How is ipsw extracting a dylib from dyld_shared_cache and keeping trie information?

[gazigazi194]

Hello,

I'm extracting the same dylib in two different ways.
first method is ipsw dyld extract dyld_shared_cache_arm64e and the second method is ipsw dyld split dyld_shared_cache_arm64e -o .

If I use the first method and throw the dylib in ida pro, it keeps all the export information even though they are out of range. But if I use the second method, it doesn't keep the export information, and I can see that in trie data structure.

How is ipsw extracting the dylib from dyld_shared_cache using the first method and keep all the export functions so that it shows up in ida pro even though the information is out of range?