[mlir] Use empty() instead of checking size() == 0 (NFC)

diff --git a/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp b/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
index 28f2052..a50cac9 100644 (file)
--- a/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
+++ b/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
@@ -400,7 +400,7 @@ struct AllocaScopeHoister : public OpRewritePattern<AllocaScopeOp> {
       return WalkResult::advance();
     });
 
-    if (!toHoist.size())
+    if (toHoist.empty())
       return failure();
     rewriter.setInsertionPoint(lastParentWithoutScope);
     for (auto op : toHoist) {