1 files changed, 29 insertions, 35 deletions

diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index 0038c9fb9ce4..9b38053c196b 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -61,6 +61,7 @@
 #include "llvm/IR/InstIterator.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Operator.h"
+#include "llvm/InitializePasses.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -141,6 +142,11 @@ INITIALIZE_PASS_END(DependenceAnalysisWrapperPass, "da", "Dependence Analysis",
 
 char DependenceAnalysisWrapperPass::ID = 0;
 
+DependenceAnalysisWrapperPass::DependenceAnalysisWrapperPass()
+    : FunctionPass(ID) {
+  initializeDependenceAnalysisWrapperPassPass(*PassRegistry::getPassRegistry());
+}
+
 FunctionPass *llvm::createDependenceAnalysisWrapperPass() {
   return new DependenceAnalysisWrapperPass();
 }
@@ -164,25 +170,25 @@ void DependenceAnalysisWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequiredTransitive<LoopInfoWrapperPass>();
 }
 
-
 // Used to test the dependence analyzer.
-// Looks through the function, noting loads and stores.
+// Looks through the function, noting instructions that may access memory.
 // Calls depends() on every possible pair and prints out the result.
 // Ignores all other instructions.
 static void dumpExampleDependence(raw_ostream &OS, DependenceInfo *DA) {
   auto *F = DA->getFunction();
   for (inst_iterator SrcI = inst_begin(F), SrcE = inst_end(F); SrcI != SrcE;
        ++SrcI) {
-    if (isa<StoreInst>(*SrcI) || isa<LoadInst>(*SrcI)) {
+    if (SrcI->mayReadOrWriteMemory()) {
       for (inst_iterator DstI = SrcI, DstE = inst_end(F);
            DstI != DstE; ++DstI) {
-        if (isa<StoreInst>(*DstI) || isa<LoadInst>(*DstI)) {
-          OS << "da analyze - ";
+        if (DstI->mayReadOrWriteMemory()) {
+          OS << "Src:" << *SrcI << " --> Dst:" << *DstI << "\n";
+          OS << "  da analyze - ";
           if (auto D = DA->depends(&*SrcI, &*DstI, true)) {
             D->dump(OS);
             for (unsigned Level = 1; Level <= D->getLevels(); Level++) {
               if (D->isSplitable(Level)) {
-                OS << "da analyze - split level = " << Level;
+                OS << "  da analyze - split level = " << Level;
                 OS << ", iteration = " << *DA->getSplitIteration(*D, Level);
                 OS << "!\n";
               }
@@ -876,14 +882,13 @@ void DependenceInfo::removeMatchingExtensions(Subscript *Pair) {
   }
 }
 
-
 // Examine the scev and return true iff it's linear.
 // Collect any loops mentioned in the set of "Loops".
-bool DependenceInfo::checkSrcSubscript(const SCEV *Src, const Loop *LoopNest,
-                                       SmallBitVector &Loops) {
-  const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Src);
+bool DependenceInfo::checkSubscript(const SCEV *Expr, const Loop *LoopNest,
+                                    SmallBitVector &Loops, bool IsSrc) {
+  const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Expr);
   if (!AddRec)
-    return isLoopInvariant(Src, LoopNest);
+    return isLoopInvariant(Expr, LoopNest);
   const SCEV *Start = AddRec->getStart();
   const SCEV *Step = AddRec->getStepRecurrence(*SE);
   const SCEV *UB = SE->getBackedgeTakenCount(AddRec->getLoop());
@@ -896,33 +901,25 @@ bool DependenceInfo::checkSrcSubscript(const SCEV *Src, const Loop *LoopNest,
   }
   if (!isLoopInvariant(Step, LoopNest))
     return false;
-  Loops.set(mapSrcLoop(AddRec->getLoop()));
-  return checkSrcSubscript(Start, LoopNest, Loops);
+  if (IsSrc)
+    Loops.set(mapSrcLoop(AddRec->getLoop()));
+  else
+    Loops.set(mapDstLoop(AddRec->getLoop()));
+  return checkSubscript(Start, LoopNest, Loops, IsSrc);
 }
 
-
+// Examine the scev and return true iff it's linear.
+// Collect any loops mentioned in the set of "Loops".
+bool DependenceInfo::checkSrcSubscript(const SCEV *Src, const Loop *LoopNest,
+                                       SmallBitVector &Loops) {
+  return checkSubscript(Src, LoopNest, Loops, true);
+}
 
 // Examine the scev and return true iff it's linear.
 // Collect any loops mentioned in the set of "Loops".
 bool DependenceInfo::checkDstSubscript(const SCEV *Dst, const Loop *LoopNest,
                                        SmallBitVector &Loops) {
-  const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Dst);
-  if (!AddRec)
-    return isLoopInvariant(Dst, LoopNest);
-  const SCEV *Start = AddRec->getStart();
-  const SCEV *Step = AddRec->getStepRecurrence(*SE);
-  const SCEV *UB = SE->getBackedgeTakenCount(AddRec->getLoop());
-  if (!isa<SCEVCouldNotCompute>(UB)) {
-    if (SE->getTypeSizeInBits(Start->getType()) <
-        SE->getTypeSizeInBits(UB->getType())) {
-      if (!AddRec->getNoWrapFlags())
-        return false;
-    }
-  }
-  if (!isLoopInvariant(Step, LoopNest))
-    return false;
-  Loops.set(mapDstLoop(AddRec->getLoop()));
-  return checkDstSubscript(Start, LoopNest, Loops);
+  return checkSubscript(Dst, LoopNest, Loops, false);
 }
 
 
@@ -3407,8 +3404,7 @@ DependenceInfo::depends(Instruction *Src, Instruction *Dst,
   if (Src == Dst)
     PossiblyLoopIndependent = false;
 
-  if ((!Src->mayReadFromMemory() && !Src->mayWriteToMemory()) ||
-      (!Dst->mayReadFromMemory() && !Dst->mayWriteToMemory()))
+  if (!(Src->mayReadOrWriteMemory() && Dst->mayReadOrWriteMemory()))
     // if both instructions don't reference memory, there's no dependence
     return nullptr;
 
@@ -3780,8 +3776,6 @@ DependenceInfo::depends(Instruction *Src, Instruction *Dst,
   return std::make_unique<FullDependence>(std::move(Result));
 }
 
-
-
 //===----------------------------------------------------------------------===//
 // getSplitIteration -
 // Rather than spend rarely-used space recording the splitting iteration