1 //===- AliasSetTracker.cpp - Alias Sets Tracker implementation-------------===//
39     "alias-set-saturation-threshold", cl::Hidden, cl::init(250),
40     cl::desc("The maximum total number of memory locations alias "
43 /// mergeSetIn - Merge the specified alias set into this alias set.
46   assert(!AS.Forward && "Alias set is already forwarding!");  in mergeSetIn()
49   // Update the alias and access types of this set...  in mergeSetIn()
51   Alias  |= AS.Alias;  in mergeSetIn()
53   if (Alias == SetMustAlias) {  in mergeSetIn()
55     // find a must-alias pair between them, this set becomes a may alias.  in mergeSetIn()
61       Alias = SetMayAlias;  in mergeSetIn()
98   // If we've removed the saturated alias set, set saturated marker back to  in removeAliasSet()
107   assert(RefCount == 0 && "Cannot remove non-dead alias set from tracker!");  in removeFromTracker()
115     // If we cannot find a must-alias with any of the existing MemoryLocs, we  in addMemoryLocation()
116     // must downgrade to may-alias.  in addMemoryLocation()
120       Alias = SetMayAlias;  in addMemoryLocation()
140     Alias = SetMayAlias;  in addUnknownInst()
146   Alias = SetMayAlias;  in addUnknownInst()
151 /// alias one of the members in the set return the appropriate AliasResult.
161     AliasResult AR = AA.alias(MemLoc, ASMemLoc);  in aliasesMemoryLocation()
215 /// mergeAliasSetsForMemoryLocation - Given a memory location, merge all alias
216 /// sets that may alias it. Return the unified set, or nullptr if no aliasing
217 /// set was found. A known existing alias set for the pointer value of the
229     // An alias set that already contains a memory location with the same  in mergeAliasSetsForMemoryLocation()
233     // a known exception are undef pointer values, where alias(undef, undef) is  in mergeAliasSetsForMemoryLocation()
245       // If this is the first alias set ptr can go into, remember it.  in mergeAliasSetsForMemoryLocation()
262       // If this is the first alias set ptr can go into, remember it.  in findAliasSetForUnknownInst()
273   // The alias sets are indexed with a map from the memory locations' pointer  in getAliasSetFor()
275   // alias set associated with its pointer.  in getAliasSetFor()
286     // At this point, the AST is saturated, so we only have one active alias  in getAliasSetFor()
287     // set. That means we already know which alias set we want to return, and  in getAliasSetFor()
294     // Add it to the alias set it aliases.  in getAliasSetFor()
297     // Otherwise create a new alias set to hold the new memory location.  in getAliasSetFor()
302   // Register memory location in selected alias set.  in getAliasSetFor()
304   // Register selected alias set in pointer map (or ensure it is consistent with  in getAliasSetFor()
309                              "be in different alias sets");  in getAliasSetFor()
367     return; // doesn't alias anything  in addUnknown()
439          "Merging AliasSetTracker objects with different Alias Analyses!");  in add()
441   // Loop over all of the alias sets in AST, adding the members contained  in add()
442   // therein into the current alias sets.  This can cause alias sets to be  in add()
446       continue; // Ignore forwarding alias sets  in add()
448     // If there are any call sites in the alias set, add them to this AST.  in add()
452     // Loop over all of the memory locations in this alias set.  in add()
463   // Collect all alias sets, so that we can drop references with impunity  in mergeAllAliasSets()
474   AliasAnyAS->Alias = AliasSet::SetMayAlias;  in mergeAllAliasSets()
502     // elements to alias each-other.  in addMemoryLocation()
515   OS << (Alias == SetMustAlias ? "must" : "may") << " alias, ";  in print()
555   OS << "Alias Set Tracker: " << AliasSets.size();  in print()
558   OS << " alias sets for " << PointerMap.size() << " pointer values.\n";  in print()
580   OS << "Alias sets for function '" << F.getName() << "':\n";  in run()