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by adrian_b 640 days ago
It is said that NSA has requested the addition of POPCNT to the Control Data Corporation CDC 6600 (1964), as a condition for procurement.

The condition has remained in force later, so all its successors, like CDC 7600 (1969) or Cray-1 (1976), have included POPCNT.

POPCNT has been added to the x86 ISA by AMD, in "Barcelona", in 2007, presumably because some customer for AMD Opteron has requested it. This happened during the period when the AMD server CPUs were much better than the Intel Xeons, so any wise customer was buying Opterons, not Xeons. Intel has followed AMD and it has added POPCNT to Nehalem, in 2008/2009 (for server CPUs, Nehalem has been the first that was better for any purpose than the AMD server CPUs, unlike for consumer CPUs, where Intel had surpassed AMD already since the middle of 2007, with Core 2).

2 comments

> POPCNT has been added to the x86 ISA by AMD, in "Barcelona", in 2007, presumably because some customer for AMD Opteron has requested it.

Might have been Cray, they were using Opteron in that era.

And any clue about what they were doing with POPCNT? Does it has any particular use in encryption?