[llvm] Construct SmallVector with ArrayRef (NFC) (#102712)

Without this patch, the constructor arguments come from
SmallVectorImpl, not ArrayRef.  This patch switches them to ArrayRef
so that we can construct SmallVector with a single argument.

Note that LLVM Programmer’s Manual prefers ArrayRef to SmallVectorImpl
for flexibility.

Author: kazutakahirata

llvm/include/llvm/Analysis/ScalarEvolution.h

@@ -427,9 +427,7 @@ class SCEVUnionPredicate final : public SCEVPredicate {
 public:
   SCEVUnionPredicate(ArrayRef<const SCEVPredicate *> Preds);
 
-  const SmallVectorImpl<const SCEVPredicate *> &getPredicates() const {
-    return Preds;
-  }
+  ArrayRef<const SCEVPredicate *> getPredicates() const { return Preds; }
 
   /// Implementation of the SCEVPredicate interface
   bool isAlwaysTrue() const override;

llvm/lib/Analysis/ScalarEvolution.cpp

@@ -14914,8 +14914,7 @@ void PredicatedScalarEvolution::addPredicate(const SCEVPredicate &Pred) {
   if (Preds->implies(&Pred))
     return;
 
-  auto &OldPreds = Preds->getPredicates();
-  SmallVector<const SCEVPredicate*, 4> NewPreds(OldPreds.begin(), OldPreds.end());
+  SmallVector<const SCEVPredicate *, 4> NewPreds(Preds->getPredicates());
   NewPreds.push_back(&Pred);
   Preds = std::make_unique<SCEVUnionPredicate>(NewPreds);
   updateGeneration();

llvm/lib/Transforms/Utils/LCSSA.cpp

@@ -335,12 +335,11 @@ bool llvm::formLCSSAForInstructions(SmallVectorImpl<Instruction *> &Worklist,
 
 // Compute the set of BasicBlocks in the loop `L` dominating at least one exit.
 static void computeBlocksDominatingExits(
-    Loop &L, const DominatorTree &DT,
-    const SmallVectorImpl<BasicBlock *> &ExitBlocks,
+    Loop &L, const DominatorTree &DT, ArrayRef<BasicBlock *> ExitBlocks,
     SmallSetVector<BasicBlock *, 8> &BlocksDominatingExits) {
   // We start from the exit blocks, as every block trivially dominates itself
   // (not strictly).
-  SmallVector<BasicBlock *, 8> BBWorklist(ExitBlocks.begin(), ExitBlocks.end());
+  SmallVector<BasicBlock *, 8> BBWorklist(ExitBlocks);
 
   while (!BBWorklist.empty()) {
     BasicBlock *BB = BBWorklist.pop_back_val();

llvm/utils/TableGen/Common/DAGISelMatcher.cpp

@@ -91,10 +91,10 @@ SwitchTypeMatcher::~SwitchTypeMatcher() {
     delete C.second;
 }
 
-CheckPredicateMatcher::CheckPredicateMatcher(
-    const TreePredicateFn &pred, const SmallVectorImpl<unsigned> &Ops)
+CheckPredicateMatcher::CheckPredicateMatcher(const TreePredicateFn &pred,
+                                             ArrayRef<unsigned> Ops)
     : Matcher(CheckPredicate), Pred(pred.getOrigPatFragRecord()),
-      Operands(Ops.begin(), Ops.end()) {}
+      Operands(Ops) {}
 
 TreePredicateFn CheckPredicateMatcher::getPredicate() const {
   return TreePredicateFn(Pred);

llvm/utils/TableGen/Common/DAGISelMatcher.h

@@ -452,7 +452,7 @@ class CheckPredicateMatcher : public Matcher {
 
 public:
   CheckPredicateMatcher(const TreePredicateFn &pred,
-                        const SmallVectorImpl<unsigned> &Operands);
+                        ArrayRef<unsigned> Operands);
 
   TreePredicateFn getPredicate() const;
   unsigned getNumOperands() const;