slli.uw

Shift left unsigned word (Immediate)

This instruction is defined by:

anyOf:
- B, version >= B@1.0.0
- Zba, version >= Zba@1.0.0

This instruction is included in the following profiles:

RVA22U64 (Mandatory)
RVA23U64 (Mandatory)
RVB23U64 (Mandatory)

Encoding

Assembly format

slli.uw rd, rs1, shamt

Synopsis

This instruction takes the least-significant word of rs1, zero-extends it, and shifts it left by the immediate.

This instruction is the same as slli with zext.w performed on rs1 before shifting.

Access

M	HS	U	VS	VU
Always	Always	Always	Always	Always

Always

Decode Variables

Bits<6> shamt = $encoding[25:20];
Bits<5> rs1 = $encoding[19:15];
Bits<5> rd = $encoding[11:7];

idl

Execution

IDL
Sail

if (implemented?(ExtensionName::B) && (CSR[misa].B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
X[rd] = X[rs1][31:0] << shamt;

idl

{
  let rs1_val = X(rs1);
  let result : xlenbits = zero_extend(rs1_val[31..0]) << shamt;
  X(rd) = result;
  RETIRE_SUCCESS
}

sail

Exceptions

This instruction may result in the following synchronous exceptions:

IllegalInstruction