Exposing findDefsUsedOutsideOfLoop as a Loop utility

[ashutosh.nema]

Summary

In this patch exposed ‘findDefsUsedOutsideOfLoop’ as a utility.

Found ‘findDefsUsedOutsideOfLoop’ is a common method and it should be moved as a utility.
It’s useful for the users of LoopVersioning.

Thanks,
Ashutosh

[anemet]

Hi Ashutosh,

Thanks for improving this.

include/llvm/Transforms/Utils/LoopUtils.h

285–286

Nit: I don't think this second line is necessary to describe the API, I would drop it.

lib/Transforms/Scalar/LoopDistribute.cpp

60–78

You also need to move this to LoopUtils.cpp.

[anemet]

Should be OK to commit after these changes. Thanks again.

[ashutosh.nema]

Thanks Adam, will incorporate these comments and check-in.

Regards,
Ashutosh

[anemet]

Ashutosh, please don't forget to close this with the commit revision.

[ashutosh.nema]

Revision: 245416

include/llvm/Transforms/Utils/LoopUtils.h

 /// exception, it takes LICMSafetyInfo and loop as argument.
 /// Updates safety information in LICMSafetyInfo argument.
 void computeLICMSafetyInfo(LICMSafetyInfo *, Loop *);
 
 /// \brief Checks if the given PHINode in a loop header is an induction
 /// variable. Returns true if this is an induction PHI along with the step
 /// value.
 bool isInductionPHI(PHINode *, ScalarEvolution *, ConstantInt *&);
+
+/// \brief Returns the instructions that use values defined in the loop.
+/// Iterates over loop instruction and get its outsider users.
+SmallVector<Instruction *, 8> findDefsUsedOutsideOfLoop(Loop *L);
 }
 
 #endif

lib/Transforms/Scalar/LoopDistribute.cpp

 #include "llvm/Analysis/LoopAccessAnalysis.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
 #include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/Transforms/Utils/LoopUtils.h"
 #include "llvm/Transforms/Utils/LoopVersioning.h"
 #include <list>
 
 #define LDIST_NAME "loop-distribute"
 #define DEBUG_TYPE LDIST_NAME
 
 using namespace llvm;
 
 static cl::opt<bool>
     LDistVerify("loop-distribute-verify", cl::Hidden,
                 cl::desc("Turn on DominatorTree and LoopInfo verification "
                          "after Loop Distribution"),
                 cl::init(false));
 
 static cl::opt<bool> DistributeNonIfConvertible(
     "loop-distribute-non-if-convertible", cl::Hidden,
     cl::desc("Whether to distribute into a loop that may not be "
              "if-convertible by the loop vectorizer"),
     cl::init(false));
 
 STATISTIC(NumLoopsDistributed, "Number of loops distributed");
 
+/// \brief Returns the instructions that use values defined in the loop.
+SmallVector<Instruction *, 8> llvm::findDefsUsedOutsideOfLoop(Loop *L) {
+  SmallVector<Instruction *, 8> UsedOutside;
+
+  for (auto *Block : L->getBlocks())
+    // FIXME: I believe that this could use copy_if if the Inst reference could
+    // be adapted into a pointer.
+    for (auto &Inst : *Block) {
+      auto Users = Inst.users();
+      if (std::any_of(Users.begin(), Users.end(), [&](User *U) {
+            auto *Use = cast<Instruction>(U);
+            return !L->contains(Use->getParent());
+          }))
+        UsedOutside.push_back(&Inst);
+    }
+
+  return UsedOutside;
+}
+
 namespace {
 /// \brief Maintains the set of instructions of the loop for a partition before
 /// cloning.  After cloning, it hosts the new loop.
 class InstPartition {
   typedef SmallPtrSet<Instruction *, 8> InstructionSet;
 
 public:
   InstPartition(Instruction *I, Loop *L, bool DepCycle = false)
for (auto &Dep : InterestingDependences)
         DEBUG(Dep.print(dbgs(), 2, Instructions));
       }
   }
 
 private:
   AccessesType Accesses;
 };
 
-/// \brief Returns the instructions that use values defined in the loop.
-static SmallVector<Instruction *, 8> findDefsUsedOutsideOfLoop(Loop *L) {
-  SmallVector<Instruction *, 8> UsedOutside;
-
-  for (auto *Block : L->getBlocks())
-    // FIXME: I believe that this could use copy_if if the Inst reference could
-    // be adapted into a pointer.
-    for (auto &Inst : *Block) {
-      auto Users = Inst.users();
-      if (std::any_of(Users.begin(), Users.end(), [&](User *U) {
-            auto *Use = cast<Instruction>(U);
-            return !L->contains(Use->getParent());
-          }))
-        UsedOutside.push_back(&Inst);
-    }
-
-  return UsedOutside;
-}
-
 /// \brief The pass class.
 class LoopDistribute : public FunctionPass {
 public:
   LoopDistribute() : FunctionPass(ID) {
     initializeLoopDistributePass(*PassRegistry::getPassRegistry());
   }
 
   bool runOnFunction(Function &F) override {