PyPy 1.6 Released - Full Python 2.7.1 Implementation

Post by lliiffee » Fri, Aug 19, 2011, 12:53 AM UTC

sjs wrote: post #31

lliiffee wrote: post #30

Earlier quoted context omitted.

LLVM would seem to (maybe? possibly!?) be a good solution, but I was never able to convincingly determine if it was likely to solve my problems, and the documentation seemed to be quite sparse for doing what I wanted to do. (This was a couple years ago, however, and I've love to be proven wrong.)

Instead of generating C code you might be able to generate LLVM IR and have it execute immediately, saved to disk, or both. I don't know how it will perform for you or how high level your generated C is though, it may not be realistic. Or use it to compile your C as it is pretty quick. It's not going to speed things up by orders of magnitude but every bit helps.

  A[12800]=A[0] * A[6400];
  A[12801]=A[1] * A[6480];
  A[12802]=A[12800] + A[12801];
  A[12803]=A[2] * A[6560];
  A[12804]=A[12802] + A[12803];
  A[12805]=A[3] * A[6640];

Post by vgnet » Fri, Aug 19, 2011, 2:49 AM UTC

socratic wrote: post #33

Are there production users of PyPy? I feel like PyPy has always been the most academically interesting Python implementation. But has it taken away mindshare from CPython?

Post by carterschonwald » Fri, Aug 19, 2011, 3:26 AM UTC

lliiffee wrote: post #29

carterschonwald wrote: post #26

Earlier quoted context omitted.

Off hand and guessing about the problem: You might want to look at approaches that use dual numbers. Likewise, in instead of inlining the procedures, generate a differentiated version of each procedure with a new name. If those don't cover your problems, perhaps look at how other autodiff tools for C do it?

For being offhand, those are very good guesses! Dual numbers won't be efficient, as I want reverse-mode autodiff. As to the multiple procedures: Well, as I was doing it, even a single procedure can be many hundreds of megabytes large. Even for very very simple code, however, I noticed that GCC was superlinear in code size. I suppose I could somewhat arbitrarily break up the code into arbitrary functions. I wonder if…

Post by lliiffee » Fri, Aug 19, 2011, 3:50 AM UTC

carterschonwald wrote: post #36

lliiffee wrote: post #29

Earlier quoted context omitted.

For being offhand, those are very good guesses! Dual numbers won't be efficient, as I want reverse-mode autodiff. As to the multiple procedures: Well, as I was doing it, even a single procedure can be many hundreds of megabytes large. Even for very very simple code, however, I noticed that GCC was superlinear in code size. I suppose I could somewhat arbitrarily break up the code into arbitrary functions. I wonder if…

it sounds like you're getting lots of code duplication. 1) try running a common subexpression elimination process on your code before doing the autodiffing, and create a procedure for each shared expression 2) for prim ops, again, have a procedure created for the diffed version instead of inlining, and sub in the procedure instead. perhaps something like these ideas would help If you want an example of a nice high le…

Post by socratic » Fri, Aug 19, 2011, 4:35 AM UTC

vgnet wrote: post #39

socratic wrote: post #37

Earlier quoted context omitted.

To me, this list seems to suggest the opposite actually. [1] is the company where one of the main developers of PyPy works. [2] appears to be a discussion where they are looking for anyone using PyPy in production. [3] seems to be an article about someone experimenting with PyPy for git processing. [4] is the developers looking for non-toy examples of production use so that they can get more funding.

It suggests that there aren't many production users, true. But it does prove that there are some.