Re: push parser implemenation

[Akim Demaille]

Le 7 avr. 06 à 14:42, Akim Demaille a écrit :

> Benchmark: timing 50 iterations of push-pure, push-push, push-yacc,  
> yacc-pure, yacc-yacc...
>  push-pure: 64 wallclock secs ( 0.00 usr  0.07 sys + 45.05 cusr   
> 1.36 csys = 46.48 CPU) @ 714.29/s (n=50)
>  push-push: 77 wallclock secs ( 0.00 usr  0.07 sys + 50.53 cusr   
> 1.56 csys = 52.16 CPU) @ 714.29/s (n=50)
>  push-yacc: 66 wallclock secs ( 0.00 usr  0.07 sys + 45.51 cusr   
> 1.40 csys = 46.98 CPU) @ 714.29/s (n=50)
>  yacc-pure: 55 wallclock secs ( 0.00 usr  0.07 sys + 36.98 cusr   
> 1.25 csys = 38.30 CPU) @ 714.29/s (n=50)
>  yacc-yacc: 54 wallclock secs ( 0.00 usr  0.07 sys + 38.12 cusr   
> 1.23 csys = 39.42 CPU) @ 714.29/s (n=50)
>            Rate push-push yacc-yacc yacc-pure push-pure push-yacc
> push-push 714/s        --        0%        0%        0%       -0%
> yacc-yacc 714/s        0%        --        0%        0%       -0%
> yacc-pure 714/s        0%        0%        --        0%       -0%
> push-pure 714/s        0%        0%        0%        --       -0%
> push-yacc 714/s        0%        0%        0%        0%        --
>
> I confess I don't understand the table output by this Perl module
> here.  What is this "rate"?

Now (that I read the code) I have it: to compute the rate, it sums  
the usr and sys time for the parent (i.e., the call to "system")  
which is consistenly 0.07 here for the 50 iterations.  Hence, a  
"rate" of 50/0.07 / 714,285714285714.

If I change the cmpthese call into "cmpthese ($res, 'nop')" (nop  
stands for noparents), and similarly for timethese, then I have  
better results:


No optimization:
Benchmark: timing 50 iterations of push-pure, push-push, push-yacc,  
yacc-pure, yacc-yacc...
push-pure: 64 wallclock secs (45.00 cusr +  1.26 csys = 46.26 CPU) @   
1.08/s (n=50)
push-push: 66 wallclock secs (50.38 cusr +  1.21 csys = 51.59 CPU) @   
0.97/s (n=50)
push-yacc: 68 wallclock secs (45.49 cusr +  1.30 csys = 46.79 CPU) @   
1.07/s (n=50)
yacc-pure: 57 wallclock secs (36.95 cusr +  1.17 csys = 38.12 CPU) @   
1.31/s (n=50)
yacc-yacc: 57 wallclock secs (38.06 cusr +  1.17 csys = 39.23 CPU) @   
1.27/s (n=50)
             Rate push-push push-yacc push-pure yacc-yacc yacc-pure
push-push 0.969/s        --       -9%      -10%      -24%      -26%
push-yacc  1.07/s       10%        --       -1%      -16%      -19%
push-pure  1.08/s       12%        1%        --      -15%      -18%
yacc-yacc  1.27/s       32%       19%       18%        --       -3%
yacc-pure  1.31/s       35%       23%       21%        3%        --

(as an aside, there is no point in not using pure parsers: they are  
slightly faster.  But I'm on a PPC, so I wouldn't be surprised if  
more stuff be kept in registers, hence easily beating global  
variables...  Maybe the figures would be different on Intel chips).

With -O2:

Benchmark: timing 50 iterations of push-pure, push-push, push-yacc,  
yacc-pure, yacc-yacc...
push-pure: 30 wallclock secs (20.94 cusr +  0.88 csys = 21.82 CPU) @   
2.29/s (n=50)
push-push: 34 wallclock secs (22.96 cusr +  0.95 csys = 23.91 CPU) @   
2.09/s (n=50)
push-yacc: 30 wallclock secs (21.47 cusr +  0.91 csys = 22.38 CPU) @   
2.23/s (n=50)
yacc-pure: 26 wallclock secs (17.78 cusr +  0.85 csys = 18.63 CPU) @   
2.68/s (n=50)
yacc-yacc: 25 wallclock secs (18.50 cusr +  0.85 csys = 19.35 CPU) @   
2.58/s (n=50)
            Rate push-push push-yacc push-pure yacc-yacc yacc-pure
push-push 2.09/s        --       -6%       -9%      -19%      -22%
push-yacc 2.23/s        7%        --       -3%      -14%      -17%
push-pure 2.29/s       10%        3%        --      -11%      -15%
yacc-yacc 2.58/s       24%       16%       13%        --       -4%
yacc-pure 2.68/s       28%       20%       17%        4%        --

For fun, -O3:

Benchmark: timing 50 iterations of push-pure, push-push, push-yacc,  
yacc-pure, yacc-yacc...
push-pure: 26 wallclock secs (17.99 cusr +  0.84 csys = 18.83 CPU) @   
2.66/s (n=50)
push-push: 28 wallclock secs (19.84 cusr +  0.86 csys = 20.70 CPU) @   
2.42/s (n=50)
push-yacc: 27 wallclock secs (18.46 cusr +  0.89 csys = 19.35 CPU) @   
2.58/s (n=50)
yacc-pure: 22 wallclock secs (15.88 cusr +  0.82 csys = 16.70 CPU) @   
2.99/s (n=50)
yacc-yacc: 22 wallclock secs (16.43 cusr +  0.81 csys = 17.24 CPU) @   
2.90/s (n=50)
            Rate push-push push-yacc push-pure yacc-yacc yacc-pure
push-push 2.42/s        --       -7%       -9%      -17%      -19%
push-yacc 2.58/s        7%        --       -3%      -11%      -14%
push-pure 2.66/s       10%        3%        --       -8%      -11%
yacc-yacc 2.90/s       20%       12%        9%        --       -3%
yacc-pure 2.99/s       24%       16%       13%        3%        --




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