c# – 为什么IF和条件运算符之间的IL有这么大差异？

然而,他们没有(见下文),他们确实有不同的IL.试图绕过它我的假设是这是条件运算符获得的性能优化,因为它的范围有限.

想知道我的假设是否正确,也许还有更多的假设？

同样在IF的IL中,有一些围绕int值的检查(L_000c,L_000d,L_000f),我无法弄清楚其含义.这使我认为这是一个更强大的解决方案,但由于IF范围更广,性能成本.

IF代码

var result = "";
if (Environment.Is64BitOperatingSystem)
{
    result = "Yes";
}
else
{
    result = "No";
}
Console.WriteLine(result);

条件运算符的代码(我意识到差异,但无论我如何改变它 – 分配给变量等……它几乎没有区别)

Console.WriteLine("Is the OS x64? {0}",Environment.Is64BitOperatingSystem ? "Yes" : "No");

IL为IF

L_0001: ldstr ""
L_0006: stloc.0 
L_0007: call bool [mscorlib]System.Environment::get_Is64BitOperatingSystem()
L_000c: ldc.i4.0 
L_000d: ceq 
L_000f: stloc.2 
L_0010: ldloc.2 
L_0011: brtrue.s L_001d
L_0013: nop 
L_0014: ldstr "Yes"
L_0019: stloc.0 
L_001a: nop 
L_001b: br.s L_0025
L_001d: nop 
L_001e: ldstr "No"
L_0023: stloc.0 
L_0024: nop 
L_0025: ldloc.0 
L_0026: call void [mscorlib]System.Console::WriteLine(string)

IL为条件

L_002c: ldstr "Is the OS x64? {0}"
L_0031: call bool [mscorlib]System.Environment::get_Is64BitOperatingSystem()
L_0036: brtrue.s L_003f
L_0038: ldstr "No"
L_003d: br.s L_0044
L_003f: ldstr "Yes"
L_0044: call void [mscorlib]System.Console::WriteLine(string,object)