SLLIW

Shift Left Logical Immediate Word

SLLIW rd, rs1, shamt

Shifts the lower 32 bits of rs1 left by a constant, sign-extending the result.

Details

SLLIW performs a logical left shift of the lower 32 bits of rs1 by the 5-bit immediate, sign-extends the 32-bit result to 64 bits, and writes it to rd.

Pseudocode Operation

R[rd] = sext((R[rs1] << shamt)[31:0]);

Example

SLLIW x10, x11, 4

Encoding

Binary Layout
0000000
31:25
shamt
24:20
rs1
19:15
001
14:12
rd
11:7
0011011
6:0
 
Format I-Type (Shift)
Opcode 0x1B
Extension RV64I

Operands

  • rd
    Destination register (integer)
  • rs1
    Source
  • shamt
    Shift Amount (0-31)