pcmpbf - 2024.2 English

Description

The contents of register rA are bytewise compared with the contents in register rB.

• rD is loaded with the position of the first matching byte pair, starting with MSB as position 1, and comparing until LSB as position 4
• If none of the byte pairs match, rD is set to 0

Pseudocode

if rB[0:7] = rA[0:7] then
   (rD) ← 1
else
   if rB[8:15] = rA[8:15] then
      (rD) ← 2
   else
      if rB[16:23] = rA[16:23] then
         (rD) ← 3
      else
         if rB[24:31] = rA[24:31] then
            (rD) ← 4
         else
            (rD) ← 0

Registers Altered

• rD

Latency

• 1 cycle

Note

• This instruction is only available when the parameter C_USE_PCMP_INSTR is set to 1.