similar to: [LLVMdev] Parallelism in HLVM

The (new) HLVM project is continuing to improve and I have graphed and analysed some performance-related data. Beating OCaml on numerical performance using LLVM turned out to be quite easy on x86: http://flyingfrogblog.blogspot.com/2009/03/performance-ocaml-vs-hlvm-beta-04.html This was achieved using a single optimization pass in HLVM (unrolling) and none of LLVM's own IR optimization

I have committed the changes to HLVM that bring it up to date with respect to the new LLVM 2.6 release: http://hlvm.forge.ocamlcore.org/ This required handling of llcontexts and the injection of a call to the new Llvm_executionengine.initialize_native_target function (that is undocumented) *before* the JIT EE is created, otherwise LLVM resorts to the LLVM interpreter which breaks at

What happened to the HLVM project? I understand it was intended to be a high-level VM specifically for dynamic languages and this post indicates that it was integrated into the LLVM project last year: http://www.nabble.com/NEWS:-HLVM-merges-with-LLVM-td9627113.html But I cannot find any code in LLVM that looks like it would have come from HLVM. -- Dr Jon Harrop, Flying Frog Consultancy

On Monday 04 January 2010 03:33:06 Simon Harris wrote: > On 04/01/2010, at 3:01 PM, Jon Harrop wrote: > > I am certainly interested in tail calls because my HLVM project relies > > upon LLVM's tail call elimination. However, I do not understand what tail > > calls LLVM is not currently eliminating that you plan to eliminate? > > Mutual recursion for a start: >

I have been working on a high-level virtual machine built upon LLVM since Christmas 2008 and just released the first working version: http://forge.ocamlcore.org/projects/hlvm/ This alpha release of HLVM provides: . Unit, bool, int and float primitive types. . Tuples (as first-class structs). . Homogeneous array type. . Boxed value type. . Function pointers. . Generic printing. . Full tail

I just upgraded HLVM from LLVM 2.7 to 2.8 and started seeing stack overflows so I think TCO isn't working. Have there been any obvious changes that would cause this? -- Dr Jon Harrop, Flying Frog Consultancy Ltd. http://www.ffconsultancy.com

The ocamldoc-generated documentation for HLVM is now available here: http://www.ffconsultancy.com/ocaml/hlvm/docs/ -- Dr Jon Harrop, Flying Frog Consultancy Ltd. http://www.ffconsultancy.com/?e

HLVM is a garbage collected virtual machine built upon LLVM: http://forge.ocamlcore.org/projects/hlvm/ The development of HLVM was described in a series of three OCaml Journal articles that turned out to be among our most popular. Consequently, we have decided to run another series of related articles that build upon this foundation in order to develop complete compilers. The first article

To illustrate the value of value types to the OCaml community I recently did a couple of benchmarks. The first was similar to a hash table and stores key-value pairs unboxed in an array: http://groups.google.com/group/fa.caml/msg/8430ebdb687b9268 The second is the hailstone benchmark that the Haskell guys found gave huge performance improvements when using LLVM from GHC:

On Monday 04 January 2010 01:12:55 Simon Harris wrote: > I'm investigating "improving" the TCO facilities in LLVM to provide for > "hard" tail calls. Specifically, this would involve extending the existing > implementation to discard the stack frame for the caller before executing > the callee. I would then like to extend this further by performing hard >

On Feb 5, 2010, at 7:19 PM, Jon Harrop wrote: > On Friday 05 February 2010 23:35:15 Evan Cheng wrote: >> Does anyone actually using it? > > Yes, many LLVM-based projects rely upon TCO to work correctly. Ok, that's all I need to know. > >> I'd prefer to just remove it to clean up the implementation if no one has >> any objections. > > Are you

On Saturday 06 February 2010 02:42:47 Evan Cheng wrote: > On Feb 5, 2010, at 7:19 PM, Jon Harrop wrote: > > On Friday 05 February 2010 23:35:15 Evan Cheng wrote: > >> Does anyone actually using it? > > > > Yes, many LLVM-based projects rely upon TCO to work correctly. > > Ok, that's all I need to know. > > >> I'd prefer to just remove it to

On Tue, Feb 16, 2010 at 2:47 AM, Jon Harrop <jon at ffconsultancy.com> wrote: > On Tuesday 16 February 2010 03:51:00 Jianzhou Zhao wrote: >> Does anyone know if there is any realistic project using LLVM-OCaml >> Bindings? > > I've written a VM in OCaml built upon LLVM using LLVM's OCaml bindings: > >  http://www.ffconsultancy.com/ocaml/hlvm/ > > There

>From a cursory glance, it looks like something is messing with the stack canarys. Probably a stack buffer overflow. On Tue, Mar 10, 2009 at 11:41 PM, Jon Harrop <jon at ffconsultancy.com> wrote: > > Someone is trying to work on HLVM with me but they're hitting a problem that > we have not been able to resolve. Specifically, GCC seems to be performing > some kind of

On Thursday 19 February 2009 03:31:04 DeLesley Hutchins wrote: > > The same can be said of closures, garbage collection and a dozen other > > features that also cannot feasibly be added to LLVM. > > > > The only logical solution is to build a HLVM on top of LLVM and share > > that between these high-level language implementations. > > This is an excellent point.

On Tuesday 16 June 2009 15:44:04 Aaron Gray wrote: > Jon Harrop wrote: > >Even if this puts LLVM at an unfair disadvantage, I think you will find > >that > >LLVM will thrash MLton's current x86 backend anyway. > > > >I did some benchmarking on HLVM and found that it was often several times > >faster than OCaml when the GC is not the bottleneck: > >

On Sun, Jan 4, 2009 at 2:36 PM, Jon Harrop <jon at ffconsultancy.com> wrote: (...) > But I cannot find any code in LLVM that looks like it would have come from > HLVM. Don't know about the status of the project, but the code seems to be here: http://llvm.org/viewvc/llvm-project/ (in directory "hlvm") Regards, Kevin André

On Friday 05 February 2010 23:35:15 Evan Cheng wrote: > Does anyone actually using it? Yes, many LLVM-based projects rely upon TCO to work correctly. > I'd prefer to just remove it to clean up the implementation if no one has > any objections. Are you saying that you want to remove LLVM's working TCO and replace it with something that is faster but broken? I think you may

Hi Jon, I've read your articles about HLVM, and that was one of the reasons that convinced me to try out LLVM. Actually my VM has been implemented in C++, but as long as it is not extremely complex, I might port it to OCaml that sounds more compact for this kind of programs. Did you find any significant performance loss when using OCaml over C++ ? Runtime performance is quite

The LLVM 2.6-compatible IR below is derived from the HLVM test suite and is one of the things I've noticed going wrong. However, I just discovered that it works with LLVM 2.6 and with LLVM SVN when run through lli or llc without -tailcallopt but when I use: $ llvm-as -f aout.ll $ llc -tailcallopt -f aout.bc -o aout.s $ gcc -lm aout.s -o aout and the latest LLVM SVN it starts to print