rol

Rotate left (Register)

This instruction is defined by:

Encoding

Synopsis

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

Access

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

XReg shamt = X[rs2][5:0];
X[rd] = (X[rs1] << shamt) | (X[rs1] >> (64 - shamt));

if (implemented?(ExtensionName::B) && (CSR[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));