In SoftwareSerial::recv, only calculate the new tail once

matthijskooijman · matthijskooijman · commit ddbe3174f03c · 2015-01-26T17:03:25.000+01:00
This shortens the generated code a bit more.
diff --git a/hardware/arduino/avr/libraries/SoftwareSerial/SoftwareSerial.cpp b/hardware/arduino/avr/libraries/SoftwareSerial/SoftwareSerial.cpp
@@ -259,11 +259,12 @@ void SoftwareSerial::recv()
       d = ~d;
 
     // if buffer full, set the overflow flag and return
-    if ((_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF != _receive_buffer_head) 
+    uint8_t next = (_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF;
+    if (next != _receive_buffer_head)
     {
       // save new data in buffer: tail points to where byte goes
       _receive_buffer[_receive_buffer_tail] = d; // save new byte
-      _receive_buffer_tail = (_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF;
+      _receive_buffer_tail = next;
     } 
     else 
     {

Original file line number	Diff line number	Diff line change
`@@ -259,11 +259,12 @@ void SoftwareSerial::recv()`
`259`	`259`	`d = ~d;`
`260`	`260`
`261`	`261`	`// if buffer full, set the overflow flag and return`
`262`		`- if ((_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF != _receive_buffer_head)`
	`262`	`+ uint8_t next = (_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF;`
	`263`	`+ if (next != _receive_buffer_head)`
`263`	`264`	`{`
`264`	`265`	`// save new data in buffer: tail points to where byte goes`
`265`	`266`	`_receive_buffer[_receive_buffer_tail] = d; // save new byte`
`266`		`- _receive_buffer_tail = (_receive_buffer_tail + 1) % _SS_MAX_RX_BUFF;`
	`267`	`+ _receive_buffer_tail = next;`
`267`	`268`	`}`
`268`	`269`	`else`
`269`	`270`	`{`