avoid conversion from Char to String to Symbol in some LinearAlgebra routines

stdlib/LinearAlgebra/src/LinearAlgebra.jl

@@ -226,14 +226,28 @@ end
 
 function char_uplo(uplo::Symbol)
     if uplo == :U
-        'U'
+        return 'U'
     elseif uplo == :L
-        'L'
+        return 'L'
     else
-        throw(ArgumentError("uplo argument must be either :U (upper) or :L (lower)"))
+        throw_uplo()
     end
 end
 
+function sym_uplo(uplo::Char)
+    if uplo == 'U'
+        return :U
+    elseif uplo == 'L'
+        return :L
+    else
+        throw_uplo()
+    end
+end
+
+
+@noinline throw_uplo() = throw(ArgumentError("uplo argument must be either :U (upper) or :L (lower)"))
+
+
 """
     ldiv!(Y, A, B) -> Y
 

stdlib/LinearAlgebra/src/cholesky.jl

@@ -356,9 +356,9 @@ function getproperty(C::CholeskyPivoted{T}, d::Symbol) where T<:BlasFloat
     Cfactors = getfield(C, :factors)
     Cuplo    = getfield(C, :uplo)
     if d == :U
-        return UpperTriangular(Symbol(Cuplo) == d ? Cfactors : copy(Cfactors'))
+        return UpperTriangular(sym_uplo(Cuplo) == d ? Cfactors : copy(Cfactors'))
     elseif d == :L
-        return LowerTriangular(Symbol(Cuplo) == d ? Cfactors : copy(Cfactors'))
+        return LowerTriangular(sym_uplo(Cuplo) == d ? Cfactors : copy(Cfactors'))
     elseif d == :p
         return getfield(C, :piv)
     elseif d == :P

stdlib/LinearAlgebra/src/symmetric.jl

@@ -162,10 +162,10 @@ for (S, H) in ((:Symmetric, :Hermitian), (:Hermitian, :Symmetric))
                 throw(ArgumentError("Cannot construct $($S); uplo doesn't match"))
             end
         end
-        $S(A::$H) = $S(A.data, Symbol(A.uplo))
+        $S(A::$H) = $S(A.data, sym_uplo(A.uplo))
         function $S(A::$H, uplo::Symbol)
             if A.uplo == char_uplo(uplo)
-                return $S(A.data, Symbol(A.uplo))
+                return $S(A.data, sym_uplo(A.uplo))
             else
                 throw(ArgumentError("Cannot construct $($S); uplo doesn't match"))
             end
@@ -185,7 +185,7 @@ size(A::HermOrSym) = size(A.data)
 @inline function getindex(A::Symmetric, i::Integer, j::Integer)
     @boundscheck checkbounds(A, i, j)
     @inbounds if i == j
-        return symmetric(A.data[i, j], Symbol(A.uplo))::symmetric_type(eltype(A.data))
+        return symmetric(A.data[i, j], sym_uplo(A.uplo))::symmetric_type(eltype(A.data))
     elseif (A.uplo == 'U') == (i < j)
         return A.data[i, j]
     else
@@ -195,7 +195,7 @@ end
 @inline function getindex(A::Hermitian, i::Integer, j::Integer)
     @boundscheck checkbounds(A, i, j)
     @inbounds if i == j
-        return hermitian(A.data[i, j], Symbol(A.uplo))::hermitian_type(eltype(A.data))
+        return hermitian(A.data[i, j], sym_uplo(A.uplo))::hermitian_type(eltype(A.data))
     elseif (A.uplo == 'U') == (i < j)
         return A.data[i, j]
     else
@@ -236,14 +236,14 @@ similar(A::Union{Symmetric,Hermitian}, ::Type{T}, dims::Dims{N}) where {T,N} = s
 function Matrix(A::Symmetric)
     B = copytri!(convert(Matrix, copy(A.data)), A.uplo)
     for i = 1:size(A, 1)
-        B[i,i] = symmetric(B[i,i], Symbol(A.uplo))::symmetric_type(eltype(A.data))
+        B[i,i] = symmetric(B[i,i], sym_uplo(A.uplo))::symmetric_type(eltype(A.data))
     end
     return B
 end
 function Matrix(A::Hermitian)
     B = copytri!(convert(Matrix, copy(A.data)), A.uplo, true)
     for i = 1:size(A, 1)
-        B[i,i] = hermitian(B[i,i], Symbol(A.uplo))::hermitian_type(eltype(A.data))
+        B[i,i] = hermitian(B[i,i], sym_uplo(A.uplo))::hermitian_type(eltype(A.data))
     end
     return B
 end
@@ -252,10 +252,10 @@ Array(A::Union{Symmetric,Hermitian}) = convert(Matrix, A)
 parent(A::HermOrSym) = A.data
 Symmetric{T,S}(A::Symmetric{T,S}) where {T,S<:AbstractMatrix} = A
 Symmetric{T,S}(A::Symmetric) where {T,S<:AbstractMatrix} = Symmetric{T,S}(convert(S,A.data),A.uplo)
-AbstractMatrix{T}(A::Symmetric) where {T} = Symmetric(convert(AbstractMatrix{T}, A.data), Symbol(A.uplo))
+AbstractMatrix{T}(A::Symmetric) where {T} = Symmetric(convert(AbstractMatrix{T}, A.data), sym_uplo(A.uplo))
 Hermitian{T,S}(A::Hermitian{T,S}) where {T,S<:AbstractMatrix} = A
 Hermitian{T,S}(A::Hermitian) where {T,S<:AbstractMatrix} = Hermitian{T,S}(convert(S,A.data),A.uplo)
-AbstractMatrix{T}(A::Hermitian) where {T} = Hermitian(convert(AbstractMatrix{T}, A.data), Symbol(A.uplo))
+AbstractMatrix{T}(A::Hermitian) where {T} = Hermitian(convert(AbstractMatrix{T}, A.data), sym_uplo(A.uplo))
 
 copy(A::Symmetric{T,S}) where {T,S} = (B = copy(A.data); Symmetric{T,typeof(B)}(B,A.uplo))
 copy(A::Hermitian{T,S}) where {T,S} = (B = copy(A.data); Hermitian{T,typeof(B)}(B,A.uplo))
@@ -442,9 +442,9 @@ mul!(C::StridedMatrix{T}, A::StridedMatrix{T}, B::Hermitian{T,<:StridedMatrix})
 
 for T in (:Symmetric, :Hermitian), op in (:*, :/)
     # Deal with an ambiguous case
-    @eval ($op)(A::$T, x::Bool) = ($T)(($op)(A.data, x), Symbol(A.uplo))
+    @eval ($op)(A::$T, x::Bool) = ($T)(($op)(A.data, x), sym_uplo(A.uplo))
     S = T == :Hermitian ? :Real : :Number
-    @eval ($op)(A::$T, x::$S) = ($T)(($op)(A.data, x), Symbol(A.uplo))
+    @eval ($op)(A::$T, x::$S) = ($T)(($op)(A.data, x), sym_uplo(A.uplo))
 end
 
 function factorize(A::HermOrSym{T}) where T
@@ -481,8 +481,8 @@ function _inv(A::HermOrSym)
     end
     B
 end
-inv(A::Hermitian{<:Any,<:StridedMatrix}) = Hermitian(_inv(A), Symbol(A.uplo))
-inv(A::Symmetric{<:Any,<:StridedMatrix}) = Symmetric(_inv(A), Symbol(A.uplo))
+inv(A::Hermitian{<:Any,<:StridedMatrix}) = Hermitian(_inv(A), sym_uplo(A.uplo))
+inv(A::Symmetric{<:Any,<:StridedMatrix}) = Symmetric(_inv(A), sym_uplo(A.uplo))
 
 eigen!(A::RealHermSymComplexHerm{<:BlasReal,<:StridedMatrix}) = Eigen(LAPACK.syevr!('V', 'A', A.uplo, A.data, 0.0, 0.0, 0, 0, -1.0)...)