[Bug target/56807] mingw32: Conflict between stack realignment and stack probe destroys function argument in EAX

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56807

--- Comment #22 from H.J. Lu <hjl.tools at gmail dot com> ---
That piece of code is only trigged by -mstack-arg-probe, which is
specific to Windows:

  else if (!ix86_target_stack_probe ()
           || frame.stack_pointer_offset < CHECK_STACK_LIMIT)
    {
      pro_epilogue_adjust_stack (stack_pointer_rtx, stack_pointer_rtx,
                                 GEN_INT (-allocate), -1,
                                 m->fs.cfa_reg == stack_pointer_rtx);
    }
  else  
    {
      rtx eax = gen_rtx_REG (Pmode, AX_REG);
      rtx r10 = NULL; 
      rtx (*adjust_stack_insn)(rtx, rtx, rtx); 
      const bool sp_is_cfa_reg = (m->fs.cfa_reg == stack_pointer_rtx);
      bool eax_live = false;
      bool r10_live = false;

      if (TARGET_64BIT)
        r10_live = (DECL_STATIC_CHAIN (current_function_decl) != 0);
      if (!TARGET_64BIT_MS_ABI)
        eax_live = ix86_eax_live_at_start_p ();

Is it possible to write a test with eax_live == true and r10_live == true?