Hi, Sergey!

thanks for the patch! LGTM

Sergey

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.

The benchmark input is given by redirecting the corresponding
<FASTA_5000000> file generated by the `libs/fasta.lua 5e6`. The output
from the benchmark is redirected to /dev/null. Checks are skipped since
the output is very huge, and it is overkill to store it in the
repository.
---
 perf/LuaJIT-benches/revcomp.lua | 84 +++++++++++++++++++++++----------
 1 file changed, 59 insertions(+), 25 deletions(-)

diff --git a/perf/LuaJIT-benches/revcomp.lua b/perf/LuaJIT-benches/revcomp.lua
index 34fe347b..6e8a7049 100644
--- a/perf/LuaJIT-benches/revcomp.lua
+++ b/perf/LuaJIT-benches/revcomp.lua
@@ -1,3 +1,14 @@
+-- The benchmark to check the performance of hash table lookups by
+-- constant keys, string manipulations, and read/write
+-- operations.
+-- This benchmark reads the line-by-line a redirected FASTA format
+-- file from stdin, which is generated by the <fasta.lua>
+-- benchmark, and writes the id, description, and the
+-- reverse-complement sequence in FASTA format to stdout.
+-- For the details see:
+-- https://benchmarksgame-team.pages.debian.net/benchmarksgame/description/revcomp.html
+
+local bench = require("bench").new(arg)
 
 local sub = string.sub
 iubc = setmetatable({
@@ -9,29 +20,52 @@ iubc = setmetatable({
 }, { __index = function(t, s)
   local r = t[sub(s, 2)]..t[sub(s, 1, 1)]; t[s] = r; return r end })
 
-local wcode = [=[
-return function(t, n)
-  if n == 1 then return end
-  local iubc, sub, write = iubc, string.sub, io.write
-  local s = table.concat(t, "", 1, n-1)
-  for i=#s-59,1,-60 do
-    write(]=]
-for i=59,3,-4 do wcode = wcode.."iubc[sub(s, i+"..(i-3)..", i+"..i..")], " end
-wcode = wcode..[=["\n")
-  end
-  local r = #s % 60
-  if r ~= 0 then
-    for i=r,1,-4 do write(iubc[sub(s, i-3 < 1 and 1 or i-3, i)]) end
-    write("\n")
-  end
-end
-]=]
-local writerev = loadstring(wcode)()
+local stdout = io.output()
+
+bench:add({
+  name = "revcomp",
+  -- The compare with the result output file is inconvenient.
+  skip_check = true,
+  setup = function()
+    io.output("/dev/null")
+  end,
+  payload = function()
+    local wcode = [=[
+    return function(t, n)
+      if n == 1 then return end
+      local iubc, sub, write = iubc, string.sub, io.write
+      local s = table.concat(t, "", 1, n - 1)
+      for i = #s - 59, 1, -60 do
+        write(]=]
+    for i = 59, 3, -4 do
+      wcode = wcode.."iubc[sub(s, i + "..(i - 3)..", i + "..i..")], "
+    end
+    wcode = wcode..[=["\n")
+      end
+      local r = #s % 60
+      if r ~= 0 then
+        for i = r, 1, -4 do write(iubc[sub(s, i - 3 < 1 and 1 or i - 3, i)]) end
+        write("\n")
+      end
+    end
+    ]=]

could you also apply the patch below with formatting?

diff --git a/perf/LuaJIT-benches/revcomp.lua b/perf/LuaJIT-benches/revcomp.lua
index 6e8a7049..9050110e 100644
--- a/perf/LuaJIT-benches/revcomp.lua
+++ b/perf/LuaJIT-benches/revcomp.lua
@@ -38,9 +38,9 @@ bench:add({
       for i = #s - 59, 1, -60 do
         write(]=]
     for i = 59, 3, -4 do
-      wcode = wcode.."iubc[sub(s, i + "..(i - 3)..", i + "..i..")], "
+      wcode = wcode .. "iubc[sub(s, i + " .. (i - 3) .. ", i + " .. i .. ")], "
     end
-    wcode = wcode..[=["\n")
+    wcode = wcode .. [=["\n")
       end
       local r = #s % 60
       if r ~= 0 then
@@ -54,7 +54,10 @@ bench:add({
     local t, n = {}, 1
     for line in io.lines() do
       local c = sub(line, 1, 1)
-      if c == ">" then writerev(t, n); io.write(line, "\n"); n = 1
+      if c == ">" then
+        writerev(t, n);
+        io.write(line, "\n");
+        n = 1
       elseif c ~= ";" then t[n] = line; n = n + 1 end
     end
     writerev(t, n)

+    local writerev = loadstring(wcode)()
+
+    local t, n = {}, 1
+    for line in io.lines() do
+      local c = sub(line, 1, 1)
+      if c == ">" then writerev(t, n); io.write(line, "\n"); n = 1
+      elseif c ~= ";" then t[n] = line; n = n + 1 end
+    end
+    writerev(t, n)
+    -- Repeat operation several times.
+    io.stdin:seek("set", 0)
+  end,
+  teardown = function()
+    io.output(stdout)
+  end,
+  -- Amount of symbols in the input file.
+  items = 5e6,
+})
 
-local t, n = {}, 1
-for line in io.lines() do
-  local c = sub(line, 1, 1)
-  if c == ">" then writerev(t, n); io.write(line, "\n"); n = 1
-  elseif c ~= ";" then t[n] = line; n = n + 1 end
-end
-writerev(t, n)
+bench:run_and_report()