Re: qsort (was Re: Solaris)

Martijn van Oosterhout wrote:

> Anyway, on a Debian Woody machine here I get:
>
>10^6 items, mod = 100
>
>Value (i = index)       BSD      GLIBC (seconds)
>random() * mod          1.58     2.29
>i % mod                 0.52     1.69
>i / (ITEMS / mod)       0.38     1.09
>i ^ 0x5555555           1.18     1.67
>
>It would seem to support the theory that the BSD qsort is faster than the
>Glibc one. The results seem quite repeatable (repeats give +/- 5%).
>
Martin's test on two Linux machines here gives :

10^6 items, mod = 100

1) Mandrake 9 (x86 - Linux 2.4.19, glibc 2.2.5, gcc 3.2)

Value (i = index)       BSD      GLIBC (seconds)
random() * mod          2.20     2.70
i % mod                 0.80     2.10
i / (ITEMS / mod)       0.53     1.28
i ^ 0x5555555           1.64     1.95

2) Yellowdog 2.3 (ppc - Linux 2.4.19, glibc 2.2.5. gcc 2.95.4)

Value (i = index)       BSD      GLIBC (seconds)
random() * mod          1.74     3.12
i % mod                 0.69     2.65
i / (ITEMS / mod)       0.55     1.66
i ^ 0x5555555           1.42     2.45

Interestingly, the the ppc machine gets more improvement from the BSD
qsort than the x86 one does.

regards

Mark