bug ? apply_change_group & insn_invalid_p

[Denis Chertykov <denisc at overta dot ru>]

The `apply_change_group' wide used in GCC for applying changes to
insns and check insns.

Description of apply_change_group:

/* Apply a group of changes previously issued with `validate_change'.
   Return 1 if all changes are valid, zero otherwise.  */


`apply_change_group' use the `insn_invalid_p' for checking an insn
validity.

But, the `insn_invalid_p' even not test a result of `recog'.
Is this right ?

Denis.


insn_invalid_p:

/* This subroutine of apply_change_group verifies whether the changes to INSN
   were valid; i.e. whether INSN can still be recognized.  */
int
insn_invalid_p (insn)
     rtx insn;
{
  rtx pat = PATTERN (insn);
  int num_clobbers = 0;
  /* If we are before reload and the pattern is a SET, see if we can add
     clobbers.  */
  int icode = recog (pat, insn,
		     (GET_CODE (pat) == SET
		      && ! reload_completed && ! reload_in_progress)
		     ? &num_clobbers : 0);
  int is_asm = icode < 0 && asm_noperands (PATTERN (insn)) >= 0;

  
  /* If this is an asm and the operand aren't legal, then fail.  Likewise if
     this is not an asm and the insn wasn't recognized.  */
  if ((is_asm && ! check_asm_operands (PATTERN (insn)))
      || (!is_asm && icode < 0))
    return 1;

  /* If we have to add CLOBBERs, fail if we have to add ones that reference
     hard registers since our callers can't know if they are live or not.
     Otherwise, add them.  */
  if (num_clobbers > 0)
    {
      rtx newpat;

      if (added_clobbers_hard_reg_p (icode))
	return 1;

      newpat = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num_clobbers + 1));
      XVECEXP (newpat, 0, 0) = pat;
      add_clobbers (newpat, icode);
      PATTERN (insn) = pat = newpat;
    }

  /* After reload, verify that all constraints are satisfied.  */
  if (reload_completed)
    {
      extract_insn (insn);

      if (! constrain_operands (1))
	return 1;
    }

  INSN_CODE (insn) = icode;
  return 0;
}

The `insn_invalid_p' even not test return of `recog' and returns 0
even if insn invalid.


Denis.