Re: [Tarantool-patches] [PATCH v1 luajit 09/41] perf: adjust fannkuch in LuaJIT-benches

[Sergey Kaplun via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Hi, Sergey!
Thanks for the review!
Fixed your comments and updated the branch.

On 17.11.25, Sergey Bronnikov wrote:
> Hi, Sergey,
> 
> thanks for the patch!
> 
> Sergey
> 
> On 10/24/25 13:50, Sergey Kaplun wrote:
> > This patch adjusts the aforementioned test to use the benchmark
> > framework introduced before. The default arguments are adjusted
> > according to the <PARAM_x86.txt> file. The arguments to the script still
> > can be provided in the command line run.
> > ---
> >
> > I'm not sure that amount of permutations is the correct items count.
> > Have you any other suggestions?
> >
> >   perf/LuaJIT-benches/fannkuch.lua | 37 +++++++++++++++++++++++++++++---
> >   1 file changed, 34 insertions(+), 3 deletions(-)
> >
> > diff --git a/perf/LuaJIT-benches/fannkuch.lua b/perf/LuaJIT-benches/fannkuch.lua
> > index 2a4cd426..c963c66f 100644
> > --- a/perf/LuaJIT-benches/fannkuch.lua
> > +++ b/perf/LuaJIT-benches/fannkuch.lua
> 
> I'm highly recommend adding description to benchmarks.
> 
> At least to the tests from "benchmarks game" suite.
> 
> You can use descriptions from the [1] and [2].
> 
> 1. https://benchmarksgame-team.pages.debian.net/benchmarksgame/
> 
> 2. 
> https://en.wikipedia.org/wiki/The_Computer_Language_Benchmarks_Game#Benchmark_programs

Added the short description, as you suggested:

===================================================================
diff --git a/perf/LuaJIT-benches/fannkuch.lua b/perf/LuaJIT-benches/fannkuch.lua
index 2328e058..f51e0eaf 100644
--- a/perf/LuaJIT-benches/fannkuch.lua
+++ b/perf/LuaJIT-benches/fannkuch.lua
@@ -1,3 +1,10 @@
+-- The benchmark that checks the performance of operations on
+-- small integers and vectors of integers and the performance of
+-- inner loops of the benchmark. The benchmark finds the maximum
+-- number of flips in the table needed for any permutation.
+-- For the details see:
+-- https://benchmarksgame-team.pages.debian.net/benchmarksgame/description/fannkuchredux.html
+
 local bench = require("bench").new(arg)
 
 local function fannkuch(n)
===================================================================

> 
> 
> > @@ -1,3 +1,4 @@
> > +local bench = require("bench").new(arg)
> >   
> >   local function fannkuch(n)
> >     local p, q, s, odd, check, maxflips = {}, {}, {}, true, 0, 0
> > @@ -6,7 +7,7 @@ local function fannkuch(n)
> >       -- Print max. 30 permutations.
> >       if check < 30 then
> >         if not p[n] then return maxflips end	-- Catch n = 0, 1, 2.
> > -      io.write(unpack(p)); io.write("\n")
> > +      -- io.write(unpack(p)); io.write("\n")
> isn't better to remove at all?

OK, removed:

===================================================================
diff --git a/perf/LuaJIT-benches/fannkuch.lua b/perf/LuaJIT-benches/fannkuch.lua
index c963c66f..ceb13ca6 100644
--- a/perf/LuaJIT-benches/fannkuch.lua
+++ b/perf/LuaJIT-benches/fannkuch.lua
@@ -7,7 +7,6 @@ local function fannkuch(n)
     -- Print max. 30 permutations.
     if check < 30 then
       if not p[n] then return maxflips end      -- Catch n = 0, 1, 2.
-      -- io.write(unpack(p)); io.write("\n")
       check = check + 1
     end
     -- Copy and flip.
===================================================================

> >         check = check + 1
> >       end
> >       -- Copy and flip.
> > @@ -46,5 +47,35 @@ local function fannkuch(n)
> >     until false
> >   end
> >   
> > -local n = tonumber(arg and arg[1]) or 1
> > -io.write("Pfannkuchen(", n, ") = ", fannkuch(n), "\n")
> > +local n = tonumber(arg and arg[1]) or 11
> > +
> > +-- Precomputed numbers taken from:
> please add description of the paper as well: "Performing Lisp Analysis 
> of the FANNKUCH Benchmark"

Added:

===================================================================
diff --git a/perf/LuaJIT-benches/fannkuch.lua b/perf/LuaJIT-benches/fannkuch.lua
index ceb13ca6..2328e058 100644
--- a/perf/LuaJIT-benches/fannkuch.lua
+++ b/perf/LuaJIT-benches/fannkuch.lua
@@ -48,7 +48,8 @@ end
 
 local n = tonumber(arg and arg[1]) or 11
 
--- Precomputed numbers taken from:
+-- Precomputed numbers taken from "Performing Lisp Analysis of the
+-- FANNKUCH Benchmark":
 -- https://dl.acm.org/doi/pdf/10.1145/382109.382124
 local FANNKUCH = { 0, 1, 2, 4, 7, 10, 16, 22, 30, 38, 51, 65, 80 }
 
===================================================================

> > +--https://dl.acm.org/doi/pdf/10.1145/382109.382124
> > +local FANNKUCH = { 0, 1, 2, 4, 7, 10, 16, 22, 30, 38, 51, 65, 80 }
> > +

<snipped>

-- 
Best regards,
Sergey Kaplun