promote is not needed after JuliaLang#30471

base/math.jl

@@ -546,7 +546,7 @@ function hypot(x::Number, y::Number)
     else
         r = ay / ax
     end
-    rr = ax * sqrt(1 + r * r)
+    rr = ax * sqrt(oneunit(r) + r * r)
 
     if isnan(r)
         if isinf(x) || isinf(y)
@@ -563,14 +563,13 @@ end
 
 Compute the hypotenuse ``\\sqrt{\\sum x_i^2}`` avoiding overflow and underflow.
 """
-hypot(x::Number...) = _hypot(promote(x...))
-function _hypot(x::NTuple{N,<:Number}) where {N}
+function hypot(x::Number...) where {N}
     N == 0 && error("invalid hypot() call without arguments")
     # speculatively try fast naive approach
     s = sum(abs2.(float.(x)))
     if isnan(s)
         return any(isinf, x) ? oftype(sqrt(s), Inf) : sqrt(s) # IEEE 754
-    elseif isinf(s) || s ≤ _floatmin(s) * (N-1) # FIXME: revisit when #30387 is resolved
+    elseif isinf(s) || float(s) ≤ _floatmin(float(s)) * (N-1)
         # if overflow/underflow, try normalization
         ma = maximum(abs.(float.(x)))
         if iszero(ma) || isinf(ma)
@@ -587,7 +586,6 @@ _floatmin(x::AbstractFloat) = _floatmin(typeof(x))
 _floatmin(::Type{T}) where {T<:AbstractFloat} = nextfloat(zero(T)) / eps(T)
 _floatmin(::Type{T}) where {T<:IEEEFloat} = floatmin(T)
 
-
 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)