Examples with RegisterSpec com.taobao.android.dx.rop.code.RegisterSpec used on opensource projects

Example 66 with RegisterSpec

use of com.taobao.android.dx.rop.code.RegisterSpec in project atlas by alibaba.

the class ConstCollector method getConstsSortedByCountUse.

/**
     * Gets all of the collectable constant values used in this method,
     * sorted by most used first. Skips non-collectable consts, such as
     * non-string object constants
     *
     * @return {@code non-null;} list of constants in most-to-least used order
     */
private ArrayList<TypedConstant> getConstsSortedByCountUse() {
    int regSz = ssaMeth.getRegCount();
    final HashMap<TypedConstant, Integer> countUses = new HashMap<TypedConstant, Integer>();
    /*
         * Each collected constant can be used by just one local
         * (used only if COLLECT_ONE_LOCAL is true).
         */
    final HashSet<TypedConstant> usedByLocal = new HashSet<TypedConstant>();
    // Count how many times each const value is used.
    for (int i = 0; i < regSz; i++) {
        SsaInsn insn = ssaMeth.getDefinitionForRegister(i);
        if (insn == null || insn.getOpcode() == null)
            continue;
        RegisterSpec result = insn.getResult();
        TypeBearer typeBearer = result.getTypeBearer();
        if (!typeBearer.isConstant())
            continue;
        TypedConstant cst = (TypedConstant) typeBearer;
        // Find defining instruction for move-result-pseudo instructions
        if (insn.getOpcode().getOpcode() == RegOps.MOVE_RESULT_PSEUDO) {
            int pred = insn.getBlock().getPredecessors().nextSetBit(0);
            ArrayList<SsaInsn> predInsns;
            predInsns = ssaMeth.getBlocks().get(pred).getInsns();
            insn = predInsns.get(predInsns.size() - 1);
        }
        if (insn.canThrow()) {
            /*
                 * Don't move anything other than strings -- the risk
                 * of changing where an exception is thrown is too high.
                 */
            if (!(cst instanceof CstString) || !COLLECT_STRINGS) {
                continue;
            }
            /*
                 * We can't move any throwable const whose throw will be
                 * caught, so don't count them.
                 */
            if (insn.getBlock().getSuccessors().cardinality() > 1) {
                continue;
            }
        }
        /*
             * TODO: Might be nice to try and figure out which local
             * wins most when collected.
             */
        if (ssaMeth.isRegALocal(result)) {
            if (!COLLECT_ONE_LOCAL) {
                continue;
            } else {
                if (usedByLocal.contains(cst)) {
                    // Count one local usage only.
                    continue;
                } else {
                    usedByLocal.add(cst);
                }
            }
        }
        Integer has = countUses.get(cst);
        if (has == null) {
            countUses.put(cst, 1);
        } else {
            countUses.put(cst, has + 1);
        }
    }
    // Collect constants that have been reused.
    ArrayList<TypedConstant> constantList = new ArrayList<TypedConstant>();
    for (Map.Entry<TypedConstant, Integer> entry : countUses.entrySet()) {
        if (entry.getValue() > 1) {
            constantList.add(entry.getKey());
        }
    }
    // Sort by use, with most used at the beginning of the list.
    Collections.sort(constantList, new Comparator<Constant>() {

        public int compare(Constant a, Constant b) {
            int ret;
            ret = countUses.get(b) - countUses.get(a);
            if (ret == 0) {
                /*
                     * Provide sorting determinisim for constants with same
                     * usage count.
                     */
                ret = a.compareTo(b);
            }
            return ret;
        }

        @Override
        public boolean equals(Object obj) {
            return obj == this;
        }
    });
    return constantList;
}