c.jalr

Jump and Link Register

C.JALR (jump and link register) performs the same operation as C.JR, but additionally writes the address of the instruction following the jump (pc+2) to the link register, x1. C.JALR expands to jalr x1, 0(xs1).

Assembly format

c.jalr xs1

Decode Variables

Bits<5> xs1 = $encoding[11:7];

Execution

if (implemented?(ExtensionName::C) && MISA_CSR_IMPLEMENTED && (CSR[misa].C == 1'b0)) {
  reserved_instruction($encoding);
}
XReg addr = X[xs1];
XReg returnaddr;
returnaddr = $pc + 2;
X[1] = returnaddr;
jump(addr);

Exceptions

This instruction may result in the following synchronous exceptions:

  • IllegalInstruction

  • InstructionAddressMisaligned

Encoding

svg

Defining extension

Zca

Access

M

Always

Containing profiles

  • Mandatory: None

  • Optional: RVA20S64, RVA20U64, RVA22S64, RVA22U64, RVA23S64, RVA23U64, RVB23S64, RVB23U64, RVI20U32, RVI20U64