roriw

Rotate right word (Immediate)

This instruction is defined by:

Encoding

Synopsis

This instruction performs a rotate right on the least-significant word of rs1 by the amount in the least-significant log2(XLEN) bits of shamt. The resulting word value is sign-extended by copying bit 31 to all of the more-significant bits.

Access

Always

Decode Variables

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

Execution

Pruned, XLEN == 64
Original

XReg rs1_word = X[rs1][31:0];
XReg unextended_result = (X[rs1] >> shamt) | (X[rs1] << (32 - shamt));
X[rd] = {{32{unextended_result[31]}}, unextended_result};

if (implemented?(ExtensionName::B) && (CSR[misa].B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
XReg rs1_word = X[rs1][31:0];
XReg unextended_result = (X[rs1] >> shamt) | (X[rs1] << (32 - shamt));
X[rd] = {{32{unextended_result[31]}}, unextended_result};