From: johnl@taugh.com   
      
   According to John Levine  :   
   >>One possible reason for the additional instruction is that there is a   
   >>hardware feature that provides a speedup; in that case the hardware   
   >>feature, not the microcode is the reason for the speedup.  Is there   
   >>such a hardware feature for SORT LISTS, and if so, what is it?   
      
   I found a 2020 IBM JR&D article that describes it in some detail.   
   It's some fairly simple hardware that keeps pointers to the keys   
   in fast SRAM so it can do what IBM calls a looser tree merge sort   
   and everyone else seems to call a loser tree merge sort.   
      
   --   
   Regards,   
   John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for   
   Dummies",   
   Please consider the environment before reading this e-mail. https://jl.ly   
      
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