Inlined HardwareSerial calls to RX ISR.

Moreover, declaring pointers-to-registers as const and using initializer
list in class constructor allows the compiler to further improve inlining
performance.

This change recovers about 50 bytes of program space on single-UART devices.

See #1711

1 files changed, 1 insertions, 90 deletions

diff --git a/cores/arduino/HardwareSerial.cpp b/cores/arduino/HardwareSerial.cpp
index d7f1fca..5d62273 100644
--- a/cores/arduino/HardwareSerial.cpp
+++ b/cores/arduino/HardwareSerial.cpp
@@ -26,64 +26,14 @@
 #include <string.h>
 #include <inttypes.h>
 #include "Arduino.h"
-#include "wiring_private.h"
 
 #include "HardwareSerial.h"
+#include "HardwareSerial_private.h"
 
 // this next line disables the entire HardwareSerial.cpp, 
 // this is so I can support Attiny series and any other chip without a uart
 #if defined(HAVE_HWSERIAL0) || defined(HAVE_HWSERIAL1) || defined(HAVE_HWSERIAL2) || defined(HAVE_HWSERIAL3)
 
-// Ensure that the various bit positions we use are available with a 0
-// postfix, so we can always use the values for UART0 for all UARTs. The
-// alternative, passing the various values for each UART to the
-// HardwareSerial constructor also works, but makes the code bigger and
-// slower.
-#if !defined(TXC0)
-#if defined(TXC)
-// On ATmega8, the uart and its bits are not numbered, so there is no TXC0 etc.
-#define TXC0 TXC
-#define RXEN0 RXEN
-#define TXEN0 TXEN
-#define RXCIE0 RXCIE
-#define UDRIE0 UDRIE
-#define U2X0 U2X
-#define UPE0 UPE
-#define UDRE0 UDRE
-#elif defined(TXC1)
-// Some devices have uart1 but no uart0
-#define TXC0 TXC1
-#define RXEN0 RXEN1
-#define TXEN0 TXEN1
-#define RXCIE0 RXCIE1
-#define UDRIE0 UDRIE1
-#define U2X0 U2X1
-#define UPE0 UPE1
-#define UDRE0 UDRE1
-#else
-#error No UART found in HardwareSerial.cpp
-#endif
-#endif // !defined TXC0
-
-// Check at compiletime that it is really ok to use the bit positions of
-// UART0 for the other UARTs as well, in case these values ever get
-// changed for future hardware.
-#if defined(TXC1) && (TXC1 != TXC0 || RXEN1 != RXEN0 || RXCIE1 != RXCIE0 || \
-		      UDRIE1 != UDRIE0 || U2X1 != U2X0 || UPE1 != UPE0 || \
-		      UDRE1 != UDRE0)
-#error "Not all bit positions for UART1 are the same as for UART0"
-#endif
-#if defined(TXC2) && (TXC2 != TXC0 || RXEN2 != RXEN0 || RXCIE2 != RXCIE0 || \
-		      UDRIE2 != UDRIE0 || U2X2 != U2X0 || UPE2 != UPE0 || \
-		      UDRE2 != UDRE0)
-#error "Not all bit positions for UART2 are the same as for UART0"
-#endif
-#if defined(TXC3) && (TXC3 != TXC0 || RXEN3 != RXEN0 || RXCIE3 != RXCIE0 || \
-		      UDRIE3 != UDRIE0 || U3X3 != U3X0 || UPE3 != UPE0 || \
-		      UDRE3 != UDRE0)
-#error "Not all bit positions for UART3 are the same as for UART0"
-#endif
-
 // SerialEvent functions are weak, so when the user doesn't define them,
 // the linker just sets their address to 0 (which is checked below).
 // The Serialx_available is just a wrapper around Serialx.available(),
@@ -127,28 +77,6 @@ void serialEventRun(void)
 
 // Actual interrupt handlers //////////////////////////////////////////////////////////////
 
-void HardwareSerial::_rx_complete_irq(void)
-{
-  if (bit_is_clear(*_ucsra, UPE0)) {
-    // No Parity error, read byte and store it in the buffer if there is
-    // room
-    unsigned char c = *_udr;
-    int i = (unsigned int)(_rx_buffer_head + 1) % SERIAL_BUFFER_SIZE;
-
-    // if we should be storing the received character into the location
-    // just before the tail (meaning that the head would advance to the
-    // current location of the tail), we're about to overflow the buffer
-    // and so we don't write the character or advance the head.
-    if (i != _rx_buffer_tail) {
-      _rx_buffer[_rx_buffer_head] = c;
-      _rx_buffer_head = i;
-    }
-  } else {
-    // Parity error, read byte but discard it
-    unsigned char c = *_udr;
-  };
-}
-
 void HardwareSerial::_tx_udr_empty_irq(void)
 {
   // If interrupts are enabled, there must be more data in the output
@@ -169,23 +97,6 @@ void HardwareSerial::_tx_udr_empty_irq(void)
   }
 }
 
-// Constructors ////////////////////////////////////////////////////////////////
-
-HardwareSerial::HardwareSerial(
-  volatile uint8_t *ubrrh, volatile uint8_t *ubrrl,
-  volatile uint8_t *ucsra, volatile uint8_t *ucsrb,
-  volatile uint8_t *ucsrc, volatile uint8_t *udr)
-{
-  _tx_buffer_head = _tx_buffer_tail = 0;
-  _rx_buffer_head = _rx_buffer_tail = 0;
-  _ubrrh = ubrrh;
-  _ubrrl = ubrrl;
-  _ucsra = ucsra;
-  _ucsrb = ucsrb;
-  _ucsrc = ucsrc;
-  _udr = udr;
-}
-
 // Public Methods //////////////////////////////////////////////////////////////
 
 void HardwareSerial::begin(unsigned long baud, byte config)