From b4df50bb19877e00c358530aee3759d15d1ea09d Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 10:51:16 +0200
Subject: [PATCH 01/16] Implement the correct hash function.

---
 src/vecexpr.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/vecexpr.jl b/src/vecexpr.jl
index 1e8a83ba..c18059f9 100644
--- a/src/vecexpr.jl
+++ b/src/vecexpr.jl
@@ -80,7 +80,7 @@ end
 
 """The hash of the e-node."""
 @inline v_hash(n::VecExpr)::Id = @inbounds n.data[1]
-Base.hash(n::VecExpr) = v_hash(n) # IdKey not necessary here
+Base.hash(n::VecExpr, h::UInt) = hash(v_hash(n), h) # IdKey not necessary here
 Base.:(==)(a::VecExpr, b::VecExpr) = (@view a.data[2:end]) == (@view b.data[2:end])
 
 """Set e-node hash to zero."""

From f987d6650284b9117e6f43d99cf7247656ee2993 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 10:52:38 +0200
Subject: [PATCH 02/16] Fix upwards update of semantic analysis values.

---
 src/EGraphs/egraph.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index f645e44a..23073362 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -72,7 +72,7 @@ end
 function merge_analysis_data!(a::EClass{D}, b::EClass{D})::Tuple{Bool,Bool,Union{D,Nothing}} where {D}
   if !isnothing(a.data) && !isnothing(b.data)
     new_a_data = join(a.data, b.data)
-    (a.data == new_a_data, b.data == new_a_data, new_a_data)
+    (a.data != new_a_data, b.data != new_a_data, new_a_data)
   elseif isnothing(a.data) && !isnothing(b.data)
     # a merged, b not merged
     (true, false, b.data)

From 313c5e88866a70aea2088998b574e6b3481381b4 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 10:53:47 +0200
Subject: [PATCH 03/16] Remove unused code

---
 src/EGraphs/egraph.jl | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index 23073362..f7f9ed45 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -223,22 +223,6 @@ Returns the canonical e-class id for a given e-class.
 
 @inline Base.getindex(g::EGraph, i::Id) = g.classes[IdKey(find(g, i))]
 
-# function canonicalize(g::EGraph, n::VecExpr)::VecExpr
-#   if !v_isexpr(n)
-#     v_hash!(n)
-#     return n
-#   end
-#   l = v_arity(n)
-#   new_n = v_new(l)
-#   v_set_flag!(new_n, v_flags(n))
-#   v_set_head!(new_n, v_head(n))
-#   for i in v_children_range(n)
-#     @inbounds new_n[i] = find(g, n[i])
-#   end
-#   v_hash!(new_n)
-#   new_n
-# end
-
 function canonicalize!(g::EGraph, n::VecExpr)
   v_isexpr(n) || @goto ret
   for i in (VECEXPR_META_LENGTH + 1):length(n)
@@ -252,7 +236,6 @@ end
 
 function lookup(g::EGraph, n::VecExpr)::Id
   canonicalize!(g, n)
-  h = IdKey(v_hash(n))
 
   haskey(g.memo, n) ? find(g, g.memo[n]) : 0
 end

From f14229d59e754ceb36b39298c2611de79a8e9e10 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 10:55:36 +0200
Subject: [PATCH 04/16] Fix check_memo()

---
 src/EGraphs/egraph.jl | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index f7f9ed45..d7610c33 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -237,7 +237,8 @@ end
 function lookup(g::EGraph, n::VecExpr)::Id
   canonicalize!(g, n)
 
-  haskey(g.memo, n) ? find(g, g.memo[n]) : 0
+  id = get(g.memo, n, zero(Id))
+  iszero(id) ? id : find(g, id)
 end
 
 
@@ -256,7 +257,8 @@ Inserts an e-node in an [`EGraph`](@ref)
 function add!(g::EGraph{ExpressionType,Analysis}, n::VecExpr, should_copy::Bool)::Id where {ExpressionType,Analysis}
   canonicalize!(g, n)
 
-  haskey(g.memo, n) && return g.memo[n]
+  id = get(g.memo, n, zero(Id))
+  iszero(id) || return id
 
   if should_copy
     n = copy(n)
@@ -456,9 +458,8 @@ function check_memo(g::EGraph)::Bool
   for (id, class) in g.classes
     @assert id.val == class.id
     for node in class.nodes
-      if haskey(test_memo, node)
-        old_id = test_memo[node]
-        test_memo[node] = id.val
+      old_id = get!(test_memo, node, id.val)
+      if old_id != id.val
         @assert find(g, old_id) == find(g, id.val) "Unexpected equivalence $node $(g[find(g, id.val)].nodes) $(g[find(g, old_id)].nodes)"
       end
     end

From 6b6522ec5e0fb25a699ffee5c36a9abfc4c822b3 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 11:12:55 +0200
Subject: [PATCH 05/16] Fix an issue where enodes are not added to memo.

---
 src/EGraphs/egraph.jl | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index d7610c33..08b74a8c 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -416,9 +416,8 @@ function process_unions!(g::EGraph{ExpressionType,AnalysisType})::Int where {Exp
     while !isempty(g.pending)
       (node::VecExpr, eclass_id::Id) = pop!(g.pending)
       canonicalize!(g, node)
-      if haskey(g.memo, node)
-        old_class_id = g.memo[node]
-        g.memo[node] = eclass_id
+      old_class_id = get!(g.memo, node, eclass_id)
+      if old_class_id != eclass_id
         did_something = union!(g, old_class_id, eclass_id)
         # TODO unique! can node dedup be moved here? compare performance
         # did_something && unique!(g[eclass_id].nodes)

From 84d2e30a834ae451f671be6c1e6193380f4a33e6 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 11:22:02 +0200
Subject: [PATCH 06/16] Simplify code

---
 src/EGraphs/egraph.jl | 38 ++++++++++++++++----------------------
 1 file changed, 16 insertions(+), 22 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index 08b74a8c..e73f21f7 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -304,28 +304,22 @@ function addexpr!(g::EGraph, se)::Id
   se isa EClass && return se.id
   e = preprocess(se)
 
-  n = if isexpr(e)
-    args = iscall(e) ? arguments(e) : children(e)
-    ar = length(args)
-    n = v_new(ar)
-    v_set_flag!(n, VECEXPR_FLAG_ISTREE)
-    iscall(e) && v_set_flag!(n, VECEXPR_FLAG_ISCALL)
-
-    h = iscall(e) ? operation(e) : head(e)
-    v_set_head!(n, add_constant!(g, h))
-
-    # get the signature from op and arity 
-    v_set_signature!(n, hash(maybe_quote_operation(h), hash(ar)))
-
-    for i in v_children_range(n)
-      @inbounds n[i] = addexpr!(g, args[i - VECEXPR_META_LENGTH])
-    end
-    n
-  else # constant enode
-    VecExpr(Id[Id(0), Id(0), Id(0), add_constant!(g, e)])
+  isexpr(e) || return add!(g, VecExpr(Id[Id(0), Id(0), Id(0), add_constant!(g, e)]), false)
+
+  args = iscall(e) ? arguments(e) : children(e)
+  ar = length(args)
+  n = v_new(ar)
+  v_set_flag!(n, VECEXPR_FLAG_ISTREE)
+  iscall(e) && v_set_flag!(n, VECEXPR_FLAG_ISCALL)
+  h = iscall(e) ? operation(e) : head(e)
+  v_set_head!(n, add_constant!(g, h))
+  # get the signature from op and arity
+  v_set_signature!(n, hash(maybe_quote_operation(h), hash(ar)))
+  for i in v_children_range(n)
+    @inbounds n[i] = addexpr!(g, args[i - VECEXPR_META_LENGTH])
   end
-  id = add!(g, n, false)
-  return id
+
+  add!(g, n, false)
 end
 
 """
@@ -490,7 +484,7 @@ for more details.
 function rebuild!(g::EGraph)
   n_unions = process_unions!(g)
   trimmed_nodes = rebuild_classes!(g)
-  # @assert check_memo(g)
+  @assert check_memo(g)
   # @assert check_analysis(g)
   g.clean = true
 

From 7adb07ec5ba55a738ff1d1d0ccaa58e5d28cb034 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 12:33:49 +0200
Subject: [PATCH 07/16] Add code to make sure we do not canonicalize vecexpr in
 memo

---
 src/EGraphs/egraph.jl | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index e73f21f7..b83319f6 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -224,6 +224,8 @@ Returns the canonical e-class id for a given e-class.
 @inline Base.getindex(g::EGraph, i::Id) = g.classes[IdKey(find(g, i))]
 
 function canonicalize!(g::EGraph, n::VecExpr)
+  orig = copy(n)
+  inmemo = any(entry -> objectid(entry) == objectid(n), keys(g.memo))
   v_isexpr(n) || @goto ret
   for i in (VECEXPR_META_LENGTH + 1):length(n)
     @inbounds n[i] = find(g, n[i])
@@ -231,6 +233,7 @@ function canonicalize!(g::EGraph, n::VecExpr)
   v_unset_hash!(n)
   @label ret
   v_hash!(n)
+  @assert orig == n || !inmemo
   n
 end
 

From 9b3d0e488074842b1399a9e745de23cfcc461322 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 12:36:23 +0200
Subject: [PATCH 08/16] Make sure nodes in dictionaries (memo and pending) are
 cloned

---
 src/EGraphs/egraph.jl | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index b83319f6..77daea30 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -271,17 +271,17 @@ function add!(g::EGraph{ExpressionType,Analysis}, n::VecExpr, should_copy::Bool)
 
   if v_isexpr(n)
     for c_id in v_children(n)
-      addparent!(g.classes[IdKey(c_id)], n, id)
+      addparent!(g.classes[IdKey(c_id)], copy(n), id)
     end
   end
 
-  g.memo[n] = id
+  g.memo[copy(n)] = id
 
   add_class_by_op(g, n, id)
   eclass = EClass{Analysis}(id, VecExpr[n], Pair{VecExpr,Id}[], make(g, n))
   g.classes[IdKey(id)] = eclass
   modify!(g, eclass)
-  push!(g.pending, n => id)
+  push!(g.pending, copy(n) => id)
 
   return id
 end
@@ -412,6 +412,7 @@ function process_unions!(g::EGraph{ExpressionType,AnalysisType})::Int where {Exp
   while !isempty(g.pending) || !isempty(g.analysis_pending)
     while !isempty(g.pending)
       (node::VecExpr, eclass_id::Id) = pop!(g.pending)
+      node = copy(node)
       canonicalize!(g, node)
       old_class_id = get!(g.memo, node, eclass_id)
       if old_class_id != eclass_id

From 6c7a56aa096e3bddeb1129e4983873d348d45cce Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 12:42:01 +0200
Subject: [PATCH 09/16] Use in!() instead of in() for UniqueQueue push!()

---
 src/EGraphs/uniquequeue.jl | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/EGraphs/uniquequeue.jl b/src/EGraphs/uniquequeue.jl
index aade15d6..ca68c336 100644
--- a/src/EGraphs/uniquequeue.jl
+++ b/src/EGraphs/uniquequeue.jl
@@ -12,8 +12,17 @@ end
 UniqueQueue{T}() where {T} = UniqueQueue{T}(Set{T}(), T[])
 
 function Base.push!(uq::UniqueQueue{T}, x::T) where {T}
-  if !(x in uq.set)
-    push!(uq.set, x)
+  # checks if x is contained in s and adds x if it is not, using a single hash call and lookup
+  # available from Julia 1.11
+  function in!(x::T, s::Set)
+    idx, sh = Base.ht_keyindex2_shorthash!(s.dict, x)
+    idx > 0 && return true
+    _setindex!(s.dict, nothing, x, -idx, sh)
+    
+    false
+  end
+
+  if !in!(x, uq.set)
     push!(uq.vec, x)
   end
 end

From a4fe7a2c27e252034980f3c1dd7d3ad9d0c026a2 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Fri, 23 Aug 2024 12:45:58 +0200
Subject: [PATCH 10/16] Comment runtime assertions

---
 src/EGraphs/egraph.jl | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index 77daea30..9f7fae89 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -224,8 +224,8 @@ Returns the canonical e-class id for a given e-class.
 @inline Base.getindex(g::EGraph, i::Id) = g.classes[IdKey(find(g, i))]
 
 function canonicalize!(g::EGraph, n::VecExpr)
-  orig = copy(n)
-  inmemo = any(entry -> objectid(entry) == objectid(n), keys(g.memo))
+  # orig = copy(n)
+  # inmemo = any(entry -> objectid(entry) == objectid(n), keys(g.memo))
   v_isexpr(n) || @goto ret
   for i in (VECEXPR_META_LENGTH + 1):length(n)
     @inbounds n[i] = find(g, n[i])
@@ -233,7 +233,7 @@ function canonicalize!(g::EGraph, n::VecExpr)
   v_unset_hash!(n)
   @label ret
   v_hash!(n)
-  @assert orig == n || !inmemo
+  # @assert orig == n || !inmemo
   n
 end
 
@@ -488,7 +488,7 @@ for more details.
 function rebuild!(g::EGraph)
   n_unions = process_unions!(g)
   trimmed_nodes = rebuild_classes!(g)
-  @assert check_memo(g)
+  # @assert check_memo(g)
   # @assert check_analysis(g)
   g.clean = true
 

From d916a0d3379f9fc8cd98536b0e5891096a34d82b Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Sat, 24 Aug 2024 11:05:04 +0200
Subject: [PATCH 11/16] Fix function call in in!()

---
 src/EGraphs/uniquequeue.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/EGraphs/uniquequeue.jl b/src/EGraphs/uniquequeue.jl
index ca68c336..f5181ba5 100644
--- a/src/EGraphs/uniquequeue.jl
+++ b/src/EGraphs/uniquequeue.jl
@@ -17,7 +17,7 @@ function Base.push!(uq::UniqueQueue{T}, x::T) where {T}
   function in!(x::T, s::Set)
     idx, sh = Base.ht_keyindex2_shorthash!(s.dict, x)
     idx > 0 && return true
-    _setindex!(s.dict, nothing, x, -idx, sh)
+    Base._setindex!(s.dict, nothing, x, -idx, sh)
     
     false
   end

From d5dce5d0de29cf97da7533d059883dd0b51bb5d2 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Sat, 24 Aug 2024 11:27:42 +0200
Subject: [PATCH 12/16] Remove unnecessary copies of VecExpr

---
 src/EGraphs/egraph.jl | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index 6898687b..2de89a83 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -272,17 +272,17 @@ function add!(g::EGraph{ExpressionType,Analysis}, n::VecExpr, should_copy::Bool)
 
   if v_isexpr(n)
     for c_id in v_children(n)
-      addparent!(g.classes[IdKey(c_id)], copy(n), id)
+      addparent!(g.classes[IdKey(c_id)], n, id)
     end
   end
 
-  g.memo[copy(n)] = id
+  g.memo[n] = id
 
   add_class_by_op(g, n, id)
-  eclass = EClass{Analysis}(id, VecExpr[n], Pair{VecExpr,Id}[], make(g, n))
+  eclass = EClass{Analysis}(id, VecExpr[copy(n)], Pair{VecExpr,Id}[], make(g, n))
   g.classes[IdKey(id)] = eclass
   modify!(g, eclass)
-  push!(g.pending, copy(n) => id)
+  push!(g.pending, n => id)
 
   return id
 end

From fbdfc73f455b74835724e947881e6fa11a07ca14 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Sat, 24 Aug 2024 11:28:05 +0200
Subject: [PATCH 13/16] Improve add_class_by_op to use a single dictionary
 lookup

---
 src/EGraphs/egraph.jl | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index 2de89a83..2d833210 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -248,11 +248,8 @@ end
 
 function add_class_by_op(g::EGraph, n, eclass_id)
   key = IdKey(v_signature(n))
-  if haskey(g.classes_by_op, key)
-    push!(g.classes_by_op[key], eclass_id)
-  else
-    g.classes_by_op[key] = [eclass_id]
-  end
+  vec = get!(g.classes_by_op, key, Vector{Id}())
+  push!(vec, eclass_id)
 end
 
 """

From f74d552d55b4b316266eb65aeb179c1e7da7714e Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Sat, 24 Aug 2024 20:40:06 +0200
Subject: [PATCH 14/16] Removed old commented code.

---
 src/EGraphs/egraph.jl | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index 2d833210..5937ddad 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -225,8 +225,6 @@ Returns the canonical e-class id for a given e-class.
 @inline Base.getindex(g::EGraph, i::Id) = g.classes[IdKey(find(g, i))]
 
 function canonicalize!(g::EGraph, n::VecExpr)
-  # orig = copy(n)
-  # inmemo = any(entry -> objectid(entry) == objectid(n), keys(g.memo))
   v_isexpr(n) || @goto ret
   for i in (VECEXPR_META_LENGTH + 1):length(n)
     @inbounds n[i] = find(g, n[i])
@@ -234,7 +232,6 @@ function canonicalize!(g::EGraph, n::VecExpr)
   v_unset_hash!(n)
   @label ret
   v_hash!(n)
-  # @assert orig == n || !inmemo
   n
 end
 

From a3ebcb6e4f443946c82a07e6b6c1cc68197c4272 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Sat, 24 Aug 2024 20:45:46 +0200
Subject: [PATCH 15/16] Move in!() outside of push!()

---
 src/EGraphs/uniquequeue.jl | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/src/EGraphs/uniquequeue.jl b/src/EGraphs/uniquequeue.jl
index f5181ba5..7c080156 100644
--- a/src/EGraphs/uniquequeue.jl
+++ b/src/EGraphs/uniquequeue.jl
@@ -12,16 +12,6 @@ end
 UniqueQueue{T}() where {T} = UniqueQueue{T}(Set{T}(), T[])
 
 function Base.push!(uq::UniqueQueue{T}, x::T) where {T}
-  # checks if x is contained in s and adds x if it is not, using a single hash call and lookup
-  # available from Julia 1.11
-  function in!(x::T, s::Set)
-    idx, sh = Base.ht_keyindex2_shorthash!(s.dict, x)
-    idx > 0 && return true
-    Base._setindex!(s.dict, nothing, x, -idx, sh)
-    
-    false
-  end
-
   if !in!(x, uq.set)
     push!(uq.vec, x)
   end
@@ -39,4 +29,16 @@ function Base.pop!(uq::UniqueQueue{T}) where {T}
   v
 end
 
-Base.isempty(uq::UniqueQueue) = isempty(uq.vec)
\ No newline at end of file
+Base.isempty(uq::UniqueQueue) = isempty(uq.vec)
+
+# Helper for push!()
+# checks if x is contained in s and adds x if it is not, using a single hash call and lookup
+# available from Julia 1.11
+function in!(x::T, s::Set{T}) where {T}
+  idx, sh = Base.ht_keyindex2_shorthash!(s.dict, x)
+  idx > 0 && return true
+  Base._setindex!(s.dict, nothing, x, -idx, sh)
+  
+  false
+end
+

From 66ea780fe36a5d821b02a18d92ff32aa19701cca Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Sun, 25 Aug 2024 11:23:43 +0200
Subject: [PATCH 16/16] Revert change in UniqueQueue as it does not work with
 Julia v1.8

---
 src/EGraphs/uniquequeue.jl | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/src/EGraphs/uniquequeue.jl b/src/EGraphs/uniquequeue.jl
index 7c080156..512bb61a 100644
--- a/src/EGraphs/uniquequeue.jl
+++ b/src/EGraphs/uniquequeue.jl
@@ -12,7 +12,8 @@ end
 UniqueQueue{T}() where {T} = UniqueQueue{T}(Set{T}(), T[])
 
 function Base.push!(uq::UniqueQueue{T}, x::T) where {T}
-  if !in!(x, uq.set)
+  if !(x in uq.set)
+    push!(uq.set, x)
     push!(uq.vec, x)
   end
 end
@@ -30,15 +31,3 @@ function Base.pop!(uq::UniqueQueue{T}) where {T}
 end
 
 Base.isempty(uq::UniqueQueue) = isempty(uq.vec)
-
-# Helper for push!()
-# checks if x is contained in s and adds x if it is not, using a single hash call and lookup
-# available from Julia 1.11
-function in!(x::T, s::Set{T}) where {T}
-  idx, sh = Base.ht_keyindex2_shorthash!(s.dict, x)
-  idx > 0 && return true
-  Base._setindex!(s.dict, nothing, x, -idx, sh)
-  
-  false
-end
-