Add Loop contains utility methods for testing whether a loop

contains another loop, or an instruction. The loop form is
substantially more efficient on large loops than the typical
code it replaces.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91654 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/LoopInfo.h

@@ -93,12 +93,28 @@ public:
   BlockT *getHeader() const { return Blocks.front(); }
   LoopT *getParentLoop() const { return ParentLoop; }
 
-  /// contains - Return true if the specified basic block is in this loop
+  /// contains - Return true if the specified loop is contained within in
+  /// this loop.
+  ///
+  bool contains(const LoopT *L) const {
+    if (L == this) return true;
+    if (L == 0)    return false;
+    return contains(L->getParentLoop());
+  }
+    
+  /// contains - Return true if the specified basic block is in this loop.
   ///
   bool contains(const BlockT *BB) const {
     return std::find(block_begin(), block_end(), BB) != block_end();
   }
 
+  /// contains - Return true if the specified instruction is in this loop.
+  ///
+  template<class InstT>
+  bool contains(const InstT *Inst) const {
+    return contains(Inst->getParent());
+  }
+
   /// iterator/begin/end - Return the loops contained entirely within this loop.
   ///
   const std::vector<LoopT *> &getSubLoops() const { return SubLoops; }

lib/Analysis/IVUsers.cpp

@@ -53,7 +53,7 @@ static bool containsAddRecFromDifferentLoop(const SCEV *S, Loop *L) {
       if (newLoop == L)
         return false;
       // if newLoop is an outer loop of L, this is OK.
-      if (newLoop->contains(L->getHeader()))
+      if (newLoop->contains(L))
         return false;
     }
     return true;
@@ -148,7 +148,7 @@ static bool IVUseShouldUsePostIncValue(Instruction *User, Instruction *IV,
                                        Loop *L, LoopInfo *LI, DominatorTree *DT,
                                        Pass *P) {
   // If the user is in the loop, use the preinc value.
-  if (L->contains(User->getParent())) return false;
+  if (L->contains(User)) return false;
 
   BasicBlock *LatchBlock = L->getLoopLatch();
   if (!LatchBlock)
@@ -209,7 +209,7 @@ bool IVUsers::AddUsersIfInteresting(Instruction *I) {
     return false;  // Non-reducible symbolic expression, bail out.
 
   // Keep things simple. Don't touch loop-variant strides.
-  if (!Stride->isLoopInvariant(L) && L->contains(I->getParent()))
+  if (!Stride->isLoopInvariant(L) && L->contains(I))
     return false;
 
   SmallPtrSet<Instruction *, 4> UniqueUsers;
@@ -324,7 +324,7 @@ const SCEV *IVUsers::getReplacementExpr(const IVStrideUse &U) const {
   if (U.isUseOfPostIncrementedValue())
     RetVal = SE->getAddExpr(RetVal, U.getParent()->Stride);
   // Evaluate the expression out of the loop, if possible.
-  if (!L->contains(U.getUser()->getParent())) {
+  if (!L->contains(U.getUser())) {
     const SCEV *ExitVal = SE->getSCEVAtScope(RetVal, L->getParentLoop());
     if (ExitVal->isLoopInvariant(L))
       RetVal = ExitVal;

lib/Analysis/LoopInfo.cpp

@@ -56,7 +56,7 @@ bool Loop::isLoopInvariant(Value *V) const {
 /// loop-invariant.
 ///
 bool Loop::isLoopInvariant(Instruction *I) const {
-  return !contains(I->getParent());
+  return !contains(I);
 }
 
 /// makeLoopInvariant - If the given value is an instruciton inside of the

lib/Analysis/ScalarEvolution.cpp

@@ -298,7 +298,7 @@ bool SCEVAddRecExpr::isLoopInvariant(const Loop *QueryLoop) const {
     return false;
 
   // This recurrence is variant w.r.t. QueryLoop if QueryLoop contains L.
-  if (QueryLoop->contains(L->getHeader()))
+  if (QueryLoop->contains(L))
     return false;
 
   // This recurrence is variant w.r.t. QueryLoop if any of its operands
@@ -333,7 +333,7 @@ bool SCEVUnknown::isLoopInvariant(const Loop *L) const {
   // Instructions are never considered invariant in the function body
   // (null loop) because they are defined within the "loop".
   if (Instruction *I = dyn_cast<Instruction>(V))
-    return L && !L->contains(I->getParent());
+    return L && !L->contains(I);
   return true;
 }
 
@@ -3774,7 +3774,7 @@ static PHINode *getConstantEvolvingPHI(Value *V, const Loop *L) {
   // If this is not an instruction, or if this is an instruction outside of the
   // loop, it can't be derived from a loop PHI.
   Instruction *I = dyn_cast<Instruction>(V);
-  if (I == 0 || !L->contains(I->getParent())) return 0;
+  if (I == 0 || !L->contains(I)) return 0;
 
   if (PHINode *PN = dyn_cast<PHINode>(I)) {
     if (L->getHeader() == I->getParent())
@@ -4091,7 +4091,7 @@ const SCEV *ScalarEvolution::computeSCEVAtScope(const SCEV *V, const Loop *L) {
   // If this is a loop recurrence for a loop that does not contain L, then we
   // are dealing with the final value computed by the loop.
   if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(V)) {
-    if (!L || !AddRec->getLoop()->contains(L->getHeader())) {
+    if (!L || !AddRec->getLoop()->contains(L)) {
       // To evaluate this recurrence, we need to know how many times the AddRec
       // loop iterates.  Compute this now.
       const SCEV *BackedgeTakenCount = getBackedgeTakenCount(AddRec->getLoop());

lib/CodeGen/MachineLICM.cpp

@@ -322,7 +322,7 @@ bool MachineLICM::IsLoopInvariantInst(MachineInstr &I) {
 
     // If the loop contains the definition of an operand, then the instruction
     // isn't loop invariant.
-    if (CurLoop->contains(RegInfo->getVRegDef(Reg)->getParent()))
+    if (CurLoop->contains(RegInfo->getVRegDef(Reg)))
       return false;
   }
 

lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -258,7 +258,7 @@ void IndVarSimplify::RewriteLoopExitValues(Loop *L,
 
         // Check that InVal is defined in the loop.
         Instruction *Inst = cast<Instruction>(InVal);
-        if (!L->contains(Inst->getParent()))
+        if (!L->contains(Inst))
           continue;
 
         // Okay, this instruction has a user outside of the current loop

lib/Transforms/Scalar/LICM.cpp

@@ -433,7 +433,7 @@ bool LICM::isNotUsedInLoop(Instruction &I) {
         if (PN->getIncomingValue(i) == &I)
           if (CurLoop->contains(PN->getIncomingBlock(i)))
             return false;
-    } else if (CurLoop->contains(User->getParent())) {
+    } else if (CurLoop->contains(User)) {
       return false;
     }
   }
@@ -831,7 +831,7 @@ void LICM::FindPromotableValuesInLoop(
          UI != UE; ++UI) {
       // Ignore instructions not in this loop.
       Instruction *Use = dyn_cast<Instruction>(*UI);
-      if (!Use || !CurLoop->contains(Use->getParent()))
+      if (!Use || !CurLoop->contains(Use))
         continue;
 
       if (!isa<LoadInst>(Use) && !isa<StoreInst>(Use)) {

lib/Transforms/Scalar/LoopIndexSplit.cpp

@@ -288,7 +288,7 @@ bool LoopIndexSplit::runOnLoop(Loop *IncomingLoop, LPPassManager &LPM_Ref) {
 // isUsedOutsideLoop - Returns true iff V is used outside the loop L.
 static bool isUsedOutsideLoop(Value *V, Loop *L) {
   for(Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E; ++UI)
-    if (!L->contains(cast<Instruction>(*UI)->getParent()))
+    if (!L->contains(cast<Instruction>(*UI)))
       return true;
   return false;
 }
@@ -842,7 +842,7 @@ void LoopIndexSplit::updatePHINodes(BasicBlock *ExitBB, BasicBlock *Latch,
       for (Value::use_iterator UI = PHV->use_begin(), E = PHV->use_end(); 
            UI != E; ++UI) 
         if (PHINode *U = dyn_cast<PHINode>(*UI)) 
-          if (LP->contains(U->getParent())) {
+          if (LP->contains(U)) {
             NewV = U;
             break;
           }

lib/Transforms/Scalar/LoopStrengthReduce.cpp

@@ -388,7 +388,7 @@ void BasedUser::RewriteInstructionToUseNewBase(const SCEV *NewBase,
     // If this is a use outside the loop (which means after, since it is based
     // on a loop indvar) we use the post-incremented value, so that we don't
     // artificially make the preinc value live out the bottom of the loop.
-    if (!isUseOfPostIncrementedValue && L->contains(Inst->getParent())) {
+    if (!isUseOfPostIncrementedValue && L->contains(Inst)) {
       if (NewBasePt && isa<PHINode>(OperandValToReplace)) {
         InsertPt = NewBasePt;
         ++InsertPt;
@@ -429,7 +429,7 @@ void BasedUser::RewriteInstructionToUseNewBase(const SCEV *NewBase,
       // that case(?).
       Instruction *OldLoc = dyn_cast<Instruction>(OperandValToReplace);
       BasicBlock *PHIPred = PN->getIncomingBlock(i);
-      if (L->contains(OldLoc->getParent())) {
+      if (L->contains(OldLoc)) {
         // If this is a critical edge, split the edge so that we do not insert
         // the code on all predecessor/successor paths.  We do this unless this
         // is the canonical backedge for this loop, as this can make some
@@ -446,7 +446,7 @@ void BasedUser::RewriteInstructionToUseNewBase(const SCEV *NewBase,
           // is outside of the loop, and PredTI is in the loop, we want to
           // move the block to be immediately before the PHI block, not
           // immediately after PredTI.
-          if (L->contains(PHIPred) && !L->contains(PN->getParent()))
+          if (L->contains(PHIPred) && !L->contains(PN))
             NewBB->moveBefore(PN->getParent());
 
           // Splitting the edge can reduce the number of PHI entries we have.
@@ -458,7 +458,7 @@ void BasedUser::RewriteInstructionToUseNewBase(const SCEV *NewBase,
       Value *&Code = InsertedCode[PHIPred];
       if (!Code) {
         // Insert the code into the end of the predecessor block.
-        Instruction *InsertPt = (L->contains(OldLoc->getParent())) ?
+        Instruction *InsertPt = (L->contains(OldLoc)) ?
                                 PHIPred->getTerminator() :
                                 OldLoc->getParent()->getTerminator();
         Code = InsertCodeForBaseAtPosition(NewBase, PN->getType(),
@@ -697,7 +697,7 @@ RemoveCommonExpressionsFromUseBases(std::vector<BasedUser> &Uses,
     // it is clearly shared across all the IV's.  If the use is outside the loop
     // (which means after it) we don't want to factor anything *into* the loop,
     // so just use 0 as the base.
-    if (L->contains(Uses[0].Inst->getParent()))
+    if (L->contains(Uses[0].Inst))
       std::swap(Result, Uses[0].Base);
     return Result;
   }
@@ -722,7 +722,7 @@ RemoveCommonExpressionsFromUseBases(std::vector<BasedUser> &Uses,
     // after the loop to affect base computation of values *inside* the loop,
     // because we can always add their offsets to the result IV after the loop
     // is done, ensuring we get good code inside the loop.
-    if (!L->contains(Uses[i].Inst->getParent()))
+    if (!L->contains(Uses[i].Inst))
       continue;
     NumUsesInsideLoop++;
 
@@ -778,7 +778,7 @@ RemoveCommonExpressionsFromUseBases(std::vector<BasedUser> &Uses,
     // and a Result in the same instruction (for example because it would
     // require too many registers).  Check this.
     for (unsigned i=0; i<NumUses; ++i) {
-      if (!L->contains(Uses[i].Inst->getParent()))
+      if (!L->contains(Uses[i].Inst))
         continue;
       // We know this is an addressing mode use; if there are any uses that
       // are not, FreeResult would be Zero.
@@ -814,7 +814,7 @@ RemoveCommonExpressionsFromUseBases(std::vector<BasedUser> &Uses,
     // the final IV value coming into those uses does.  Instead of trying to
     // remove the pieces of the common base, which might not be there,
     // subtract off the base to compensate for this.
-    if (!L->contains(Uses[i].Inst->getParent())) {
+    if (!L->contains(Uses[i].Inst)) {
       Uses[i].Base = SE->getMinusSCEV(Uses[i].Base, Result);
       continue;
     }
@@ -1109,7 +1109,7 @@ const SCEV *LoopStrengthReduce::CollectIVUsers(const SCEV *Stride,
     // If the user is not in the current loop, this means it is using the exit
     // value of the IV.  Do not put anything in the base, make sure it's all in
     // the immediate field to allow as much factoring as possible.
-    if (!L->contains(UsersToProcess[i].Inst->getParent())) {
+    if (!L->contains(UsersToProcess[i].Inst)) {
       UsersToProcess[i].Imm = SE->getAddExpr(UsersToProcess[i].Imm,
                                              UsersToProcess[i].Base);
       UsersToProcess[i].Base =
@@ -1353,7 +1353,7 @@ static Instruction *FindIVIncInsertPt(std::vector<BasedUser> &UsersToProcess,
                                       const Loop *L) {
   if (UsersToProcess.size() == 1 &&
       UsersToProcess[0].isUseOfPostIncrementedValue &&
-      L->contains(UsersToProcess[0].Inst->getParent()))
+      L->contains(UsersToProcess[0].Inst))
     return UsersToProcess[0].Inst;
   return L->getLoopLatch()->getTerminator();
 }
@@ -1626,7 +1626,7 @@ LoopStrengthReduce::StrengthReduceIVUsersOfStride(const SCEV *Stride,
         // loop to ensure it is dominated by the increment. In case it's the
         // only use of the iv, the increment instruction is already before the
         // use.
-        if (L->contains(User.Inst->getParent()) && User.Inst != IVIncInsertPt)
+        if (L->contains(User.Inst) && User.Inst != IVIncInsertPt)
           User.Inst->moveBefore(IVIncInsertPt);
       }
 
@@ -1688,7 +1688,7 @@ LoopStrengthReduce::StrengthReduceIVUsersOfStride(const SCEV *Stride,
         // common base, and are adding it back here.  Use the same expression
         // as before, rather than CommonBaseV, so DAGCombiner will zap it.
         if (!CommonExprs->isZero()) {
-          if (L->contains(User.Inst->getParent()))
+          if (L->contains(User.Inst))
             RewriteExpr = SE->getAddExpr(RewriteExpr,
                                        SE->getUnknown(CommonBaseV));
           else
@@ -2363,7 +2363,7 @@ static bool isUsedByExitBranch(ICmpInst *Cond, Loop *L) {
 static bool ShouldCountToZero(ICmpInst *Cond, IVStrideUse* &CondUse,
                               ScalarEvolution *SE, Loop *L,
                               const TargetLowering *TLI = 0) {
-  if (!L->contains(Cond->getParent()))
+  if (!L->contains(Cond))
     return false;
 
   if (!isa<SCEVConstant>(CondUse->getOffset()))

lib/Transforms/Scalar/LoopUnswitch.cpp

@@ -877,7 +877,7 @@ void LoopUnswitch::RewriteLoopBodyWithConditionConstant(Loop *L, Value *LIC,
     
     for (unsigned i = 0, e = Users.size(); i != e; ++i)
       if (Instruction *U = cast<Instruction>(Users[i])) {
-        if (!L->contains(U->getParent()))
+        if (!L->contains(U))
           continue;
         U->replaceUsesOfWith(LIC, Replacement);
         Worklist.push_back(U);
@@ -888,7 +888,7 @@ void LoopUnswitch::RewriteLoopBodyWithConditionConstant(Loop *L, Value *LIC,
     // can.  This case occurs when we unswitch switch statements.
     for (unsigned i = 0, e = Users.size(); i != e; ++i)
       if (Instruction *U = cast<Instruction>(Users[i])) {
-        if (!L->contains(U->getParent()))
+        if (!L->contains(U))
           continue;
 
         Worklist.push_back(U);

lib/Transforms/Utils/BreakCriticalEdges.cpp

@@ -309,10 +309,10 @@ BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum,
         if (TIL == DestLoop) {
           // Both in the same loop, the NewBB joins loop.
           DestLoop->addBasicBlockToLoop(NewBB, LI->getBase());
-        } else if (TIL->contains(DestLoop->getHeader())) {
+        } else if (TIL->contains(DestLoop)) {
           // Edge from an outer loop to an inner loop.  Add to the outer loop.
           TIL->addBasicBlockToLoop(NewBB, LI->getBase());
-        } else if (DestLoop->contains(TIL->getHeader())) {
+        } else if (DestLoop->contains(TIL)) {
           // Edge from an inner loop to an outer loop.  Add to the outer loop.
           DestLoop->addBasicBlockToLoop(NewBB, LI->getBase());
         } else {

lib/Transforms/Utils/LoopUnroll.cpp

@@ -194,7 +194,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
     OrigPHINode.push_back(PN);
     if (Instruction *I = 
                 dyn_cast<Instruction>(PN->getIncomingValueForBlock(LatchBlock)))
-      if (L->contains(I->getParent()))
+      if (L->contains(I))
         LastValueMap[I] = I;
   }
 
@@ -222,7 +222,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
           PHINode *NewPHI = cast<PHINode>(ValueMap[OrigPHINode[i]]);
           Value *InVal = NewPHI->getIncomingValueForBlock(LatchBlock);
           if (Instruction *InValI = dyn_cast<Instruction>(InVal))
-            if (It > 1 && L->contains(InValI->getParent()))
+            if (It > 1 && L->contains(InValI))
               InVal = LastValueMap[InValI];
           ValueMap[OrigPHINode[i]] = InVal;
           New->getInstList().erase(NewPHI);
@@ -244,7 +244,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
              UI != UE;) {
           Instruction *UseInst = cast<Instruction>(*UI);
           ++UI;
-          if (isa<PHINode>(UseInst) && !L->contains(UseInst->getParent())) {
+          if (isa<PHINode>(UseInst) && !L->contains(UseInst)) {
             PHINode *phi = cast<PHINode>(UseInst);
             Value *Incoming = phi->getIncomingValueForBlock(*BB);
             phi->addIncoming(Incoming, New);
@@ -295,7 +295,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, LoopInfo* LI, LPPassManager* LPM)
       // If this value was defined in the loop, take the value defined by the
       // last iteration of the loop.
       if (Instruction *InValI = dyn_cast<Instruction>(InVal)) {
-        if (L->contains(InValI->getParent()))
+        if (L->contains(InValI))
           InVal = LastValueMap[InVal];
       }
       PN->addIncoming(InVal, LastIterationBB);