Comparator with two noninverting inputs?
In this context, it means that the comparator can be triggered by comparison of the inverting input against both of the two non-inverting inputs. My impression (though I'm not 100% certain on this) is that the inverting input needs to exceed both of the non-inverting inputs to switch the output. The input hooked to the soft-start pin is dominant at start up, but during normal operation, the 800 mV reference is dominant. This means that at start-up, the inductor current cycles more slowly than during normal operation.

Here's the description from the datasheet of the what the comparator does during normal operation:


  The inductor current 
  increases until either the current exceeds the peak current 
  comparator threshold or the voltage on the VFB pin 
  exceeds 800mV, at which time the high side power switch 
  is turned off, and the low side power switch (N-channel 
  MOSFET) turns on. The inductor current ramps down until 
  the reverse current comparator trips, signaling that the 
  current is close to zero. If the voltage on the VFB pin is 
  still less than the 800mV reference, the high side power 
  switch is turned on again and another cycle commences.