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Why is there huge performance hit in 2048x2048 versus 2047x2047 array multiplication?
... your cache. L is always power of 2.
The six comes from fact that 2^6 == 64 bytes is standard size of cache line.
Now what does this mean? Well it means that if I have address X and address Y and
(X >> 6) - (Y >> 6) is divisible by L (i.e. some large power of 2), they will be stored i...
How can I remove specific rules from iptables?
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492
Execute the same commands but replace the "-A" with "-D". For example:
iptables -A ...
beco...
C# Double - ToString() formatting with two decimal places but no rounding
...Truncate(myDoubleValue * 100) / 100;
For instance:
If the number is 50.947563 and you use the following, the following will happen:
- Math.Truncate(50.947563 * 100) / 100;
- Math.Truncate(5094.7563) / 100;
- 5094 / 100
- 50.94
And there's your answer truncated, now to format the string simply ...
Fast ceiling of an integer division in C / C++
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401
For positive numbers
unsigned int x, y, q;
To round up ...
q = (x + y - 1) / y;
or (avoi...
NOT IN vs NOT EXISTS
...ley. In the example there the number of logical reads increase from around 400 to 500,000.
Additionally the fact that a single NULL can reduce the row count to zero makes cardinality estimation very difficult. If SQL Server assumes that this will happen but in fact there were no NULL rows in the da...
Mercurial error: abort no username supplied
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94
Solution:
On my Windows install, the Mercurial.ini did not get propagated. It also needs a user...
Sending and Receiving SMS and MMS in Android (pre Kit Kat Android 4.4)
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answered Feb 14 '13 at 13:23
Manan SharmaManan Sharma
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Syntax behind sorted(key=lambda: …)
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edited Oct 24 '14 at 14:06
Gaurang Tandon
5,39799 gold badges3333 silver badges6868 bronze badges
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How to use enums as flags in C++?
...num AnimalFlags
{
HasClaws = 1,
CanFly = 2,
EatsFish = 4,
Endangered = 8
};
inline AnimalFlags operator|(AnimalFlags a, AnimalFlags b)
{
return static_cast<AnimalFlags>(static_cast<int>(a) | static_cast<int>(b));
}
Etc. rest of the bit operators. Modi...
Is it better to call ToList() or ToArray() in LINQ queries?
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answered May 1 '13 at 17:42
JaredParJaredPar
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