static bool
register_name (expressionS *expressionP, struct svp64_ctx *svp64)
{
  char *name;
  char *start;
  char c;
  char save_lex = lex_type[':'];
  const struct powerpc_pd_reg *reg = NULL;

  /* Find the spelling of the operand.  */
  start = name = input_line_pointer;
  if (name[0] == '%' && ISALPHA (name[1]))
    name = ++input_line_pointer;

  else if (!reg_names_p || !ISALPHA (name[0]))
    return false;

  if (svp64)
    lex_type[':'] |= LEX_NAME;
  c = get_symbol_name (&name);
  lex_type[':'] = save_lex;

  if (svp64)
    reg = reg_name_search (svp64_registers, svp64_num_registers, name);
  if (reg == NULL)
    reg = reg_name_search (pre_defined_registers, REG_NAME_CNT, name);

  /* Put back the delimiting char.  */
  *input_line_pointer = c;

  /* Look to see if it's in the register table.  */
  if (reg != NULL)
    {
      expressionP->X_op = O_register;
      expressionP->X_add_number = reg->value;
      expressionP->X_md = reg->flags;

      /* Make the rest nice.  */
      expressionP->X_add_symbol = NULL;
      expressionP->X_op_symbol = NULL;
      return true;
    }

  /* Reset the line as if we had not done anything.  */
  input_line_pointer = start;
  return false;
}