slli.uw

Shift left unsigned word (Immediate)

This instruction is defined by:

  • anyOf:

    • B, version >= 0

    • Zba, version >= 0

This instruction is included in the following profiles:

  • RVA22S64 (Mandatory)

  • RVA22U64 (Mandatory)

Encoding

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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

Decode Variables

Bits<5> shamt = $encoding[24:20];
Bits<5> rs1 = $encoding[19:15];
Bits<5> rd = $encoding[11:7];

Execution

  • IDL

  • Sail

if (implemented?(ExtensionName::B) && (CSR[misa].B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
X[rd] = X[rs1][31:0] << shamt;
{
  let rs1_val = X(rs1);
  let result : xlenbits = zero_extend(rs1_val[31..0]) << shamt;
  X(rd) = result;
  RETIRE_SUCCESS
}

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction