search for: stackmap

HI All, I am current working with SIMD instruction along with stackmap features. Recently I encountered a problem involving legalizing stackmap. In my stackmap, I record all the live values existing at the callsite. One of the operands in my stackmap is an illegal vector type for arm64 architecture ( *v4f64*) and requires vector splitting in order to legalize the nod...

Hi all, I've run into a couple bugs recently that affected stackmap liveness analysis in various ways: http://llvm.org/bugs/show_bug.cgi?id=19224 - function arguments stay live unnecessarily http://llvm.org/bugs/show_bug.cgi?id=21265 - eflags can end up as a live out http://llvm.org/bugs/show_bug.cgi?id=21266 - %rip can end up as a live out The first two have noth...

I think what's happening is BranchFolder::MaintainLiveIns is using a forward analysis on top of these missing kill flags, and updating the BB-live-ins/live-outs with an incorrect set of registers. Then when the stackmaps liveness analysis happens, it's not doing anything wrong, but it starts with the wrong set of live registers and will propagate those to the point of the patchpoint/stackmap. For now it might be possible to just fix BranchFolder (and also TailDuplicatePass::TailDuplicate) to use a backwards a...

...ted it in interpreter, as an initial step. However, now I'm trying to make it in JIT. My first step is to extract function state at an arbitrary point. So, I interrupt function at any point (from within JIT) and pause to extract state. My problem now is with state. By searching I found about stackmap new intrinsic. I got idea about what it does and I think it may help greatly in my task. However, I could not find any source about how to use it exactly, specially, how to retrieve information stored in a stackmap. I'm not understanding the concept of intrinsics very well.? Again, I tried to f...

...lip R <listmail at philipreames.com> wrote: > On 10/22/13 10:34 AM, Filip Pizlo wrote: >> On Oct 22, 2013, at 9:53 AM, Philip R <listmail at philipreames.com> wrote: >> >>> On 10/17/13 10:39 PM, Andrew Trick wrote: >>>> This is a proposal for adding Stackmaps and Patchpoints to LLVM. The >>>> first client of these features is the JavaScript compiler within the >>>> open source WebKit project. >>>> >>> I have a couple of comments on your proposal. None of these are major enough to prevent submission. >&g...

...icrosoft.com> wrote: > > Regarding Call-site size specification: > > CoreCLR (https://github.com/dotnet/coreclr <https://github.com/dotnet/coreclr>) requires the size of the Call-instruction to be reported in the GCInfo encoding. > > The runtime performs querries for StackMap records using instruction offsets as follows: > 1) Offset at the end of the call instruction (offset of next instruction-1) if the call instruction occurs in code where GC can only take control at safe-points. As part of this change it would be great if LLVM could now guarantee that the ca...

On Oct 22, 2013, at 9:53 AM, Philip R <listmail at philipreames.com> wrote: > On 10/17/13 10:39 PM, Andrew Trick wrote: >> This is a proposal for adding Stackmaps and Patchpoints to LLVM. The >> first client of these features is the JavaScript compiler within the >> open source WebKit project. >> > I have a couple of comments on your proposal. None of these are major enough to prevent submission. > > - As others have said, I...

Hi Hal, no, as far as I can recall we don’t make that guarantee for StackMap Records. Although, since we record the StackMap Records in function order and in instruction order inside a function this has always been true, but that wasn’t intentional. This format shouldn’t change this, but it also isn’t something that we programmatically enforce. Do you depend on that behavi...

Hi @ll, over the past year we gained more experience with the patchpoint/stackmap/statepoint intrinsics and it exposed limitations in the stackmap format. The following proposal includes feedback and request from several interested parties and I would like to hear your feedback. Missing correlation between functions and stackmap records: Originally the client had to keep track...

...lipreames.com> wrote: > >> On 10/22/13 10:34 AM, Filip Pizlo wrote: >>> On Oct 22, 2013, at 9:53 AM, Philip R <listmail at philipreames.com> wrote: >>> >>>> On 10/17/13 10:39 PM, Andrew Trick wrote: >>>>> This is a proposal for adding Stackmaps and Patchpoints to LLVM. The >>>>> first client of these features is the JavaScript compiler within the >>>>> open source WebKit project. >>>>> >>>> I have a couple of comments on your proposal. None of these are major enough to prevent su...

On 10/22/13 10:34 AM, Filip Pizlo wrote: > On Oct 22, 2013, at 9:53 AM, Philip R <listmail at philipreames.com> wrote: > >> On 10/17/13 10:39 PM, Andrew Trick wrote: >>> This is a proposal for adding Stackmaps and Patchpoints to LLVM. The >>> first client of these features is the JavaScript compiler within the >>> open source WebKit project. >>> >> I have a couple of comments on your proposal. None of these are major enough to prevent submission. >> >> - As...

On 10/17/13 10:39 PM, Andrew Trick wrote: > This is a proposal for adding Stackmaps and Patchpoints to LLVM. The > first client of these features is the JavaScript compiler within the > open source WebKit project. > I have a couple of comments on your proposal. None of these are major enough to prevent submission. - As others have said, I'd prefer an experimental...

Sounds good. I will add that to the StackMap documentation when I update it for v2. —Juergen > On Jul 10, 2015, at 9:40 AM, Hal Finkel <hfinkel at anl.gov> wrote: > > No, but I've noticed that it is true in practice, and so I think that we should say something about it one way or another. Especially since, in switching t...

This is a proposal for adding Stackmaps and Patchpoints to LLVM. The first client of these features is the JavaScript compiler within the open source WebKit project. A Stackmap is a record of variable locations (registers and stack offsets) at a particular instruction address. A Patchpoint is an instruction address at which space is r...

Hi all, I don't know if I understand everything, but it seems really interesting for a runtime developer, stackmap and patchpoint looks perfect for a lot of optimizations :) I just have few question to verify if I understand what are these stackmaps and patchpoints, and I discuss the GC after. * I have a first very simple scenario (useful in vmkit). Let's imagine that we want to lazily build the layout of...

Dear All I need to read the stackmap section at runtime of the inspected application. I've read the documentation of stackmap and found this paragraph: "A JIT compiler can easily access this section by providing its own memory manager via the LLVM C API LLVMCreateSimpleMCJITMemoryManager(). When creating the memory manager,...

...gt;> On 10/22/13 10:34 AM, Filip Pizlo wrote: >>>>> On Oct 22, 2013, at 9:53 AM, Philip R <listmail at philipreames.com> wrote: >>>>> >>>>>> On 10/17/13 10:39 PM, Andrew Trick wrote: >>>>>>> This is a proposal for adding Stackmaps and Patchpoints to LLVM. The >>>>>>> first client of these features is the JavaScript compiler within the >>>>>>> open source WebKit project. >>>>>>> >>>>>> I have a couple of comments on your proposal. None of thes...

...rote: > > On Oct 23, 2013, at 5:27 PM, Philip Reames <listmail at philipreames.com > <mailto:listmail at philipreames.com>> wrote: > >>> The implementation of the two intrinsics is actually very similar. >>> In this case, the difference would be that llvm.stackmap does not >>> reserve space for patching, while llvm.patchpoint does. >> I'm slightly confused by this given that stackmap takes an argument >> indicating the number of nops to emit as well, but it's not worth >> debating this any more. Let's move on. We c...

...te: >>>> On Oct 22, 2013, at 9:53 AM, Philip R <listmail at philipreames.com >>>> <mailto:listmail at philipreames.com>> wrote: >>>> >>>>> On 10/17/13 10:39 PM, Andrew Trick wrote: >>>>>> This is a proposal for adding Stackmaps and Patchpoints to LLVM. The >>>>>> first client of these features is the JavaScript compiler within the >>>>>> open source WebKit project. >>>>>> >>>>> I have a couple of comments on your proposal. None of these are >>&g...

Hello, I'm currently looking into integrating the patchpoint and stackmap intrinsics into my pet project. In their current implementation (3.4 and trunk) the code to emit the additional section is only executed on Darwin. This is however quickly fixed: Add a ".llvm_stackmaps"-Section for ELF in MCObjectFileInfo and execute StackMaps::serializeToStackMapSection...