Minor optimization in shiftOut function

1 files changed, 7 insertions, 4 deletions

diff --git a/cores/arduino/wiring_shift.c b/cores/arduino/wiring_shift.c
index 2b6f7a8..042a95a 100644
--- a/cores/arduino/wiring_shift.c
+++ b/cores/arduino/wiring_shift.c
@@ -42,10 +42,13 @@ void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val)
 	uint8_t i;
 
 	for (i = 0; i < 8; i++)  {
-		if (bitOrder == LSBFIRST)
-			digitalWrite(dataPin, !!(val & (1 << i)));
-		else	
-			digitalWrite(dataPin, !!(val & (1 << (7 - i))));
+		if (bitOrder == LSBFIRST) {
+			digitalWrite(dataPin, val & 1);
+			val >>= 1;
+		} else {	
+			digitalWrite(dataPin, val & 128);
+			val <<= 1;
+		}
 			
 		digitalWrite(clockPin, HIGH);
 		digitalWrite(clockPin, LOW);