Find on sorted range slower?
Tofu Ninja via Digitalmars-d-learn
digitalmars-d-learn at puremagic.com
Thu Aug 6 17:35:56 PDT 2015
void main()
{
auto a = new int[100*1024*1024];
for(int i = 0; i < 100*1024*1024; i++)
{
a[i] = i;
}
enum f = 100*1024*1000;
StopWatch sw;
{
sw.start();
auto temp = assumeSorted(a).find(f);
sw.stop();
}
auto t1 = sw.peek();
sw.reset();
{
sw.start();
auto temp = a.find(f);
sw.stop();
}
auto t2 = sw.peek();
writeln("Sorted\t", t1.length);
writeln("Regular\t", t2.length);
writeln("Ratio\t", float(t1.length)/ float(t2.length));
}
I am getting the assumeSorted version to be about 3x slower than
the regular find, that seems very counter intuitive. Anyone know
why this would be, seems like a very odd thing to happen. I
expected the assumeSorted to be faster, expect it to do a binary
search, instead if a linear one.
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