rori

Rotate right (Immediate)

This instruction is defined by:

Encoding

Synopsis

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

Always

Decode Variables

Bits<6> shamt = $encoding[25:20];
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 = shamt[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) ? shamt[4:0] : shamt[5:0];
X[rd] = (X[rs1] >> shamt) | (X[rs1] << (xlen() - shamt));

Exceptions

This instruction may result in the following synchronous exceptions:

IllegalInstruction