I think this is something I might have read about in the past, but are
there plans to make y = a*b use an already allocated y?
On Tuesday, October 18, 2016 at 12:38:00 PM UTC-4, Stefan Karpinski wrote:
>
> A_mul_B!(Y, A, B) -> Y
>
> Calculates the matrix-matrix or matrix-vector product A⋅B and stores the
> result in Y, overwriting the
> existing value of Y. Note that Y must not be aliased with either A or B.
>
> julia> A=[1.0 2.0; 3.0 4.0]; B=[1.0 1.0; 1.0 1.0]; Y = similar(B);
> A_mul_B!(Y, A, B);
>
> julia> Y
> 2×2 Array{Float64,2}:
> 3.0 3.0
> 7.0 7.0
>
> On Tue, Oct 18, 2016 at 10:27 AM, <zamani.m...@gmail.com <javascript:>>
> wrote:
>
>> hi guys
>> is there a way to reduce allocated memory in matrix multiplications?
>>
>> for example this code blew in my machine gives :
>>
>> function test4(n)
>> a = rand(n,n)
>> for i = 1:100
>> a*a
>> end
>> end
>>
>>
>> ---------------------- answer ----------------------
>> test4(1)
>> # force compiling
>>
>> @time test4(1000)
>> 16.589743 seconds (433 allocations: 770.587 MB, 0.68% gc time)
>>
>
>
