|
| 1 | +""" |
| 2 | + Implements broadcasting functions that operate elementwise and recursively across `Tuple`s, `NamedTuple`s, `SArray`s, and `ForwardDiff.Dual` numbers. |
| 3 | +
|
| 4 | + The functions are: |
| 5 | + - `badd` (broadcast add) |
| 6 | + - `bsub` (broadcast sub) |
| 7 | + - `bmul` (broadcast mul) |
| 8 | + - `bdiv` (broadcast div) |
| 9 | + - `bmax` (broadcast max) |
| 10 | + - `bmin` (broadcast min) |
| 11 | +
|
| 12 | +Note that because it is recursive, `bmul(a, b)` will not necessarilly do the same thing as `map(*, a, b)`. For example, if `a` and `b` are tuples of `SMatrices`, `bmul` will multiply them elementwise, while `map` will multiply them as matrices. This is because `bmul` will call `bmul` on the elements of `a` and `b`, while `map` will call `*` on the elements of `a` and `b`. |
| 13 | +""" |
1 | 14 | module RecursiveTupleMath |
2 | 15 |
|
3 | | -# Write your package code here. |
| 16 | +export bmax, bmin, badd, bsub, bmul, bdiv |
| 17 | + |
| 18 | +using StaticArrays, ForwardDiff |
| 19 | + |
| 20 | +@inline lt_fast(a, b) = a < b |
| 21 | +@inline lt_fast(a::Float64, b::Float64) = Base.lt_float_fast(a, b) |
| 22 | +@inline lt_fast(a::Float32, b::Float32) = Base.lt_float_fast(a, b) |
| 23 | +@inline le_fast(a, b) = a <= b |
| 24 | +@inline le_fast(a::Float64, b::Float64) = Base.le_float_fast(a, b) |
| 25 | +@inline le_fast(a::Float32, b::Float32) = Base.le_float_fast(a, b) |
| 26 | + |
| 27 | +@inline gt_fast(a, b) = lt_fast(b, a) |
| 28 | +@inline ge_fast(a, b) = le_fast(b, a) |
| 29 | + |
| 30 | +@inline badd(a, b) = Base.FastMath.add_fast(a, b) |
| 31 | +@inline bsub(a, b) = Base.FastMath.sub_fast(a, b) |
| 32 | +@inline bmul(a, b) = Base.FastMath.mul_fast(a, b) |
| 33 | +@inline bdiv(a, b) = Base.FastMath.div_fast(a, b) |
| 34 | +@inline bmax(a, b) = ifelse(gt_fast(a, b), a, b) |
| 35 | +@inline bmin(a, b) = ifelse(lt_fast(a, b), a, b) |
| 36 | + |
| 37 | +for bf ∈ [:bmax, :bmin, :badd, :bsub, :bmul, :bdiv] |
| 38 | + @eval begin |
| 39 | + # fall back to fast |
| 40 | + # terminating case |
| 41 | + @inline $bf(::Number, ::Tuple{}) = () |
| 42 | + @inline $bf(::Tuple{}, ::Number) = () |
| 43 | + @inline $bf(::Number, ::Nothing) = nothing |
| 44 | + @inline $bf(::Nothing, ::Number) = nothing |
| 45 | + |
| 46 | + # broadcast |
| 47 | + @inline $bf(x::Number, y::StaticArray{S}) where {S} = SArray{S}($bf(x, Tuple(y))) |
| 48 | + @inline $bf(y::StaticArray{S}, x::Number) where {S} = SArray{S}($bf(Tuple(y), x)) |
| 49 | + @inline $bf(x::Number, y::NamedTuple{S}) where {S} = NamedTuple{S}($bf(x, Tuple(y))) |
| 50 | + @inline $bf(y::NamedTuple{S}, x::Number) where {S} = NamedTuple{S}($bf(Tuple(y), x)) |
| 51 | + |
| 52 | + @inline $bf(a::NamedTuple{S}, b::NamedTuple{S}) where {S} = |
| 53 | + NamedTuple{S}($bf(Tuple(a), Tuple(b))) |
| 54 | + @inline $bf(a::StaticArray{S}, b::StaticArray{S}) where {S} = |
| 55 | + SArray{S}($bf(Tuple(a), Tuple(b))) |
| 56 | + |
| 57 | + # recurse |
| 58 | + @inline $bf(a::Number, b::Tuple{T,Vararg}) where {T} = |
| 59 | + ($bf(a, first(b)), $bf(a, Base.tail(b))...) |
| 60 | + @inline $bf(b::Tuple{T,Vararg}, a::Number) where {T} = |
| 61 | + ($bf(first(b), a), $bf(Base.tail(b), a)...) |
| 62 | + @inline $bf(a::Tuple{T,Vararg}, b::Tuple{T,Vararg}) where {T} = |
| 63 | + ($bf(first(a), first(b)), $bf(Base.tail(a), Base.tail(b))...) |
| 64 | + |
| 65 | + @inline $bf(a::Tuple, b::Tuple) = map($bf, a, b) |
| 66 | + end |
| 67 | +end |
| 68 | +@inline bsub(x::Number) = Base.FastMath.sub_fast(x) |
| 69 | +@inline bsub(x::Tuple) = map(bsub, x) |
| 70 | +@inline bsub(x::NamedTuple) = map(bsub, x) |
| 71 | +@inline bsub(x::StaticArray{S}) where {S} = SArray{S}(map(bsub, Tuple(x))) |
| 72 | + |
| 73 | +@static if VERSION < v"1.7" |
| 74 | + struct Returns{T} |
| 75 | + v::T |
| 76 | + end |
| 77 | + (r::Returns)(_) = r.v |
| 78 | +end |
| 79 | +@inline function btuple(v, ::Val{D}) where {D} |
| 80 | + ntuple(Returns(v), Val(D)) |
| 81 | +end |
| 82 | + |
| 83 | +# @inline |
| 84 | + |
| 85 | +ForwardDiff.@define_binary_dual_op( |
| 86 | + RecursiveTupleMath.badd, |
| 87 | + ForwardDiff.Dual{Txy}(badd(x.value, y.value), badd(x.partials.values, y.partials.values)), |
| 88 | + ForwardDiff.Dual{Tx}(badd(x.value, y), x.partials), |
| 89 | + ForwardDiff.Dual{Ty}(badd(x, y.value), y.partials.values) |
| 90 | +) |
| 91 | +ForwardDiff.@define_binary_dual_op( |
| 92 | + RecursiveTupleMath.bsub, |
| 93 | + ForwardDiff.Dual{Txy}(bsub(x.value, y.value), bsub(x.partials.values, y.partials.values)), |
| 94 | + ForwardDiff.Dual{Tx}(bsub(x.value, y), x.partials), |
| 95 | + ForwardDiff.Dual{Ty}(bsub(x, y.value), bsub(y.partials.values)) |
| 96 | +) |
| 97 | +ForwardDiff.@define_binary_dual_op( |
| 98 | + RecursiveTupleMath.bmul, |
| 99 | + ForwardDiff.Dual{Txy}( |
| 100 | + bmul(x.value, y.value), |
| 101 | + badd(bmul(x.value, y.partials.values), bmul(x.partials.values, y.value)), |
| 102 | + ), |
| 103 | + ForwardDiff.Dual{Tx}(bmul(x.value, y), bmul(x.partials.values, y)), |
| 104 | + ForwardDiff.Dual{Ty}(bmul(x, y.value), bmul(x, y.partials.values)) |
| 105 | +) |
| 106 | +ForwardDiff.@define_binary_dual_op( |
| 107 | + RecursiveTupleMath.bdiv, |
| 108 | + ForwardDiff.Dual{Txy}( |
| 109 | + bdiv(x.value, y.value), |
| 110 | + bdiv( |
| 111 | + bsub(bmul(x.partials.values, y.value), bmul(x.value, y.partials.values)), |
| 112 | + bmul(y.value, y.value), |
| 113 | + ), |
| 114 | + ), |
| 115 | + ForwardDiff.Dual{Tx}(bdiv(x.value, y), bdiv(bmul(x.partials.values, y), bmul(y, y))), |
| 116 | + ForwardDiff.Dual{Ty}( |
| 117 | + bdiv(x, y.value), |
| 118 | + bdiv(bsub(bmul(x, y.partials.values)), bmul(y.value, y.value)), |
| 119 | + ), |
| 120 | +) |
| 121 | +ForwardDiff.@define_binary_dual_op( |
| 122 | + RecursiveTupleMath.bmax, |
| 123 | + begin |
| 124 | + cmp = gt_fast(x.value, y.value) |
| 125 | + v = ifelse(cmp, x.value, y.value) |
| 126 | + bcmp = btuple(cmp, Val(length(x.partials))) |
| 127 | + p = map(ifelse, bcmp, x.partials.values, y.partials.values) |
| 128 | + ForwardDiff.Dual{Txy}(v, p) |
| 129 | + end, |
| 130 | + begin |
| 131 | + cmp = gt_fast(x.value, y) |
| 132 | + v = ifelse(cmp, x.value, y) |
| 133 | + bcmp = btuple(cmp, Val(length(x.partials))) |
| 134 | + bnil = map(zero, x.partials.values) |
| 135 | + p = map(ifelse, bcmp, x.partials.values, bnil) |
| 136 | + ForwardDiff.Dual{Tx}(v, p) |
| 137 | + end, |
| 138 | + begin |
| 139 | + cmp = gt_fast(x, y.value) |
| 140 | + v = ifelse(cmp, x, y.value) |
| 141 | + bcmp = btuple(cmp, Val(length(y.partials))) |
| 142 | + bnil = map(zero, y.partials.values) |
| 143 | + p = map(ifelse, bcmp, bnil, y.partials.values) |
| 144 | + ForwardDiff.Dual{Ty}(v, p) |
| 145 | + end, |
| 146 | +) |
| 147 | +ForwardDiff.@define_binary_dual_op( |
| 148 | + RecursiveTupleMath.bmin, |
| 149 | + begin |
| 150 | + cmp = lt_fast(x.value, y.value) |
| 151 | + v = ifelse(cmp, x.value, y.value) |
| 152 | + bcmp = btuple(cmp, Val(length(x.partials))) |
| 153 | + p = map(ifelse, bcmp, x.partials.values, y.partials.values) |
| 154 | + ForwardDiff.Dual{Txy}(v, p) |
| 155 | + end, |
| 156 | + begin |
| 157 | + cmp = lt_fast(x.value, y) |
| 158 | + v = ifelse(cmp, x.value, y) |
| 159 | + bcmp = btuple(cmp, Val(length(x.partials))) |
| 160 | + bnil = map(zero, x.partials.values) |
| 161 | + p = map(ifelse, bcmp, x.partials.values, bnil) |
| 162 | + ForwardDiff.Dual{Tx}(v, p) |
| 163 | + end, |
| 164 | + begin |
| 165 | + cmp = lt_fast(x, y.value) |
| 166 | + v = ifelse(cmp, x, y.value) |
| 167 | + bcmp = btuple(cmp, Val(length(y.partials))) |
| 168 | + bnil = map(zero, y.partials.values) |
| 169 | + p = map(ifelse, bcmp, bnil, y.partials.values) |
| 170 | + ForwardDiff.Dual{Ty}(v, p) |
| 171 | + end, |
| 172 | +) |
4 | 173 |
|
5 | 174 | end |
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