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 * permitted provided that the following conditions are met:
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 * 1. Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided
 * with the distribution.
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 * 3. Neither the name of the copyright holder nor the names of its contributors may be used to
 * endorse or promote products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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package com.oracle.truffle.llvm.runtime;

public interface LLVMFunction {

    long SULONG_FUNCTION_POINTER_TAG = 0xDEAD_FACE_0000_0000L;
    long UPPER_MASK = 0xFFFF_FFFF_0000_0000L;
    long LOWER_MASK = 0x0000_0000_FFFF_FFFFL;

    static long tagSulongFunctionPointer(long sulongPointer) {
        assert (sulongPointer & UPPER_MASK) == 0;
        return sulongPointer | SULONG_FUNCTION_POINTER_TAG;
    }

    static int getSulongFunctionIndex(long sulongPointer) {
        assert isSulongFunctionPointer(sulongPointer);
        return (int) (sulongPointer & LOWER_MASK);
    }

    static boolean isSulongFunctionPointer(long functionPointer) {
        return (functionPointer & UPPER_MASK) == SULONG_FUNCTION_POINTER_TAG;
    }

    static boolean isExternNativeFunctionPointer(long functionPointer) {
        return !isSulongFunctionPointer(functionPointer);
    }

    long getFunctionPointer();

    boolean isNullFunction();

}