Assert set_param_alignment_attribute's alignment is a power of 2

src/values/call_site_value.rs

@@ -455,6 +455,10 @@ impl CallSiteValue {
 
     /// Shortcut for setting the alignment `Attribute` for this `CallSiteValue`.
     ///
+    /// # Panics
+    ///
+    /// When the alignment is not a power of 2.
+    ///
     /// # Example
     ///
     /// ```no_run
@@ -475,6 +479,8 @@ impl CallSiteValue {
     /// call_site_value.set_param_alignment_attribute(0, 2);
     /// ```
     pub fn set_param_alignment_attribute(&self, index: u32, alignment: u32) {
+        assert_eq!(alignment.count_ones(), 1, "Alignment must be a power of two.");
+
         unsafe {
             LLVMSetInstrParamAlignment(self.as_value_ref(), index, alignment)
         }

tests/all/test_values.rs

@@ -60,7 +60,7 @@ fn test_call_site() {
 
     assert_eq!(call_site.get_call_convention(), 2);
 
-    call_site.set_param_alignment_attribute(0, 12);
+    call_site.set_param_alignment_attribute(0, 16);
 }
 
 #[test]