make (*)(::Adjoint{Vector}, ::Vector) non-recursive (#35257)

* make (*)(::Adjoint{Vector}, ::Vector) non-recursive

* fix matmul test

* code simplification

Author: dkarrasch

stdlib/LinearAlgebra/src/adjtrans.jl

@@ -242,13 +242,10 @@ Broadcast.broadcast_preserving_zero_d(f, tvs::Union{Number,TransposeAbsVec}...)
 ## multiplication *
 
 # Adjoint/Transpose-vector * vector
-*(u::AdjointAbsVec, v::AbstractVector) = dot(u.parent, v)
+*(u::AdjointAbsVec{T}, v::AbstractVector{T}) where {T<:Number} = dot(u.parent, v)
 *(u::TransposeAbsVec{T}, v::AbstractVector{T}) where {T<:Real} = dot(u.parent, v)
-function *(u::TransposeAbsVec, v::AbstractVector)
-    require_one_based_indexing(u, v)
-    @boundscheck length(u) == length(v) || throw(DimensionMismatch())
-    return sum(@inbounds(u[k]*v[k]) for k in 1:length(u))
-end
+*(u::AdjOrTransAbsVec, v::AbstractVector) = sum(uu*vv for (uu, vv) in zip(u, v))
+
 # vector * Adjoint/Transpose-vector
 *(u::AbstractVector, v::AdjOrTransAbsVec) = broadcast(*, u, v)
 # Adjoint/Transpose-vector * Adjoint/Transpose-vector

stdlib/LinearAlgebra/test/matmul.jl

@@ -550,7 +550,7 @@ end
     @test  transpose(Xv2)*Xv2     ≈ XtX
     @test (transpose(Xv3)*Xv3)[1] ≈ XtX
     @test  Xv1'*Xv1     ≈ XcX
-    @test Xv2'*Xv2 ≈ norm(Xv2)^2
+    @test  Xv2'*Xv2     ≈ XcX
     @test (Xv3'*Xv3)[1] ≈ XcX
     @test (Xv1*transpose(Xv1))[1] ≈ XXt
     @test  Xv2*transpose(Xv2)     ≈ XXt