[Transforms] Construct SmallVector with iterator ranges (NFC)

llvm/lib/Transforms/IPO/ExpandVariadics.cpp

@@ -604,9 +604,7 @@ ExpandVariadics::defineVariadicWrapper(Module &M, IRBuilder<> &Builder,
   Builder.CreateIntrinsic(Intrinsic::vastart, {DL.getAllocaPtrType(Ctx)},
                           {VaListInstance});
 
-  SmallVector<Value *> Args;
-  for (Argument &A : F.args())
-    Args.push_back(&A);
+  SmallVector<Value *> Args(llvm::make_pointer_range(F.args()));
 
   Type *ParameterType = ABI->vaListParameterType(M);
   if (ABI->vaListPassedInSSARegister())

llvm/lib/Transforms/Scalar/ConstraintElimination.cpp

@@ -1740,9 +1740,7 @@ static bool eliminateConstraints(Function &F, DominatorTree &DT, LoopInfo &LI,
                                  OptimizationRemarkEmitter &ORE) {
   bool Changed = false;
   DT.updateDFSNumbers();
-  SmallVector<Value *> FunctionArgs;
-  for (Value &Arg : F.args())
-    FunctionArgs.push_back(&Arg);
+  SmallVector<Value *> FunctionArgs(llvm::make_pointer_range(F.args()));
   ConstraintInfo Info(F.getDataLayout(), FunctionArgs);
   State S(DT, LI, SE);
   std::unique_ptr<Module> ReproducerModule(

llvm/lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -599,9 +599,8 @@ bool IndVarSimplify::simplifyAndExtend(Loop *L,
       L->getBlocks()[0]->getModule(), Intrinsic::experimental_guard);
   bool HasGuards = GuardDecl && !GuardDecl->use_empty();
 
-  SmallVector<PHINode *, 8> LoopPhis;
-  for (PHINode &PN : L->getHeader()->phis())
-    LoopPhis.push_back(&PN);
+  SmallVector<PHINode *, 8> LoopPhis(
+      llvm::make_pointer_range(L->getHeader()->phis()));
 
   // Each round of simplification iterates through the SimplifyIVUsers worklist
   // for all current phis, then determines whether any IVs can be

llvm/lib/Transforms/Scalar/LoopInterchange.cpp

@@ -1574,13 +1574,11 @@ static void moveLCSSAPhis(BasicBlock *InnerExit, BasicBlock *InnerHeader,
     P.eraseFromParent();
   }
 
-  SmallVector<PHINode *, 8> LcssaInnerExit;
-  for (PHINode &P : InnerExit->phis())
-    LcssaInnerExit.push_back(&P);
+  SmallVector<PHINode *, 8> LcssaInnerExit(
+      llvm::make_pointer_range(InnerExit->phis()));
 
-  SmallVector<PHINode *, 8> LcssaInnerLatch;
-  for (PHINode &P : InnerLatch->phis())
-    LcssaInnerLatch.push_back(&P);
+  SmallVector<PHINode *, 8> LcssaInnerLatch(
+      llvm::make_pointer_range(InnerLatch->phis()));
 
   // Lcssa PHIs for values used outside the inner loop are in InnerExit.
   // If a PHI node has users outside of InnerExit, it has a use outside the

llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp

@@ -361,9 +361,8 @@ class ConstantTerminatorFoldingImpl {
     for (BasicBlock *BB : DeadExitBlocks) {
       // Eliminate all Phis and LandingPads from dead exits.
       // TODO: Consider removing all instructions in this dead block.
-      SmallVector<Instruction *, 4> DeadInstructions;
-      for (auto &PN : BB->phis())
-        DeadInstructions.push_back(&PN);
+      SmallVector<Instruction *, 4> DeadInstructions(
+          llvm::make_pointer_range(BB->phis()));
 
       if (auto *LandingPad = dyn_cast<LandingPadInst>(BB->getFirstNonPHIIt()))
         DeadInstructions.emplace_back(LandingPad);

llvm/lib/Transforms/Utils/BasicBlockUtils.cpp

@@ -165,9 +165,7 @@ bool llvm::DeleteDeadPHIs(BasicBlock *BB, const TargetLibraryInfo *TLI,
                           MemorySSAUpdater *MSSAU) {
   // Recursively deleting a PHI may cause multiple PHIs to be deleted
   // or RAUW'd undef, so use an array of WeakTrackingVH for the PHIs to delete.
-  SmallVector<WeakTrackingVH, 8> PHIs;
-  for (PHINode &PN : BB->phis())
-    PHIs.push_back(&PN);
+  SmallVector<WeakTrackingVH, 8> PHIs(llvm::make_pointer_range(BB->phis()));
 
   bool Changed = false;
   for (unsigned i = 0, e = PHIs.size(); i != e; ++i)

llvm/lib/Transforms/Utils/CodeExtractor.cpp

@@ -91,10 +91,7 @@ static bool isBlockValidForExtraction(const BasicBlock &BB,
   // don't hoist code that uses another basicblock address, as it's likely to
   // lead to unexpected behavior, like cross-function jumps
   SmallPtrSet<User const *, 16> Visited;
-  SmallVector<User const *, 16> ToVisit;
-
-  for (Instruction const &Inst : BB)
-    ToVisit.push_back(&Inst);
+  SmallVector<User const *, 16> ToVisit(llvm::make_pointer_range(BB));
 
   while (!ToVisit.empty()) {
     User const *Curr = ToVisit.pop_back_val();

llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp

@@ -1715,9 +1715,8 @@ SCEVExpander::replaceCongruentIVs(Loop *L, const DominatorTree *DT,
                                   SmallVectorImpl<WeakTrackingVH> &DeadInsts,
                                   const TargetTransformInfo *TTI) {
   // Find integer phis in order of increasing width.
-  SmallVector<PHINode*, 8> Phis;
-  for (PHINode &PN : L->getHeader()->phis())
-    Phis.push_back(&PN);
+  SmallVector<PHINode *, 8> Phis(
+      llvm::make_pointer_range(L->getHeader()->phis()));
 
   if (TTI)
     // Use stable_sort to preserve order of equivalent PHIs, so the order

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -8267,9 +8267,8 @@ EpilogueVectorizerEpilogueLoop::createEpilogueVectorizedLoopSkeleton() {
   // The vec.epilog.iter.check block may contain Phi nodes from inductions or
   // reductions which merge control-flow from the latch block and the middle
   // block. Update the incoming values here and move the Phi into the preheader.
-  SmallVector<PHINode *, 4> PhisInBlock;
-  for (PHINode &Phi : VecEpilogueIterationCountCheck->phis())
-    PhisInBlock.push_back(&Phi);
+  SmallVector<PHINode *, 4> PhisInBlock(
+      llvm::make_pointer_range(VecEpilogueIterationCountCheck->phis()));
 
   for (PHINode *Phi : PhisInBlock) {
     Phi->moveBefore(LoopVectorPreHeader->getFirstNonPHIIt());