Intrinsics shown as Any in typed ast

[bjarthur]

in the output of @code_warntype below, note the ::Any, which on the REPL appears red, but here i capitalize. is there something i should alter about my function definition, or is this a bug elsewhere?

julia> foo(x::Float64) = sqrt(x)
foo (generic function with 1 method)

julia> @code_warntype foo(5.0)
Variables:
  #self#::#foo
  x::Float64

Body:
  begin  # none, line 1:
      return (Base.Math.box)(Base.Math.Float64,(Base.Math.sqrt_llvm)(_2::Float64)::ANY)::Float64
  end::Float64

[KristofferC]

I had the same question when I started using Julia: https://groups.google.com/forum/#!topic/julia-users/g9O9Ik5OAJA

[yuyichao]

There's nothing wrong with the method and there's no type instability. I think most of them are fixed but I did notice some of the math ones are not handled...

[bjarthur]

thanks.

is the ::Union{} that @code_warntype returns in red when indexing with colon also not something to worry about? see the line after 37: in the example below.

julia> foo(x::Array{Float64,2}) = x[1,:]=1.0
foo (generic function with 1 method)

julia> x=zeros(3,3)
3x3 Array{Float64,2}:
 0.0  0.0  0.0
 0.0  0.0  0.0
 0.0  0.0  0.0

julia> foo(x)
1.0

julia> x
3x3 Array{Float64,2}:
 1.0  1.0  1.0
 0.0  0.0  0.0
 0.0  0.0  0.0

julia> @code_warntype foo(x)
Variables:
  #self#::#foo
  x::Array{Float64,2}
  #temp#::Bool
  __temp__::Bool
  __temp__::Bool

Body:
  begin  # none, line 1:
      GenSym(13) = Main.: # abstractarray.jl, line 546: # abstractarray.jl, line 547:
      $(Expr(:inbounds, false))
      GenSym(11) = 1
      GenSym(12) = GenSym(13) # multidimensional.jl, line 304:
      $(Expr(:boundscheck, true))
      $(Expr(:inbounds, false))
      GenSym(7) = GenSym(11)
      GenSym(8) = GenSym(12) # abstractarray.jl, line 150:
      GenSym(3) = GenSym(7) # abstractarray.jl, line 157: # abstractarray.jl, line 158:
      GenSym(5) = (Base.arraysize)(_2::Array{Float64,2},1)::Int64 # abstractarray.jl, line 131:
      unless (Base.sle_int)(1,GenSym(3))::Bool goto 22
      _4::Bool = (Base.sle_int)(GenSym(3),GenSym(5))::Bool
      goto 24
      22: 
      _4::Bool = false
      24: 
      unless _4::Bool goto 30
      (Base.arraysize)(_2::Array{Float64,2},2)::Int64 # abstractarray.jl, line 132:
      _3::ANY = true
      goto 32
      30: 
      _3::ANY= false
      32: 
      GenSym(4) = _3::Bool
      unless GenSym(4) goto 37
      _5::Bool = GenSym(4)
      goto 39
      37: 
      _5::Bool = (Base.throw_boundserror)(_2::Array{Float64,2},(top(tuple))(GenSym(3),GenSym(8))::Tuple{Int64,Colon})::UNION{}
      39: 
      $(Expr(:inbounds, :pop))
      _5::Bool
      $(Expr(:boundscheck, :(Base.pop))) # multidimensional.jl, line 305:
      $(Expr(:inbounds, false))
      GenSym(9) = GenSym(11)
      GenSym(10) = GenSym(12) # multidimensional.jl, line 308:
      $(Expr(:inbounds, :pop))
      $(Expr(:inbounds, :pop))
      (Base._unsafe_batchsetindex!)(_2::Array{Float64,2},$(Expr(:new, Base.Repeated{Float64}, 1.0)),GenSym(9),GenSym(10))::Array{Float64,2}
      return 1.0
  end::Float64

note this example has two ::Anys as well, near lines 24: and 30:.

[KristofferC]

A decent heuristic is, unless it is a type instability in one of the variables under Variables: or in the end: in the end of the output, then don't worry about it.

[yuyichao]

The Union{} means the line throws an error. The consensus was that it is useful to know if you are throwing an error unexpectedly #13295. The ::Any for variable assignment is #15714 .

[bjarthur]

thanks. and sorry for not thinking of searching for @code_warntype.