similar to: [LLVMdev] Alias Analysis Changes

Hi together, i want to create a map containing a set of aliases for each value. For example, for a code like: int main() { int i; int *p1 = &i; int *p2 = &i; return 0; } the map should contain something like: {i --> (p1, p2), ..... } For that, i do followings in my pass: AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); AliasSetTracker *tracker =

Hello, I got a strange result when I used alias analysis DSAA, can you tell what is wrong? 1. The following is the primary body of my pass "fps.cpp": AliasAnalysis *AA = &getAnalysis<AliasAnalysis>(); AliasSetTracker AST(*AA); for (Module::iterator fi = M.begin(), fe = M.end(); fi != fe; ++fi ) for (Function::iterator bi = fi->begin(), be = fi->end(); bi

Hi, Your problem is that the function arguments, which are makes as noalias, are not being directly used as the base objects of the array accesses: > %v0.addr = alloca float*, align 8 > %v1.addr = alloca float*, align 8 > %v2.addr = alloca float*, align 8 > %t.addr = alloca float*, align 8 ... > store float* %v0, float** %v0.addr, align 8 > store float* %v1, float** %v1.addr,

Oh, your meaning is pointers in a aliasset have equal address logically? But I think that two pointers are alias means they point to a same memory object, so if pointers "p" and "q" are alias, it seem as p = q, not &p = &q. Another question is about "forwarding". "AliasSet[XXXX, 0] may alias, Mod/Ref forwarding to YYYY" (XXXX != YYYY) means the

Hi, LLVM community: I found basicaa seems not to tell must-not-alias for __restrict__ arguments in c/c++. It only compares two pointers and the underlying objects they point to. I wonder how clang does alias analysis for c/c++ keyword restrict. let assume we compile the following code: $cat myalias.cc float foo(float * __restrict__ v0, float * __restrict__ v1, float * __restrict__ v2, float *

Hi all, I have a problem with alias aliasing results returned by the alias set tracker and the alias analysis evaluator. so i call opt tool to run my module with the following options "-anders-aa -aa-eval -print-alias-sets -print-all-alias-modref-info" i use 2 classes to print alias analysis, the AliasSetTracket and AliasAnalysisEvaluator. but they give different results. here is a

Hi again! Replying in chronological order: > On Thu, Jul 9, 2020 at 6:51 PM Shuai Wang <wangshuai901 at gmail.com > <mailto:wangshuai901 at gmail.com>> wrote: > > Hey Matt, > > That's awesome. Thank you very much for all the information and > clarification! Just a few follow up questions. Could you kindly shed > some lights on it? Thank

Hi all, I'm working on an Pass that needs results from an alias analysis. More precisely, I'd like to use the AliasSetTracker class. I added AU.addRequired<AliasAnalysis>(); at the right place. I know the defaut AliasAnalysis does nothing and I currently get everything as "may" aliases. My tool is standalone and does not use opt, so I can't simply do something like

On 01/27/2016 07:53 AM, Daniel Berlin wrote: > > > On Wed, Jan 27, 2016 at 1:27 AM, Roman Gareev <gareevroman at gmail.com > <mailto:gareevroman at gmail.com>> wrote: > > Thank you for the idea! Could you please explain it? > > > Which part are you having trouble with, so i know where to concetrate? > > If I’m not > mistaken, you advise

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

Hi! On 7/10/2020 07:17, Shuai Wang wrote: > Hello! > > Thank you very much! Yes, that makes a lot of sense to me. However, just > want to point out two things that are still unclear: > > 1. The output contains a alias set of only one element, for instance: > "must alias, Mod       Pointers: (i32* %y, LocationSize::precise(4))" > > This one really confused

I'm current facing an issue related to AliasSetTracker/LICM: the transitive closure of the alias sets is materially more conservative than individual aliasing queries and this conservatism leads to generally worse optimization in LICM. For instance, consider this module: declare i32 @only_reads() readonly declare void @escape(i32*, i32*, i32*) define void @f(i32 %count) { entry: %a =

Thank you, Chris. The following is my comprehension about the AliasSetTracker, please correct me. 1. A aliasset "as" represents a memory object, and all pointer "p" in "as" represent values with the type of pointer that may/must point to the memory object "as". 2. If a aliasset is "forwarding", it has been merged to another aliasset and I

On 06/12/2015 04:14 PM, Andrew Trick wrote: >> On Jun 12, 2015, at 2:52 PM, Philip Reames <listmail at philipreames.com> wrote: >> >> >> >> On 06/12/2015 02:10 PM, Andrew Trick wrote: >>>> On Jun 12, 2015, at 2:06 PM, Daniel Berlin <dberlin at dberlin.org> wrote: >>>> >>>> On Fri, Jun 12, 2015 at 2:03 PM, Andrew Trick

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)

Hi all, I have a problem with alias aliasing results returned by the alias set tracker and the alias analysis evaluator. so i call opt tool to run my module with the following options "-anders-aa -aa-eval -print-alias-sets -print-all-alias-modref-info" i use 2 classes to print alias analysis, the AliasSetTracket and AliasAnalysisEvaluator. but they give different results. here is a

On Fri, Sep 14, 2018 at 4:25 PM Philip Reames <listmail at philipreames.com> wrote: > This is going OT from the original thread, but, what the heck... > Sorry, not my intention, I was just giving another reason why getting promotion done in LICM differently would be helpful. > Alina, can you explain the challenge with implementing promotion over > MemorySSA? On the surface, it

Thank you for the idea! Could you please explain it? If I’m not mistaken, you advise to insert the unknown insts of an every AS from AliasSetTracker::add(const AliasSetTracker &AST) into a smallptrset and consequently append it to merged alias sets from AliasSetTracker::findAliasSetForUnknownInst. I think that Philip proposed something similar to your approach in

Yes, it is a pass. Here is a very general overview of the file structure as far as the AA is concerned. LLVM is not my strong-suit, I do hardware simulators, not compilers. using namespace llvm; char RelRecovery::ID = 0; static RegisterPass<RelRecovery> X("relRecovery", "Reliability transformation for lightweight recovery"); void

Dear llvm contributors, Could you please advise me how to skip checks, which are performed in AliasSet::aliasesUnknownInst, of unknown instructions from different alias sets of an alias set tracker that is a parameter of ‘AliasSetTracker::add(const AliasSetTracker &AST)’? If this wasn’t available at the moment and someone could review me, I would try to implement it. A temporary patch can be