similar to: [LLVMdev] Beginner GCRoot Questions

On Sun, Apr 27, 2008 at 9:34 PM, Gordon Henriksen <gordonhenriksen at mac.com> wrote: > As for the compiler plugin interface, I suggest you ignore it > initially and use the provided shadow-stack option for the time being. > The shadow stack generates significantly suboptimal code, but will let > you avoid writing some platform-specific code. Instead, simply copy > the

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

Hi all, I'm toying around with LLVM's GC support and am struggling with the following. I have a little test snippet (a .ll file with IR) that uses llvm.gcroot to mark a GC root, but when I compile it to assembly with llc, followed by generating an executable with gcc I get an error related to exception handling: 22:40|melis at juggle2:~/projects/llvm_gc> cat root.ll %obj = type { i8*,

Hi Team, I'm working on a new pure functional language and I'm trying to add GC support for that. Because all vars are immutable, the IR that my frontend generates are all register based, i.e. no alloca, and no readmem, writemem unless accessing/constructing structs. If I use the traditional GC with gcroot intrinsic, it will need to emit more code for liveness tracking, storing the IR

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>

The linker is going off in the weeds trying to parse the dwarf unwind info. The CIE has: Leh_frame_common_begin0: .long 0 ## CIE Identifier Tag .byte 1 ## DW_CIE_VERSION .asciz "zLR" ## CIE Augmentation .byte 1 ## CIE Code Alignment Factor .byte 120 ## CIE Data Alignment

Hi, If I type define i32 @main() gc "shadow-stack" { entry: %0 = alloca i8* %1 = call i8* @malloc(i64 1) store i8* %1, i8** %0 call void @llvm.gcroot(i8** %0, i8* null) ret i32 0 } declare i8* @malloc(i64) declare void @llvm.gcroot(i8**, i8*) nounwind in test.ll and then do > llc test.ll > gcc test.s I get the error ld: in

This is an interesting problem. The GC code is being converted into 'invokes' instead of calls: define i32 @main() gc "shadow-stack" { entry: %gc_frame = alloca %gc_stackentry.main %gc_currhead = load %gc_stackentry** @llvm_gc_root_chain %gc_frame.map = getelementptr %gc_stackentry.main* %gc_frame, i32 0, i32 0, i32 1 store %gc_map* getelementptr inbounds (%gc_map.0*

Solved by using alloca i8*, i32 2 which the system seems happy enough with, and bitcasting to the actual type for rest of the code after llvm.gcroot. Not entirely sure if this is a terrible workaround or exactly the way gcroot is supposed to be used... On Wed, Nov 1, 2017 at 11:59 AM, Nikodemus Siivola < nikodemus at random-state.net> wrote: > I'm allocating { i8*, i32 } on the

On Apr 28, 2008, at 14:28, Lane Schwartz wrote: > On Sun, Apr 27, 2008 at 9:34 PM, Gordon Henriksen > <gordonhenriksen at mac.com> wrote: > >> As for the compiler plugin interface, I suggest you ignore it >> initially and use the provided shadow-stack option for the time >> being. The shadow stack generates significantly suboptimal code, >> but will

On 2008-04-27, at 21:29, Lane Schwartz wrote: > Hi guys, Hi Lane! This is a lot of questions. I'm not going to answer each individually, but will instead give general guidance to help you avoid the pain points… > I somehow need to inform the garbage collection runtime (my > copycollector.c) about my variables - specifically about gc roots. > So, after I get new memory

As I've mentioned on the mailing list a couple of times over the last few months, we've been working on an approach for supporting precise fully relocating garbage collection in LLVM. I am happy to announce that we now have a version of the code available for public view and discussion. https://github.com/AzulSystems/llvm-late-safepoint-placement

I'm allocating { i8*, i32 } on the stack, and would like to add this as a GC root, but I'm having trouble figuring this out. This works as expected: declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata) define i8* @bar(i8* %x) gc "shadow-stack" { entry: %objptr = alloca i8* call void @llvm.gcroot(i8** %objptr, i8* null) store i8* %x, i8** %objptr %v = load i8*, i8**

On Mon, Apr 21, 2008 at 8:13 PM, Gordon Henriksen <gordonhenriksen at mac.com> wrote: > > Hi Terence, > > > I think you're getting hung up on the details of the shadow stack collector. > The shadow stack is a GC that is possible within this framework, but of > course could be implemented without any special support. Its presence is > more misleading than anything

Hello LLVM community, We have been experimenting with using LLVM IR as a target for a managed (dynamically typed) language via an AOT compiler (including a backend for ARM). One main challenge is getting the garbage collection right: We would like to be able to implement a moving collector. This requires us to a) find a precise set of root pointers and b) be able to rewrite those pointers after

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

Hi, I currently write a LLVM backend for RPython, a programming language and toolchain to write dynamic language interpreters. For example, this toolchain powers PyPy, a fast Python interpreter. In the moment the implementation uses a shadowstack to manage garbage collection stack roots. To improve performance, I experimented with LLVM's garbage collection support. It works by marking a

Hi Terence, On 2008-04-20, at 20:08, Terence Parr wrote: > I've exhausted what I can do on my own to make a GC example bind > (usual googling, reading, playing, looking at source). I can't find > the shadow collector lib or perhaps the -l options needed to link my > sample (not even to point where I'm figuring out GC actually as I > can't link). The shadow

Howdy do LLVM folks! I've exhausted what I can do on my own to make a GC example bind (usual googling, reading, playing, looking at source). I can't find the shadow collector lib or perhaps the -l options needed to link my sample (not even to point where I'm figuring out GC actually as I can't link). Not sure this IR is correct but here is what I've been playing

I've been looking at inlining invokes / calls done through statepoints and I want to have a design discussion before I sink too much time into something I'll have to throw away. I'm not actively working on adding inlining support to patchpoints, but I suspect these issues are applicable towards teaching LLVM to inline through patchpoints as well. There are two distinct problems to