[Polly][PATCH] Use reference to clarify pointer can never be null

[Tobias Grosser]

---
 include/polly/ScopDetection.h  |  2 +-
 include/polly/TempScopInfo.h   |  2 +-
 lib/Analysis/ScopDetection.cpp |  7 ++-----
 lib/Analysis/ScopInfo.cpp      |  4 ++--
 lib/Analysis/TempScopInfo.cpp  | 16 +++++++---------
 5 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/include/polly/ScopDetection.h b/include/polly/ScopDetection.h
index 492634a..47edc2c 100644
--- a/include/polly/ScopDetection.h
+++ b/include/polly/ScopDetection.h
@@ -334,7 +334,7 @@ public:
   bool isMaxRegionInScop(const Region &R, bool Verify = true) const;
 
   /// @brief Return the set of loops in non-affine subregions for @p R.
-  const BoxedLoopsSetTy *getBoxedLoops(const Region *R) const;
+  const BoxedLoopsSetTy &getBoxedLoops(const Region *R) const;
 
   /// @brief Return true if @p SubR is a non-affine subregion in @p ScopR.
   bool isNonAffineSubRegion(const Region *SubR, const Region *ScopR) const;
diff --git a/include/polly/TempScopInfo.h b/include/polly/TempScopInfo.h
index f37b052..6c1d62b 100644
--- a/include/polly/TempScopInfo.h
+++ b/include/polly/TempScopInfo.h
@@ -266,7 +266,7 @@ class TempScopInfo : public FunctionPass {
   /// @return     The IRAccess to describe the access function of the
   ///             instruction.
   IRAccess buildIRAccess(Instruction *Inst, Loop *L, Region *R,
-                         const ScopDetection::BoxedLoopsSetTy *BoxedLoops);
+                         const ScopDetection::BoxedLoopsSetTy &BoxedLoops);
 
   /// @brief Analyze and extract the cross-BB scalar dependences (or,
   ///        dataflow dependencies) of an instruction.
diff --git a/lib/Analysis/ScopDetection.cpp b/lib/Analysis/ScopDetection.cpp
index a0385a6..28ea895 100644
--- a/lib/Analysis/ScopDetection.cpp
+++ b/lib/Analysis/ScopDetection.cpp
@@ -1037,12 +1037,9 @@ bool ScopDetection::isNonAffineSubRegion(const Region *SubR,
   return NonAffineSubRegionMap.lookup(ScopR).count(SubR);
 }
 
-const ScopDetection::BoxedLoopsSetTy *
+const ScopDetection::BoxedLoopsSetTy &
 ScopDetection::getBoxedLoops(const Region *R) const {
-  auto BLMIt = BoxedLoopsMap.find(R);
-  if (BLMIt == BoxedLoopsMap.end())
-    return nullptr;
-  return &BLMIt->second;
+  return BoxedLoopsMap.find(R)->second;
 }
 
 void polly::ScopDetection::verifyRegion(const Region &R) const {
diff --git a/lib/Analysis/ScopInfo.cpp b/lib/Analysis/ScopInfo.cpp
index 911c662..3583bcc 100644
--- a/lib/Analysis/ScopInfo.cpp
+++ b/lib/Analysis/ScopInfo.cpp
@@ -1630,14 +1630,14 @@ bool Scop::buildAliasGroups(AliasAnalysis &AA) {
 static unsigned getMaxLoopDepthInRegion(const Region &R, LoopInfo &LI,
                                         ScopDetection &SD) {
 
-  const ScopDetection::BoxedLoopsSetTy *BoxedLoops = SD.getBoxedLoops(&R);
+  const ScopDetection::BoxedLoopsSetTy &BoxedLoops = SD.getBoxedLoops(&R);
 
   unsigned MinLD = INT_MAX, MaxLD = 0;
   for (BasicBlock *BB : R.blocks()) {
     if (Loop *L = LI.getLoopFor(BB)) {
       if (!R.contains(L))
         continue;
-      if (BoxedLoops && BoxedLoops->count(L))
+      if (BoxedLoops.count(L))
         continue;
       unsigned LD = L->getLoopDepth();
       MinLD = std::min(MinLD, LD);
diff --git a/lib/Analysis/TempScopInfo.cpp b/lib/Analysis/TempScopInfo.cpp
index 7bfd564..0fa861b 100644
--- a/lib/Analysis/TempScopInfo.cpp
+++ b/lib/Analysis/TempScopInfo.cpp
@@ -214,7 +214,7 @@ extern MapInsnToMemAcc InsnToMemAcc;
 
 IRAccess
 TempScopInfo::buildIRAccess(Instruction *Inst, Loop *L, Region *R,
-                            const ScopDetection::BoxedLoopsSetTy *BoxedLoops) {
+                            const ScopDetection::BoxedLoopsSetTy &BoxedLoops) {
   unsigned Size;
   Type *SizeType;
   enum IRAccess::TypeKind Type;
@@ -244,13 +244,11 @@ TempScopInfo::buildIRAccess(Instruction *Inst, Loop *L, Region *R,
 
   // Check if the access depends on a loop contained in a non-affine subregion.
   bool isVariantInNonAffineLoop = false;
-  if (BoxedLoops) {
-    SetVector<const Loop *> Loops;
-    findLoops(AccessFunction, Loops);
-    for (const Loop *L : Loops)
-      if (BoxedLoops->count(L))
-        isVariantInNonAffineLoop = true;
-  }
+  SetVector<const Loop *> Loops;
+  findLoops(AccessFunction, Loops);
+  for (const Loop *L : Loops)
+    if (BoxedLoops.count(L))
+      isVariantInNonAffineLoop = true;
 
   bool IsAffine = !isVariantInNonAffineLoop &&
                   isAffineExpr(R, AccessFunction, *SE, BasePointer->getValue());
@@ -287,7 +285,7 @@ void TempScopInfo::buildAccessFunctions(Region &R, BasicBlock &BB,
   Loop *L = LI->getLoopFor(&BB);
 
   // The set of loops contained in non-affine subregions that are part of R.
-  const ScopDetection::BoxedLoopsSetTy *BoxedLoops = SD->getBoxedLoops(&R);
+  auto BoxedLoops = SD->getBoxedLoops(&R);
 
   for (BasicBlock::iterator I = BB.begin(), E = --BB.end(); I != E; ++I) {
     Instruction *Inst = I;
-- 
2.1.0