Branching in Rotate function

[Google Code Exporter]

I noticed the following code in the rotate function:

static uint64 Rotate(uint64 val, int shift)
{
  // Avoid shifting by 64: doing so yields an undefined result.
  return shift == 0 ? val : ((val >> shift) | (val << (64 - shift)));
}

Wouldn't it be faster to do an additional bitwise-and instead of introducing 
branching? For example:

  return ( (val >> shift) | ( val << ((64 - shift) & 63) ) );

Original issue reported on code.google.com by [e-mail] on 13 Feb 2013 at 12:36

[Google Code Exporter]

The way I use Rotate, the shift is always a manifest constant, so evaluating 
"shift == 0" happens at compile time.

Original comment by [e-mail] on 20 Jun 2013 at 10:01

• Changed state: WontFix