Fighter's Tactical Shift: extra movement?

The Fighter's Tactical Shift says with your Bonus Action, "you can move up to half your Speed without provoking Opportunity Attacks."

Is that in addition to your base movement, or is part of that (consuming half your movement that round)?

I've seen conflicting takes on this.

It's in addition because it's using a bonus action to move, not your movement. It's just tied to the same statistic 

Just to expand on what Davyd said: there are abilities that allow you special movement options that do consume your movement, but they always say that explicitly.

The Cartographer Artificer, for instance, has a teleportation ability that says "you can spend an amount of movement equal to half your Speed". In that case, your movement is actually being spent, because the feature explicitly says it is. Something that just says "you can move up to your Speed" or "up to half your Speed" doesn't spend any movement because it doesn't say it spends any movement.

Very cool, thanks!