From b6ba4b6aab4f5886866bd125a2e09940892dcac6 Mon Sep 17 00:00:00 2001
From: Matthijs Kooijman <matthijs@stdin.nl>
Date: Wed, 23 Apr 2014 17:45:10 +0200
Subject: [PATCH] In SoftwareSerial::recv, only calculate the new tail once

This shortens the generated code a bit more.
---
 libraries/SoftwareSerial/SoftwareSerial.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/libraries/SoftwareSerial/SoftwareSerial.cpp b/libraries/SoftwareSerial/SoftwareSerial.cpp
index cafd0c4..42f796b 100644
--- a/libraries/SoftwareSerial/SoftwareSerial.cpp
+++ b/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 
     {