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<p>Hi, Sergey!</p>
<p>thanks for the patch! Generally LGTM, but the test failed on my
machine with:</p>
<p>$ ./build/src/luajit perf/LuaJIT-benches/euler14-bit.lua <br>
./build/src/luajit: not enough memory<br>
<br>
</p>
<p>Sergey</p>
<div class="moz-cite-prefix">On 12/26/25 12:17, Sergey Kaplun wrote:<br>
</div>
<blockquote type="cite"
cite="mid:388c8793a03f3a9bf0dbe4f4f8fde40687c4573f.1766738771.git.skaplun@tarantool.org">
<pre wrap="" class="moz-quote-pre">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.
---
perf/LuaJIT-benches/euler14-bit.lua | 65 ++++++++++++++++++++++-------
1 file changed, 49 insertions(+), 16 deletions(-)
diff --git a/perf/LuaJIT-benches/euler14-bit.lua b/perf/LuaJIT-benches/euler14-bit.lua
index 537f2bf3..c4ae3713 100644
--- a/perf/LuaJIT-benches/euler14-bit.lua
+++ b/perf/LuaJIT-benches/euler14-bit.lua
@@ -1,22 +1,55 @@
+-- The benchmark to check the performance of bitwise operations.
+-- It finds the longest Collatz sequence using bitwise arithmetic.
+-- For the details see:
+-- <a class="moz-txt-link-freetext" href="https://projecteuler.net/problem=14">https://projecteuler.net/problem=14</a>
+
+local bench = require("bench").new(arg)
local bit = require("bit")
local bnot, bor, band = bit.bnot, bit.bor, bit.band
local shl, shr = bit.lshift, bit.rshift
-local N = tonumber(arg and arg[1]) or 10000000
-local cache, m, n = { 1 }, 1, 1
-if arg and arg[2] then cache = nil end
-for i=2,N do
- local j = i
- for len=1,1000000000 do
- j = bor(band(shr(j,1), band(j,1)-1), band(shl(j,1)+j+1, bnot(band(j,1)-1)))
- if cache then
- local x = cache[j]; if x then j = x+len; break end
- elseif j == 1 then
- j = len+1; break
+local DEFAULT_N = 2e7
+local N = tonumber(arg and arg[1]) or DEFAULT_N
+local drop_cache = arg and arg[2]
+
+bench:add({
+ name = "euler14_bit",
+ payload = function()
+ local cache, m, n = { 1 }, 1, 1
+ if drop_cache then cache = nil end
+ for i = 2, N do
+ local j = i
+ for len = 1, 1000000000 do
+ j = bor(
+ band(shr(j, 1), band(j, 1) - 1),
+ band(shl(j, 1) + j + 1, bnot(band(j, 1) - 1))
+ )
+ if cache then
+ local x = cache[j]
+ if x then
+ j = x + len
+ break
+ end
+ elseif j == 1 then
+ j = len + 1
+ break
+ end
+ end
+ if cache then cache[i] = j end
+ if j > m then m, n = j, i end
end
- end
- if cache then cache[i] = j end
- if j > m then m, n = j, i end
-end
-io.write("Found ", n, " (chain length: ", m, ")\n")
+ return {n = n, m = m}
+ end,
+ checker = function(res)
+ if N ~= DEFAULT_N then
+ -- Test only for the default.
+ return true
+ else
+ return res.n == 18064027 and res.m == 623
+ end
+ end,
+ items = N,
+})
+
+bench:run_and_report()
</pre>
</blockquote>
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