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Merged
amontoison merged 2 commits into from
Apr 11, 2025
Merged

Remove some useless operations in dynamic orders #248

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02cbb8f
Remove some useless operations in dynamic orders
gdalle Apr 10, 2025
c391051
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gdalle Apr 10, 2025
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111 changes: 55 additions & 56 deletions src/order.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -203,9 +203,6 @@ function DegreeBucketsSMC(::Type{T}, degrees::Vector{T}, dmax::Integer) where {T
return DegreeBucketsSMC(degrees, bucket_storage, bucket_low, bucket_high, positions)
end

maxdeg(db::DegreeBucketsColPack) = length(db.buckets) - 1
maxdeg(db::DegreeBucketsSMC) = length(db.bucket_low) - 1

function nonempty_bucket(db::DegreeBucketsSMC, d::Integer)
return db.bucket_high[d + 1] >= db.bucket_low[d + 1]
end
Expand All @@ -220,31 +217,14 @@ function degree_increasing(; degtype, direction)
return increasing
end

function mark_ordered!(db::AbstractDegreeBuckets{T}, v::Integer) where {T}
db.degrees[v] = -1
db.positions[v] = typemin(T)
return nothing
end

already_ordered(db::AbstractDegreeBuckets, v::Integer) = db.degrees[v] == -1

function pop_next_candidate!(db::AbstractDegreeBuckets; direction::Symbol)
dmax = maxdeg(db)
if direction == :low2high
candidate_degree = dmax + 1
for d in dmax:-1:0
if nonempty_bucket(db, d)
candidate_degree = d
break
end
end
else
candidate_degree = -1
for d in 0:dmax
if nonempty_bucket(db, d)
candidate_degree = d
break
end
function pop_next_candidate!(db::AbstractDegreeBuckets; degree_range::OrdinalRange)
(; degrees) = db
# degree_range is used to avoid going through the empty parts of 0:dmax
candidate_degree = -1
for d in degree_range
if nonempty_bucket(db, d)
candidate_degree = d
break
end
end
if db isa DegreeBucketsColPack
Expand All @@ -255,21 +235,22 @@ function pop_next_candidate!(db::AbstractDegreeBuckets; direction::Symbol)
(; bucket_storage, bucket_high) = db
high = bucket_high[candidate_degree + 1]
candidate = bucket_storage[high]
bucket_storage[high] = -1
bucket_high[candidate_degree + 1] -= 1
end
mark_ordered!(db, candidate)
return candidate
# mark as ordered
degrees[candidate] = -1
# returning candidate degree is useful to update degree_range
return candidate, candidate_degree
end

function update_bucket!(
db::DegreeBucketsSMC, v::Integer; degtype::Symbol, direction::Symbol
db::DegreeBucketsSMC, v::Integer, d::Integer; degtype::Symbol, direction::Symbol
)
(; degrees, bucket_storage, bucket_low, bucket_high, positions) = db
d, p = degrees[v], positions[v]
low, high = bucket_low[d + 1], bucket_high[d + 1]
p = positions[v]
# select previous or next bucket for the move
if degree_increasing(; degtype, direction)
high = bucket_high[d + 1]
# move the vertex w located at the end of the current bucket to v's position
w = bucket_storage[high]
bucket_storage[p] = w
Expand All @@ -279,14 +260,15 @@ function update_bucket!(
bucket_high[d + 1] -= 1
# move v to the beginning of the next bucket (!= ColPack)
d_new = d + 1
low_new, high_new = bucket_low[d_new + 1], bucket_high[d_new + 1]
low_new = bucket_low[d_new + 1]
bucket_storage[low_new - 1] = v
# grow next bucket to the left
bucket_low[d_new + 1] -= 1
# update v's stats
degrees[v] = d_new
positions[v] = low_new - 1
else
low = bucket_low[d + 1]
# move the vertex w located at the start of the current bucket to v's position (!= ColPack)
w = bucket_storage[low]
bucket_storage[p] = w
Expand All @@ -296,7 +278,7 @@ function update_bucket!(
bucket_low[d + 1] += 1
# move v to the end of the previous bucket
d_new = d - 1
low_new, high_new = bucket_low[d_new + 1], bucket_high[d_new + 1]
high_new = bucket_high[d_new + 1]
bucket_storage[high_new + 1] = v
# grow previous bucket to the right
bucket_high[d_new + 1] += 1
Expand All @@ -308,22 +290,22 @@ function update_bucket!(
end

function update_bucket!(
db::DegreeBucketsColPack, v::Integer; degtype::Symbol, direction::Symbol
db::DegreeBucketsColPack, v::Integer, d::Integer; degtype::Symbol, direction::Symbol
)
(; degrees, buckets, positions) = db
d, p = degrees[v], positions[v]
p = positions[v]
bucket = buckets[d + 1]
# select previous or next bucket for the move
d_new = degree_increasing(; degtype, direction) ? d + 1 : d - 1
bucket_new = buckets[d_new + 1]
# put v at the end of its bucket by swapping
w = bucket[end]
bucket[p] = w
positions[w] = p
bucket[end] = v
positions[w] = p
positions[v] = length(bucket)
# move v from the old bucket to the new one
@assert pop!(bucket) == v
pop!(bucket)
push!(bucket_new, v)
degrees[v] = d_new
positions[v] = length(bucket_new)
Expand All @@ -333,26 +315,35 @@ end
function vertices(
g::AdjacencyGraph{T}, ::DynamicDegreeBasedOrder{degtype,direction,reproduce_colpack}
) where {T<:Integer,degtype,direction,reproduce_colpack}
true_degrees = degrees = T[degree(g, v) for v in vertices(g)]
max_degrees = maximum(true_degrees)
degrees = T[degree(g, v) for v in vertices(g)]
dmax = maximum(degrees)
if degree_increasing(; degtype, direction)
fill!(degrees, zero(T))
end
db = if reproduce_colpack
DegreeBucketsColPack(T, degrees, max_degrees)
DegreeBucketsColPack(T, degrees, dmax)
else
DegreeBucketsSMC(T, degrees, max_degrees)
DegreeBucketsSMC(T, degrees, dmax)
end
nv = nb_vertices(g)
π = Vector{T}(undef, nv)
index_π = (direction == :low2high) ? (1:nv) : (nv:-1:1)
index_π = (direction == :low2high) ? (1:nv) : reverse(1:nv)
degree_range = (direction == :low2high) ? reverse(0:dmax) : (0:dmax)
for index in index_π
u = pop_next_candidate!(db; direction)
u, du = pop_next_candidate!(db; degree_range)

π[index] = u
for v in neighbors(g, u)
!has_diagonal(g) || (u == v && continue)
already_ordered(db, v) && continue
update_bucket!(db, v; degtype, direction)
dv = degrees[v]
dv == -1 && continue
update_bucket!(db, v, dv; degtype, direction)
end
# no need to look much further than du next time
degree_range = if direction == :low2high
reverse(0:min(du + 1, dmax))
else
max(du - 1, 0):dmax
end
end
return π
Expand All @@ -366,42 +357,50 @@ function vertices(
other_side = 3 - side
# compute dist-2 degrees in an optimized way
n = nb_vertices(g, Val(side))
degrees_dist2 = degrees = zeros(T, n)
degrees = zeros(T, n)
visited = zeros(T, n)
for v in vertices(g, Val(side))
for w1 in neighbors(g, Val(side), v)
for w2 in neighbors(g, Val(other_side), w1)
if w2 != v && visited[w2] != v
degrees_dist2[v] += 1
degrees[v] += 1
visited[w2] = v
end
end
end
end
maxd2 = maximum(degrees_dist2)
dmax = maximum(degrees)
if degree_increasing(; degtype, direction)
fill!(degrees, zero(T))
end
db = if reproduce_colpack
DegreeBucketsColPack(T, degrees, maxd2)
DegreeBucketsColPack(T, degrees, dmax)
else
DegreeBucketsSMC(T, degrees, maxd2)
DegreeBucketsSMC(T, degrees, dmax)
end
π = Vector{T}(undef, n)
index_π = (direction == :low2high) ? (1:n) : (n:-1:1)
degree_range = (direction == :low2high) ? reverse(0:dmax) : (0:dmax)
for index in index_π
u = pop_next_candidate!(db; direction)
u, du = pop_next_candidate!(db; degree_range)
π[index] = u
for w in neighbors(g, Val(side), u)
for v in neighbors(g, Val(other_side), w)
if v != u && visited[v] != -u
# Use -u such that we don't need to fill "visited" with 0 after the computation of the dist-2 degrees
visited[v] = -u
already_ordered(db, v) && continue
update_bucket!(db, v; degtype, direction)
dv = degrees[v]
dv == -1 && continue
update_bucket!(db, v, dv; degtype, direction)
end
end
end
# no need to look much further than du next time
degree_range = if direction == :low2high
reverse(0:min(du + 1, dmax))
else
max(du - 1, 0):dmax
end
end
return π
end
Expand Down
2 changes: 2 additions & 0 deletions test/order.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -97,6 +97,8 @@ end;
IncidenceDegree(; reproduce_colpack=true),
DynamicLargestFirst(),
DynamicLargestFirst(; reproduce_colpack=true),
DynamicDegreeBasedOrder{:forward,:high2low}(),
DynamicDegreeBasedOrder{:forward,:high2low}(; reproduce_colpack=true),
]
@testset "AdjacencyGraph" begin
for (n, p) in Iterators.product(20:20:100, 0.0:0.1:0.2)
Expand Down
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