[Bug-apl] Fun With Benchmarks

[fred]

Ok, so infinite precision integer arithmetic takes over 50 seconds with
GNU APL to compute 300!

Um... not good. Actually, this is horrific.

I will attempt to put this into perspective. I use the interpretive
SNOBOL4 implementation from Griswold. This is code that implements a
SNOBOL4 interpreter. The implementation is that the code implementing
the interpreter (which was written in the 1960's) is macro-expanded
into a C program, which is then compiled and run to actually interpret
the SNOBOL4 language source.

Ok? This is the SLOWEST SNOBOL4 implementation that I know...

I used an infinite precision arithmetic package written 40 years ago
(specifically, for education -- not for performance). Now, one of the
reasons this package is slow is that it REDEFINES '+', '-', '*', '/'
operators AT RUN TIME... Not only are the data types dynamic, the
actual functions are also dynamic, and have been redefined. 

Now, if you are still with me -- an interpreter that is macro expanded
to C running a run-time binding operator redefinition program in a
language where strings are immutable, and must be completely
hashed/copied on each change... and has complete mark/sweep garbage
collection -- again, implemented in the macro expanded interpreter.

Let us look at the code:

-include 'INFINIP.INC'
    infinip_start() ;* redefine basic math functions to work on strings
    x = '1'
    i = 1
    l = 300
    t = time()
top gt(i, l) :s(btm)
    x = x * i
    i = i + 1 :(top)
btm t = time() - t
    output = x
    output = t ' milliseconds'
end

Now, I had a problem running the Davos code (but I haven't attempted
debugging - 52 seconds seemed extreme) -- but I assume 52 seconds is..
um.. normal. I will run this code on a 1.5Ghz Intel i5 (this is my
Linux tablet, a three year old Acer Iconia tablet):

$ snobol4 -s ifact
30605751221644063603537046129726862938858880417357699941677674125947653
31767168674655152914224775733499391478887017263688642639077590031542268
42927906974559841225476930271954604008012215776252176854255965356903506
78872526432189626429936520457644883038890975394348962543605322598077652
12708224376394491201286786753683057122936819436499564604981664502277165
00185176546469340112226034729724066333258583506870150169794168850353752
13755491028912640715715483028228493795263658014523523315693648223343679
92545940952768206080622328123873838808170496000000000000000000000000000
00000000000000000000000000000000000000000000000
20315.096404 milliseconds
SNOBOL4 statistics summary-
          1.080 ms. Compilation time
      20315.416 ms. Execution time
       36453943 Statements executed, 19353232 failed
        1834289 Arithmetic operations performed
        7899675 Pattern matches performed
            338 Regenerations of dynamic storage
       1680.975 ms. Execution time in GC
              0 Reads performed
              2 Writes performed
        557.290 ns. Average per statement executed
       1794.398 Thousand statements per second
$
 
20.3 seconds total. Since this was running with ONLY 8MB memory
(default), and EVERY string change needed a new copy, 338 garbage
collections where needed. That is mark&sweep. GC took 1.7 seconds (of
that 20.3 seconds total)

FredW