Muladd! (useful?)

photor · October 30, 2022, 7:54am

Hi, I know there is the muladd function, but it seems there isn’t an in-place version muladd! of it?

jling · October 30, 2022, 7:57am

JuliaLang/julia/blob/v1.8.2/stdlib/LinearAlgebra/src/matmul.jl#L246


      
          Base.muladd(x::TransposeAbsVec, A::AbstractMatrix, z::Union{Number, AbstractVecOrMat}) =
              transpose(muladd(transpose(A), transpose(x), transpose(z)))
          
          
function Base.muladd(A::StridedMaybeAdjOrTransMat{<:Number}, y::AbstractVector{<:Number}, z::Union{Number, AbstractVector})
              T = promote_type(eltype(A), eltype(y), eltype(z))
              C = similar(A, T, axes(A,1))
              C .= z
              mul!(C, A, y, true, true)
          end
          
          
function Base.muladd(A::StridedMaybeAdjOrTransMat{<:Number}, B::StridedMaybeAdjOrTransMat{<:Number}, z::Union{Number, AbstractVecOrMat})
              T = promote_type(eltype(A), eltype(B), eltype(z))
              C = similar(A, T, axes(A,1), axes(B,2))
              C .= z
              mul!(C, A, B, true, true)
          end
          
          
"""
              mul!(Y, A, B) -> Y
          
          
Calculates the matrix-matrix or matrix-vector product ``AB`` and stores the result in `Y`,