Re^5: profiling XS routines

Okay. I got I::C to work, and these are the results I get from running your (unmodified) benchmark here:

C:\test>792136.pl
Benchmark: timing 1 iterations of list, ref...
      list:  0 wallclock secs ( 0.05 usr +  0.00 sys =  0.05 CPU) @ 21
+.28/s (n=1)
            (warning: too few iterations for a reliable count)
       ref:  0 wallclock secs ( 0.03 usr +  0.00 sys =  0.03 CPU) @ 32
+.26/s (n=1)
            (warning: too few iterations for a reliable count)
2000001000000
2000001000000

C:\test>792136.pl
Benchmark: timing 1 iterations of list, ref...
      list:  0 wallclock secs ( 0.05 usr +  0.00 sys =  0.05 CPU) @ 21
+.28/s (n=1)
            (warning: too few iterations for a reliable count)
       ref:  0 wallclock secs ( 0.03 usr +  0.00 sys =  0.03 CPU) @ 31
+.25/s (n=1)
            (warning: too few iterations for a reliable count)
2000001000000
2000001000000

C:\test>792136.pl
Benchmark: timing 1 iterations of list, ref...
      list:  0 wallclock secs ( 0.05 usr +  0.00 sys =  0.05 CPU) @ 21
+.28/s (n=1)
            (warning: too few iterations for a reliable count)
       ref:  0 wallclock secs ( 0.03 usr +  0.00 sys =  0.03 CPU) @ 31
+.25/s (n=1)
            (warning: too few iterations for a reliable count)
2000001000000
2000001000000
[download]

Which is consistant enough to confirm my intuition. I'm not sure why you are getting different results--but I urge you to look closely at them.

BTW: Can you tell me where PERL_BITFIELD16 is typedef'd on your setup, because it was entirely missing as far as I can see on mine. Once I added:

#define OPCODE U16

#ifdef PERL_MAD
#  define MADPROP_IN_BASEOP    MADPROP*    op_madprop;
#else
#  define MADPROP_IN_BASEOP
#endif

typedef unsigned int PERL_BITFIELD16; /// <<< I added this!
typedef PERL_BITFIELD16 Optype;
[download]

I::C started working again?

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Re^6: profiling XS routines by syphilis (Archbishop) on Aug 30, 2009 at 05:37 UTC
Can you tell me where PERL_BITFIELD16 is typedef'd on your setup For me, it's in lib/CORE/perl.h: `/* macros to define bit-fields in structs. / #ifndef PERL_BITFIELD8 # define PERL_BITFIELD8 unsigned #endif #ifndef PERL_BITFIELD16 # define PERL_BITFIELD16 unsigned #endif #ifndef PERL_BITFIELD32 # define PERL_BITFIELD32 unsigned #endif` [download] As for the timings, I've done such comparisons before on other machines and other operating systems - eg on my aging linux box (Pentium-III) running the same script (but with 10 iterations instead of 1) I get 0.42 for 'list' and '0.49' for 'ref'. Whenever I've run this sort of comparison, I've found very little difference. Given that you're measuring such miniscule amounts of time, it might be more meaningful if you were to run (say) 30 iterations instead of 1 - ie: `timethese (30, { 'list' => '$list = sum_as_list(@x);', 'ref' => '$ref = sum_as_ref(\@x);', });` [download] I don't know why this AMD64 (Vista64) timing is so slow in comparison to your box and my aging linux box .... didn't realise it was* so slow until now.... Cheers, Rob	[reply] [d/l] [select]

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Re^6: profiling XS routines
by syphilis (Archbishop) on Aug 30, 2009 at 05:37 UTC

Can you tell me where PERL_BITFIELD16 is typedef'd on your setup

/* macros to define bit-fields in structs. */
#ifndef PERL_BITFIELD8
#  define PERL_BITFIELD8 unsigned
#endif
#ifndef PERL_BITFIELD16
#  define PERL_BITFIELD16 unsigned
#endif
#ifndef PERL_BITFIELD32
#  define PERL_BITFIELD32 unsigned
#endif
[download]

timethese (30, {
'list' => '$list = sum_as_list(@x);',
'ref'  => '$ref  = sum_as_ref(\@x);',
});
[download]

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