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faster hypot(::IEEEFloat...) #48130

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Merged
oscardssmith merged 5 commits into from
Jan 28, 2023
Merged

faster hypot(::IEEEFloat...) #48130

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ad39de1
skip redundant check
mikmoore Jan 5, 2023
9d7a2ef
faster hypot for IEEEFloat
mikmoore Jan 5, 2023
1a0340c
indentation
mikmoore Jan 5, 2023
fe6a0ce
Merge branch 'master' into hypot
mikmoore Jan 7, 2023
00fc254
Revert "skip redundant check"
mikmoore Jan 9, 2023
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13 changes: 12 additions & 1 deletion base/math.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -832,7 +832,7 @@ _hypot(x::ComplexF16, y::ComplexF16) = Float16(_hypot(ComplexF32(x), ComplexF32(

function _hypot(x::NTuple{N,<:Number}) where {N}
maxabs = maximum(abs, x)
if isnan(maxabs) && any(isinf, x)
if any(isinf, x)
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return typeof(maxabs)(Inf)
elseif (iszero(maxabs) || isinf(maxabs))
return maxabs
Expand All @@ -841,6 +841,17 @@ function _hypot(x::NTuple{N,<:Number}) where {N}
end
end

function _hypot(x::NTuple{N,T}) where {N,T<:IEEEFloat}
infT = convert(T, Inf)
x = abs.(x) # doesn't change result but enables computational shortcuts
any(==(infT), x) && return infT # return Inf even if an argument is NaN
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maxabs = reinterpret(T, maximum(z -> reinterpret(Signed, z), x)) # for abs(::IEEEFloat) values, a ::BitInteger cast does not change the result
iszero(maxabs) && return maxabs
y = abs2.(x ./ maxabs)
a2 = @fastmath reduce(+, y) # allow sum to be reordered
return sqrt(a2) * maxabs
end

atan(y::Real, x::Real) = atan(promote(float(y),float(x))...)
atan(y::T, x::T) where {T<:AbstractFloat} = Base.no_op_err("atan", T)

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