Bug: OCaml timings are wrong.

[craff]

Language (if applicable)

OCaml

Description

I can not reproduce your ocaml's timing by far. On the site it is 5x slower than C which is simply wrong. Here is a test on my machine

raffalli@oulala2:~/Programming/speed-comparison/src$ ocamlopt -O3 leibniz.ml -o leibniz_ocaml.exe
raffalli@oulala2:~/Programming/speed-comparison/src$ gcc -O3 leibniz.c -o leibniz_c.exe
raffalli@oulala2:~/Programming/speed-comparison/src$ time ./leibniz_c.exe 
3.1415926545880506

real    0m0,857s
user    0m0,853s
sys     0m0,004s
raffalli@oulala2:~/Programming/speed-comparison/src$ time ./leibniz_ocaml.exe 
3.1415926525897171

real    0m0,857s
user    0m0,853s
sys     0m0,004s

Expected Behavior

Timing between 1~1.5 time compared to C.

[craff]

Remark : the script compile with -O2, but it should not make any difference:

raffalli@oulala2:~/Programming/speed-comparison/src$ ocamlopt -O2 leibniz.ml -o leibniz_ocaml.exe
raffalli@oulala2:~/Programming/speed-comparison/src$ time ./leibniz_ocaml.exe 
3.1415926525897171

real    0m0,860s
user    0m0,860s
sys     0m0,000s
raffalli@oulala2:~/Programming/speed-comparison/src$ ocamlopt -O3 leibniz.ml -o leibniz_ocaml.exe
raffalli@oulala2:~/Programming/speed-comparison/src$ time ./leibniz_ocaml.exe 
3.1415926525897171

real    0m0,880s
user    0m0,876s
sys     0m0,004s

[craff]

Compiling C agressivly (has your script does, altough does not explain the difference):

raffalli@oulala2:~/Programming/speed-comparison/src$ gcc -O3 -s -mtune=native -flto=auto -fomit-frame-pointer -fno-signed-zeros -fno-trapping-math -fassociative-math leibniz.c
raffalli@oulala2:~/Programming/speed-comparison/src$ time ./a.out
3.1415926545870398

real    0m0,589s
user    0m0,588s
sys     0m0,000s