Add warning about binary issue on mac

Author: Crown421

README.md

@@ -13,6 +13,9 @@ Until Julia 0.6 the package was registered as `VML.jl`.
 
 Similar packages are [Yeppp.jl](https://github.com/JuliaMath/Yeppp.jl), which wraps the open source Yeppp library, and [AppleAccelerate.jl](https://github.com/JuliaMath/AppleAccelerate.jl), which provides access to macOS's Accelerate framework.
 
+### Warning for macOS
+There is currently [the following](https://github.com/JuliaPackaging/BinaryBuilder.jl/issues/700) issue between the artifacts used by `SpecialFunctions.jl` and `MKL_jll`. Unless `IntelVectorMath` is loaded first, there might be wrong results coming from a small number of function for particular input array lengths. 
+
 ## Basic install
 
 To install IntelVectorMath.jl run

src/IntelVectorMath.jl

@@ -8,6 +8,12 @@ const IVM = IntelVectorMath
 # import Base: .^, ./
 include("setup.jl")
 
+function __init__()
+    if Sys.isapple() && :SpecialFunctions in names(Main; imported = true)
+        @warn "It appears SpecialFunctions was loaded prior to this package, which currently on mac may lead to wrong results. For further details see github.com/JuliaMath/IntelVectorMath.jl"
+    end
+end
+
 for t in (Float32, Float64, ComplexF32, ComplexF64)
     # Unary, real or complex
     def_unary_op(t, t, :acos, :acos!, :Acos)