******************************************************************************
Program:
int printf(const char *, ...);
struct a {
  unsigned b;
  unsigned c;
} e, *f = &e;
int d = 1;
int main() {
  for (; d; d--) {
    struct a g[] = {{2, 1}, {2, 1}};
    *f = g[1];
  }
  printf("%d\n", e.c);
}
*******************************************************************************
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 20210609 (experimental) (GCC)

git version: 53cb324cb4f9475d4eabcd9f5a858c5edaacc0cf
*******************************************************************************
Command Lines:
$ gcc -O3 -fno-tree-sra -Wall -Wextra -fno-strict-aliasing -fwrapv a.c -o
a1.out
$ gcc a.c -o a2.out
$ ./a1.out
0
$ ./a2.out
1