Merge pull request #3015 from rtfeldman/matrix-more-bitvec

Matrix more bitvec

compiler/can/src/def.rs

@@ -192,17 +192,12 @@ fn sort_type_defs_before_introduction(
     }
 
     // find the strongly connected components and their relations
-    let nodes: Vec<_> = (0..capacity as u32).collect();
-
-    let mut output = Vec::with_capacity(capacity);
-
-    for group in matrix.strongly_connected_components(&nodes).groups() {
-        for index in group.iter_ones() {
-            output.push(symbols[index])
-        }
-    }
-
-    output
+    matrix
+        .strongly_connected_components_all()
+        .groups()
+        .flat_map(|group| group.iter_ones())
+        .map(|index| symbols[index])
+        .collect()
 }
 
 #[inline(always)]
@@ -790,14 +785,10 @@ pub(crate) fn sort_can_defs(
         };
     }
 
-    let nodes: Vec<_> = (0..defs.len() as u32).collect();
-
     // We first perform SCC based on any reference, both variable usage and calls
     // considering both value definitions and function bodies. This will spot any
     // recursive relations between any 2 definitions.
-    let sccs = def_ordering
-        .references
-        .strongly_connected_components(&nodes);
+    let sccs = def_ordering.references.strongly_connected_components_all();
 
     let mut declarations = Vec::new();
 
@@ -838,10 +829,9 @@ pub(crate) fn sort_can_defs(
             // boom = \{} -> boom {}
             //
             // In general we cannot spot faulty recursion (halting problem) so this is our best attempt
-            let nodes: Vec<_> = group.iter_ones().map(|v| v as u32).collect();
             let direct_sccs = def_ordering
                 .direct_references
-                .strongly_connected_components(&nodes);
+                .strongly_connected_components_subset(group);
 
             let declaration = if direct_sccs.groups().count() == 1 {
                 // all defs are part of the same direct cycle, that is invalid!
@@ -1571,8 +1561,7 @@ fn correct_mutual_recursive_type_alias<'a>(
 
     let mut solved_aliases = bitvec::vec::BitVec::<usize>::repeat(false, capacity);
 
-    let group: Vec<_> = (0u32..capacity as u32).collect();
-    let sccs = matrix.strongly_connected_components(&group);
+    let sccs = matrix.strongly_connected_components_all();
 
     // scratchpad to store aliases that are modified in the current iteration.
     // Only used when there is are more than one alias in a group. See below why

compiler/can/src/reference_matrix.rs

@@ -129,8 +129,14 @@ impl ReferenceMatrix {
         TopologicalSort::Groups { groups }
     }
 
-    /// Get the strongly-connected components of the set of input nodes.
-    pub fn strongly_connected_components(&self, nodes: &[u32]) -> Sccs {
+    /// Get the strongly-connected components all nodes in the matrix
+    pub fn strongly_connected_components_all(&self) -> Sccs {
+        let bitvec = BitVec::repeat(true, self.length);
+        self.strongly_connected_components_subset(&bitvec)
+    }
+
+    /// Get the strongly-connected components of a set of input nodes.
+    pub fn strongly_connected_components_subset(&self, nodes: &BitSlice) -> Sccs {
         let mut params = Params::new(self.length, nodes);
 
         'outer: loop {
@@ -176,15 +182,15 @@ struct Params {
     p: Vec<u32>,
     s: Vec<u32>,
     scc: Sccs,
-    scca: Vec<u32>,
+    scca: BitVec,
 }
 
 impl Params {
-    fn new(length: usize, group: &[u32]) -> Self {
+    fn new(length: usize, group: &BitSlice) -> Self {
         let mut preorders = vec![Preorder::Removed; length];
 
-        for value in group {
-            preorders[*value as usize] = Preorder::Empty;
+        for index in group.iter_ones() {
+            preorders[index] = Preorder::Empty;
         }
 
         Self {
@@ -196,7 +202,7 @@ impl Params {
                 matrix: ReferenceMatrix::new(length),
                 components: 0,
             },
-            scca: Vec::new(),
+            scca: BitVec::repeat(false, length),
         }
     }
 }
@@ -210,7 +216,7 @@ fn recurse_onto(length: usize, bitvec: &BitVec, v: usize, params: &mut Params) {
     params.p.push(v as u32);
 
     for w in bitvec[v * length..][..length].iter_ones() {
-        if !params.scca.contains(&(w as u32)) {
+        if !params.scca[w] {
             match params.preorders[w] {
                 Preorder::Filled(pw) => loop {
                     let index = *params.p.last().unwrap();
@@ -241,7 +247,7 @@ fn recurse_onto(length: usize, bitvec: &BitVec, v: usize, params: &mut Params) {
                 .scc
                 .matrix
                 .set_row_col(params.scc.components, node as usize, true);
-            params.scca.push(node);
+            params.scca.set(node as usize, true);
             params.preorders[node as usize] = Preorder::Removed;
             if node as usize == v {
                 break;