2 files changed, 48 insertions, 0 deletions
diff --git a/gcc/rust/typecheck/rust-tyty.cc b/gcc/rust/typecheck/rust-tyty.cc
index 84aa835..c509d9b 100644
--- a/gcc/rust/typecheck/rust-tyty.cc
+++ b/gcc/rust/typecheck/rust-tyty.cc
@@ -2441,6 +2441,9 @@ ReferenceType::is_equal (const BaseType &other) const
     return false;
 
   auto other2 = static_cast<const ReferenceType &> (other);
+  if (mutability () != other2.mutability ())
+    return false;
+
   return get_base ()->is_equal (*other2.get_base ());
 }
 
@@ -2535,6 +2538,9 @@ PointerType::is_equal (const BaseType &other) const
     return false;
 
   auto other2 = static_cast<const PointerType &> (other);
+  if (mutability () != other2.mutability ())
+    return false;
+
   return get_base ()->is_equal (*other2.get_base ());
 }
 
diff --git a/gcc/testsuite/rust/compile/issue-1289.rs b/gcc/testsuite/rust/compile/issue-1289.rs
new file mode 100644
index 0000000..8634f1d
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-1289.rs
@@ -0,0 +1,42 @@
+extern "C" {
+    fn printf(s: *const i8, ...);
+}
+
+mod intrinsics {
+    extern "rust-intrinsic" {
+        pub fn offset<T>(dst: *const T, offset: isize) -> *const T;
+    }
+}
+
+#[lang = "mut_ptr"]
+impl<T> *mut T {
+    pub const unsafe fn offset(self, count: isize) -> *mut T {
+        unsafe { intrinsics::offset(self, count) as *mut T }
+    }
+
+    pub const unsafe fn add(self, count: usize) -> Self {
+        unsafe { self.offset(count as isize) }
+    }
+}
+
+#[lang = "const_ptr"]
+impl<T> *const T {
+    pub const unsafe fn offset(self, count: isize) -> *mut T {
+        // { dg-warning "associated function is never used" "" { target *-*-* } .-1 }
+        unsafe { intrinsics::offset(self, count) as *mut T }
+    }
+
+    pub const unsafe fn add(self, count: usize) -> Self {
+        // { dg-warning "associated function is never used" "" { target *-*-* } .-1 }
+        unsafe { self.offset(count as isize) }
+    }
+}
+
+fn main() -> i32 {
+    let a: *mut _ = &mut 123;
+    unsafe {
+        let _b = a.add(123);
+    }
+
+    0
+}