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by astn 2755 days ago
Yeah, sometimes the compiler unrolls too much and innocent looking one-liner can be compiled into a monstrosity like this:

https://godbolt.org/z/aKtko5

2 comments

Are there no compilers which attempt to look at that code, decide 'that looks like 1<<(num-2) when n>=2', and replace the code entirely?

There must be so many examples of bubble sort where quicksort would be better, and other code patterns which can be identified and replaced with something orders of magnitude faster.

Is that more performant?