better upper bounds in apply_type_tfunc for NamedTuple #32699
Closed
Description
Here's an example where the resulting NamedTuple{names, _A) where _A type is not ideal since it completely discards valid information up to that point.
8 ── %21 = Base.getfield(%14, :id)::Array{Int64,1}
│ %22 = Base.arrayref(true, %21, %15)::Int64
│ %23 = Base.getfield(%16, :salary)::Array{Union{Missing, Float64},1}
│ %24 = Base.arrayref(true, %23, %17)::Union{Missing, Float64}
│ %25 = (isa)(%24, Missing)::Bool
└─── goto #10 if not %25
9 ── goto #13
10 ─ %28 = (isa)(%24, Float64)::Bool
└─── goto #12 if not %28
11 ─ %30 = π (%24, Float64)
│ %31 = Base.sitofp(Float64, 2)::Float64
│ %32 = Base.mul_float(%30, %31)::Float64
└─── goto #13
12 ─ Core.throw(ErrorException("fatal error in type inference (type bound)"))::Union{}
└─── $(Expr(:unreachable))::Union{}
13 ┄ %36 = φ (#9 => $(QuoteNode(missing)), #11 => %32)::Union{Missing, Float64}
│ %37 = Core.tuple(%22, %36)::Tuple{Int64,Union{Missing, Float64}}
│ %38 = (NamedTuple{(:id, :y),T} where T<:Tuple)(%37)::NamedTuple{(:id, :y),_A} where _A@JeffBezanson thought it should be valid/fine to include an upper bound here, so that we end up with NamedTuple{(:id, :y), _A} where _A <: Tuple{Int64, Union{Missing, Float64}