[Bug target/67940] New: Wrong stack alignment adjustment

["hjl.tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67940

            Bug ID: 67940
           Summary: Wrong stack alignment adjustment
           Product: gcc
           Version: 5.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: ubizjak at gmail dot com
  Target Milestone: ---

On gcc-5-branch, i386 has

  if (stack_realign_fp)
    offset = (offset + stack_alignment_needed) & -stack_alignment_needed;
...
         to pass verification of stack_pointer_offset at the end.  */
      m->fs.sp_offset = (m->fs.sp_offset + align_bytes) & -align_bytes;

-1 is missing.