add CSE optimization tests for iterating over slice #150065

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Merged

Jan 25, 2026

tests/codegen-llvm/slice_cse_optimization.rs

-Original file line number
+Diff line change
@@ -0,0 +1,46 @@
+    //! Various iterating method over slice correctly optimized using common subexpression elimination.
+    //! Checks function has memory(argmem: read) attribute.
+    //! Regression test for <https://github.com/rust-lang/rust/issues/119573>.
+    //@ compile-flags: -O
+    #![crate_type = "lib"]
+    // CHECK-LABEL: @has_zero_iter
+    // CHECK-SAME: #[[ATTR:[0-9]+]]
+    #[inline(never)]
+    #[unsafe(no_mangle)]
+    pub fn has_zero_iter(xs: &[u8]) -> bool {
+        xs.iter().any(|&x| x == 0)
+    }
+    // CHECK-LABEL: @has_zero_ptr
+    // CHECK-SAME: #[[ATTR]]
+    #[inline(never)]
+    #[unsafe(no_mangle)]
+    fn has_zero_ptr(xs: &[u8]) -> bool {
+        let range = xs.as_ptr_range();
+        let mut start = range.start;
+        let end = range.end;
+        while start < end {
+            unsafe {
+                if *start == 0 {
+                    return true;
+                }
+                start = start.add(1);
+            }
+        }
+        false
+    }
+    // CHECK-LABEL: @has_zero_for
+    // CHECK-SAME: #[[ATTR]]
+    #[inline(never)]
+    #[unsafe(no_mangle)]
+    fn has_zero_for(xs: &[u8]) -> bool {
+        for x in xs {
+            if *x == 0 {
+                return true;
+            }
+        }
+        false
+    }
+    // CHECK: attributes #[[ATTR]] = { {{.*}}memory(argmem: read){{.*}} }

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