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Optimize comparison in Cmp() #85

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Merged
holiman merged 2 commits into from
Jul 5, 2021
Merged

Optimize comparison in Cmp() #85

holiman merged 2 commits into from
Jul 5, 2021

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@fyrchik
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@fyrchik fyrchik commented Jul 5, 2021 •
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We can do it with a single comparison. The speed up for the bad case is ~30%.

name                   old time/op    new time/op    delta
_Cmp/single/big-8        13.1ns ± 4%    13.1ns ± 2%     ~     (p=0.887 n=10+9)
_Cmp/single/uint256-8    5.40ns ± 3%    4.69ns ± 3%  -13.17%  (p=0.000 n=10+9)

name                   old alloc/op   new alloc/op   delta
_Cmp/single/big-8         0.00B          0.00B          ~     (all equal)
_Cmp/single/uint256-8     0.00B          0.00B          ~     (all equal)

name                   old allocs/op  new allocs/op  delta
_Cmp/single/big-8          0.00           0.00          ~     (all equal)
_Cmp/single/uint256-8      0.00           0.00          ~     (all equal)

fyrchik and others added 2 commits July 5, 2021 14:00
@fyrchik
Improve Cmp() benchmark
46615d3 
We should check for both `a < b` and `a > b` cases
to get more realistic results.

Signed-off-by: Evgenii Stratonikov <[email protected]>
@fyrchik
Optimize Cmp()
95adbae 
In case when first argument is greater or equal then the second
we will perform 2 comparisons. This commit implements `Cmp` using only 1.
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fyrchik commented Jul 5, 2021

I am not sure if this is the right way to change benchmark (we get duration of 2 operations), but it seems simpler than making 2 more benchmarks.

holiman
holiman reviewed Jul 5, 2021
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LGTM, thanks!

@holiman holiman merged commit 792909f into holiman:master Jul 5, 2021
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@fyrchik @holiman