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Speed up BitArray packing #13946

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Merged
merged 3 commits into from
Nov 13, 2015
Merged

Speed up BitArray packing #13946

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73242ec
Inline set_index!(::BitArray, ::Any, ::Int)
carlobaldassi Nov 11, 2015
d7cd023
Speed up BitArray packing
carlobaldassi Nov 12, 2015
7fee9ab
Avoid branching in unsafe_bitsetindex!
carlobaldassi Nov 12, 2015
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23 changes: 6 additions & 17 deletions base/bitarray.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -310,21 +310,17 @@ function convert{T,N}(::Type{BitArray{N}}, A::AbstractArray{T,N})
ind = 1
@inbounds begin
for i = 1:length(Bc)-1
u = UInt64(1)
c = UInt64(0)
for j = 0:63
A[ind]!=0 && (c |= u)
c |= (UInt64(A[ind] != 0) << j)
ind += 1
u <<= 1
end
Bc[i] = c
end
u = UInt64(1)
c = UInt64(0)
for j = 0:_mod64(l-1)
A[ind]!=0 && (c |= u)
c |= (UInt64(A[ind] != 0) << j)
ind += 1
u <<= 1
end
Bc[end] = c
end
Expand Down Expand Up @@ -359,15 +355,12 @@ end
i1, i2 = get_chunks_id(i)
u = UInt64(1) << i2
@inbounds begin
if x
Bc[i1] |= u
else
Bc[i1] &= ~u
end
c = Bc[i1]
Bc[i1] = ifelse(x, c | u, c & ~u)
end
end

setindex!(B::BitArray, x, i::Int) = (checkbounds(B, i); unsafe_setindex!(B, x, i))
@inline setindex!(B::BitArray, x, i::Int) = (checkbounds(B, i); unsafe_setindex!(B, x, i))
@inline function unsafe_setindex!(B::BitArray, x, i::Int)
unsafe_bitsetindex!(B.chunks, convert(Bool, x), i)
return B
Expand Down Expand Up @@ -417,11 +410,7 @@ function unsafe_setindex!(B::BitArray, X::AbstractArray, I::BitArray)
if Imsk & u != 0
lx < c && throw_setindex_mismatch(X, c)
x = convert(Bool, unsafe_getindex(X, c))
if x
C |= u
else
C &= ~u
end
C = ifelse(x, C | u, C & ~u)
c += 1
end
u <<= 1
Expand Down
28 changes: 23 additions & 5 deletions base/broadcast.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -103,16 +103,34 @@ end
const bitcache_chunks = 64 # this can be changed
const bitcache_size = 64 * bitcache_chunks # do not change this

function bpack(z::UInt64)
z |= z >>> 7
z |= z >>> 14
z |= z >>> 28
z &= 0xFF
return z
end

function dumpbitcache(Bc::Vector{UInt64}, bind::Int, C::Vector{Bool})
ind = 1
nc = min(bitcache_chunks, length(Bc)-bind+1)
for i = 1:nc
u = UInt64(1)
C8 = reinterpret(UInt64, C)
nc8 = (nc >>> 3) << 3
@inbounds for i = 1:nc8
c = UInt64(0)
for j = 0:8:63
c |= (bpack(C8[ind]) << j)
ind += 1
end
Bc[bind] = c
bind += 1
end
ind = (ind-1) << 3 + 1
@inbounds for i = (nc8+1):nc
c = UInt64(0)
for j = 1:64
C[ind] && (c |= u)
for j = 0:63
c |= (UInt64(C[ind]) << j)
ind += 1
u <<= 1
end
Bc[bind] = c
bind += 1
Expand Down