[BugFix] Handle vectorized SelectNode in codegen_cuda (#2843)

* [BugFix] Handle vectorized SelectNode in codegen_cuda

* address review comments

* [BugFix] Fix cuda codegen vectorized SelectNode when condition is a scalar

testing/python/issue/test_tilelang_issue_2682.py

@@ -0,0 +1,31 @@
+"""Regression test for issue #2682.
+
+T.vectorized with T.Select incorrectly generates scalar ternary expressions.
+CodeGenTileLangCUDA misses the handling of vectorized SelectNode, causing
+a fallback to CodeGenC in tvm that generates a scalar ternary expression.
+"""
+
+import tilelang
+import tilelang.language as T
+import tilelang.testing
+
+
+NUM_ELEMENTS = 4
+
+
+def test_vectorized_select():
+    @T.prim_func
+    def kernel(
+        source: T.Tensor[(NUM_ELEMENTS,), T.float32],
+        destination: T.Tensor[(NUM_ELEMENTS,), T.float32],
+    ):
+        with T.Kernel(1, threads=1):
+            for index in T.vectorized(NUM_ELEMENTS):
+                value = source[index]
+                destination[index] = T.Select(value > 0.0, value, value + 1.0)
+
+    tilelang.compile(kernel)
+
+
+if __name__ == "__main__":
+    tilelang.testing.main()