MC: Remove implicit ilist iterator conversions, NFC

[oota-llvm.git] / lib / Analysis / LoopAccessAnalysis.cpp

diff --git a/lib/Analysis/LoopAccessAnalysis.cpp b/lib/Analysis/LoopAccessAnalysis.cpp
index b931589ed04340eeb410fb14ca600c9fb9a31fcf..14c3c57e4c96d1b670af120f21f8528efa442ccb 100644 (file)
--- a/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/lib/Analysis/LoopAccessAnalysis.cpp
@@ -1593,10 +1593,13 @@ static Instruction *getFirstInst(Instruction *FirstInst, Value *V,
   return nullptr;
 }
 
-/// \brief IR Values for the lower and upper bounds of a pointer evolution.
+/// \brief IR Values for the lower and upper bounds of a pointer evolution.  We
+/// need to use value-handles because SCEV expansion can invalidate previously
+/// expanded values.  Thus expansion of a pointer can invalidate the bounds for
+/// a previous one.
 struct PointerBounds {
-  Value *Start;
-  Value *End;
+  TrackingVH<Value> Start;
+  TrackingVH<Value> End;
 };
 
 /// \brief Expand code for the lower and upper bound of the pointer group \p CG
@@ -1668,6 +1671,8 @@ std::pair<Instruction *, Instruction *> LoopAccessInfo::addRuntimeChecks(
 
   for (const auto &Check : ExpandedChecks) {
     const PointerBounds &A = Check.first, &B = Check.second;
+    // Check if two pointers (A and B) conflict where conflict is computed as:
+    // start(A) <= end(B) && start(B) <= end(A)
     unsigned AS0 = A.Start->getType()->getPointerAddressSpace();
     unsigned AS1 = B.Start->getType()->getPointerAddressSpace();
 
@@ -1797,7 +1802,7 @@ bool LoopAccessAnalysis::runOnFunction(Function &F) {
   SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
   auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
   TLI = TLIP ? &TLIP->getTLI() : nullptr;
-  AA = &getAnalysis<AliasAnalysis>();
+  AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
   DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
   LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
 
@@ -1806,7 +1811,7 @@ bool LoopAccessAnalysis::runOnFunction(Function &F) {
 
 void LoopAccessAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
     AU.addRequired<ScalarEvolutionWrapperPass>();
-    AU.addRequired<AliasAnalysis>();
+    AU.addRequired<AAResultsWrapperPass>();
     AU.addRequired<DominatorTreeWrapperPass>();
     AU.addRequired<LoopInfoWrapperPass>();
 
@@ -1818,7 +1823,7 @@ static const char laa_name[] = "Loop Access Analysis";
 #define LAA_NAME "loop-accesses"
 
 INITIALIZE_PASS_BEGIN(LoopAccessAnalysis, LAA_NAME, laa_name, false, true)
-INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
+INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)