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Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?
...a,2) by compiling it into a*a , but the call pow(a,6) is not optimized and will actually call the library function pow , which greatly slows down the performance. (In contrast, Intel C++ Compiler , executable icc , will eliminate the library call for pow(a,6) .)
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Break promise chain and call a function based on the step in the chain where it is broken (rejected)
...et's say you have something like the following:
stepOne()
.then(stepTwo, handleErrorOne)
.then(stepThree, handleErrorTwo)
.then(null, handleErrorThree);
To better understand what's happening, let's pretend this is synchronous code with try/catch blocks:
try {
try {
try {
...
~x + ~y == ~(x + y) is always false?
...
Assume for the sake of contradiction that there exists some x and some y (mod 2n) such that
~(x+y) == ~x + ~y
By two's complement*, we know that,
-x == ~x + 1
<==> -1 == ~x + x
Noting this result, we have,
~(x+y) == ~x + ~y
<==> ~(x+y) + (x+y) == ~x + ~y...
Eliminate space before \begin{itemize} [closed]
...
yes, but sometimes the fight is too much to handle.
– Stefano Borini
Jul 2 '09 at 12:50
30
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Differences between “java -cp” and “java -jar”?
...he difference between running a Java application with java -cp CLASSPATH and java -jar JAR_FILE_PATH ? Is one of them preferred to the other for running a Java application? I mean which one of these ways is more expensive for JVM (according to their machine resources usage)?
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Sort JavaScript object by key
...swers to this question are outdated, never matched implementation reality, and have officially become incorrect now that the ES6/ES2015 spec has been published.
See the section on property iteration order in Exploring ES6 by Axel Rauschmayer:
All methods that iterate over property keys do so ...
MIN/MAX vs ORDER BY and LIMIT
...d field, using MIN() requires a single full pass of the table. Using SORT and LIMIT requires a filesort. If run against a large table, there would likely be a significant difference in percieved performance. As a meaningless data point, MIN() took .36s while SORT and LIMIT took .84s against a 106...
How to remove all line breaks from a string
I have a text in a textarea and I read it out using the .value attribute.
16 Answers
1...
How do I redirect in expressjs while passing some context?
...gs. You'll need to ensure that the values are properly encodeURIComponent and decodeURIComponent.
app.get('/category', function(req, res) {
var string = encodeURIComponent('something that would break');
res.redirect('/?valid=' + string);
});
You can snag that in your other route by getting t...
Optimal number of threads per core
Let's say I have a 4-core CPU, and I want to run some process in the minimum amount of time. The process is ideally parallelizable, so I can run chunks of it on an infinite number of threads and each thread takes the same amount of time.
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