improve safe frame compression performance 7-15%#74
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The frame encoding uses a fixed size hashtable. By creating a special hashtable with a Box<[u32; 4096]> size, in combination with the bit shift of 4, which is also moved into a constant, the compiler can remove the bounds checks. For that to happen, the compiler also needs to recognize the `>> 48` right shift from the hash algorithm (u64 >> 52 <= 4096), which is the case. Yey It also means we can use less `unsafe` for the unsafe version
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The frame encoding uses a fixed size hashtable.
By creating a special hashtable with a Box<[u32; 4096]> size,
in combination with the bit shift of 4, which is also moved into a constant,
the compiler can remove the bounds checks.
For that to happen, the compiler also needs to recognize the
>> 48rightshift from the hash algorithm (u64 >> 52 <= 4096), which is the case. Yey