[LIR] Push check into helper function. NFC.

llvm-svn: 254416

Author: Chad Rosier

llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp

@@ -257,6 +257,10 @@ static unsigned getStoreStride(const SCEVAddRecExpr *StoreEv) {
 }
 
 bool LoopIdiomRecognize::isLegalStore(StoreInst *SI) {
+  // Don't touch volatile stores.
+  if (!SI->isSimple())
+    return false;
+
   Value *StoredVal = SI->getValueOperand();
   Value *StorePtr = SI->getPointerOperand();
 
@@ -287,10 +291,6 @@ void LoopIdiomRecognize::collectStores(BasicBlock *BB) {
     if (!SI)
       continue;
 
-    // Don't touch volatile stores.
-    if (!SI->isSimple())
-      continue;
-
     // Make sure this is a strided store with a constant stride.
     if (!isLegalStore(SI))
       continue;