[gambit-list] Patch to speed bignum division in common case

Bradley Lucier lucier at math.purdue.edu
Mon Sep 30 20:52:49 EDT 2013


On 09/25/2013 09:58 PM, Bradley Lucier wrote:
>
>
> The problem is with -m32, not -m64.  I'll look at it, sorry.

Here is a fix.  It passes "make check" on both 32-bit and 64-bit x86.

I've included a little quotient "torture test" in case you want to 
incorporate it into error.scm.

Brad

The times for 32-bit on my Core i7:

Original:

time ./pidigits2-gambit > /dev/null
(time (digits 10000))
     13233 ms real time
     13192 ms cpu time (13040 user, 152 system)
     2840 collections accounting for 266 ms real time (224 user, 4 system)
     12119389176 bytes allocated
     192981 minor faults
     no major faults
13.040u 0.152s 0:13.23 99.6%    0+0k 0+0io 0pf+0w

New:

time ./pidigits2-gambit > /dev/null
(time (digits 10000))
     11236 ms real time
     11200 ms cpu time (11108 user, 92 system)
     2300 collections accounting for 216 ms real time (232 user, 0 system)
     9808248640 bytes allocated
     127024 minor faults
     no major faults
11.120u 0.092s 0:11.24 99.7%    0+0k 0+0io 0pf+0w

For 64-bit:

Original:

time ./pidigits2-gambit > /dev/null
(time (digits 10000))
     5632 ms real time
     5612 ms cpu time (5552 user, 60 system)
     2965 collections accounting for 203 ms real time (212 user, 4 system)
     12173461160 bytes allocated
     59591 minor faults
     no major faults
5.556u 0.060s 0:05.63 99.6%    0+0k 0+0io 0pf+0w

New:

time ./pidigits2-gambit > /dev/null
(time (digits 10000))
     4645 ms real time
     4632 ms cpu time (4592 user, 40 system)
     2389 collections accounting for 159 ms real time (140 user, 0 system)
     9831319240 bytes allocated
     35307 minor faults
     no major faults
4.592u 0.040s 0:04.64 99.7%    0+0k 0+0io 0pf+0w

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