amocas.h.aq
Atomic compare-and-swap halfword (acquire)
Atomically with acquire ordering:
-
Load the halfword at address xs1
-
Write the sign-extended value into xd
-
Compare the loaded value with the least-significant halfword of register xs2
-
If equal, write the least-significant halfword of register xs2+1 to the address in xs1
Decode Variables
Bits<5> xs2 = $encoding[24:20];
Bits<5> xs1 = $encoding[19:15];
Bits<5> xd = $encoding[11:7];Execution
if (!implemented?(ExtensionName::Zabha)) {
raise(ExceptionCode::IllegalInstruction, mode(), $encoding);
}
memory_model_acquire();
XReg virtual_address = X[xs1];