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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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package com.oracle.truffle.js.nodes.binary;

import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
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.js.nodes.JavaScriptNode;
import com.oracle.truffle.js.nodes.cast.JSToNumericNode;
import com.oracle.truffle.js.runtime.BigInt;
import com.oracle.truffle.js.runtime.Errors;

import java.util.Set;

@NodeInfo(shortName = "**")
public abstract class JSExponentiateNode extends JSBinaryNode {

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

    public static JavaScriptNode create(JavaScriptNode left, JavaScriptNode right) {
        return JSExponentiateNodeGen.create(left, right);
    }

    public static JSExponentiateNode create() {
        return (JSExponentiateNode) create(null, null);
    }

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

    @Specialization
    protected double doDouble(double a, double b) {
        return Math.pow(a, b);
    }

    @Specialization(guards = "isBigIntNegativeVal(b)")
    protected void doBigIntNegativeExponent(@SuppressWarnings("unused") BigInt a, @SuppressWarnings("unused") BigInt b) {
        throw Errors.createRangeError("Exponent must be positve");
    }

    @Specialization(guards = {"isBigIntZero(a)", "!isBigIntZero(b)", "!isBigIntNegativeVal(b)"})
    @SuppressWarnings("unused")
    protected BigInt doBigIntZero(BigInt a, BigInt b) {
        return BigInt.ZERO;
    }

    @Specialization(guards = {"isBigIntZero(b)"})
    protected BigInt doBigIntZeroPowZero(@SuppressWarnings("unused") BigInt a, @SuppressWarnings("unused") BigInt b) {
        return BigInt.ONE;
    }

    @Specialization(guards = {"!isBigIntZero(a)", "!isBigIntZero(b)", "!isBigIntNegativeVal(b)"})
    @TruffleBoundary
    protected BigInt doBigInt(BigInt a, BigInt b) {
        if (b.compareTo(BigInt.MAX_INT) < 0) {
            try {
                return a.pow(b.intValue());
            } catch (ArithmeticException ae) {
                throw Errors.createRangeErrorBigIntMaxSizeExceeded();
            }
        } else {
            if (a.compareTo(BigInt.ONE) == 0) {
                return BigInt.ONE;
            } else if (a.compareTo(BigInt.NEGATIVE_ONE) == 0) {
                return b.testBit(0) ? BigInt.NEGATIVE_ONE : BigInt.ONE;
            }
            throw Errors.createRangeErrorBigIntMaxSizeExceeded();
        }
    }

    @Specialization(replaces = "doDouble")
    protected Object doGeneric(Object a, Object b,
                    @Cached("create()") JSExponentiateNode nestedExponentiateNode,
                    @Cached("create()") JSToNumericNode toNumeric1Node,
                    @Cached("create()") JSToNumericNode toNumeric2Node,
                    @Cached("create()") BranchProfile mixedNumericTypes) {
        Object operandA = toNumeric1Node.execute(a);
        Object operandB = toNumeric2Node.execute(b);
        ensureBothSameNumericType(operandA, operandB, mixedNumericTypes);
        return nestedExponentiateNode.execute(operandA, operandB);
    }

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

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