libera/#ecl - IRC Chatlog

4:17:21 sgithens How much usage of the "the" special operator does ECL make use?

4:18:11 sgithens Certain parts of my project are littered with `(the fixnum ...` and I'm wondering if it still makes a difference for performance now. (30 years later)

5:50:58 jackdaniel sgithens: do you mean benchmarks?

5:51:41 jackdaniel generally, when the implementation knows that both integers are fixnums and that they will fit in a fixnum, then the operation may be done using registers

5:52:44 jackdaniel otherwise (assuming #'+), you need to do a dispatch on types, and that also an expansion with a few IFs and possibly call to a specialized function, i.e add_big_fix(x, y)

5:53:08 jackdaniel so knowing that something is a fixnum, even today, has performance impact if you want to squeeze everything from it

5:53:42 jackdaniel that said, computers are fast today, so unless you do something really computationally intensive, you don't need to aggresively optimize programs

5:53:56 jackdaniel also, aggressive optimizations often go at the cost of safety

5:54:14 jackdaniel and (also often) at the cost of space

5:54:22 jackdaniel so it is all tradeoffs

7:09:11 jackdaniel n.b I've used my live decompiler and verify, that structure access is slow because accessors are not inlined (we go through symbol to get the function)