Bitwise Operations - 2023.2 English

AI Engine Kernel and Graph Programming Guide (UG1079)

Document ID
UG1079
Release Date
2023-12-04
Version
2023.2 English

The following AI Engine APIs allow bitwise AND, OR, XOR, and NOT operations on a scalar value and all the elements of the input vector with same type, or on two input vectors with same type and size.

  • aie::bit_and
  • aie::bit_or
  • aie::bit_xor

The following AI Engine API allows bitwise NOT operations on the elements of the input vector.

  • aie::bit_not
Note: The aie::bit_* operations are emulated on a scalar processor in the AI Engine.
aie::vector<int16,8> iv,iv2;

// 0xf bit AND with each component of iv
aie::vector<int16,8> iv_bit_and=aie::bit_and((int16)0xf,iv);
aie::vector<int16,8> iv_bit_or=aie::bit_or((int16)0xf,iv);
aie::vector<int16,8> iv_bit_xor=aie::bit_xor((int16)0xf,iv);

// bit AND on each component of iv and iv2
aie::vector<int16,8> iv_bit_and2=aie::bit_and(iv,iv2);
aie::vector<int16,8> iv_bit_or2=aie::bit_or(iv,iv2);
aie::vector<int16,8> iv_bit_xor2=aie::bit_xor(iv,iv2);
aie::vector<int16,8> iv_not=aie::bit_not(iv);

The following AI Engine APIs shift all components of a vector right or left by specified number of bits.

  • aie::downshift: Shifts each component of a vector arithmetically (signed extended) right by specific bits.
    aie::vector<int16,8> iv_down=aie::downshift(iv,2);
  • aie::upshift: Shifts each component left by specific bits. Filled by 0.
    aie::vector<int16,8> iv_up=aie::upshift(iv,2);
  • aie::logical_downshift: Shifts each component of a vector logically (zero extended) right by specific bits.
    aie::vector<int16,8> iv_logic_down=aie::logical_downshift(iv,2);