[meta] Uniquely number every instruction in the Rust crate;

cranelift/codegen/meta/src/constant_hash.rs

@@ -1,3 +1,5 @@
+use std::iter;
+
 pub fn simple_hash(s: &str) -> usize {
     let mut h: u32 = 5381;
     for c in s.chars() {
@@ -9,8 +11,12 @@ pub fn simple_hash(s: &str) -> usize {
 /// Compute an open addressed, quadratically probed hash table containing
 /// `items`. The returned table is a list containing the elements of the
 /// iterable `items` and `None` in unused slots.
-pub fn generate_table<T, H: Fn(&T) -> usize>(items: &Vec<T>, hash_function: H) -> Vec<Option<&T>> {
-    let size = (1.20 * items.len() as f64) as usize;
+pub fn generate_table<'cont, T, I: iter::Iterator<Item = &'cont T>, H: Fn(&T) -> usize>(
+    items: I,
+    num_items: usize,
+    hash_function: H,
+) -> Vec<Option<&'cont T>> {
+    let size = (1.20 * num_items as f64) as usize;
     // TODO do we really need the multiply by two here?
     let size = if size.is_power_of_two() {
         size * 2
@@ -18,10 +24,10 @@ pub fn generate_table<T, H: Fn(&T) -> usize>(items: &Vec<T>, hash_function: H) -
         size.next_power_of_two()
     };
 
-    let mut table: Vec<Option<&T>> = vec![None; size];
+    let mut table = vec![None; size];
 
     for i in items {
-        let mut h = hash_function(i) % size;
+        let mut h = hash_function(&i) % size;
         let mut s = 0;
         while table[h].is_some() {
             s += 1;
@@ -36,7 +42,7 @@ pub fn generate_table<T, H: Fn(&T) -> usize>(items: &Vec<T>, hash_function: H) -
 #[test]
 fn test_generate_table() {
     let v = vec!["Hello".to_string(), "world".to_string()];
-    let table = generate_table(&v, |s| simple_hash(&s));
+    let table = generate_table(v.iter(), v.len(), |s| simple_hash(&s));
     assert_eq!(
         table,
         vec![