similar to: [LLVMdev] Garbage collection questions

On Mon, 27 Feb 2006, Sandro Magi wrote: > Couple of questions: Ok, it's been a long while since I've worked on the GC stuff, but I'll try to help :) > 1. void llvm_gc_write(void *V, void *ObjPtr, void **FieldPtr) > > I haven't seen an adequate explanation of these, but I'm guessing: > void *V: value being written to the field > void *ObjPtr: current value

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

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

Ok, that makes sense :). , Tobias On Wed, 21 Jul 2004, Chris Lattner wrote: > On Wed, 21 Jul 2004, Tobias Nurmiranta wrote: > > > void *llvm_gc_read(void *ObjPtr, void **FieldPtr) { > > > return *FieldPtr; > > > } > > > > Hm, but doesn't FieldPtr need to be calculated target-specific in those > > cases? > > For the field pointer, one

On Wed, 21 Jul 2004, Tobias Nurmiranta wrote: > > void *llvm_gc_read(void *ObjPtr, void **FieldPtr) { > > return *FieldPtr; > > } > > Hm, but doesn't FieldPtr need to be calculated target-specific in those > cases? For the field pointer, one could use the getelementptr instruction: %pairty = { sbyte, sbyte, int* } %pairPtr = ... %fieldptr = getelementptr

On 2/27/06, Chris Lattner <sabre at nondot.org> wrote: > > 1. void llvm_gc_write(void *V, void *ObjPtr, void **FieldPtr) > > > > I haven't seen an adequate explanation of these, but I'm guessing: > > void *V: value being written to the field > > void *ObjPtr: current value of the field (ie. ObjPtr == *FieldPtr > > upon entry to llvm_gc_write)

Couple of questions: 1. void llvm_gc_write(void *V, void *ObjPtr, void **FieldPtr) I haven't seen an adequate explanation of these, but I'm guessing: void *V: value being written to the field void *ObjPtr: current value of the field (ie. ObjPtr == *FieldPtr upon entry to llvm_gc_write) void **FieldPtr: address of the field being written 2. The current semispace collector includes

On Sun, 2008-04-27 at 22:34 -0400, Gordon Henriksen wrote: > On 2008-04-27, at 21:29, Lane Schwartz wrote: > > Since this is a simple copying collector, the functions llvm_gc_read > > and llvm_gc_write won't really do much: > > void *llvm_gc_read(void *ObjPtr, void **FieldPtr) { return > > *FieldPtr; } > > void llvm_gc_write(void *V, void *ObjPtr, void

Ok, here's the new patch. (Please tell me if I shouldn't mail patches directly on the mailing list.) While I was editing LowerGC.cpp I made a little test (not part of this patch, but the diff with LowerGC.cpp in cvs is attached). I've added a new intrinsic called llvm.gcroot_value(sbyte*, sbyte*), which takes a pointer directly instead and transforms it into an alloca. The idea is the

On Wed, 21 Jul 2004, Tobias Nurmiranta wrote: > > Hi, I'm thinking out loud, please give me some feedback. > > Regarding llvm.gcread and llvm.gcwrite, wouldn't it be nicer if they are > implemented as: > > llvm.gcread(sbyte** object, uint offset) > llvm.gcwrite(sbyte* data, sbyte** object, uint offset) > > Where you also have the offset into the object. In

Again, sorry for the delay. :( On Thu, 9 Mar 2006, Sandro Magi wrote: > I've written a reference-counting garbage collector for LLVM, but I'm > still unclear on a few things. Cool! > The following piece of code that appears on > http://llvm.cs.uiuc.edu/docs/GarbageCollection.html is unclear: > > ;; As the pointer goes out of scope, store a null value into > ;;

On Apr 20, 2008, at 6:52 PM, Gordon Henriksen wrote: > On 2008-04-20, at 21:05, Terence Parr wrote: > >> On Apr 20, 2008, at 5:36 PM, Gordon Henriksen wrote: >> >>> Since the semispace heap doesn't actually work (it's an example, >>> at best), I suggest you simply copy the stack visitor into your >>> project; it's only a dozen lines of

On 3/14/06, Chris Lattner <sabre at nondot.org> wrote: > > > How exactly does this indicate X is no longer live? Is this internal > > code-generator logic/magic? > > No, this just prevents the GC from accidentally thinking that *X is live > through that pointer. The collector cannot distinguish between > pointers that are out of scope from those that aren't,

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 else. Taking a step back, the concepts are: llvm.gcroot instructs the code generator --> My GC needs to be able to

On Wed, 21 Jul 2004, Chris Lattner wrote: > > Yes, this makes a tremendous amount of sense. Do you think you could > prepare some patches to make this happen? If you have any questions, feel > free to ask :) Ok, a patch[1] is attached. I didn't care to coerce the offset, since I assume that it is an uint, but maybe I should? Hopefully I've understood the llvm source

On Wed, 21 Jul 2004, Tobias Nurmiranta wrote: > [1] I'm kind of newbie of cvs, but I did: > "cvs -z3 -d :pserver:anon at llvm-cvs.cs.uiuc.edu:/var/cvs/llvm diff llvm > gcpatch" That patch is well formed. You did exactly the right thing. :) > Ok, a patch[1] is attached. I didn't care to coerce the offset, since I > assume that it is an uint, but maybe I should?

On Wed, 21 Jul 2004, Chris Lattner wrote: > On Wed, 21 Jul 2004, Tobias Nurmiranta wrote: > > This will work, but it would be better to take two pointers in instead of > a pointer and offset. This allows the front-end to emit target-generic > code instead of target-specific code (where it would have to know the > offset to the field). To be more specific, llvm_gc_read should

On Apr 28, 2008, at 10:50, Jonathan S. Shapiro wrote: > On Sun, 2008-04-27 at 22:34 -0400, Gordon Henriksen wrote: >> On 2008-04-27, at 21:29, Lane Schwartz wrote: >>> Since this is a simple copying collector, the functions >>> llvm_gc_read and llvm_gc_write won't really do much: >>> void *llvm_gc_read(void *ObjPtr, void **FieldPtr) { return

On Sep 2, 2007 5:31 AM, Gordon Henriksen <gordonhenriksen at mac.com> wrote: > Hi Talin, > > On Sep 2, 2007, at 04:54, Talin wrote: > > > I've been looking through the documentation (http://llvm.org/docs/ > > GarbageCollection.html) on how to implement a garbage collector for > > LLVM and there's a couple of things that I don't quite understand. >

Hello, I want to add garbage collection support to a compiler with a llvm backend, using the shadow-stack compiler plugin. I read the GC tutorial in the LLVM documentation, and the paper about shadow-stacks. Im currently adding intrinsics to my generated llvm code, and trying to write code to connected it to my (existing) garbage collector library. Im not sure yet how everything fits together.