On Wed, Jun 5, 2019 at 12:26 PM James Geddes wrote:
> Annoyingly, my colleague had got the same speedup by using Numpy, but that
> does require a change to the way one arranges the calculation (and the
> change is unnatural, to my eye).
>
Also, that's cheating! Numpy is mostly written in C,
This is very helpful, thank you.
In fact, my "naive" version (in untyped Racket) was about the same speed as my
colleague's naive Python version. Switching to fl+, fl-, etc bought me a 10x
improvement (I presume from the JIT compiler avoiding boxing and unboxing?).
Annoyingly, my colleague had
Repair pushed.
At Wed, 5 Jun 2019 09:45:58 -0600, Matthew Flatt wrote:
> I had just reached the same conclusion. Specifically, it looks like a
> missing runstack sync in the JIT-inlined `unsafe-make-flrectangular`.
>
> Thanks!
>
> At Wed, 5 Jun 2019 11:40:41 -0400, Sam Tobin-Hochstadt wrote:
>
In case it's helpful as a workaround, changing the #lang line to:
#lang typed/racket #:no-optimize
will disable the type-based optimizations, so the problematic
`unsafe-make-flrectangular` isn't introduced and the segfault is avoided.
You presumably loose some performance, though, and "use this
I had just reached the same conclusion. Specifically, it looks like a
missing runstack sync in the JIT-inlined `unsafe-make-flrectangular`.
Thanks!
At Wed, 5 Jun 2019 11:40:41 -0400, Sam Tobin-Hochstadt wrote:
> I think this is a miscompilation of `unsafe-make-flrectangular` by the
> underlying
I think this is a miscompilation of `unsafe-make-flrectangular` by the
underlying Racket compiler.
The below program is a plain racket version of the code, with just one
use of unsafe, a call to `unsafe-make-flrectangular`. If that's
replaced with `make-flrectangular`, then the program works
On 05/06/2019 16:47, Philip McGrath wrote:
> What version of Racket are you using? I get a segfault in 7.2, but 7.3
> works for me.
I see the segfault in 7.1 but not in 7.2 or 7.3. Then I run it under
valgrind and I see it in all the versions. :)
It's there, but sometimes hiding.
Will take a
I'm using version 7.3, amusingly.
James
> On 5 Jun 2019, at 15:47, Philip McGrath wrote:
>
> What version of Racket are you using? I get a segfault in 7.2, but 7.3 works
> for me.
> -Philip
>
>
> On Wed, Jun 5, 2019 at 10:42 AM James Geddes wrote:
> Dear All,
>
> The following Typed
What version of Racket are you using? I get a segfault in 7.2, but 7.3
works for me.
-Philip
On Wed, Jun 5, 2019 at 10:42 AM James Geddes wrote:
> Dear All,
>
> The following Typed Racket program is intended to produce an image of the
> Mandelbrot set (but it doesn't bother actually displaying
Dear All,
The following Typed Racket program is intended to produce an image of the
Mandelbrot set (but it doesn't bother actually displaying the image).
Running the program using command-line Racket causes a crash. Specifically,
Racket terminates with the error message:
Segmentation
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