Examples with TwoRegInsn soot.toDex.instructions.TwoRegInsn used on opensource projects

Example 1 with TwoRegInsn

use of soot.toDex.instructions.TwoRegInsn in project soot by Sable.

the class RegisterAssigner method findFittingInsn.

private Insn findFittingInsn(Insn insn) {
    if (!insn.hasIncompatibleRegs()) {
        // no incompatible regs -> no fitting needed
        return null;
    }
    // we expect the dex specification to rarely change, so we hard-code the
    // mapping "unfitting -> fitting"
    Opcode opc = insn.getOpcode();
    if (insn instanceof Insn11n && opc.equals(Opcode.CONST_4)) {
        // const-4 (11n, byteReg) -> const-16 (21s, shortReg)
        Insn11n unfittingInsn = (Insn11n) insn;
        if (unfittingInsn.getRegA().fitsShort()) {
            return new Insn21s(Opcode.CONST_16, unfittingInsn.getRegA(), unfittingInsn.getLitB());
        }
    } else if (insn instanceof TwoRegInsn && opc.name.endsWith("_2ADDR")) {
        // */2addr (12x, byteReg,byteReg) -> * (23x,
        // shortReg,shortReg,shortReg)
        Register regA = ((TwoRegInsn) insn).getRegA();
        Register regB = ((TwoRegInsn) insn).getRegB();
        if (regA.fitsShort() && regB.fitsShort()) {
            // use new opcode without the "/2addr"
            int oldOpcLength = opc.name.length();
            String newOpcName = opc.name.substring(0, oldOpcLength - 6);
            Opcode newOpc = Opcode.valueOf(newOpcName);
            Register regAClone = regA.clone();
            return new Insn23x(newOpc, regA, regAClone, regB);
        }
    } else if (insn instanceof TwoRegInsn && SootToDexUtils.isNormalMove(opc)) {
        /*
			 * move+ (12x, byteReg,byteReg) -> move+/from16 (22x,
			 * shortReg,unconstReg) -> move+/16 (32x, unconstReg,unconstReg)
			 * where "+" is "", "-object" or "-wide"
			 */
        Register regA = ((TwoRegInsn) insn).getRegA();
        Register regB = ((TwoRegInsn) insn).getRegB();
        if (regA.getNumber() != regB.getNumber()) {
            return StmtVisitor.buildMoveInsn(regA, regB);
        }
    }
    // no fitting insn found
    return null;
}