From 6f32cee78189259c220b8b992d3432b39d0b2c61 Mon Sep 17 00:00:00 2001
From: zakrad <49591476+zakrad@users.noreply.github.com>
Date: Tue, 3 Nov 2026 14:19:24 +0330
Subject: [PATCH] Add codegen test for step_by(1) loop vectorization

---
 .../issues/step-by-one-vectorized-57517.rs     | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 tests/codegen-llvm/issues/step-by-one-vectorized-57517.rs

diff --git a/tests/codegen-llvm/issues/step-by-one-vectorized-57517.rs b/tests/codegen-llvm/issues/step-by-one-vectorized-57517.rs
new file mode 100644
index 0000000000000..026348febf880
--- /dev/null
+++ b/tests/codegen-llvm/issues/step-by-one-vectorized-57517.rs
@@ -0,0 +1,18 @@
+//! Regression test for <https://github.com/rust-lang/rust/issues/57517>.
+//!
+//! A loop over `iter_mut().step_by(1)` must be vectorized, like the same loop
+//! without `step_by`.
+
+//@ compile-flags: -Copt-level=3
+//@ only-x86_64
+
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @step_by_one
+#[no_mangle]
+pub fn step_by_one(arr: &mut [i32]) {
+    // CHECK: add <{{[0-9]+}} x i32>
+    for e in arr.iter_mut().step_by(1) {
+        *e = e.wrapping_add(3);
+    }
+}