[Bug tree-optimization/110446] New: [14 Regression] Wrong code at -O1/2/3/s on x86_64-pc-linux-gnu

[Bug tree-optimization/110446] New: [14 Regression] Wrong code at -O1/2/3/s on x86_64-pc-linux-gnu

[jwzeng at nuaa dot edu.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110446

            Bug ID: 110446
           Summary: [14 Regression] Wrong code at -O1/2/3/s on
                    x86_64-pc-linux-gnu
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jwzeng at nuaa dot edu.cn
  Target Milestone: ---

Link to the Compiler Explorer: https://godbolt.org/z/jE9fxsYfE

The following code snippet:

#include <stdio.h>
unsigned int a = 1387579096U;
int main() {
    a = 1 < (~a) ? 1 : (~a);
    printf("%u\n", a);
    return 0;
}

> $ /usr/gcc-trunk/bin/gcc -O0 bug.c; ./a.out
> 1
> $ /usr/gcc-trunk/bin/gcc -O1 bug.c; ./a.out
> 2907388199
> $ /usr/gcc-trunk/bin/gcc -O2 bug.c; ./a.out
> 2907388199
> $ /usr/gcc-trunk/bin/gcc -O3 bug.c; ./a.out
> 2907388199
> $ /usr/gcc-trunk/bin/gcc -Os bug.c; ./a.out
> 2907388199
When compiled with -O1/2/3/s, it prints the wrong result 2907388199 instead of
1. Earlier GCCs do not have this bug.

> $ /usr/gcc-trunk/bin/gcc --version
Using built-in specs.
COLLECT_GCC=/home/compilers/gcc/gcc-trunk/bin/gcc
COLLECT_LTO_WRAPPER=/home/compilers/gcc/gcc-trunk/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-trunk-source/gcc/configure
--enable-languages=c,c++,fortran --enable-checking=release
--enable-valgrind-annotations --disable-werror --disable-libstdcxx-pch
--enable-libgomp --enable-lto --enable-gold --with-plugin-ld=gold
--prefix=/usr/local/gcc-trunk
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20230619 (experimental) [master r14-1917-gf8e0270272] (GCC)

[Bug tree-optimization/110446] [14 Regression] Wrong code at -O1/2/3/s on x86_64-pc-linux-gnu

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110446

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2023-06-28
           Keywords|                            |wrong-code
   Target Milestone|---                         |14.0
     Ever confirmed|0                           |1

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Mine. This is basically a dup of the other phiopt issue dealing with flow
sensitive information.

[Bug tree-optimization/110446] [14 Regression] Wrong code at -O1/2/3/s on x86_64-pc-linux-gnu

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110446

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Dup of bug 110252.

*** This bug has been marked as a duplicate of bug 110252 ***