mullw

Multiply Low Word

mullw RT, RA, RB

Multiplies two 32-bit integers and stores the lower 32 bits of the 64-bit result.

Details

The Multiply Low Word instruction multiplies the low-order 32 bits of two 64-bit operands. The result is a 64-bit product, where the high-order 32 bits are placed into RT32:63 and the low-order 32 bits are undefined.

Pseudocode Operation

RT <- (RA)[32:63] * (RB)[32:63]

Programming Note

When Rc=1 (dot form), CR0 is updated with the signed comparison of the result against zero (LT, GT, EQ) and the current SO bit from XER.

Example

mullw r3, r4, r5

Encoding

Binary Layout
31
0
RT
6
RA
11
RB
16
OE
21
235
22
Rc
31
 
Format XO-form
Opcode 0x7C0001D6
Extension Base
Registers Altered CR0

Operands

  • RT
    Target
  • RA
    Src 1
  • RB
    Src 2