Saving some bytes in HardwareSerial::write

Author: chromhelm

hardware/arduino/avr/cores/arduino/HardwareSerial.cpp

@@ -213,14 +213,14 @@ void HardwareSerial::flush()
 
 size_t HardwareSerial::write(uint8_t c)
 {
+  _written = true;
   // If the buffer and the data register is empty, just write the byte
   // to the data register and be done. This shortcut helps
   // significantly improve the effective datarate at high (>
   // 500kbit/s) bitrates, where interrupt overhead becomes a slowdown.
   if (_tx_buffer_head == _tx_buffer_tail && bit_is_set(*_ucsra, UDRE0)) {
     *_udr = c;
     sbi(*_ucsra, TXC0);
-     _written = true;
     return 1;
   }
   tx_buffer_index_t i = (_tx_buffer_head + 1) % SERIAL_TX_BUFFER_SIZE;
@@ -244,10 +244,8 @@ size_t HardwareSerial::write(uint8_t c)
   _tx_buffer_head = i;
 
   sbi(*_ucsrb, UDRIE0);
-  _written = true;
 
   return 1;
 }
 
-
 #endif // whole file