Minor optimization in shiftOut function

649f9782 · luca · 5755ddea · 649f9782
Commit 649f9782 authored Apr 26, 2019 by luca
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Showing with 7 additions and 4 deletions

cores/arduino/wiring_shift.c cores/arduino/wiring_shift.c +7 -4

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--- 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);