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
This commit is contained in:
Cristian Maglie 2014-01-22 10:12:56 +01:00
parent 1848db3d66
commit 49fc2ab8ad
7 changed files with 108 additions and 98 deletions

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@ -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)

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@ -66,12 +66,12 @@
class HardwareSerial : public Stream
{
protected:
volatile uint8_t *_ubrrh;
volatile uint8_t *_ubrrl;
volatile uint8_t *_ucsra;
volatile uint8_t *_ucsrb;
volatile uint8_t *_ucsrc;
volatile uint8_t *_udr;
volatile uint8_t * const _ubrrh;
volatile uint8_t * const _ubrrl;
volatile uint8_t * const _ucsra;
volatile uint8_t * const _ucsrb;
volatile uint8_t * const _ucsrc;
volatile uint8_t * const _udr;
// Has any byte been written to the UART since begin()
bool _written;
@ -87,7 +87,7 @@ class HardwareSerial : public Stream
unsigned char _tx_buffer[SERIAL_BUFFER_SIZE];
public:
HardwareSerial(
inline 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);
@ -107,7 +107,7 @@ class HardwareSerial : public Stream
operator bool() { return true; }
// Interrupt handlers - Not intended to be called externally
void _rx_complete_irq(void);
inline void _rx_complete_irq(void);
void _tx_udr_empty_irq(void);
};

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@ -1,5 +1,6 @@
#include "Arduino.h"
#include "HardwareSerial.h"
#include "HardwareSerial_private.h"
// Each HardwareSerial is defined in its own file, sine the linker pulls
// in the entire file when any element inside is used. --gc-sections can

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@ -1,5 +1,6 @@
#include "Arduino.h"
#include "HardwareSerial.h"
#include "HardwareSerial_private.h"
// Each HardwareSerial is defined in its own file, sine the linker pulls
// in the entire file when any element inside is used. --gc-sections can

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@ -1,5 +1,6 @@
#include "Arduino.h"
#include "HardwareSerial.h"
#include "HardwareSerial_private.h"
// Each HardwareSerial is defined in its own file, sine the linker pulls
// in the entire file when any element inside is used. --gc-sections can

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@ -1,5 +1,6 @@
#include "Arduino.h"
#include "HardwareSerial.h"
#include "HardwareSerial_private.h"
// Each HardwareSerial is defined in its own file, sine the linker pulls
// in the entire file when any element inside is used. --gc-sections can

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@ -0,0 +1,95 @@
#include "wiring_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
// 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) :
_ubrrh(ubrrh), _ubrrl(ubrrl),
_ucsra(ucsra), _ucsrb(ucsrb), _ucsrc(ucsrc),
_udr(udr),
_tx_buffer_head(0), _tx_buffer_tail(0),
_rx_buffer_head(0), _rx_buffer_tail(0)
{
}
// 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;
};
}
#endif // whole file