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 * The Universal Permissive License (UPL), Version 1.0
 *
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 * (a) the Software, and
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 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
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 * Software and the Larger Work(s), and to sublicense the foregoing rights on
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 * This license is subject to the following condition:
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package com.oracle.truffle.js.nodes.binary;

import com.oracle.truffle.api.CompilerDirectives;
import com.oracle.truffle.api.dsl.Cached;
import com.oracle.truffle.api.dsl.Specialization;
import com.oracle.truffle.api.instrumentation.Tag;
import com.oracle.truffle.api.nodes.NodeInfo;
import com.oracle.truffle.api.profiles.BranchProfile;
import com.oracle.truffle.api.profiles.ConditionProfile;
import com.oracle.truffle.js.nodes.JavaScriptNode;
import com.oracle.truffle.js.nodes.Truncatable;
import com.oracle.truffle.js.nodes.access.JSConstantNode.JSConstantIntegerNode;
import com.oracle.truffle.js.nodes.cast.JSToNumericNode;
import com.oracle.truffle.js.nodes.cast.JSToUInt32Node;
import com.oracle.truffle.js.runtime.BigInt;
import com.oracle.truffle.js.runtime.Errors;
import com.oracle.truffle.js.runtime.JSConfig;
import com.oracle.truffle.js.runtime.SafeInteger;

import java.util.Set;

11.7.3 The Unsigned Right Shift Operator (>>>).
/**
 * 11.7.3 The Unsigned Right Shift Operator (>>>).
 */
@NodeInfo(shortName = ">>>")
public abstract class JSUnsignedRightShiftNode extends JSBinaryNode {

    protected JSUnsignedRightShiftNode(JavaScriptNode left, JavaScriptNode right) {
        super(left, right);
    }

    @Child private JSToUInt32Node toUInt32Node;

    public static JavaScriptNode create(JavaScriptNode left, JavaScriptNode right) {
        Truncatable.truncate(left);
        Truncatable.truncate(right);
        if (JSConfig.UseSuperOperations && right instanceof JSConstantIntegerNode) {
            return JSUnsignedRightShiftConstantNode.create(left, right);
        }
        return JSUnsignedRightShiftNodeGen.create(left, right);
    }

    static JSUnsignedRightShiftNode create() {
        return JSUnsignedRightShiftNodeGen.create(null, null);
    }

    protected final Number executeNumber(Object a, Object b) {
        return (Number) execute(a, b);
    }

    public abstract Object execute(Object a, Object b);

    protected static boolean rvalZero(int b) {
        return (b & 0x1f) == 0;
    }

    @Specialization(guards = {"rvalZero(b)", "a >= 0"})
    protected int doIntegerFast(int a, @SuppressWarnings("unused") int b) {
        return a;
    }

    @Specialization(guards = "a >= 0")
    protected int doInteger(int a, int b) {
        return a >>> b;
    }

    @Specialization(guards = "!rvalZero(b)")
    protected int doIntegerNegative(int a, int b) {
        return a >>> b;
    }

    @Specialization(guards = "rvalZero(b)")
    protected double doDoubleZero(double a, @SuppressWarnings("unused") int b) {
        return toUInt32(a);
    }

    @Specialization(guards = "!rvalZero(b)")
    protected Number doDouble(double a, int b,
                    @Cached("createBinaryProfile()") ConditionProfile returnType) {

        long lnum = toUInt32(a);
        int shiftCount = b & 0x1F;
        if (returnType.profile(lnum >= Integer.MAX_VALUE || lnum <= Integer.MIN_VALUE)) {
            return (double) (lnum >>> shiftCount);
        }
        return (int) (lnum >>> shiftCount);
    }

    @Specialization
    protected Number doIntDouble(int a, double b,
                    @Cached("create()") JSToUInt32Node rvalToUint32Node,
                    @Cached("createBinaryProfile()") ConditionProfile returnType) {

        long lnum = toUInt32(a);
        int shiftCount = (int) rvalToUint32Node.executeLong(b) & 0x1F;
        if (returnType.profile(lnum >= Integer.MAX_VALUE || lnum <= Integer.MIN_VALUE)) {
            return (double) (lnum >>> shiftCount);
        }
        return (int) (lnum >>> shiftCount);
    }

    @Specialization
    protected double doDoubleDouble(double a, double b) {
        return (toUInt32(a) >>> ((int) toUInt32(b) & 0x1F));
    }

    @Specialization
    protected Number doBigInt(@SuppressWarnings("unused") BigInt a, @SuppressWarnings("unused") BigInt b) {
        throw Errors.createTypeError("BigInts have no unsigned right shift, use >> instead");
    }

    @Specialization(guards = "!isHandled(lval, rval)")
    protected Number doGeneric(Object lval, Object rval,
                    @Cached("create()") JSToNumericNode lvalToNumericNode,
                    @Cached("create()") JSToNumericNode rvalToNumericNode,
                    @Cached("create()") JSUnsignedRightShiftNode innerShiftNode,
                    @Cached("create()") BranchProfile mixedNumericTypes) {
        Object lnum = lvalToNumericNode.execute(lval);
        Object rnum = rvalToNumericNode.execute(rval);
        ensureBothSameNumericType(lnum, rnum, mixedNumericTypes);
        return innerShiftNode.executeNumber(lnum, rnum);
    }

    private long toUInt32(Object target) {
        if (toUInt32Node == null) {
            CompilerDirectives.transferToInterpreterAndInvalidate();
            toUInt32Node = insert(JSToUInt32Node.create());
        }
        return toUInt32Node.executeLong(target);
    }

    protected static boolean isHandled(Object lval, Object rval) {
        return (lval instanceof Integer || lval instanceof Double || lval instanceof SafeInteger) && (rval instanceof Integer || rval instanceof Double || rval instanceof SafeInteger);
    }

    @Override
    public boolean isResultAlwaysOfType(Class<?> clazz) {
        return clazz == Number.class;
    }

    @Override
    protected JavaScriptNode copyUninitialized(Set<Class<? extends Tag>> materializedTags) {
        return JSUnsignedRightShiftNodeGen.create(cloneUninitialized(getLeft(), materializedTags), cloneUninitialized(getRight(), materializedTags));
    }
}