Depends on the company. Some will hand out 30%+ annual pay increases to keep people at market rates. But, many companies are happy to have high turnover in exchange for lower pay.
The only company I know of that publicly makes this (bringing existing people up to market rate) is Netflix. Can you name other companies that actually do this?
I've worked for companies that do this, although it's not publicized so I can't point you to a press release or something. Usually a very strong indicator is to look for companies who publish salaries, either publicly or to all employees. It's almost impossible for a company to underpay people when everyone knows everyone else's salary.
I believe Adobe is known to aggressively hand out raises like this. Here in Utah, at least, it's extremely difficult to get Adobe engineers to switch jobs.
Stitch Fix also does that, at least in the data science team.