c.sext.b

Sign-extend byte, 16-bit encoding

This instruction is defined by:

Encoding

Synopsis

Takes a single source/destination operand. This instruction sign-extends the least-significant byte of the source to XLEN by copying the most-significant bit in the byte (i.e., bit 7) to all of the more-significant bits.

Access

M	HS	U	VS	VU
Always	Always	Always	Always	Always

Always

Decode Variables

Bits<3> xd = $encoding[9:7];

Execution

Pruned, XLEN == 64
Original

X[creg2reg(xd)] = $signed(X[creg2reg(xd)][7:0]);

if (implemented?(ExtensionName::B) && (CSR[misa].B == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
if (implemented?(ExtensionName::C) && (CSR[misa].C == 1'b0)) {
  raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
X[creg2reg(xd)] = $signed(X[creg2reg(xd)][7:0]);