ror

Rotate right (Register)

This instruction is defined by:

Encoding

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Synopsis

This instruction performs a rotate right of rs1 by the amount in least-significant log2(XLEN) bits of rs2.

Access

M

HS

U

VS

VU

Always

Always

Always

Always

Always

Decode Variables

Bits<5> rs2 = $encoding[24:20];
Bits<5> rs1 = $encoding[19:15];
Bits<5> rd = $encoding[11:7];

Execution

  • Pruned, XLEN == 64

  • Original

if ((misa.B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
XReg shamt = X[rs2][5:0];
X[rd] = (X[rs1] >> shamt) | (X[rs1] << (64 - shamt));
if (implemented?(ExtensionName::B) && (misa.B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
XReg shamt = (xlen() == 32) ? X[rs2][4:0] : X[rs2][5:0];
X[rd] = (X[rs1] >> shamt) | (X[rs1] << (xlen() - shamt));

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction