search for: bdds

...gt;increase. > Trust me here, you don't want to use a non-sparse >bitmap. > BDD's are acceptable, but are about a 2x slowdown. With >various > optimizations that are going to be published in the next >few months, > you can get bitmaps to use just as little memory as BDDs >would, while > being much faster. > > Anyway, i've attached the patch. > The two new .h files go include/llvm/ADT > the two new .cc files go into lib/VMCore > > Of course, you can put them wherever you really want.

...exes, like gcc's, you could just use positive and negative numbers). This would need to be abstracted properly so that the union/intersect/diff/iterators operated only on the proper portions of the bitset. I'm not sure why you'd want to do this as opposed to keeping two bitsets, using bdds, or using sparse bitmaps. > > > --- 13年3月21日，周四, Daniel Berlin <dberlin at dberlin.org> 写道： > >> 发件人: Daniel Berlin <dberlin at dberlin.org> >> 主题: Re: [LLVMdev] How to describe a pointer that points to All memory(include global memory, heap, stack)? >> 收...

Hi, Daniel, thank you for your advice. Yes, ALL_MEMORY points to ALL_MEMORY. We use MD(memory descriptor) to abstract a memory location.  MD contains 4 main fields: id, base, offset, size. For these special MD (ALL_MEMORY, GLOBAL_MEMORY, STACK_MEMORY, HEAP_MEMORY),  we give them id 1, 2, 3, 4, that means MD1 is ALL_MEMORY, MD2 is GLOBAL_MEMORY, the same goes for the rest.  Then we maintain a

...all. My personal feeling (backed up by results from some other research groups, e.g. Chen et al in ISPAN'02 and Nystrom et al in PASTE'04) is that a context-sensitive heap model is critical for getting the maximum benefit from a context-sensitive pointer analysis, and I don't know that BDDs, at least as currently used, are the right approach for this. I was impressed by a completely different approach, described by Nystrom et al in SAS'04 and Nystrom's PhD thesis, for doing context-sensitive pointer analysis for C with a context-sensitive heap model. Like Whaley and Lam, and...

On Wed, Mar 5, 2008 at 3:44 AM, Xi Wang <xi.wang at gmail.com> wrote: > On Mon, Mar 3, 2008 at 6:55 PM, Richard Warburton > > <richard.warburton at gmail.com> wrote: > > > > No > > > I've got a BDD based version of andersen's around already (uncommitted). > > > It's slower in time (by a factor of 8 or so), but very slightly (1-2

...proporations, and about a 10x memory increase. Trust me here, you don't want to use a non-sparse bitmap. BDD's are acceptable, but are about a 2x slowdown. With various optimizations that are going to be published in the next few months, you can get bitmaps to use just as little memory as BDDs would, while being much faster. Anyway, i've attached the patch. The two new .h files go include/llvm/ADT the two new .cc files go into lib/VMCore Of course, you can put them wherever you really want. -------------- next part -------------- A non-text attachment was scrubbed... Name: bitmap....

...VM project. In terms of which algorithm to actually implement, I am considering implementing a BDD based algorithm, possible candidate include: Whaley + Lam [2] which simply clones points on the call-graph to generate different contexts and then performs a context insensitive analysis. This uses BDDs to reduce memory consumption. Zhu [3] Which utilises a BDD base approach for a custom context sensitive, flow insenstitive algorithm, Were I to use a BDD based approach, I would undoubtedly rely on an existing implementation, for example buddy[4], rather than implementing my own. The opinions of a...