From a403c19adeb0b02bf070b4bdc33a3d1c87a3fbd8 Mon Sep 17 00:00:00 2001 From: "David A. Mellis" Date: Thu, 11 Nov 2010 23:29:21 -0500 Subject: [PATCH] Cast to encourage optimization of Serial ring buffer index calculations. http://code.google.com/p/arduino/issues/detail?id=391 --- hardware/arduino/cores/arduino/HardwareSerial.cpp | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/hardware/arduino/cores/arduino/HardwareSerial.cpp b/hardware/arduino/cores/arduino/HardwareSerial.cpp index b25b4f181..4397efb7e 100644 --- a/hardware/arduino/cores/arduino/HardwareSerial.cpp +++ b/hardware/arduino/cores/arduino/HardwareSerial.cpp @@ -65,7 +65,7 @@ struct ring_buffer inline void store_char(unsigned char c, ring_buffer *rx_buffer) { - int i = (rx_buffer->head + 1) % RX_BUFFER_SIZE; + int i = (unsigned int)(rx_buffer->head + 1) % RX_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 @@ -231,7 +231,7 @@ void HardwareSerial::end() int HardwareSerial::available(void) { - return (RX_BUFFER_SIZE + _rx_buffer->head - _rx_buffer->tail) % RX_BUFFER_SIZE; + return (unsigned int)(RX_BUFFER_SIZE + _rx_buffer->head - _rx_buffer->tail) % RX_BUFFER_SIZE; } int HardwareSerial::peek(void) @@ -250,7 +250,7 @@ int HardwareSerial::read(void) return -1; } else { unsigned char c = _rx_buffer->buffer[_rx_buffer->tail]; - _rx_buffer->tail = (_rx_buffer->tail + 1) % RX_BUFFER_SIZE; + _rx_buffer->tail = (unsigned int)(_rx_buffer->tail + 1) % RX_BUFFER_SIZE; return c; } }