[Bug tree-optimization/112738] New: forwprop4 introduces invalid wide signed Boolean values

[kristerw at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112738

            Bug ID: 112738
           Summary: forwprop4 introduces invalid wide signed Boolean
                    values
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kristerw at gcc dot gnu.org
  Target Milestone: ---

The forwprop4 pass introduces an invalid wide Boolean when compiling the
following function with -O3 for X86_64:

  int *a, b, c, d;
  void
  foo (void)
  {
    for (; d <= 0; d++)
      b &= ((a || d) ^ c) == 1;
  }

What is happening is that forwprop4 changes the IR

  _38 = (signed int) _16;
  _59 = -_38;
  _65 = (<signed-boolean:32>) _59;

to the incorrect

  _55 = (<signed-boolean:32>) _16;
  _65 = -_55;