From 593d9e26f1ba37790d77b054f29fd2ac8b6dfc59 Mon Sep 17 00:00:00 2001
From: Gabriel Kronberger <gabriel.kronberger@heuristiclab.com>
Date: Wed, 21 Aug 2024 17:01:53 +0200
Subject: [PATCH] Global counters for VecExpr hash access.

---
 src/EGraphs/egraph.jl |  8 ++++++++
 src/vecexpr.jl        | 23 ++++++++++++++++++++---
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/EGraphs/egraph.jl b/src/EGraphs/egraph.jl
index f645e44a..f63c99c3 100644
--- a/src/EGraphs/egraph.jl
+++ b/src/EGraphs/egraph.jl
@@ -250,10 +250,14 @@ function canonicalize!(g::EGraph, n::VecExpr)
   n
 end
 
+memo_lookups = 0
+memo_add = 0
+
 function lookup(g::EGraph, n::VecExpr)::Id
   canonicalize!(g, n)
   h = IdKey(v_hash(n))
 
+  global memo_lookups += 1
   haskey(g.memo, n) ? find(g, g.memo[n]) : 0
 end
 
@@ -273,6 +277,7 @@ 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)
 
+  global memo_lookups += 1
   haskey(g.memo, n) && return g.memo[n]
 
   if should_copy
@@ -287,6 +292,7 @@ function add!(g::EGraph{ExpressionType,Analysis}, n::VecExpr, should_copy::Bool)
     end
   end
 
+  global memo_add += 1
   g.memo[n] = id
 
   add_class_by_op(g, n, id)
@@ -431,8 +437,10 @@ 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)
+      global memo_lookups += 1
       if haskey(g.memo, node)
         old_class_id = g.memo[node]
+        global memo_add += 1
         g.memo[node] = eclass_id
         did_something = union!(g, old_class_id, eclass_id)
         # TODO unique! can node dedup be moved here? compare performance
diff --git a/src/vecexpr.jl b/src/vecexpr.jl
index 1e8a83ba..9b6ae27e 100644
--- a/src/vecexpr.jl
+++ b/src/vecexpr.jl
@@ -28,6 +28,8 @@ export Id,
 
 const Id = UInt64
 
+vexpr_created = 0
+
 """
     struct VecExpr
       data::Vector{Id}
@@ -45,6 +47,11 @@ The hash value for the VecExpr is cached in the first position for faster lookup
 """
 struct VecExpr
   data::Vector{Id}
+  
+  function VecExpr(data)
+    global vexpr_created += 1
+    new(data) 
+  end
 end
 
 const VECEXPR_FLAG_ISTREE = 0x01
@@ -65,26 +72,33 @@ const VECEXPR_META_LENGTH = 4
 """Number of children in the e-node."""
 @inline v_arity(n::VecExpr)::Int = length(n.data) - VECEXPR_META_LENGTH
 
+
+cached_hash_access = 0
+cached_hash_computation = 0
 """
 Compute the hash of a `VecExpr` and store it as the first element.
 """
 @inline function v_hash!(n::VecExpr)::Id
   if iszero(n.data[1])
     n.data[1] = hash(@view n.data[2:end])
+    global cached_hash_computation += 1
   else
+    global cached_hash_access += 1
     # h = hash(@view n[2:end])
     # @assert h == n[1]
     n.data[1]
   end
 end
 
+hash_calls = 0
 """The hash of the e-node."""
-@inline v_hash(n::VecExpr)::Id = @inbounds n.data[1]
+@inline v_hash(n::VecExpr)::Id = begin global hash_calls += 1; @inbounds n.data[1] end
 Base.hash(n::VecExpr) = v_hash(n) # 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."""
-@inline v_unset_hash!(n::VecExpr)::Id = @inbounds (n.data[1] = Id(0))
+unset_hash_calls = 0
+@inline v_unset_hash!(n::VecExpr)::Id = begin global unset_hash_calls += 1; @inbounds (n.data[1] = Id(0)) end
 
 """E-class IDs of the children of the e-node."""
 @inline v_children(n::VecExpr) = @view n.data[(VECEXPR_META_LENGTH + 1):end]
@@ -99,8 +113,11 @@ Base.:(==)(a::VecExpr, b::VecExpr) = (@view a.data[2:end]) == (@view b.data[2:en
 "Update the E-Node operation ID."
 @inline v_set_head!(n::VecExpr, h::Id) = @inbounds (n.data[VECEXPR_META_LENGTH] = h)
 
+v_new_calls = 0
+v_copy_calls = 0
 """Construct a new, empty `VecExpr` with `len` children."""
 @inline function v_new(len::Int)::VecExpr
+  global v_new_calls += 1
   n = VecExpr(Vector{Id}(undef, len + VECEXPR_META_LENGTH))
   v_unset_hash!(n)
   v_unset_flags!(n)
@@ -117,7 +134,7 @@ v_pair_last(p::UInt128)::UInt64 = UInt64(p & 0xffffffffffffffff)
 @inline Base.length(n::VecExpr) = length(n.data)
 @inline Base.getindex(n::VecExpr, i) = n.data[i]
 @inline Base.setindex!(n::VecExpr, val, i) = n.data[i] = val
-@inline Base.copy(n::VecExpr) = VecExpr(copy(n.data))
+@inline Base.copy(n::VecExpr) = begin global v_copy_calls += 1; VecExpr(copy(n.data)) end
 @inline Base.lastindex(n::VecExpr) = lastindex(n.data)
 @inline Base.firstindex(n::VecExpr) = firstindex(n.data)