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struct S : IA
public void Method()
public void Test<T>(ref T t) where T : IA
static void Main (string args)
var sw = new Stopwatch();
for (int i = 0; i < 100000000; ++i)
s = new S ();
new SG().Test(ref s);
This has nothing to do with calling valuetypes, the mono JIT inlines everything into a tight loop, while the MS JIT realizes that the loop doesn't do anything and eliminates it altogether.
That's not the case. Increasing loop number count by 10 fold increases the time by 10 fold for .NET
from 52 to 551
The loop doesn't do anything, MS is just better at removing this nothingness than we are.
-O=all now reduces this to 71 from 462, and running with the LLVM backend reduces it to 1.