Hi, Sergey,

thanks for the patch! See my comments.

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.
---
 perf/LuaJIT-benches/nbody.lua | 127 ++++++++++++++++++++--------------
 1 file changed, 74 insertions(+), 53 deletions(-)

diff --git a/perf/LuaJIT-benches/nbody.lua b/perf/LuaJIT-benches/nbody.lua
index e0ff8f77..f01c20a3 100644
--- a/perf/LuaJIT-benches/nbody.lua
+++ b/perf/LuaJIT-benches/nbody.lua
@@ -1,56 +1,12 @@
+local bench = require("bench").new(arg)
 
 local sqrt = math.sqrt
 
 local PI = 3.141592653589793
 local SOLAR_MASS = 4 * PI * PI
 local DAYS_PER_YEAR = 365.24
-local bodies = {
-  { -- Sun
-    x = 0,
-    y = 0,
-    z = 0,
-    vx = 0,
-    vy = 0,
-    vz = 0,
-    mass = SOLAR_MASS
-  },
-  { -- Jupiter
-    x = 4.84143144246472090e+00,
-    y = -1.16032004402742839e+00,
-    z = -1.03622044471123109e-01,
-    vx = 1.66007664274403694e-03 * DAYS_PER_YEAR,
-    vy = 7.69901118419740425e-03 * DAYS_PER_YEAR,
-    vz = -6.90460016972063023e-05 * DAYS_PER_YEAR,
-    mass = 9.54791938424326609e-04 * SOLAR_MASS
-  },
-  { -- Saturn
-    x = 8.34336671824457987e+00,
-    y = 4.12479856412430479e+00,
-    z = -4.03523417114321381e-01,
-    vx = -2.76742510726862411e-03 * DAYS_PER_YEAR,
-    vy = 4.99852801234917238e-03 * DAYS_PER_YEAR,
-    vz = 2.30417297573763929e-05 * DAYS_PER_YEAR,
-    mass = 2.85885980666130812e-04 * SOLAR_MASS
-  },
-  { -- Uranus
-    x = 1.28943695621391310e+01,
-    y = -1.51111514016986312e+01,
-    z = -2.23307578892655734e-01,
-    vx = 2.96460137564761618e-03 * DAYS_PER_YEAR,
-    vy = 2.37847173959480950e-03 * DAYS_PER_YEAR,
-    vz = -2.96589568540237556e-05 * DAYS_PER_YEAR,
-    mass = 4.36624404335156298e-05 * SOLAR_MASS
-  },
-  { -- Neptune
-    x = 1.53796971148509165e+01,
-    y = -2.59193146099879641e+01,
-    z = 1.79258772950371181e-01,
-    vx = 2.68067772490389322e-03 * DAYS_PER_YEAR,
-    vy = 1.62824170038242295e-03 * DAYS_PER_YEAR,
-    vz = -9.51592254519715870e-05 * DAYS_PER_YEAR,
-    mass = 5.15138902046611451e-05 * SOLAR_MASS
-  }
-}
+local bodies
+local nbody
 
 local function advance(bodies, nbody, dt)
   for i=1,nbody do
@@ -110,10 +66,75 @@ local function offsetMomentum(b, nbody)
   b[1].vz = -pz / SOLAR_MASS
 end
 
-local N = tonumber(arg and arg[1]) or 1000
-local nbody = #bodies
+local DEFAULT_N = 5e6
+local N = tonumber(arg and arg[1]) or DEFAULT_N
 
-offsetMomentum(bodies, nbody)
-io.write( string.format("%0.9f",energy(bodies, nbody)), "\n")
-for i=1,N do advance(bodies, nbody, 0.01) end
-io.write( string.format("%0.9f",energy(bodies, nbody)), "\n")
+bench:add({
+  name = "nbody",
+  payload = function()
+    bodies = {
+      { -- Sun
+        x = 0,
+        y = 0,
+        z = 0,
+        vx = 0,
+        vy = 0,
+        vz = 0,
+        mass = SOLAR_MASS
+      },
+      { -- Jupiter
+        x = 4.84143144246472090e+00,
+        y = -1.16032004402742839e+00,
+        z = -1.03622044471123109e-01,
+        vx = 1.66007664274403694e-03 * DAYS_PER_YEAR,
+        vy = 7.69901118419740425e-03 * DAYS_PER_YEAR,
+        vz = -6.90460016972063023e-05 * DAYS_PER_YEAR,
+        mass = 9.54791938424326609e-04 * SOLAR_MASS
+      },
+      { -- Saturn
+        x = 8.34336671824457987e+00,
+        y = 4.12479856412430479e+00,
+        z = -4.03523417114321381e-01,
+        vx = -2.76742510726862411e-03 * DAYS_PER_YEAR,
+        vy = 4.99852801234917238e-03 * DAYS_PER_YEAR,
+        vz = 2.30417297573763929e-05 * DAYS_PER_YEAR,
+        mass = 2.85885980666130812e-04 * SOLAR_MASS
+      },
+      { -- Uranus
+        x = 1.28943695621391310e+01,
+        y = -1.51111514016986312e+01,
+        z = -2.23307578892655734e-01,
+        vx = 2.96460137564761618e-03 * DAYS_PER_YEAR,
+        vy = 2.37847173959480950e-03 * DAYS_PER_YEAR,
+        vz = -2.96589568540237556e-05 * DAYS_PER_YEAR,
+        mass = 4.36624404335156298e-05 * SOLAR_MASS
+      },
+      { -- Neptune
+        x = 1.53796971148509165e+01,
+        y = -2.59193146099879641e+01,
+        z = 1.79258772950371181e-01,
+        vx = 2.68067772490389322e-03 * DAYS_PER_YEAR,
+        vy = 1.62824170038242295e-03 * DAYS_PER_YEAR,
+        vz = -9.51592254519715870e-05 * DAYS_PER_YEAR,
+        mass = 5.15138902046611451e-05 * SOLAR_MASS
+      }
+    }
+    nbody = #bodies
+
+    offsetMomentum(bodies, nbody)

+
+    assert(energy(bodies, nbody) == -0.16907516382852447179,
+             "Correct start energy")
+    for i=1,N do advance(bodies, nbody, 0.01) end

+  end,
+  checker = function()
+    if N == DEFAULT_N then
+      assert(energy(bodies, nbody) == -0.16908313397890917251,
+             "Correct result energy")
+    end
+    return true
+  end,
+  items = N,
+})
+
+bench:run_and_report()