Solved few warnings.

Marlin/planner.cpp

@@ -193,7 +193,7 @@ void calculate_trapezoid_for_block(block_t *block, float entry_factor, float exi
   if (plateau_steps < 0) {
     accelerate_steps = ceil(intersection_distance(block->initial_rate, block->final_rate, acceleration, block->step_event_count));
     accelerate_steps = max(accelerate_steps,0); // Check limits due to numerical round-off
-    accelerate_steps = min(accelerate_steps,block->step_event_count);
+    accelerate_steps = min((uint32_t)accelerate_steps,block->step_event_count);//(We can cast here to unsigned, because the above line ensures that we are above zero)
     plateau_steps = 0;
   }
 

Marlin/stepper.cpp

@@ -52,8 +52,8 @@ volatile static unsigned long step_events_completed; // The number of step event
 #ifdef ADVANCE
   static long advance_rate, advance, final_advance = 0;
   static long old_advance = 0;
-#endif
   static long e_steps[3];
+#endif
 static long acceleration_time, deceleration_time;
 //static unsigned long accelerate_until, decelerate_after, acceleration_rate, initial_rate, final_rate, nominal_rate;
 static unsigned short acc_step_rate; // needed for deccelaration start point

Marlin/temperature.cpp

@@ -906,9 +906,15 @@ ISR(TIMER0_COMPB_vect)
   static unsigned char temp_state = 0;
   static unsigned char pwm_count = 1;
   static unsigned char soft_pwm_0;
+  #if EXTRUDERS > 1
   static unsigned char soft_pwm_1;
+  #endif
+  #if EXTRUDERS > 2
   static unsigned char soft_pwm_2;
+  #endif
+  #if HEATER_BED_PIN > -1
   static unsigned char soft_pwm_b;
+  #endif
   
   if(pwm_count == 0){
     soft_pwm_0 = soft_pwm[0];