reason why custom loop is faster? bad compiler? unsafe custom code? luck?(lucky cache hits)

Question

i just started learning assembly and making some custom loop for swapping two variables using C++ \'s asm{} body with Digital-Mars compiler in C-Free 5.0

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Answer 1

That's normal and changing the compiler wouldn't solve this "problem". Assembler is extremely low-level and you have control of everything. Your C++ compiler always does more than it needs. Calling a function would take more time than it would take in assembly, because the compiler protects the stack (for example). And in loop that's the same thing: Declare a new variable takes more time, add values also etc...

This question should be interesting for some more information: When is assembler faster than C?