c.addi16sp

Add a sign-extended non-zero immediate

This instruction is defined by:

Encoding

Synopsis

C.ADDI16SP adds the non-zero sign-extended 6-bit immediate to the value in the stack pointer (sp=x2), where the immediate is scaled to represent multiples of 16 in the range (-512,496). C.ADDI16SP is used to adjust the stack pointer in procedure prologues and epilogues. It expands into addi x2, x2, nzimm[9:4]. C.ADDI16SP is only valid when nzimm ≠ 0; the code point with nzimm=0 is reserved.

Access

Always

Decode Variables

Bits<10> imm = {$encoding[12], $encoding[4:3], $encoding[5], $encoding[2], $encoding[6], 4'd0};

Execution

Pruned, XLEN == 64
Original

if ((%%LINK%csr_field;misa.C;CSR[misa].C%% == 1'b0)) {
  %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
}
X[2] = X[2] + $signed(imm);

if (%%LINK%func;implemented?;implemented?%%(ExtensionName::C) && (%%LINK%csr_field;misa.C;CSR[misa].C%% == 1'b0)) {
  %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
}
X[2] = X[2] + $signed(imm);

Exceptions

This instruction may result in the following synchronous exceptions:

IllegalInstruction