rori

Rotate right (Immediate)

This instruction is defined by:

  • anyOf:

    • Zbb, version >= Zbb@1.0.0

    • Zbkb, version >= Zbkb@1.0.0

This instruction is included in the following profiles:

  • RVA22S64 (Mandatory)

  • RVA22U64 (Mandatory)

  • RVA23M64 (Mandatory)

  • RVA23S64 (Mandatory)

  • RVA23U64 (Mandatory)

  • RVB23M64 (Mandatory)

  • RVB23S64 (Mandatory)

  • RVB23U64 (Mandatory)

Encoding

This instruction has different encodings in RV32 and RV64.

  • RV32

  • RV64

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Assembly format

rori rd, rs1, shamt

Synopsis

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

This instruction performs a rotate right of rs1 by the amount in the least-significant log2(XLEN) bits of shamt. For RV32, the encodings corresponding to shamt[5]=1 are reserved.

Access

M HS U VS VU

Always

Always

Always

Always

Always

Decode Variables

  • RV32

  • RV64

Bits<5> shamt = $encoding[24:20];
Bits<5> rs1 = $encoding[19:15];
Bits<5> rd = $encoding[11:7];
Bits<6> shamt = $encoding[25:20];
Bits<5> rs1 = $encoding[19:15];
Bits<5> rd = $encoding[11:7];

Execution

  • IDL

  • Sail

if (%%LINK%func;implemented?;implemented?%%(ExtensionName::B) && (%%LINK%csr_field;misa.B;CSR[misa].B%% == 1'b0)) {
  %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
}
XReg shamt = (%%LINK%func;xlen;xlen%%() == 32) ? shamt[4:0] : shamt[5:0];
X[rd] = (X[rs1] >> shamt) | (X[rs1] << (%%LINK%func;xlen;xlen%%() - shamt));
{
  let rs1_val = X(rs1);
  let result : xlenbits = if sizeof(xlen) == 32
                          then rs1_val >>> shamt[4..0]
                          else rs1_val >>> shamt;
  X(rd) = result;
  RETIRE_SUCCESS
}

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction