[Bug target/83726] [8 Regression] ICE: in final_scan_insn, at final.c:3063

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83726

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vmakarov at gcc dot gnu.org

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Wonder if this isn't a LRA bug though, the insn in question is:
(define_insn "*movti_aarch64"
  [(set (match_operand:TI 0
         "nonimmediate_operand"  "=r, w,r,w,r,m,m,w,m")
        (match_operand:TI 1
         "aarch64_movti_operand" " rn,r,w,w,m,r,Z,m,w"))]
  "(register_operand (operands[0], TImode)
    || aarch64_reg_or_zero (operands[1], TImode))"
and aarch64_movti_operand doesn't allow CONST_WIDE_INT:
(define_predicate "aarch64_movti_operand"
  (and (match_code "reg,subreg,mem,const_int")
       (ior (match_operand 0 "register_operand")
            (ior (match_operand 0 "memory_operand")
                 (match_operand 0 "const_int_operand")))))
and the legitimate_constant_p target hook doesn't allow that either, yet
simplify_operand_subreg will do
  else if (CONSTANT_P (reg))
    {
      /* Try to simplify subreg of constant.  It is usually result of
         equivalence substitution.  */
      if (innermode == VOIDmode
          && (innermode = original_subreg_reg_mode[nop]) == VOIDmode)
        innermode = curr_static_id->operand[nop].mode;
      if ((new_reg = simplify_subreg (mode, reg, innermode,
                                      SUBREG_BYTE (operand))) != NULL_RTX)
        {
          *curr_id->operand_loc[nop] = new_reg;
          return true;
        }
    }
and nothing calls the predicate nor the legitimate_constant_p target hook for
it.
Is that because LRA operates only on constraints, not predicates, and seeing
"n" defined as:
(define_constraint "n"
  "Matches a non-symbolic integer constant."
  (and (match_test "CONST_SCALAR_INT_P (op)")
       (match_test "!flag_pic || LEGITIMATE_PIC_OPERAND_P (op)")))
doesn't indeed require anything?
If so, shouldn't *movti_aarch64 use a different constraint, that either
requires arbitrary "const_int", so just
(define_constraint "whatever"
  "..."
  (match_code "const_int"))
or requires a scalar int that satisfies target_legitimate_constant_p?