Porting Java code to D that uses << and >>> operators

[bachmeier via Digitalmars-d-learn]

I'm porting a small piece of Java code into D, but I've run into 
this:

int y1 = ((x12 & MASK12) << 22) + (x12 >>> 9) + ((x13 & MASK13) 
<< 7) + (x13 >>> 24);

I have a basic understanding of those operators in both 
languages, but I can't find a sufficiently detailed explanation 
to tell me how to translate the Java into D and know that it's 
guaranteed to give the same result. Can someone tell me the 
correct D code to use?