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| 2024-11-14 17:46:08 +0100 | Digit | (~user@user/digit) Digit |
| 2024-11-14 17:44:33 +0100 | Digitteknohippie | (~user@user/digit) (Ping timeout: 252 seconds) |
| 2024-11-14 17:42:44 +0100 | <bailsman> | It went from 4x slower to 10x faster than plain `map` |
| 2024-11-14 17:42:20 +0100 | <haskellbridge> | <Bowuigi> Oh yeah unboxing and strict data type fields can help in optimizing in general |
| 2024-11-14 17:42:00 +0100 | <geekosaur> | otherwise it'll be chasing a lot of pointers |
| 2024-11-14 17:41:51 +0100 | <geekosaur> | well, yes, that helps |
| 2024-11-14 17:40:18 +0100 | <bailsman> | need to write unboxed instances for all of your data types. |
| 2024-11-14 17:40:17 +0100 | <bailsman> | Hmmm. I had Claude.AI write an unboxed small record instance with 50+ lines of code (to my eyes absolutely horrific). Then, using Data.Vector.Unboxed.Mutable the performance is now approaching the C in-place update speed. I don't entirely trust that this won't segfault at some point, but if claude.ai did everything correctly then apparently it *is* possible to write inplace algorithms, you just |
| 2024-11-14 17:37:19 +0100 | Digit | (~user@user/digit) (Ping timeout: 265 seconds) |
| 2024-11-14 17:37:00 +0100 | Digitteknohippie | (~user@user/digit) Digit |
| 2024-11-14 17:34:26 +0100 | <haskellbridge> | <Bowuigi> It turns out that first class labels are just Proxy on a kind ranging over every possible label |
| 2024-11-14 17:33:44 +0100 | <haskellbridge> | <Bowuigi> Now that everything is solved, it's time to move to something else |
| 2024-11-14 17:21:27 +0100 | <geekosaur> | llvm still lacks support for pre-CPSed code |
| 2024-11-14 17:20:48 +0100 | aljazmc | (~aljazmc@user/aljazmc) aljazmc |
| 2024-11-14 17:19:31 +0100 | <tomsmeding> | :) |
| 2024-11-14 17:19:01 +0100 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) |
| 2024-11-14 17:16:39 +0100 | <EvanR> | ok |
| 2024-11-14 17:16:35 +0100 | <tomsmeding> | EvanR: it definitely is not |
| 2024-11-14 17:16:16 +0100 | <Inst> | probably MY skill issue :( |
| 2024-11-14 17:16:14 +0100 | <EvanR> | is llvm not the default now anyway |
| 2024-11-14 17:14:34 +0100 | <bailsman> | Inst: I compiled my benchmark with -O2 -fllvm. Does not seem meaningfully different. Is -O2 the wrong optimization level? |
| 2024-11-14 17:12:36 +0100 | <Inst> | try compile with -fllvm |
| 2024-11-14 17:12:30 +0100 | <lambdabot> | Unknown command, try @list |
| 2024-11-14 17:12:30 +0100 | <Inst> | @bailsman |
| 2024-11-14 17:11:19 +0100 | <EvanR> | in any case idiomatic haskell is a starting point for getting into the weeds for optimization |
| 2024-11-14 17:10:34 +0100 | <EvanR> | not necessarily, sometimes idiomatic haskell is faster |
| 2024-11-14 17:10:03 +0100 | <bailsman> | If you write idiomatic haskell, you get as-slow-as-you-would-expect, if you try to write in-place code, you get way-slower-than-you-would-expect. |
| 2024-11-14 17:09:25 +0100 | <EvanR> | in the case of arrays, for lookup tables |
| 2024-11-14 17:09:22 +0100 | <bailsman> | I agree with your conclusion - stop trying to be clever and just learn what idiomatic haskell code looks like. |
| 2024-11-14 17:08:53 +0100 | <EvanR> | but as a looping mechanism |
| 2024-11-14 17:08:44 +0100 | <EvanR> | in the case of list, usually not as a data structure |
| 2024-11-14 17:08:09 +0100 | <EvanR> | list and arrays in haskell are both good for certain purposes |
| 2024-11-14 17:07:25 +0100 | <EvanR> | "they are both called list" isn't that inspiring |
| 2024-11-14 17:06:59 +0100 | <EvanR> | the C version of linked list is just a bad thing to compare to haskell list unless you are careful to emulate what the haskell version did |
| 2024-11-14 17:06:20 +0100 | <bailsman> | To me the fact that the Haskell Vector is ~100ms, Haskell map is ~25ms, C allocate-new-linked-list-and-copy version is ~15ms, C array in place is ~2ms is suggestive of the fact that indeed allocating a list is slow, and it's indeed what Haskell is doing, but it's still better than trying to do an array in Haskell. |
| 2024-11-14 17:06:10 +0100 | <EvanR> | before claiming stuff about what stuff compiles to you should check it |
| 2024-11-14 17:05:01 +0100 | <EvanR> | but the specific reasons are off |
| 2024-11-14 17:04:50 +0100 | <EvanR> | "straight list processing and immutable structures are probably better in haskell than C-like mutable array munging" though is what I've been saying for days |
| 2024-11-14 17:03:44 +0100 | <geekosaur> | gc only gets involved when the pointer reaches the end of the nursery |
| 2024-11-14 17:03:31 +0100 | <geekosaur> | the nursery/gen 0 is a bump-pointer allocator |
| 2024-11-14 17:03:20 +0100 | <geekosaur> | not magic |
| 2024-11-14 17:03:13 +0100 | <bailsman> | I agree - I'm not really sure. Some GC magic probably. But the point is that it's builtin and optimized, so it's much faster than trying to emulate in-place updates, which compiles to a morass of work and not 5 asm instructions like the c version. |
| 2024-11-14 17:02:06 +0100 | <geekosaur> | because it's probably not what actually happens |
| 2024-11-14 17:01:56 +0100 | <geekosaur> | bailsman, what do you think is going on during an allocation? |
| 2024-11-14 17:01:22 +0100 | <EvanR> | yes it is |
| 2024-11-14 17:01:08 +0100 | <bailsman> | No it isn't. |
| 2024-11-14 17:00:57 +0100 | <EvanR> | allocating nodes in haskell is much faster |
| 2024-11-14 17:00:38 +0100 | <EvanR> | are you allocating nodes with malloc |
| 2024-11-14 17:00:31 +0100 | <EvanR> | that's... not going to be an apples to apples comparison |
| 2024-11-14 17:00:30 +0100 | <bailsman> | So I think I'm concluding that map is "the best you can do in haskell" because it's optimized and a builtin, and any attempt to do in place algorithms is just going to be massively slow. |