I love this fill - as it is yet another variation of the famous Billy Cobham fill, later expanded to hands and feet by Steve Gadd and then later borrowed by just about everyone. But as for this fill specifically...
When trying to figure out fills like this I think most players focus too early on the fast little notes. Is it sixteenths? Or 16th triplets? Instead let's first focus on just the accents - which in this case is the 1st note on one and the last note of every flourish (or group of fast notes) after that. And as has been pointed out there are five groups of notes, which added to the note on the first beat gives us this...

Now let's look at just the first beat. Most seem to hear this as four 16th note triplets....

And yes, at this tempo, that seems to be what Peart is playing - but let's consider this as an alternative (hang in with me on this - this is a multi-step explaination). So look at this...

Now if you place the first and last notes accurately on the 1 and the "&" - and play the 32nd's a little bit relaxed -meaning you'd start the two 32nd's just a teeny bit earlier so you wouldn't have to play the 32nd's so fast (in order to not play the note on the "&" late). This is the same kind of relaxing of a rhythm that you do with a jazz ride pattern as it gets faster and faster - at most tempos, the jazz ride pattern is a triplet thing; but as it gets faster it starts to relax or open up into something closer to straight eighths. Same idea here.
Anyway if you played the figure above with a similarly relaxed feel, it would sound remarkably like four 16th note triplets - particularly at this tempo.
Now hold that thought, while we look at something else...
Again following our "let's go for the simple stuff first" approach, I've outlined more of the basic rhythm of this YYZ fill -

Now if we leave out the very first note - don't we have a single, little 2 note phrase repeated five times - 16th 1/8th, 16th 1/8th, 16th 1/8th, 16th 1/8th, 16th 1/8th with an accent on every 1/8th?* Simple; repetitive; but nicely syncopated. Orchestrated around the drums, it's a perfectly fine fill all on its own.
* yes, the fourth group is written as a 16th followed by a 16th and a 16th rest - but functionally (again, at this tempo and in this context) a 16th note followed a 16th note rest is the same as an 1/8th note.
So finally, now that we have "the lay of the land" and really understand the underpinning of what is going on rhythmically, let's add the fast, little notes. Take the notation above and again disregarding the first note - change every one of the 16th's (the first note in each of the two note groups) into two 32nd's. Which would look like this -

Again, at this tempo, be sure to not play those 32nd's too tight or close together. But remember, you can't loosen them up by cheating on the position of the accented notes (the notes from the first example). No, those notes must stay very accurate. It's in the fast little notes that the loosening up has to happen.
Though I'd suggest nice and accurate at a slower tempo for a while - before ramping it up to the tempo of the recording.
(Obviously, I've left out the orchestration here - it just made the notation easier - and in this case, the orchestration is easy, it's the rhythm that's the challange.)
Keep in mind that there is a multitude of fills to be created from the rhythmic concepts put forth in this one fill - turn it around, chop it up, reorchestrate it, on and on.
Have fun,
David