Neat!

Do you know how to get the corresponding asm that the hostpot compiler produces? This way we can see if this difference "survives" through java...

Mike

Yonik Seeley wrote:

disclaimer: this is just for fun.... differences should be in the
noise in any complex system, and I'm not suggesting any code changes.

Actually, with 32 bit registers, x<0 should be faster than x==-1 by
one cycle.  If it doesn't test faster, then it's because of some
optimizations that could be pulled off via inlining and data flow
analysis (set of -1 followed by a check for -1, etc).

Here's the optimized code that gcc produces for a 64 bit long comparison:

       #  if (foo() == -1)
       andl    %edx, %eax
       incl    %eax
       jne     L2

       #  if (foo() < 0)
       testl   %edx, %edx
       jns     L9

-Yonik

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