From f5f984c81ae45aded523dfecac71003701f1b858 Mon Sep 17 00:00:00 2001
From: T0b1 <T0b1-iOS@users.noreply.github.com>
Date: Sun, 16 Apr 2023 14:24:26 +0200
Subject: [PATCH] Revert "try using bitmap instead of indexset"

This reverts commit 84a1e58b97e7d0a98c2bf125f61557df3ee734e2.
---
 src/ion/fast_alloc.rs | 45 +++++++++----------------------------------
 1 file changed, 9 insertions(+), 36 deletions(-)

diff --git a/src/ion/fast_alloc.rs b/src/ion/fast_alloc.rs
index 358f18b..1774dc2 100644
--- a/src/ion/fast_alloc.rs
+++ b/src/ion/fast_alloc.rs
@@ -144,8 +144,8 @@ struct FastAllocState<'a, F: Function> {
     pub vregs: Vec<VRegData>,
     pub pregs: Vec<PRegData>,
     pub blocks: Vec<BlockData>,
-    pub liveins: Vec<BlockBitmap>,
-    pub liveouts: Vec<BlockBitmap>,
+    pub liveins: Vec<IndexSet>,
+    pub liveouts: Vec<IndexSet>,
 
     pub cur_stack_slot_idx: u32,
     pub reftype_vregs_in_pregs_count: u32,
@@ -1093,7 +1093,6 @@ fn calc_use_positions_and_live_bitmaps<'a, F: Function>(
     calc_live_bitmaps(state, const_state)
 }
 
-#[derive(Clone, Debug)]
 struct BlockBitmap {
     storage: SmallVec<[u64; 2]>,
 }
@@ -1123,28 +1122,6 @@ impl BlockBitmap {
         let bit = 1u64 << (idx % 64);
         (self.storage[idx] & bit) != 0
     }
-
-    fn is_empty(&self) -> bool {
-        for &b in self.storage.iter() {
-            if b != 0 {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    pub fn union_with(&mut self, other: &Self) -> bool {
-        let mut changed = 0;
-        for (word_idx, &bits) in other.storage.iter().enumerate() {
-            if bits == 0 {
-                continue;
-            }
-            let self_word = &mut self.storage[word_idx];
-            changed |= bits & !*self_word;
-            *self_word |= bits;
-        }
-        changed != 0
-    }
 }
 
 // currently, copy from liveranges.rs
@@ -1154,12 +1131,8 @@ fn calc_live_bitmaps<'a, F: Function>(
     state: &mut FastAllocState<'a, F>,
     const_state: &ReadOnlyData,
 ) -> Result<(), RegAllocError> {
-    state
-        .liveins
-        .resize(state.blocks.len(), BlockBitmap::init(state.vregs.len()));
-    state
-        .liveouts
-        .resize(state.blocks.len(), BlockBitmap::init(state.vregs.len()));
+    state.liveins.resize(state.blocks.len(), IndexSet::new());
+    state.liveouts.resize(state.blocks.len(), IndexSet::new());
 
     // Run a worklist algorithm to precisely compute liveins and
     // liveouts.
@@ -1186,7 +1159,7 @@ fn calc_live_bitmaps<'a, F: Function>(
         if state.func.is_branch(insns.last()) {
             for i in 0..state.func.block_succs(block).len() {
                 for &param in state.func.branch_blockparams(block, insns.last(), i) {
-                    live.set(param.vreg());
+                    live.set(param.vreg(), true);
                 }
             }
         }
@@ -1198,14 +1171,14 @@ fn calc_live_bitmaps<'a, F: Function>(
                         continue;
                     }
                     if op.pos() == *pos {
-                        let was_live = live.is_set(op.vreg().vreg());
+                        let was_live = live.get(op.vreg().vreg());
                         trace!("op {:?} was_live = {}", op, was_live);
                         match op.kind() {
                             OperandKind::Use => {
-                                live.set(op.vreg().vreg());
+                                live.set(op.vreg().vreg(), true);
                             }
                             OperandKind::Def => {
-                                live.un_set(op.vreg().vreg());
+                                live.set(op.vreg().vreg(), false);
                             }
                         }
                     }
@@ -1213,7 +1186,7 @@ fn calc_live_bitmaps<'a, F: Function>(
             }
         }
         for &blockparam in state.func.block_params(block) {
-            live.un_set(blockparam.vreg());
+            live.set(blockparam.vreg(), false);
         }
 
         for &pred in state.func.block_preds(block) {