similar to: [LLVMdev] Alias analysis result

That's the reason I have defined getAnalysisUsage method. Isn't that the right way to do it? borya043 wrote: > > Hello everyone, > I am trying to find the alias between a store instruction's pointer > operand > and function arguments. This is the code, > virtual void getAnalysisUsage(AnalysisUsage &AU) const { > >

It contains the bitcode file(without any optimization) of the below program, void map(int *a) { *a=20; } int main(){ int *a=(int *)malloc(sizeof(int)); *a=15; map(a); return 0; } I want to check if the pointer operand of each store instruction aliases with the function's arguments. I have used below code for this, virtual void getAnalysisUsage(AnalysisUsage &AU) const {

I have used the follwing command, opt -load LLVComMan.so -ComMan -memdep -tbaa -mem2reg maptest.ll -S What option other than -mem2reg should be included in this case to get the right results? Does the order in which I specify the optimizations to be run make a difference? Duncan Sands wrote: > > Hi Adarsh, > >> I want to check if the values a and b in the program alias.

Hi Adarsh, > I have used the follwing command, > opt -load LLVComMan.so -ComMan -memdep -tbaa -mem2reg maptest.ll -S > What option other than -mem2reg should be included in this case to get the > right results? Does the order in which I specify the optimizations to be run > make a difference? what is in maptest.ll? Ciao, Duncan.

Yes. I've attached an updated patch that does the following: 1. Fixes the partialalias of globals/arguments 2. Enables partialalias for cases where nothing has been unified to a global/argument 3. Fixes that select was unifying the condition to the other pieces (the condition does not need to be processed :P). This was causing unnecessary aliasing. 4. Adds a regression test to

Hello all, I've read the documentation on alias analysis, and I think I understand it literally, but I just want to be sure, because it seems a bit strange. As it says on this web page <http://llvm.org/docs/AliasAnalysis.html>, The MayAlias response is used whenever the two pointers might refer to the > same object. > > The PartialAlias response is used when the two memory

I'm not exactly thrilled about the size of this diff -- I'll happily break it up into more manageable bits later today, because some of it is test fixes, another bit is a minor bug fix, etc. Important bit (WRT ConstantExpr): moved the loop body from buildGraphFrom into a new function. The body has a few tweaks to call constexprToEdges on all ConstantExprs that we encounter.

Hi Hal, Thank you for your email, that makes a lot of sense to me. I am working on some tools to use memory profiling to speculatively replace memory loads and stores with value forwarding in hardware implementations. I'd like to compare the profiled data to static alias analysis, so it would be super useful if there was a way to answer the questions about aliasing across backedges that

On Mar 31, 2010, at 3:13 PM, Owen Anderson wrote: > Some analyses, like Andersen's AA, do all their computation in their > runOnFunction(). Therefore, anything they depended on can be > destroyed after the runOnFunction() returns. What about AA itself? Would addRequired<AliasAnalysis> keep AliasAnalysis alive (but allow AliasAnalysis's dependencies to die)? >

On Thu, Aug 14, 2014 at 6:37 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > On Wed, Aug 13, 2014 at 8:35 PM, Jeremy Salwen <jeremysalwen at gmail.com> wrote: >> Hey Daniel, >> >> Thanks again for the help. I'm still a bit confused about the interface to >> the alias analysis. It seems like we are talking about different >> interfaces. >

Hi Daniel, Sorry for taking so long to respond. I spoke with a colleague more familiar with llvm who thought he could clear up my confusion, but we both came out of the conversation confused. I will try my best to explain the ambiguity. In an DAG, alias queries would be completely unambiguous. Every instruction would only be executed once, and every SSA value really would have a single static

Oh, sorry, i didn't rebase it when i changed the fix, you would have had to apply the first on top of the second. Here is one against HEAD On Wed, Jan 14, 2015 at 12:32 PM, Ana Pazos <apazos at codeaurora.org> wrote: > Daniel, your patch does not apply cleanly. Are you on the tip? > > The code I see there is no line if (QueryResult == MayAlias|| QueryResult == PartialAlias)

Oh, got it. Thanks for your explain. I misunderstand what getLocation does. If I would like to get the result of alias analysis referring to the stored value, what should I do in llvm? On 2/16/15 1:42 PM, Hal Finkel wrote: > ----- Original Message ----- >> From: "Haopeng Liu" <hyliuhp at gmail.com> >> To: "Hal Finkel" <hfinkel at anl.gov> >>

On Mar 31, 2010, at 2:53 PM, Trevor Harmon wrote: > I'm a bit confused about the distinction between addRequired and > addRequiredTransitive in AnalysisUsage. From PassAnalysisSupport.h: > > "REQUIRES (must be available when the pass runs), REQUIRES TRANSITIVE > (must be available throughout the lifetime of the pass)." > > The part that's confusing me

Hello LLVMdev, I’m using LLVM to do static analysis exclusively (without any code generation). To implement this analysis, I’m using multiple address spaces to disambiguate the purpose of the pointed memory. Since address spaces never alias in my model, I set on to implement an alias analysis pass that would exactly provide this information, as I’m seeing a couple of otherwise dead store that

Howdy, I'm working on writing a dependence analyzer (rather like what LoopDependenceAnalysis wants to be, except a bit more general). While this is a problem of many parts, I'm currently focusing on finding pairs of memory references to test for dependence. Consider this contrived C code: double test2(int n, double *restrict A, double *restrict B, bool flag) { if (flag) { A[0] =

Hi, I'm attempting to do some alias analysis & other memory inspection. I've written a pointless AliasAnalysis pass (that says everything must alias) to attempt to verify that my pass is getting picked up & run by opt. I run opt with: opt -load ~/Applications/llvm/lib/MustAA.so -must-aa -aa-eval -debug < trace0.ll I see my pass being initialized, but never being called (I see

On Jul 25, 2009, at 4:48 PM, Jakub Staszak wrote: > Hello, > > Sorry for my stupid mistakes. I hope that everything is fine now. > This patch fixes PR2218. There are no loads in example, however > "instcombine" changes memcpy() into store/load. Hi Jakub, Sorry for the delay, I'm way behind on code review. Generally if you respond quickly, I'll remember

On Thu, Jan 15, 2015 at 1:26 PM, Nick Lewycky <nlewycky at google.com> wrote: > On 15 January 2015 at 13:10, Daniel Berlin <dberlin at dberlin.org> wrote: > >> Yes. >> I've attached an updated patch that does the following: >> >> 1. Fixes the partialalias of globals/arguments >> 2. Enables partialalias for cases where nothing has been unified to

Hey Daniel, Thanks again for the help. I'm still a bit confused about the interface to the alias analysis. It seems like we are talking about different interfaces. Has it changed from what the documentation says? As far as I can tell, the documentation takes a specific Value*, and no information about which dynamic execution it is talking about. When you say "Right. It's a