Update llvm and clang to release_38 branch r261369.

1 files changed, 41 insertions, 106 deletions

diff --git a/contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 2c0d317..17c25df 100644
--- a/contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -1409,14 +1409,15 @@ private:
 /// different operations.
 class LoopVectorizationCostModel {
 public:
-  LoopVectorizationCostModel(Loop *L, PredicatedScalarEvolution &PSE,
-                             LoopInfo *LI, LoopVectorizationLegality *Legal,
+  LoopVectorizationCostModel(Loop *L, ScalarEvolution *SE, LoopInfo *LI,
+                             LoopVectorizationLegality *Legal,
                              const TargetTransformInfo &TTI,
                              const TargetLibraryInfo *TLI, DemandedBits *DB,
                              AssumptionCache *AC, const Function *F,
-                             const LoopVectorizeHints *Hints)
-      : TheLoop(L), PSE(PSE), LI(LI), Legal(Legal), TTI(TTI), TLI(TLI), DB(DB),
-        AC(AC), TheFunction(F), Hints(Hints) {}
+                             const LoopVectorizeHints *Hints,
+                             SmallPtrSetImpl<const Value *> &ValuesToIgnore)
+      : TheLoop(L), SE(SE), LI(LI), Legal(Legal), TTI(TTI), TLI(TLI), DB(DB),
+        TheFunction(F), Hints(Hints), ValuesToIgnore(ValuesToIgnore) {}
 
   /// Information about vectorization costs
   struct VectorizationFactor {
@@ -1464,9 +1465,6 @@ public:
   SmallVector<RegisterUsage, 8>
   calculateRegisterUsage(const SmallVector<unsigned, 8> &VFs);
 
-  /// Collect values we want to ignore in the cost model.
-  void collectValuesToIgnore();
-
 private:
   /// Returns the expected execution cost. The unit of the cost does
   /// not matter because we use the 'cost' units to compare different
@@ -1498,8 +1496,8 @@ public:
 
   /// The loop that we evaluate.
   Loop *TheLoop;
-  /// Predicated scalar evolution analysis.
-  PredicatedScalarEvolution &PSE;
+  /// Scev analysis.
+  ScalarEvolution *SE;
   /// Loop Info analysis.
   LoopInfo *LI;
   /// Vectorization legality.
@@ -1508,17 +1506,13 @@ public:
   const TargetTransformInfo &TTI;
   /// Target Library Info.
   const TargetLibraryInfo *TLI;
-  /// Demanded bits analysis.
+  /// Demanded bits analysis
   DemandedBits *DB;
-  /// Assumption cache.
-  AssumptionCache *AC;
   const Function *TheFunction;
-  /// Loop Vectorize Hint.
+  // Loop Vectorize Hint.
   const LoopVectorizeHints *Hints;
-  /// Values to ignore in the cost model.
-  SmallPtrSet<const Value *, 16> ValuesToIgnore;
-  /// Values to ignore in the cost model when VF > 1.
-  SmallPtrSet<const Value *, 16> VecValuesToIgnore;
+  // Values to ignore in the cost model.
+  const SmallPtrSetImpl<const Value *> &ValuesToIgnore;
 };
 
 /// \brief This holds vectorization requirements that must be verified late in
@@ -1763,10 +1757,19 @@ struct LoopVectorize : public FunctionPass {
       return false;
     }
 
+    // Collect values we want to ignore in the cost model. This includes
+    // type-promoting instructions we identified during reduction detection.
+    SmallPtrSet<const Value *, 32> ValuesToIgnore;
+    CodeMetrics::collectEphemeralValues(L, AC, ValuesToIgnore);
+    for (auto &Reduction : *LVL.getReductionVars()) {
+      RecurrenceDescriptor &RedDes = Reduction.second;
+      SmallPtrSetImpl<Instruction *> &Casts = RedDes.getCastInsts();
+      ValuesToIgnore.insert(Casts.begin(), Casts.end());
+    }
+
     // Use the cost model.
-    LoopVectorizationCostModel CM(L, PSE, LI, &LVL, *TTI, TLI, DB, AC, F,
-                                  &Hints);
-    CM.collectValuesToIgnore();
+    LoopVectorizationCostModel CM(L, PSE.getSE(), LI, &LVL, *TTI, TLI, DB, AC,
+                                  F, &Hints, ValuesToIgnore);
 
     // Check the function attributes to find out if this function should be
     // optimized for size.
@@ -4636,6 +4639,8 @@ void InterleavedAccessInfo::analyzeInterleaving(
 
   // Holds all interleaved store groups temporarily.
   SmallSetVector<InterleaveGroup *, 4> StoreGroups;
+  // Holds all interleaved load groups temporarily.
+  SmallSetVector<InterleaveGroup *, 4> LoadGroups;
 
   // Search the load-load/write-write pair B-A in bottom-up order and try to
   // insert B into the interleave group of A according to 3 rules:
@@ -4663,6 +4668,8 @@ void InterleavedAccessInfo::analyzeInterleaving(
 
     if (A->mayWriteToMemory())
       StoreGroups.insert(Group);
+    else
+      LoadGroups.insert(Group);
 
     for (auto II = std::next(I); II != E; ++II) {
       Instruction *B = II->first;
@@ -4710,6 +4717,12 @@ void InterleavedAccessInfo::analyzeInterleaving(
   for (InterleaveGroup *Group : StoreGroups)
     if (Group->getNumMembers() != Group->getFactor())
       releaseGroup(Group);
+
+  // Remove interleaved load groups that don't have the first and last member.
+  // This guarantees that we won't do speculative out of bounds loads.
+  for (InterleaveGroup *Group : LoadGroups)
+    if (!Group->getMember(0) || !Group->getMember(Group->getFactor() - 1))
+      releaseGroup(Group);
 }
 
 LoopVectorizationCostModel::VectorizationFactor
@@ -4734,7 +4747,7 @@ LoopVectorizationCostModel::selectVectorizationFactor(bool OptForSize) {
   }
 
   // Find the trip count.
-  unsigned TC = PSE.getSE()->getSmallConstantTripCount(TheLoop);
+  unsigned TC = SE->getSmallConstantTripCount(TheLoop);
   DEBUG(dbgs() << "LV: Found trip count: " << TC << '\n');
 
   MinBWs = computeMinimumValueSizes(TheLoop->getBlocks(), *DB, &TTI);
@@ -4936,7 +4949,7 @@ unsigned LoopVectorizationCostModel::selectInterleaveCount(bool OptForSize,
     return 1;
 
   // Do not interleave loops with a relatively small trip count.
-  unsigned TC = PSE.getSE()->getSmallConstantTripCount(TheLoop);
+  unsigned TC = SE->getSmallConstantTripCount(TheLoop);
   if (TC > 1 && TC < TinyTripCountInterleaveThreshold)
     return 1;
 
@@ -5164,15 +5177,15 @@ LoopVectorizationCostModel::calculateRegisterUsage(
     // Ignore instructions that are never used within the loop.
     if (!Ends.count(I)) continue;
 
+    // Skip ignored values.
+    if (ValuesToIgnore.count(I))
+      continue;
+
     // Remove all of the instructions that end at this location.
     InstrList &List = TransposeEnds[i];
     for (unsigned int j = 0, e = List.size(); j < e; ++j)
       OpenIntervals.erase(List[j]);
 
-    // Skip ignored values.
-    if (ValuesToIgnore.count(I))
-      continue;
-
     // For each VF find the maximum usage of registers.
     for (unsigned j = 0, e = VFs.size(); j < e; ++j) {
       if (VFs[j] == 1) {
@@ -5182,12 +5195,8 @@ LoopVectorizationCostModel::calculateRegisterUsage(
 
       // Count the number of live intervals.
       unsigned RegUsage = 0;
-      for (auto Inst : OpenIntervals) {
-        // Skip ignored values for VF > 1.
-        if (VecValuesToIgnore.count(Inst))
-          continue;
+      for (auto Inst : OpenIntervals)
         RegUsage += GetRegUsage(Inst->getType(), VFs[j]);
-      }
       MaxUsages[j] = std::max(MaxUsages[j], RegUsage);
     }
 
@@ -5331,7 +5340,6 @@ LoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) {
   if (VF > 1 && MinBWs.count(I))
     RetTy = IntegerType::get(RetTy->getContext(), MinBWs[I]);
   Type *VectorTy = ToVectorTy(RetTy, VF);
-  auto SE = PSE.getSE();
 
   // TODO: We need to estimate the cost of intrinsic calls.
   switch (I->getOpcode()) {
@@ -5633,79 +5641,6 @@ bool LoopVectorizationCostModel::isConsecutiveLoadOrStore(Instruction *Inst) {
   return false;
 }
 
-void LoopVectorizationCostModel::collectValuesToIgnore() {
-  // Ignore ephemeral values.
-  CodeMetrics::collectEphemeralValues(TheLoop, AC, ValuesToIgnore);
-
-  // Ignore type-promoting instructions we identified during reduction
-  // detection.
-  for (auto &Reduction : *Legal->getReductionVars()) {
-    RecurrenceDescriptor &RedDes = Reduction.second;
-    SmallPtrSetImpl<Instruction *> &Casts = RedDes.getCastInsts();
-    VecValuesToIgnore.insert(Casts.begin(), Casts.end());
-  }
-
-  // Ignore induction phis that are only used in either GetElementPtr or ICmp
-  // instruction to exit loop. Induction variables usually have large types and
-  // can have big impact when estimating register usage.
-  // This is for when VF > 1.
-  for (auto &Induction : *Legal->getInductionVars()) {
-    auto *PN = Induction.first;
-    auto *UpdateV = PN->getIncomingValueForBlock(TheLoop->getLoopLatch());
-
-    // Check that the PHI is only used by the induction increment (UpdateV) or
-    // by GEPs. Then check that UpdateV is only used by a compare instruction or
-    // the loop header PHI.
-    // FIXME: Need precise def-use analysis to determine if this instruction
-    // variable will be vectorized.
-    if (std::all_of(PN->user_begin(), PN->user_end(),
-                    [&](const User *U) -> bool {
-                      return U == UpdateV || isa<GetElementPtrInst>(U);
-                    }) &&
-        std::all_of(UpdateV->user_begin(), UpdateV->user_end(),
-                    [&](const User *U) -> bool {
-                      return U == PN || isa<ICmpInst>(U);
-                    })) {
-      VecValuesToIgnore.insert(PN);
-      VecValuesToIgnore.insert(UpdateV);
-    }
-  }
-
-  // Ignore instructions that will not be vectorized.
-  // This is for when VF > 1.
-  for (auto bb = TheLoop->block_begin(), be = TheLoop->block_end(); bb != be;
-       ++bb) {
-    for (auto &Inst : **bb) {
-      switch (Inst.getOpcode()) {
-      case Instruction::GetElementPtr: {
-        // Ignore GEP if its last operand is an induction variable so that it is
-        // a consecutive load/store and won't be vectorized as scatter/gather
-        // pattern.
-
-        GetElementPtrInst *Gep = cast<GetElementPtrInst>(&Inst);
-        unsigned NumOperands = Gep->getNumOperands();
-        unsigned InductionOperand = getGEPInductionOperand(Gep);
-        bool GepToIgnore = true;
-
-        // Check that all of the gep indices are uniform except for the
-        // induction operand.
-        for (unsigned i = 0; i != NumOperands; ++i) {
-          if (i != InductionOperand &&
-              !PSE.getSE()->isLoopInvariant(PSE.getSCEV(Gep->getOperand(i)),
-                                            TheLoop)) {
-            GepToIgnore = false;
-            break;
-          }
-        }
-
-        if (GepToIgnore)
-          VecValuesToIgnore.insert(&Inst);
-        break;
-      }
-      }
-    }
-  }
-}
 
 void InnerLoopUnroller::scalarizeInstruction(Instruction *Instr,
                                              bool IfPredicateStore) {