Preston Briggs <preston.briggs at gmail.com> writes:> On Mon, Feb 6, 2012 at 12:13 PM, Sebastian Pop <spop at codeaurora.org> wrote: >> [many things, but I'm only going to focus on one of them] >> Would you consider using Polly http://polly.grosser.es to avoid >> writing this code? > > My impression is that Polly (and polyhedral analysis generally) > doesn't do want I want. But I'm happy to talk about it 'cause I might > be wrong.I think you are right. However, Polly might be useful as one layer in a dependence tester. I haven't thought too deeply about it but polyhedral analysis can do some pretty cool things. I'm really not clear on what something like CLooG would do with the linear recurrence example. But the analysis side of Polly might be quite useful. -Dave
On 02/07/2012 05:12 PM, David A. Greene wrote:> > Preston Briggs<preston.briggs at gmail.com> writes: > >> On Mon, Feb 6, 2012 at 12:13 PM, Sebastian Pop<spop at codeaurora.org> wrote: >>> [many things, but I'm only going to focus on one of them] >>> Would you consider using Polly http://polly.grosser.es to avoid >>> writing this code? >> >> My impression is that Polly (and polyhedral analysis generally) >> doesn't do want I want. But I'm happy to talk about it 'cause I might >> be wrong. > > I think you are right. However, Polly might be useful as one layer in a > dependence tester. I haven't thought too deeply about it but polyhedral > analysis can do some pretty cool things. > > I'm really not clear on what something like CLooG would do with the > linear recurrence example. But the analysis side of Polly might be > quite useful.CLooG does not do anything to it. It is just a layer to lower a high level abstraction back to imperative control flow. The question her is, if the linear recurrence example and similar code can be easily optimized within the high level polyhedral abstraction without having to rewrite on the LLVM-IR layer. If you provide the expected output, I may give this a try. Tobi
On Tue, Feb 7, 2012 at 8:17 AM, Tobias Grosser <tobias at grosser.es> wrote:>The question her is, > if the linear recurrence example and similar code can be easily optimized > within the high level polyhedral abstraction without having to rewrite on > the LLVM-IR layer. If you provide the expected output, I may give this a > try.I expect it's more of a research problem, versus simply coding. I've looked some, and don't find anything about handling recurrences and reductions inside a polyhedral framework. But more eyes may see more... The paper I refer to for solving these is here: http://www.springerlink.com/content/x1346405k3834474/ Preston