[SCEV] Use reverse() (NFC)

Author: nikic

llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp

@@ -2822,9 +2822,7 @@ static const SCEV *getExprBase(const SCEV *S) {
     // there's nothing more complex.
     // FIXME: not sure if we want to recognize negation.
     const SCEVAddExpr *Add = cast<SCEVAddExpr>(S);
-    for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(Add->op_end()),
-           E(Add->op_begin()); I != E; ++I) {
-      const SCEV *SubExpr = *I;
+    for (const SCEV *SubExpr : reverse(Add->operands())) {
       if (SubExpr->getSCEVType() == scAddExpr)
         return getExprBase(SubExpr);
 

llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp

@@ -747,9 +747,8 @@ Value *SCEVExpander::visitAddExpr(const SCEVAddExpr *S) {
   // so that pointer operands are inserted first, which the code below relies on
   // to form more involved GEPs.
   SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops;
-  for (std::reverse_iterator<SCEVAddExpr::op_iterator> I(S->op_end()),
-       E(S->op_begin()); I != E; ++I)
-    OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I));
+  for (const SCEV *Op : reverse(S->operands()))
+    OpsAndLoops.push_back(std::make_pair(getRelevantLoop(Op), Op));
 
   // Sort by loop. Use a stable sort so that constants follow non-constants and
   // pointer operands precede non-pointer operands.
@@ -811,9 +810,8 @@ Value *SCEVExpander::visitMulExpr(const SCEVMulExpr *S) {
   // Collect all the mul operands in a loop, along with their associated loops.
   // Iterate in reverse so that constants are emitted last, all else equal.
   SmallVector<std::pair<const Loop *, const SCEV *>, 8> OpsAndLoops;
-  for (std::reverse_iterator<SCEVMulExpr::op_iterator> I(S->op_end()),
-       E(S->op_begin()); I != E; ++I)
-    OpsAndLoops.push_back(std::make_pair(getRelevantLoop(*I), *I));
+  for (const SCEV *Op : reverse(S->operands()))
+    OpsAndLoops.push_back(std::make_pair(getRelevantLoop(Op), Op));
 
   // Sort by loop. Use a stable sort so that constants follow non-constants.
   llvm::stable_sort(OpsAndLoops, LoopCompare(SE.DT));