sllw

Shift left logical word

Shift the 32-bit value in xs1 left by the value in the lower 5 bits of xs2, and store the sign-extended result in xd.

This instruction must have data-independent timing when extension Zkt is enabled.

Assembly format

sllw rd, rs1, rs2

Decode Variables

Bits<5> xs2 = $encoding[24:20];
Bits<5> xs1 = $encoding[19:15];
Bits<5> xd = $encoding[11:7];

Execution

  • IDL

  • Sail

X[xd] = sext(X[xs1] << X[xs2][4:0], 31);
{
  let xs1_val = (X(xs1))[31..0];
  let xs2_val = (X(xs2))[31..0];
  let result : bits(32) = match op {
    RISCV_ADDW => xs1_val + xs2_val,
    RISCV_SUBW => xs1_val - xs2_val,
    RISCV_SLLW => xs1_val << (xs2_val[4..0]),
    RISCV_SRLW => xs1_val >> (xs2_val[4..0]),
    RISCV_SRAW => shift_right_arith32(xs1_val, xs2_val[4..0])
  };
  X(xd) = sign_extend(result);
  RETIRE_SUCCESS
}

Encoding

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Defining extension

  • I, version >= I@2.1.0

Access

M HS U VS VU

Always

Always

Always

Always

Always

Containing profiles

  • Mandatory: MockProfile 64-bit S-mode, MockProfile 64-bit Unpriv, RVA20S64, RVA20U64, RVA22S64, RVA22U64, RVA23M64, RVA23S64, RVA23U64, RVB23M64, RVB23S64, RVB23U64, RVI20U32, RVI20U64

  • Optional: