will be this simple conditional operator optimized at compile time ? (.net)

Question

Working with legacy code, I found I got are lot of statements (more than 500) like this

bool isAEqualsB = (a == b) ? true : false;

Does it make any sense to rewrite it like this ?

bool isAEqualsB = (a == b)

Or will be optimized at compile time ?

Thanks in advance,

Santi! =)

Answer 1

Ignore the performance - that's so unlikely to be a bottleneck, it shouldn't be what you think about until you've proved that it's relevant with appropriate benchmarks.

I would absolutely care about the readability though - and from that point of view, I consider the second approach to be much better, and would certainly use it.

EDIT: In terms of optimization, it looks like the C# compiler doesn't optimize it:

  // First form
  IL_0000:  ldarg.0
  IL_0001:  ldarg.1
  IL_0002:  beq.s      IL_0007
  IL_0004:  ldc.i4.0
  IL_0005:  br.s       IL_0008
  IL_0007:  ldc.i4.1
  IL_0008:  stloc.0

  // Second form
  IL_0009:  ldarg.0
  IL_000a:  ldarg.1
  IL_000b:  ceq
  IL_000d:  stloc.1

However, it's not the IL that will matter of course - it's what the JIT compiler does. Now even the difference in IL size may mean the difference between inlining and not...