c.jalr

Jump and Link Register.

This instruction is defined by:

anyOf:
- C, version >= 0
- Zca, version >= 0

This instruction is included in the following profiles:

Encoding

Assembly format

c.jalr rs1

Synopsis

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(rs1).

Access

M	HS	U	VS	VU
Always	Always	Always	Always	Always

Always

Decode Variables

Bits<5> rs1 = $encoding[11:7];

Execution

if (implemented?(ExtensionName::C) && (CSR[misa].C == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
XReg returnaddr;
returnaddr = $pc + 2;
jump(X[rs1]);
X[1] = returnaddr;

Exceptions

This instruction may result in the following synchronous exceptions:

IllegalInstruction
InstructionAddressMisaligned