vpopcnth

Pseudocode Operation

for i in 0 to 7 do
  count ← 0
  halfword ← vB[i*16 : i*16+15]
  for j in 0 to 15 do
    if halfword[j] = 1 then
      count ← count + 1
  vD[i*16 : i*16+15] ← count

Programming Note

This instruction is useful for counting the number of set bits in each halfword of a vector, which can be helpful in various bit manipulation tasks. Ensure that the Vector Facility (VEC) is enabled in the Machine State Register (MSR) before using this instruction; otherwise, it will raise an exception. The operation is performed on 8 halfwords per vector register, and there are no specific alignment requirements for the data being processed.

Example