Function luaK_exp2anyreg

3rd/lua-5.4.3/src/lcode.c:936–951

** Ensures final expression result is in some (any) register ** and return that register. */

** and return that register.
*/
int luaK_exp2anyreg (FuncState *fs, expdesc *e) {
  luaK_dischargevars(fs, e);
  if (e->k == VNONRELOC) {  /* expression already has a register? */
    if (!hasjumps(e))  /* no jumps? */
      return e->u.info;  /* result is already in a register */
    if (e->u.info >= luaY_nvarstack(fs)) {  /* reg. is not a local? */
      exp2reg(fs, e, e->u.info);  /* put final result in it */
      return e->u.info;
    }
    /* else expression has jumps and cannot change its register
       to hold the jump values, because it is a local variable.
       Go through to the default case. */
  }
  luaK_exp2nextreg(fs, e);  /* default: use next available register */
  return e->u.info;
}


/*