[LV] Move addRuntimeCheck to LoopAccessAnalysis

This will allow it to be shared with the new Loop Distribution pass.

getFirstInst is currently duplicated across LoopVectorize.cpp and
LoopAccessAnalysis.cpp.  This is a short-term work-around until we figure out
a better solution.

NFC.  (The code moved is adjusted a bit for the name of the Loop member and
that PtrRtCheck is now a reference rather than a pointer.)

llvm-svn: 228418

1 files changed, 5 insertions, 104 deletions

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 8d9d4d9cf83..f43a60773a6 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -271,13 +271,6 @@ protected:
   typedef DenseMap<std::pair<BasicBlock*, BasicBlock*>,
                    VectorParts> EdgeMaskCache;
 
-  /// \brief Add code that checks at runtime if the accessed arrays overlap.
-  ///
-  /// Returns a pair of instructions where the first element is the first
-  /// instruction generated in possibly a sequence of instructions and the
-  /// second value is the final comparator value or NULL if no check is needed.
-  std::pair<Instruction *, Instruction *> addRuntimeCheck(Instruction *Loc);
-
   /// \brief Add checks for strides that where assumed to be 1.
   ///
   /// Returns the last check instruction and the first check instruction in the
@@ -751,6 +744,10 @@ public:
     return LAA.getRuntimePointerCheck();
   }
 
+  LoopAccessAnalysis *getLAA() {
+    return &LAA;
+  }
+
   /// This function returns the identity element (or neutral element) for
   /// the operation K.
   static Constant *getReductionIdentity(ReductionKind K, Type *Tp);
@@ -2009,102 +2006,6 @@ InnerLoopVectorizer::addStrideCheck(Instruction *Loc) {
   return std::make_pair(FirstInst, TheCheck);
 }
 
-std::pair<Instruction *, Instruction *>
-InnerLoopVectorizer::addRuntimeCheck(Instruction *Loc) {
-  LoopAccessAnalysis::RuntimePointerCheck *PtrRtCheck =
-    Legal->getRuntimePointerCheck();
-
-  Instruction *tnullptr = nullptr;
-  if (!PtrRtCheck->Need)
-    return std::pair<Instruction *, Instruction *>(tnullptr, tnullptr);
-
-  unsigned NumPointers = PtrRtCheck->Pointers.size();
-  SmallVector<TrackingVH<Value> , 2> Starts;
-  SmallVector<TrackingVH<Value> , 2> Ends;
-
-  LLVMContext &Ctx = Loc->getContext();
-  SCEVExpander Exp(*SE, "induction");
-  Instruction *FirstInst = nullptr;
-
-  for (unsigned i = 0; i < NumPointers; ++i) {
-    Value *Ptr = PtrRtCheck->Pointers[i];
-    const SCEV *Sc = SE->getSCEV(Ptr);
-
-    if (SE->isLoopInvariant(Sc, OrigLoop)) {
-      DEBUG(dbgs() << "LV: Adding RT check for a loop invariant ptr:" <<
-            *Ptr <<"\n");
-      Starts.push_back(Ptr);
-      Ends.push_back(Ptr);
-    } else {
-      DEBUG(dbgs() << "LV: Adding RT check for range:" << *Ptr << '\n');
-      unsigned AS = Ptr->getType()->getPointerAddressSpace();
-
-      // Use this type for pointer arithmetic.
-      Type *PtrArithTy = Type::getInt8PtrTy(Ctx, AS);
-
-      Value *Start = Exp.expandCodeFor(PtrRtCheck->Starts[i], PtrArithTy, Loc);
-      Value *End = Exp.expandCodeFor(PtrRtCheck->Ends[i], PtrArithTy, Loc);
-      Starts.push_back(Start);
-      Ends.push_back(End);
-    }
-  }
-
-  IRBuilder<> ChkBuilder(Loc);
-  // Our instructions might fold to a constant.
-  Value *MemoryRuntimeCheck = nullptr;
-  for (unsigned i = 0; i < NumPointers; ++i) {
-    for (unsigned j = i+1; j < NumPointers; ++j) {
-      // No need to check if two readonly pointers intersect.
-      if (!PtrRtCheck->IsWritePtr[i] && !PtrRtCheck->IsWritePtr[j])
-        continue;
-
-      // Only need to check pointers between two different dependency sets.
-      if (PtrRtCheck->DependencySetId[i] == PtrRtCheck->DependencySetId[j])
-       continue;
-      // Only need to check pointers in the same alias set.
-      if (PtrRtCheck->AliasSetId[i] != PtrRtCheck->AliasSetId[j])
-        continue;
-
-      unsigned AS0 = Starts[i]->getType()->getPointerAddressSpace();
-      unsigned AS1 = Starts[j]->getType()->getPointerAddressSpace();
-
-      assert((AS0 == Ends[j]->getType()->getPointerAddressSpace()) &&
-             (AS1 == Ends[i]->getType()->getPointerAddressSpace()) &&
-             "Trying to bounds check pointers with different address spaces");
-
-      Type *PtrArithTy0 = Type::getInt8PtrTy(Ctx, AS0);
-      Type *PtrArithTy1 = Type::getInt8PtrTy(Ctx, AS1);
-
-      Value *Start0 = ChkBuilder.CreateBitCast(Starts[i], PtrArithTy0, "bc");
-      Value *Start1 = ChkBuilder.CreateBitCast(Starts[j], PtrArithTy1, "bc");
-      Value *End0 =   ChkBuilder.CreateBitCast(Ends[i],   PtrArithTy1, "bc");
-      Value *End1 =   ChkBuilder.CreateBitCast(Ends[j],   PtrArithTy0, "bc");
-
-      Value *Cmp0 = ChkBuilder.CreateICmpULE(Start0, End1, "bound0");
-      FirstInst = getFirstInst(FirstInst, Cmp0, Loc);
-      Value *Cmp1 = ChkBuilder.CreateICmpULE(Start1, End0, "bound1");
-      FirstInst = getFirstInst(FirstInst, Cmp1, Loc);
-      Value *IsConflict = ChkBuilder.CreateAnd(Cmp0, Cmp1, "found.conflict");
-      FirstInst = getFirstInst(FirstInst, IsConflict, Loc);
-      if (MemoryRuntimeCheck) {
-        IsConflict = ChkBuilder.CreateOr(MemoryRuntimeCheck, IsConflict,
-                                         "conflict.rdx");
-        FirstInst = getFirstInst(FirstInst, IsConflict, Loc);
-      }
-      MemoryRuntimeCheck = IsConflict;
-    }
-  }
-
-  // We have to do this trickery because the IRBuilder might fold the check to a
-  // constant expression in which case there is no Instruction anchored in a
-  // the block.
-  Instruction *Check = BinaryOperator::CreateAnd(MemoryRuntimeCheck,
-                                                 ConstantInt::getTrue(Ctx));
-  ChkBuilder.Insert(Check, "memcheck.conflict");
-  FirstInst = getFirstInst(FirstInst, Check, Loc);
-  return std::make_pair(FirstInst, Check);
-}
-
 void InnerLoopVectorizer::createEmptyLoop() {
   /*
    In this function we generate a new loop. The new loop will contain
@@ -2329,7 +2230,7 @@ void InnerLoopVectorizer::createEmptyLoop() {
   // faster.
   Instruction *MemRuntimeCheck;
   std::tie(FirstCheckInst, MemRuntimeCheck) =
-      addRuntimeCheck(LastBypassBlock->getTerminator());
+    Legal->getLAA()->addRuntimeCheck(LastBypassBlock->getTerminator());
   if (MemRuntimeCheck) {
     // Create a new block containing the memory check.
     BasicBlock *CheckBlock =