Re: [Bug-apl] performance in of ¨

[Christian Robert]

I think you fixed it. No longer running O(NxN) (still slower than native C++, I 
can live with that, no problems)

btw, When I defined this test function two days ago:


      f2def 'FE'

      )sic
      )erase FE

      ∇Z←A (LO FE) B;rho_Z;N;N_max
rho_Z←⍴B ◊ N←⎕IO ◊ A←,A ◊ N_max←N+⍴B←,B ◊ Z←N_max⍴0
LOOP: Z[N]←⊂(⊃A[N]) LO ⊃B[N] ◊ →(N_max>N←N+1)⍴LOOP
Z←rho_Z⍴Z
∇
      )fns
D   MEASURE     MEASURE2    Replace     df  f2def   ltrim   rtrim   time    
trim    vert
      ⍝ FE does not appear here ! But *is* a function

      ⍝ but this function name appear in ⎕nl 4

      D ⎕nl ¨ ⍳4
┌4──────────────────────┐
│┌⊖┐ ┌⊖┐ ┌8───────┐ ┌2─┐│
│⌽ │ ⌽ │ 1D       │ ↓FE││
│└─┘ └─┘ 1MEASURE │ └──┘│
│        │MEASURE2│     │
│        │Replace │     │
│        │df      │     │
│        │f2def   │     │
│        │ltrim   │     │
│        │rtrim   │     │
│        │time    │     │
│        │trim    │     │
│        │vert    │     │
│        └────────┘     │
└∊──────────────────────┘

what is {quad}nl 4 ?

why 'FE' not displayed in ")fns" ?

Xtian.


On 2016-06-18 16:21, Juergen Sauermann wrote:
> Hi,
>
> I believe I have fixed the problem,*SVN **749*.
>
> The fault was actually not related to macros but a general problem
> affecting the performance of virtually all workspaces.
>
> The time-consuming line in the EACH macro was this:
>
> *LOOP: Z[N]←⊂(⊃A[N]) LO ⊃B[N] ◊ →(N_max>N←N+1)⍴LOOP*
>
> Due to an inefficiency in the runtime parser, the parser would, for example, 
> first resolve
> B (which creates a copy of B) and then index the copy to obtain B[N] . Same for 
> A.
> If B has N items then this would generate N copies of B, each copy taking O(N) 
> cycles,
> and therefore the runtime of the above innocent looking LOOP would be O(N×N).
>
> Macros are a little slower than their built-in siblings, but the code that 
> could be removed
> by using macros belonged to the most error-prone in the past, and some of the 
> built-in
> operators (which are called when their function argument(s) are primitive 
> functions) could
> also be simplified.
>
> /// Jürgen