minor speedups

* added IRAM_ATTR_YN to some frequently used color functions
* small optimization for fade_out: pixel already has "target color"

wled00/FX_fcn.cpp

@@ -1216,6 +1216,7 @@ void Segment::fade_out(uint8_t rate) {
 
   for (uint_fast16_t y = 0; y < rows; y++) for (uint_fast16_t x = 0; x < cols; x++) {
     uint32_t color = is2D() ? getPixelColorXY(x, y) : getPixelColor(x);
+    if (color == color2) continue;  // WLEDMM speedup - pixel color = target color, so nothing to do
     int w1 = W(color);
     int r1 = R(color);
     int g1 = G(color);

wled00/colors.cpp

@@ -35,7 +35,7 @@ IRAM_ATTR_YN uint32_t color_blend(uint32_t color1, uint32_t color2, uint_fast16_
  * color add function that preserves ratio
  * idea: https://github.com/Aircoookie/WLED/pull/2465 by https://github.com/Proto-molecule
  */
-uint32_t color_add(uint32_t c1, uint32_t c2)
+IRAM_ATTR_YN uint32_t color_add(uint32_t c1, uint32_t c2)   // WLEDMM added IRAM_ATTR_YN
 {
   uint32_t r = R(c1) + R(c2);
   uint32_t g = G(c1) + G(c2);
@@ -362,7 +362,7 @@ void calcGammaTable(float gamma)
 }
 
 // used for individual channel or brightness gamma correction
-uint8_t gamma8(uint8_t b)
+IRAM_ATTR_YN uint8_t gamma8(uint8_t b)   // WLEDMM added IRAM_ATTR_YN
 {
   return gammaT[b];
 }

wled00/led.cpp

@@ -68,7 +68,7 @@ void toggleOnOff()
 
 
 //scales the brightness with the briMultiplier factor
-byte scaledBri(byte in)
+IRAM_ATTR_YN byte scaledBri(byte in)  // WLEDMM added IRAM_ATTR_YN
 {
   if (briMultiplier == 100) return(in); // WLEDMM shortcut
   uint_fast16_t val = ((uint_fast16_t)in*(uint_fast16_t)briMultiplier)/100; // WLEDMM