search for: globalmodref

...onceptually it could make sense as a separate analysis. I think Shuxin is pointing out that using a flag is a more straightforward approach, simpler to engineer, and has some potential benefits (although not huge benefits). Either way, it could still make sense to factor the logic across GlobalOpt/GlobalModRef if it’s not too messy. -Andy -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20131029/2ff4cdc4/attachment.html>

>> 2) is just for being pedantic :-) >> >> One might otherwise argue in this snippet, x apparently does not have >> its addr taken, >> however, it's illegal to say that "x" and "*p" don't alias. > Wait, really? I thought that "volatile static int x" just meant that the value of x was volatile; not that 'x' might

Hello I am trying to enable globalsmodref-aa by default. globalmodref-aa is a ModulePass and therefore can be invalidated and need to be rerun. I see globalsmodref-aa is enabled in LTO passmanager by adding the analysis pass explicitly. I wonder whether globalsmodref-aa can be enabled/run based on pass dependencies, i.e. those indicated in getAnalysisUsage(). Than...

...e it chains onto another pass (e.g. ds- aa) to have a go at. > This will continue until it finds a definite answer or runs out of AA > passes. Hi David, At this level, I can understand how it works. I was confused because I have been looking at the source code for implementing them. All the globalmodref, scev-aa, steenaa and ds-aa are only subclasses of the AliasAnalysis class, so I cannot see how ds-aa can automatically call basicaa. What I guess is that the order of the flags matters. This means if I want to chain a simple AA (say, -basicaa) and a fancier one (ds-aa), I should add the -basicaa...

Jianzhou Zhao <jianzhou <at> seas.upenn.edu> writes: > At this level, I can understand how it works. I was confused because I > have been looking at the source code for implementing them. All the > globalmodref, scev-aa, steenaa and ds-aa are only subclasses of the > AliasAnalysis class, so I cannot see how ds-aa can automatically call > basicaa. There's some magic in the pass registration which adds them with a `previous' link between AA passes, so the base AliasAnalysis class ends up ca...

Ryan's second question should be more generally phrased for the entire AliasAnalysis interface, not just DSA: will it work to ask alias queries or mod/ref queries for a pair of pointers or a pair of instructions in two different functions? --Vikram http://www.cs.uiuc.edu/~vadve http://llvm.cs.uiuc.edu/ On Oct 16, 2006, at 1:45 PM, Chris Lattner wrote: > On Mon, 16 Oct 2006, Ryan

Before the fix, the compiler may simply return 'noalias' for cases it can not really prove to be noalias, but actually correct by luck (or even wrong noalias, but does not result in miscompile). It would be useful to find out the set of missed noalias queries from GlobalModRef with your benchmark and examine if there is some improvement can be done. David On Fri, Jul 17, 2015 at 6:32 AM, Evgeny Astigeevich < Evgeny.Astigeevich at arm.com> wrote: > Yes, the regression is stable. I double checked this. A full benchmark > run consists of at least 10 sub-run...

Jianzhou Zhao <jianzhou <at> seas.upenn.edu> writes: > The documents say that all the aa analysis are chained, and give an > example like opt -basicaa -ds-aa -licm. In this case, does ds-aa > automatically call basicaa for the case when ds-aa can only return > MayAlias? This looks magic to me. Is this handled by AnalysisGroup > magically? As I understand it, the

On Tue, Jan 3, 2012 at 4:55 PM, Chris Lattner <clattner at apple.com> wrote: > On Jan 3, 2012, at 1:53 PM, Jianzhou Zhao wrote: >> I see. I asked the question because LLVM provides several alias >> analysis, and I was wondering how to decide which one should be used >> for compiling most programs. >> >> I think the basicaa is the default one, but by looking

Hey, thanks for benchmarking. How stable is the 2% regression? Michael ran some benchmarks with GlobalsModRef completely disabled and the only differences were in the noise. This was a complete spec2k6 run along with some others. Based on the number of benchmarks run there, I'm going to go ahead and submit these patches, but if you can clarify the impact here, we can look at potentially some