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Why does GCC generate 15-20% faster code if I optimize for size instead of speed?
I first noticed in 2009 that GCC (at least on my projects and on my machines) have the tendency to generate noticeably faster code if I optimize for size ( -Os ) instead of speed ( -O2 or -O3 ), and I have been wondering ever since why.
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Simple C example of doing an HTTP POST and consuming the response
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+50
A message has a header part and a message body separated by a blank line. The blank line is ALWAYS needed even if there is no message...
How to print a number with commas as thousands separators in JavaScript
... ====>"} ${x} => ${result}`);
return pass;
}
let failures = 0;
failures += !test(0, "0");
failures += !test(100, "100");
failures += !test(1000, "1,000");
failures += !test(10000, "10,000");
failures += !test(100000, "100,000");
failures += !test(1000000, "...
How to scale down a range of numbers with a known min and max value
...l. I want the height and width of each ellipse to be in a range of say 1-30. I have methods that find the minimum and maximum values from my data set, but I won't have the min and max until runtime. Is there an easy way to do this?
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Replace all non Alpha Numeric characters, New Lines, and multiple White Space with one Space
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Be aware, that \W leaves the underscore. A short equivalent for [^a-zA-Z0-9] would be [\W_]
text.replace(/[\W_]+/g," ");
\W is the negation of shorthand \w for [A-Za-z0-9_] word characters (including the underscore)
Example at regex101.com
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For i = 0, why is (i += i++) equal to 0?
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This:
int i = 0;
i += i++
Can be seen as you doing (the following is a gross oversimplification):
int i = 0;
i = i + i; // i=0 because the ++ is a postfix operator and hasn't been executed
i + 1; // Note that you are discarding the calc...
How to access the ith column of a NumPy multidimensional array?
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>>> test[:,0]
array([1, 3, 5])
Similarly,
>>> test[1,:]
array([3, 4])
lets you access rows. This is covered in Section 1.4 (Indexing) of the NumPy reference. This is quick, at least in my experience. It's certainly muc...
Swapping column values in MySQL
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204
I just had to deal with the same and I'll summarize my findings.
The UPDATE table SET X=Y, Y=...
Why is a round-trip conversion via a string not safe for a double?
...mber->precision = precision;
if (((FPDOUBLE*)&value)->exp == 0x7FF) {
number->scale = (((FPDOUBLE*)&value)->mantLo || ((FPDOUBLE*)&value)->mantHi) ? SCALE_NAN: SCALE_INF;
number->sign = ((FPDOUBLE*)&value)->sign;
number->digits[0] =...
Cannot ping AWS EC2 instance
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answered May 30 '15 at 9:39
RakibRakib
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