[mort96]

So we're not talking about runtime performance, but some minor improvement in loading times? I assume that once the JVM has read the bytecode, it has its own efficient in-memory structures to track references to classes rather than using a hash map with fully qualified names as keys

[swiftcoder]

Proguard was heavily influenced by the needs of early Android devices, where memory was at a real premium. Reducing the size of static tables of strings is a worthwhile optimisation in that environment

[mort96]

Okay but we're talking about Minecraft on desktops and laptops, where the relevant optimizations would be runtime performance optimizations, no?

[swiftcoder]

Probably, but proguard tends to bundle the whole lot together

[throwaway2037]

Even a hash map with fully qualified names as keys wouldn't be so bad because Stirng is immutable in Java, so the hash code can be cached on the object.

[saagarjha]

The names need to be stored somewhere because they are exposed to the program that way

[mort96]

They have to be stored somewhere, but they don't have to be what the JVM uses when it e.g performs a function call at runtime. Just having the names in memory doesn't slow down program execution.

[saagarjha]

At runtime this is going to be a branch instruction yes