similar to: [LLVMdev] Code for late safepoint placement available

Thanks for the comments and for taking a look. On 06/05/2014 02:19 AM, David Chisnall wrote: > Hi Philip, > > The first thing that I notice on looking at the code is the lack of comments. For example, about the only comment that I see in include /llvm/IR/Statepoint.h is a note telling me that a class is only intended to be used on the stack. Doxygen comments and, for a feature like

Now that the statepoint changes have landed, I wanted to start a discussion about what's next for GC support in LLVM. I'm going to sketch out a strawman proposal, but I'm not set on any of this. I mostly just want to draw interested parties out of the woodwork. :) Overall Direction: In the short term, my intent is to preserve the functionality of the existing code, but migrate

Is anyone aware of an existing framework for asking liveness questions about SSA values in the IR? I'm looking for something more precise than the trivial definition provided by SSA itself. I can write something myself (and will if need be), but it seemed like a generic enough problem that I was surprised I couldn't find something already in tree. Anyone know of something I've

On Thu, Oct 24, 2013 at 6:42 PM, Sanjoy Das <sanjoy at azulsystems.com> wrote: > Hi Rafael, Andrew, > > Thank you for the prompt reply. > > One approach we've been considering involves representing the > constraint "pointers to heap objects are invalidated at every > safepoint" somehow in the IR itself. So, if %a and %b are values the > GC is

On Fri, Oct 25, 2013 at 8:35 PM, Philip Reames <listmail at philipreames.com>wrote: > On 10/25/13 1:10 PM, Ben Karel wrote: > > > > > On Thu, Oct 24, 2013 at 6:42 PM, Sanjoy Das <sanjoy at azulsystems.com>wrote: > >> Hi Rafael, Andrew, >> >> Thank you for the prompt reply. >> >> One approach we've been considering involves

On 10/25/13 1:10 PM, Ben Karel wrote: > > > > On Thu, Oct 24, 2013 at 6:42 PM, Sanjoy Das <sanjoy at azulsystems.com > <mailto:sanjoy at azulsystems.com>> wrote: > > Hi Rafael, Andrew, > > Thank you for the prompt reply. > > One approach we've been considering involves representing the > constraint "pointers to heap objects

I'm also highly interested in relocating-GC support from LLVM. Up until now my GC implementation has been non-relocating which is obviously kind of a bummer given that it inhibits certain classes of memory allocation/deallocation tricks. I wrote up a bunch of my findings on the implementation of my GC here: https://code.google.com/p/epoch-language/wiki/GarbageCollectionScheme Frankly I

The long term plan is a) evolving, and b) dependent on the specific use case. :) It would definitely be nice if we could support both early and late safepoint insertion. I see no reason that LLVM as a project should pick one or the other since the infrastructure required is largely overlapping. (Obviously, I'm going to be mostly working on the parts that I need, but others are always

On 02/24/2014 11:27 AM, Andrew Trick wrote: > > On Feb 24, 2014, at 11:17 AM, Philip Reames <listmail at philipreames.com > <mailto:listmail at philipreames.com>> wrote: > >> >> On 02/24/2014 12:45 AM, Andrew Trick wrote: >>> >>> On Feb 21, 2014, at 10:37 AM, Philip Reames >>> <listmail at philipreames.com <mailto:listmail at

Thanks, Philip for the "lay of the ground" picture. I think the situation I'm in, which represents my employment (and now personal technical curiosity) is that we're seeing LLVM implementations show up like every other week or month, etc. and people are asking us, "well this mathematical software of yours is great, but my engineer here tells me it's not using this LLVM

Thanks for reviving this. I completely forgot the details but I resolved this problem. Looking though the code, seems I forked RewriteStatepointsForGC pass, and change it to adding 'gc-livevars' bundle to the call/invoke inst after finding the livevars, instead of changing it to StatepointCall intrinsic. On Wed, Nov 14, 2018 at 11:48 AM Philip Reames <listmail at philipreames.com>

I've got a pseudo instruction with some tricky semantics I need help figuring out how to encode properly. For those interested, this is to support fully relocating garbage collection. I'm going to try to express the requirements clearly so that you don't need to understand the use case in detail. My end goal is to capture a list of registers and/or stack offsets for a list of

On 02/24/2014 12:45 AM, Andrew Trick wrote: > > On Feb 21, 2014, at 10:37 AM, Philip Reames <listmail at philipreames.com > <mailto:listmail at philipreames.com>> wrote: > >> >> On 02/14/2014 05:55 PM, Philip Reames wrote: >>> Splitting out a conversation which started in "make DataLayout a >>> mandatory part of Module" since the

Thanks for the feedback. I think both of the suggestions are very reasonable. I’ll incorporate them. Given there were no objections for two weeks, I’m going to go ahead with posting individual patches for review. One small question inline: On Sep 28, 2020, at 10:56 AM, Philip Reames <listmail at philipreames.com<mailto:listmail at philipreames.com>> wrote: In general, I am

For anyone following along on ToT using the gc.statepoint mechanism, you should know that ToT is currently not able to express arbitrary exceptional control flow and relocations along exceptional edges. This is a direct result of moving the gc.statepoint representation to using a token type landingpad. Essentially, we have a design inconsistency where we expect to be able to

Sorry to reply to myself here, but I had an idea regarding "issue #2" -- possibly what makes the most sense for those clients/targets is to pull the pointer difference computation/reapplication into RS4GC itself -- it could have a pass just before or after rematerialization, which runs based on a configuration flag (eventually to be driven by GCStrategy), which performs rewrites like

Thanks, I think that's a useful way to look at it (though if I wanted to bikeshed I'd suggest the name "DoubleIndirect" as a bit more precise than "VeryIndirect"). An aspect of it that I'm still puzzling over is that my target runtime (at least in its current form) doesn't have a way to represent/process a "VeryIndirect" pointer. So I'd like to

> On Oct 13, 2014, at 4:07 PM, Philip Reames <listmail at philipreames.com> wrote: > > >> On 10/13/2014 03:23 PM, Kevin Modzelewski wrote: >> With the patchpoint infrastructure, shouldn't it now be relatively straightforward to do an accurate-but-non-relocatable scan of the stack, by attaching all the GC roots as stackmap arguments to patchpoints? This is

I'm moving this to a different thread. I think the newly proposed intrinsic definitions and their current implementation are valuable regardless of how it gets tied into GC... On Oct 22, 2013, at 6:24 PM, Philip R <listmail at philipreames.com> wrote: > Adding Gael as someone who has previously discussed vmkit topics on the list. Since I'm assuming this is where the GC support

Adding Gael as someone who has previously discussed vmkit topics on the list. Since I'm assuming this is where the GC support came from, I wanted to draw this conversation to the attention of someone more familiar with the LLVM implementation than myself. On 10/22/13 4:18 PM, Andrew Trick wrote: > On Oct 22, 2013, at 3:08 PM, Filip Pizlo <fpizlo at apple.com > <mailto:fpizlo