[DA][NewPM] Handle transitive dependencies in the new-pm version of DA

[philip.pfaffe]

Summary

The analysis result of DA caches pointers to AA, SCEV, and LI, but it
never checks for their invalidation. Fix that.

[philip.pfaffe]

Rebase onto D56386 and add testcase for DA invalidation

[dmgreen]

Some of D56386 seems to be mixed up in here I think?

From what I can see of the new code, the invalidate looks a lot like the that from AA, so looks sensible. Maybe leave this open a day or so for other timezones to check, but LGTM.

[philip.pfaffe]

Rebase (and drop changes from D56386 that snuck in).

llvm/include/llvm/Analysis/DependenceAnalysis.h

template <typename T> class ArrayRef;
   /// DependenceInfo - This class is the main dependence-analysis driver.
   ///
   class DependenceInfo {
   public:
     DependenceInfo(Function *F, AliasAnalysis *AA, ScalarEvolution *SE,
                    LoopInfo *LI)
         : AA(AA), SE(SE), LI(LI), F(F) {}
 
+    /// Handle transitive invalidation when the cached analysis results go away.
+    bool invalidate(Function &F, const PreservedAnalyses &PA,
+                    FunctionAnalysisManager::Invalidator &Inv);
+
     /// depends - Tests for a dependence between the Src and Dst instructions.
     /// Returns NULL if no dependence; otherwise, returns a Dependence (or a
     /// FullDependence) with as much information as can be gleaned.
     /// The flag PossiblyLoopIndependent should be set by the caller
     /// if it appears that control flow can reach from Src to Dst
     /// without traversing a loop back edge.
     std::unique_ptr<Dependence> depends(Instruction *Src,
                                         Instruction *Dst,

llvm/lib/Analysis/DependenceAnalysis.cpp

for (unsigned VI : BV.set_bits()) {
     dbgs() << VI;
     if (BV.find_next(VI) >= 0)
       dbgs() << ' ';
   }
   dbgs() << "}\n";
 }
 #endif
 
+bool DependenceInfo::invalidate(Function &F, const PreservedAnalyses &PA,
+                                FunctionAnalysisManager::Invalidator &Inv) {
+  // Check if the analysis itself has been invalidated.
+  auto PAC = PA.getChecker<DependenceAnalysis>();
+  if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<Function>>())
+    return true;
+
+  // Check transitive dependencies.
+  return Inv.invalidate<AAManager>(F, PA) ||
+         Inv.invalidate<ScalarEvolutionAnalysis>(F, PA) ||
+         Inv.invalidate<LoopAnalysis>(F, PA);
+}
+
 // depends -
 // Returns NULL if there is no dependence.
 // Otherwise, return a Dependence with as many details as possible.
 // Corresponds to Section 3.1 in the paper
 //
 //            Practical Dependence Testing
 //            Goff, Kennedy, Tseng
 //            PLDI 1991