it depends on where the safe is.
the search warrant should say what they are looking for and where it is. ask for the warrant and read it to know what's going on. plenty of people ask to see a warrant only to not really read what it says. the warrant doesn't always give access to the WHOLE house. sometimes it's very specific, most of the time it's very vague to allow the cops leeway in their search. it's a case-by-case scenario.
keep the safe closed.
if it's a safe bought at costco, they can get the master key, if it's a REAL safe, they can't open it unless you do. if they try to force it, it breaks the glass, and the safe locks permanently. only sending it back to the manufacturer might get you're stuff back.
there's a series of jewish safes, will not mention the name on this site, that warns you that if you try and force it you're shit will be locked in there FOREVER, not even the company knows how to open it once that glass breaks and the dead-bolts lock......
anyways, if you're name is on the search warrant, and it mentions your property, and the safe is in your room. it's part of the warrant and they'll want to see what's in there.
and regardless of how much they huff and puff, they cannot open a good safe with force. only a master key, or the combination opens it.