On Wed, Jul 30, 2008 at 3:06 PM, Michael McCandless <[EMAIL PROTECTED]> wrote: > 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...
Unfortunately, no. I've looked in the past and couldn't find anything. If anyone knows of anything, it would be very cool to have though. -Yonik > 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 >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] >> > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
