[LoopDist] Move loop-versioning helper functions to Cloning, NFC

[anemet]

Summary

This makes them available to the LoopVersioning class as that is moved
to its own module in the next patch.

[hfinkel]

include/llvm/Transforms/Utils/Cloning.h

248

Does it only include the preheader if the preheader is included in the Blocks list?

lib/Transforms/Utils/CloneFunction.cpp

726

Why not just name this remapInstructionsInBlocks?

[anemet]

Address review comments:

Change remapInstructionsInLoop to remapInstructionsInBlocks

[hfinkel]

LGTM.

include/llvm/Transforms/Utils/Cloning.h

 class Trace;
 class CallGraph;
 class DataLayout;
 class Loop;
 class LoopInfo;
 class AllocaInst;
 class AliasAnalysis;
 class AssumptionCacheTracker;
+class DominatorTree;
 
 /// CloneModule - Return an exact copy of the specified module
 ///
 Module *CloneModule(const Module *M);
 Module *CloneModule(const Module *M, ValueToValueMapTy &VMap);
 
 /// ClonedCodeInfo - This struct can be used to capture information about code
 /// being cloned, while it is being cloned.

 ///
 bool InlineFunction(CallInst *C, InlineFunctionInfo &IFI,
                     bool InsertLifetime = true);
 bool InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI,
                     bool InsertLifetime = true);
 bool InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
                     bool InsertLifetime = true);
 
+/// \brief Clones a loop \p OrigLoop.  Returns the loop and the blocks in \p
+/// Blocks.
+///
+/// Updates LoopInfo and DominatorTree assuming the loop is dominated by block
+/// \p LoopDomBB.  Insert the new blocks before block specified in \p Before.
+Loop *cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB,
+                             Loop *OrigLoop, ValueToValueMapTy &VMap,
+                             const Twine &NameSuffix, LoopInfo *LI,
+                             DominatorTree *DT,
+                             SmallVectorImpl<BasicBlock *> &Blocks);
+
+/// \brief Remaps instructions in \p Blocks using the mapping in \p VMap.
+void remapInstructionsInBlocks(const SmallVectorImpl<BasicBlock *> &Blocks,
+                               ValueToValueMapTy &VMap);
+
 } // End llvm namespace
 
 #endif

lib/Transforms/Scalar/LoopDistribute.cpp

 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 Remaps instructions in a loop including the preheader.
-static void remapInstructionsInLoop(const SmallVectorImpl<BasicBlock *> &Blocks,
-                                    ValueToValueMapTy &VMap) {
-  // Rewrite the code to refer to itself.
-  for (auto *BB : Blocks)
-    for (auto &Inst : *BB)
-      RemapInstruction(&Inst, VMap,
-                       RF_NoModuleLevelChanges | RF_IgnoreMissingEntries);
-}
-
-/// \brief Clones a loop \p OrigLoop.  Returns the loop and the blocks in \p
-/// Blocks.
-///
-/// Updates LoopInfo and DominatorTree assuming the loop is dominated by block
-/// \p LoopDomBB.  Insert the new blocks before block specified in \p Before.
-static Loop *cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB,
-                                    Loop *OrigLoop, ValueToValueMapTy &VMap,
-                                    const Twine &NameSuffix, LoopInfo *LI,
-                                    DominatorTree *DT,
-                                    SmallVectorImpl<BasicBlock *> &Blocks) {
-  Function *F = OrigLoop->getHeader()->getParent();
-  Loop *ParentLoop = OrigLoop->getParentLoop();
-
-  Loop *NewLoop = new Loop();
-  if (ParentLoop)
-    ParentLoop->addChildLoop(NewLoop);
-  else
-    LI->addTopLevelLoop(NewLoop);
-
-  BasicBlock *OrigPH = OrigLoop->getLoopPreheader();
-  BasicBlock *NewPH = CloneBasicBlock(OrigPH, VMap, NameSuffix, F);
-  // To rename the loop PHIs.
-  VMap[OrigPH] = NewPH;
-  Blocks.push_back(NewPH);
-
-  // Update LoopInfo.
-  if (ParentLoop)
-    ParentLoop->addBasicBlockToLoop(NewPH, *LI);
-
-  // Update DominatorTree.
-  DT->addNewBlock(NewPH, LoopDomBB);
-
-  for (BasicBlock *BB : OrigLoop->getBlocks()) {
-    BasicBlock *NewBB = CloneBasicBlock(BB, VMap, NameSuffix, F);
-    VMap[BB] = NewBB;
-
-    // Update LoopInfo.
-    NewLoop->addBasicBlockToLoop(NewBB, *LI);
-
-    // Update DominatorTree.
-    BasicBlock *IDomBB = DT->getNode(BB)->getIDom()->getBlock();
-    DT->addNewBlock(NewBB, cast<BasicBlock>(VMap[IDomBB]));
-
-    Blocks.push_back(NewBB);
-  }
-
-  // Move them physically from the end of the block list.
-  F->getBasicBlockList().splice(Before, F->getBasicBlockList(), NewPH);
-  F->getBasicBlockList().splice(Before, F->getBasicBlockList(),
-                                NewLoop->getHeader(), F->end());
-
-  return NewLoop;
-}
-
 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)
const Loop *getDistributedLoop() const {
     return ClonedLoop ? ClonedLoop : OrigLoop;
   }
 
   /// \brief The VMap that is populated by cloning and then used in
   /// remapinstruction to remap the cloned instructions.
   ValueToValueMapTy &getVMap() { return VMap; }
 
   /// \brief Remaps the cloned instructions using VMap.
-  void remapInstructions() { remapInstructionsInLoop(ClonedLoopBlocks, VMap); }
+  void remapInstructions() {
+    remapInstructionsInBlocks(ClonedLoopBlocks, VMap);
+  }
 
   /// \brief Based on the set of instructions selected for this partition,
   /// removes the unnecessary ones.
   void removeUnusedInsts() {
     SmallVector<Instruction *, 8> Unused;
 
     for (auto *Block : OrigLoop->getBlocks())
       for (auto &Inst : *Block)
void versionLoop(Pass *P) {
     // Clone the loop including the preheader.
     //
     // FIXME: This does not currently preserve SimplifyLoop because the exit
     // block is a join between the two loops.
     SmallVector<BasicBlock *, 8> NonVersionedLoopBlocks;
     NonVersionedLoop =
         cloneLoopWithPreheader(PH, MemCheckBB, VersionedLoop, VMap,
                                ".lver.orig", LI, DT, NonVersionedLoopBlocks);
-    remapInstructionsInLoop(NonVersionedLoopBlocks, VMap);
+    remapInstructionsInBlocks(NonVersionedLoopBlocks, VMap);
 
     // Insert the conditional branch based on the result of the memchecks.
     Instruction *OrigTerm = MemCheckBB->getTerminator();
     BranchInst::Create(NonVersionedLoop->getLoopPreheader(),
                        VersionedLoop->getLoopPreheader(), MemRuntimeCheck,
                        OrigTerm);
     OrigTerm->eraseFromParent();
 

lib/Transforms/Utils/CloneFunction.cpp

 // inliner to do the dirty work of copying the body of a function around.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Utils/Cloning.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/LoopInfo.h"
 #include "llvm/IR/CFG.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
void llvm::CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
                                      SmallVectorImpl<ReturnInst*> &Returns,
                                      const char *NameSuffix, 
                                      ClonedCodeInfo *CodeInfo,
                                      Instruction *TheCall) {
   CloneAndPruneIntoFromInst(NewFunc, OldFunc, OldFunc->front().begin(), VMap,
                             ModuleLevelChanges, Returns, NameSuffix, CodeInfo,
                             nullptr);
 }
+
+/// \brief Remaps instructions in \p Blocks using the mapping in \p VMap.
+void llvm::remapInstructionsInBlocks(
+    const SmallVectorImpl<BasicBlock *> &Blocks, ValueToValueMapTy &VMap) {
+  // Rewrite the code to refer to itself.
+  for (auto *BB : Blocks)
+    for (auto &Inst : *BB)
+      RemapInstruction(&Inst, VMap,
+                       RF_NoModuleLevelChanges | RF_IgnoreMissingEntries);
+}
+
+/// \brief Clones a loop \p OrigLoop.  Returns the loop and the blocks in \p
+/// Blocks.
+///
+/// Updates LoopInfo and DominatorTree assuming the loop is dominated by block
+/// \p LoopDomBB.  Insert the new blocks before block specified in \p Before.
+Loop *llvm::cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB,
+                                   Loop *OrigLoop, ValueToValueMapTy &VMap,
+                                   const Twine &NameSuffix, LoopInfo *LI,
+                                   DominatorTree *DT,
+                                   SmallVectorImpl<BasicBlock *> &Blocks) {
+  Function *F = OrigLoop->getHeader()->getParent();
+  Loop *ParentLoop = OrigLoop->getParentLoop();
+
+  Loop *NewLoop = new Loop();
+  if (ParentLoop)
+    ParentLoop->addChildLoop(NewLoop);
+  else
+    LI->addTopLevelLoop(NewLoop);
+
+  BasicBlock *OrigPH = OrigLoop->getLoopPreheader();
+  assert(OrigPH && "No preheader");
+  BasicBlock *NewPH = CloneBasicBlock(OrigPH, VMap, NameSuffix, F);
+  // To rename the loop PHIs.
+  VMap[OrigPH] = NewPH;
+  Blocks.push_back(NewPH);
+
+  // Update LoopInfo.
+  if (ParentLoop)
+    ParentLoop->addBasicBlockToLoop(NewPH, *LI);
+
+  // Update DominatorTree.
+  DT->addNewBlock(NewPH, LoopDomBB);
+
+  for (BasicBlock *BB : OrigLoop->getBlocks()) {
+    BasicBlock *NewBB = CloneBasicBlock(BB, VMap, NameSuffix, F);
+    VMap[BB] = NewBB;
+
+    // Update LoopInfo.
+    NewLoop->addBasicBlockToLoop(NewBB, *LI);
+
+    // Update DominatorTree.
+    BasicBlock *IDomBB = DT->getNode(BB)->getIDom()->getBlock();
+    DT->addNewBlock(NewBB, cast<BasicBlock>(VMap[IDomBB]));
+
+    Blocks.push_back(NewBB);
+  }
+
+  // Move them physically from the end of the block list.
+  F->getBasicBlockList().splice(Before, F->getBasicBlockList(), NewPH);
+  F->getBasicBlockList().splice(Before, F->getBasicBlockList(),
+                                NewLoop->getHeader(), F->end());
+
+  return NewLoop;
+}