julia> using LinearAlgebra

julia> U = UpperTriangular(rand(Int,2,2)); S = Symmetric(rand(Int,2,2));

julia> @time U * S;
  0.191704 seconds (1.09 M allocations: 55.715 MiB, 6.37% gc time, 99.97% compilation time)

julia> @descend U * S;
[ Info: tracking LinearAlgebra
*(A::AbstractMatrix, B::AbstractMatrix) @ LinearAlgebra ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.12/LinearAlgebra/src/matmul.jl:114
114 function (*)(A::UpperTriangular{Int64, Matrix{Int64}}::AbstractMatrix, B::Symmetric{Int64, Matrix{Int64}}::AbstractMatrix)::Matrix{Int64}
115     TS::Type{Int64} = promote_op(matprod::Core.Const(LinearAlgebra.matprod), eltype(A::UpperTriangular{Int64, Matrix{Int64}})::Type{Int64}, eltype(B::Symmetric{Int64, Matrix{Int64}})::Type{Int64})::Type{Int64}
116     mul!(matprod_dest(A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmetric{Int64, Matrix{Int64}}, TS::Type{Int64})::Matrix{Int64}, A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmetric{Int64, Matrix{Int64}})::Matrix{Int64}
117 end
Select a call to descend into or ↩ to ascend. [q]uit. [b]ookmark.
Toggles: [w]arn, [h]ide type-stable statements, [t]ype annotations, [s]yntax highlight for Source/LLVM/Native, [j]ump to source always.
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   eltype(A::UpperTriangular{Int64, Matrix{Int64}})
   eltype(B::Symmetric{Int64, Matrix{Int64}})
   promote_op(matprod::Core.Const(LinearAlgebra.matprod), eltype(A::UpperTriangular{Int64, Matrix{Int64}})::Type{Int64}, eltype(B::Symmetric{Int64, Matrix{Int64}})::Type{Int64})
   matprod_dest(A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmetric{Int64, Matrix{Int64}}, TS::Type{Int64})
 • mul!(matprod_dest(A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmetric{Int64, Matrix{Int64}}, TS::Type{Int64})::Matrix{Int64}, A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmet…
   ↩
mul!(C, A, B) @ LinearAlgebra ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.12/LinearAlgebra/src/matmul.jl:263
263 mul!(C::Matrix{Int64}, A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmetric{Int64, Matrix{Int64}})::Matrix{Int64} = mul!(C::Matrix{Int64}, A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmetric{Int64, Matrix{Int64}}, true, false)
Select a call to descend into or ↩ to ascend. [q]uit. [b]ookmark.
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 • mul!(C::Matrix{Int64}, A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmetric{Int64, Matrix{Int64}}, true, false)
   ↩
mul!(C::AbstractMatrix, A::AbstractVecOrMat, B::AbstractVecOrMat, α::Number, β::Number) @ LinearAlgebra ~/.julia/juliaup/julia-nightly/share/julia/stdlib/v1.12/LinearAlgebra/src/matmul.jl:295
295  mul!(C::Matrix{Int64}::AbstractMatrix, A::UpperTriangular{Int64, Matrix{Int64}}::AbstractVecOrMat, B::Symmetric{Int64, Matrix{Int64}}::AbstractVecOrMat, α::Core.Const(true)::Number, β::Core.Const(false)::Number)::Matrix{Int64} = _mul!(C::Matrix{Int64}, A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmetric{Int64, Matrix{Int64}}, α::Core.Const(true), β::Core.Const(false))
Select a call to descend into or ↩ to ascend. [q]uit. [b]ookmark.
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 • _mul!(C::Matrix{Int64}, A::UpperTriangular{Int64, Matrix{Int64}}, B::Symmetric{Int64, Matrix{Int64}}, α::Core.Const(true), β::Core.Const(false))
   ↩
ERROR: FieldError: type ConcreteResult has no field `mi`, available fields: `edge`, `effects`, `result`
Stacktrace:
  [1] getproperty
    @ ./Base.jl:54 [inlined]
  [2] process_const_info(interp::Cthulhu.CthulhuInterpreter, thisinfo::Any, argtypes::Vector{Any}, rt::Any, result::Any, optimize::Bool, exct::Any)
    @ Cthulhu ~/.julia/packages/Cthulhu/GaSLZ/src/reflection.jl:138
  [3] process_info(interp::Cthulhu.CthulhuInterpreter, info::Core.Compiler.CallInfo, argtypes::Vector{Any}, rt::Any, optimize::Bool, exct::Any)
    @ Cthulhu ~/.julia/packages/Cthulhu/GaSLZ/src/reflection.jl:203
  [4] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/reflection.jl:64
  [5] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:559
  [6] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:460
  [7] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:710
  [8] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:460
  [9] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:710
 [10] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:460
 [11] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:710
 [12] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:460
 [13] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:863
 [14] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:863
 [15] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:879
 [16] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:876
 [17] __descend_with_error_handling(args::Any; terminal::Any, kwargs...)
    @ Cthulhu ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:263
 [18] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:260
 [19] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:252
 [20] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:244
 [21] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:306
 [22] top-level scope
    @ ~/.julia/packages/Cthulhu/GaSLZ/src/Cthulhu.jl:306
 [23] top-level scope
    @ REPL[4]:1

julia> versioninfo()
Julia Version 1.12.0-DEV.1542
Commit fe67097b0d2 (2024-11-02 14:48 UTC)
Build Info:
  Official https://julialang.org release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × Intel(R) Core(TM) i5-10310U CPU @ 1.70GHz
  WORD_SIZE: 64
  LLVM: libLLVM-18.1.7 (ORCJIT, skylake)
Threads: 1 default, 0 interactive, 1 GC (on 8 virtual cores)
Environment:
  JULIA_EDITOR = subl

(@v1.12) pkg> st -m Cthulhu
Status `~/.julia/environments/v1.12/Manifest.toml`
  [f68482b8] Cthulhu v2.15.2

(@v1.12) pkg> st -m TypedSyntax
Status `~/.julia/environments/v1.12/Manifest.toml`
  [d265eb64] TypedSyntax v1.4.2