This purports to discuss pass-by-copy or reference but ends up not discussing that particular issue at all since every single compiler naturally inlined and vectorized his trivial micro-benchmark.
If you were to discuss the headline issue, I guess you could delve deep into calling conventions, register pressure, various instruction set extensions that compilers can abuse to carry the data.. or you take the compiler optimizations as a hint that concerning yourself with this is mostly pointless, as long as you don't start passing huge structures by-copy.
If you were to discuss the headline issue, I guess you could delve deep into calling conventions, register pressure, various instruction set extensions that compilers can abuse to carry the data.. or you take the compiler optimizations as a hint that concerning yourself with this is mostly pointless, as long as you don't start passing huge structures by-copy.