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13:52:58
drmeister
https://github.com/clasp-developers/clasp/blob/unboxed-floats/src/llvmo/llvmoExpose.cc#L4438
13:53:23
drmeister
This is how I fixed the problem: else if (S.getProtectionFlags() & llvm::sys::Memory::MF_EXEC)
13:54:36
drmeister
llvm13 has gone off the rails with object file section names and now it's brittle to use the names to recognized "text" sections. Lang said use page protection flags and so that's what I'm doing now.
14:50:44
drmeister
I may have built and then made what I thought were trivial last minute changes and then pushed.
14:54:23
Bike
https://github.com/clasp-developers/clasp/blob/unboxed-floats/src/lisp/kernel/cmp/primitives.lsp#L456
14:55:09
Bike
while it's trying to construct an intrinsic's function type, i think, but the backtrace is kind of bad because of all the evaluator frames
14:56:36
Bike
if you're not seeing this i might have just messed up a merge, but it looked like it was fine so i dunono
14:59:05
drmeister
I think it's a merge issue on your end. But I'll stop messing around with this code now and work on other things. I don't want to mess you up.
14:59:49
drmeister
Feel free to take out the (format t "Defining primitive: ~a~%" name) from the define-primitive function.
15:11:09
drmeister
For example, I'm adding Atom_O::getPosition_BANG_(Vector3& pos) { pos = this->position; };
15:12:09
drmeister
Then in Cando code I'll use (let ((pos (geom:vec 0 0 0))) (declare (dynamic-extent pos)) (chem:do-atoms (atm molecule) (chem:get-position! pos atm) ...))
15:41:05
yitzi
drmeister: I worked out the logic on my ring test idea. Sent via gchat. I haven't tried to implement it yet.
15:46:47
yitzi
You could find the center of the ring and use the normal that mention and see if it intersects the bond.
15:51:08
drmeister
I'll give it a try. I'm working on this while writing code that doesn't allocate memory and doing other things.
17:02:36
yitzi
drmeister: That diagram I sent appears to mix up the crossing number test versus the winding number test. I'm going to tweak my method a bit.
17:19:32
Bike
just to be clear on this, any DX analysis is going to be work. i won't be able to do it today and probably not this week. i'll have to rewrite the entire meta evaluate pass (which is what's powering all these optimizations) to totally change its algorithm to do backwards dataflow
17:19:48
Bike
for this particular application it might actually be faster for me to throw in some simd intrinsics
17:21:55
Bike
does that sound okay? it's not a general solution but would probably work better for this than the general solution would
17:22:15
Bike
assuming llvm's intrinsics work as advertised, which i expect they do, given who powers llvm development
17:24:08
drmeister
It's more of a question - is what I write appropriate for what you are going to do with DX analysis?
17:25:39
Bike
i'll have to figure out how to do dynamic-extent declarations well, but yeah, that's probably fine. i /do/ already have a plan, i think, for just marking functions as dx-safe, which would mean the declarations aren't necessary
17:25:58
Bike
like in your last example here, telling the compiler that chem:get-position! doesn't let its arguments escape (or at least not the second one)
17:26:20
Bike
then the dataflow analysis would follow that back, see that p1/p2 are only used as arguments to this safe function, and so decide that it can dx-allocate them
17:27:24
drmeister
yitzi: It might be a premature optimization but it might be better if the outer loop is on the rings and generate a plane for each and then quickly eliminate all bonds that cannot intersect the plane.
17:29:35
drmeister
Bike: It would be very, very nice if the compiler can figure out what can be DX allocated.
17:31:06
Bike
currently we note some functions as calling their arguments in unchanged dynamic environments and not doing anything else with them, which (a) lets closures be dx-allocated and (b) means if they unwind they can just use longjmp instead of throw
17:31:41
Bike
https://github.com/clasp-developers/clasp/blob/main/src/lisp/kernel/cleavir/setup.lisp#L64-L174 it's done in this one place in the compiler
17:31:57
Bike
ideally that would be made into a sort of proclamation form so it could go in application code instead
17:50:22
yitzi
drmeister: Yes, I don't know if my method is fast. I am basically treating one of bond atoms as a camera and doing a projection of the ring onto a plane that goes through the second bond atom.
18:38:35
drmeister
What you are telling me is that you are going to do an analysis where you are going to make the call if a variable can be DX allocated if every function that it is passed to guarantees that it will not escape?
18:39:13
Bike
ideally yeah. it also depends on the compiler understanding the function that's called to allocate
18:39:29
Bike
like, it's not going to be able to dx allocate the list returned by (map 'list ...) probably
18:40:12
drmeister
You would have to know how long the list will be - and that cannot be determined until you run it.
18:41:16
drmeister
Will I need to make these kind of declarations? (let ((det-max (max det-x det-y det-z))) (declare (double-float det-max)) ...)
18:43:15
Bike
no, it should be able to infer that the result of max on doubles is a double, though i haven't put that in yet
18:43:44
drmeister
Your idea for DX analysis sounds very, very interesting. That could impact a lot of existing code.
18:44:32
Bike
actually, looking at the compiler macro on max it might know it's a double already, but i can check
18:44:55
drmeister
cracauer told me this morning that his recollection is that you have to declare dynamic extent on anything dynamic extent.
18:45:25
Bike
"SBCL has fairly extensive support for performing allocation on the stack when a variable is declared dynamic-extent. The dynamic-extent declarations are not verified, but are simply trusted as long as sb-ext:*stack-allocate-dynamic-extent* is true. " says the manual
18:45:52
Bike
a dx analysis is something beach has wanted for a while, since it means being able to stack allocate without relying on potentially inaccurate declarations (or at least different potentially inaccurate declarations)
18:47:02
Bike
also, with map, how it would have to work is it computes the length of the list at runtime based on the input lists, and stack allocates that
18:47:48
drmeister
CL_DEFMETHOD void OVector3_O::crossProduct_BANG_(const Vector3& other, Vector3& result )
18:47:57
drmeister
CL_DEFUN void geom__v_PLUS__BANG_(const Vector3& x, const Vector3& y, Vector3& result )
18:49:25
drmeister
Have I mentioned in the last five minutes how excited I am by these developments? Tremendously.
18:51:46
Bike
the way karlosz wrote it it just charges forward, which is naive, but reasonably quick and works fine for this arithmetic stuff where inputs depend on previous results
19:23:49
Bike
ok it does look like the compiler understands max well enough already, at least for simple cases
20:04:31
Bike
ok, now i get "error: use of undeclared identifier 'CLASP_GIT_FULL_COMMIT'" from unboxed-floats with my stuff merged in
20:14:11
Bike
we do do some weird crap with calling conventions, but i don't think we have any assembly, no
20:27:16
Bike
drmeister: i defined some defprimop macros. the simplest one, when it just calls an intrinsic, looks like this https://github.com/clasp-developers/clasp/blob/unboxed-floats/src/lisp/kernel/cleavir/primop.lisp#L166-L186
22:58:35
cracauer
are you sure the latest is all pushed to branch unboxed-floats? My Mac builds but fails to start with:
22:58:51
cracauer
JIT session error: Symbols not found: [ _wrapped_core__convert_overflow_result_to_bignum_Fixnum_sp ]