fix: special case transpose and adjoint

Author: avik-pal

src/TracedRArray.jl

@@ -179,6 +179,12 @@ function Base.permutedims(A::AnyTracedRArray{T,N}, perm) where {T,N}
     )
 end
 
+function Base.transpose(A::AnyTracedRVecOrMat)
+    A = ndims(A) == 1 ? reshape(A, :, 1) : A
+    return permutedims(A, (2, 1))
+end
+Base.adjoint(A::AnyTracedRVecOrMat{<:Real}) = transpose(A)
+
 function Base.promote_rule(
     ::Type{TracedRArray{T,N}}, ::Type{TracedRArray{S,N}}
 ) where {T,S,N}

test/basic.jl

@@ -261,3 +261,15 @@ tuple_byref2(x) = abs2.(x), tuple_byref2(x)
     # @test r2[2].a.b.data === x.data
     # @test r2[1] == abs2.([1.0 -2.0; -3.0 4.0])
 end
+
+sum_xxᵀ(x) = sum(x .* x')
+
+@testset "sum(x .* x')" begin
+    @testset "size(x): $(size(x))" for x in (rand(4, 4), rand(4,))
+        x_ca = Reactant.to_rarray(x)
+
+        sum_xxᵀ_compiled = @compile sum_xxᵀ(x_ca)
+
+        @test sum_xxᵀ_compiled(x_ca) ≈ sum_xxᵀ(x)
+    end
+end