/** Return true if the instruction can be deleted without changing program semantics. */
public boolean canBeDeleted(RegisterSet registers) {
int ard = registers.actualRegister(rd);
return (ard == SparcRegisterSet.G0_REG);
}
/** Return true if the instruction uses the register. */
public boolean uses(int register, RegisterSet registers) {
int ars1 = registers.actualRegister(rs1);
int areg = registers.actualRegister(register);
return (areg == ars1);
}
/** Return true if the instruction sets the register. */
public boolean defs(int register, RegisterSet registers) {
int ard = registers.actualRegister(rd);
int areg = registers.actualRegister(register);
return (areg == ard);
}
/** Mark the instruction as no longer needed. */
public void nullify(RegisterSet rs) {
if (rs.virtualRegister(ra) && !isMandatory()) {
super.nullify(rs);
}
}
