vm/InlineNative.c

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * Inlined native functions.  These definitions replace interpreted or
 * native implementations at runtime; "intrinsic" might be a better word.
 */
#include "Dalvik.h"

#include <math.h>

#ifdef HAVE__MEMCMP16
/* hand-coded assembly implementation, available on some platforms */
//#warning "trying memcmp16"
//#define CHECK_MEMCMP16
/* "count" is in 16-bit units */
extern u4 __memcmp16(const u2* s0, const u2* s1, size_t count);
#endif

/*
 * Some notes on "inline" functions.
 *
 * These are NOT simply native implementations.  A full method definition
 * must still be provided.  Depending on the flags passed into the VM
 * at runtime, the original or inline version may be selected by the
 * DEX optimizer.
 *
 * PLEASE DO NOT use this as the default location for native methods.
 * The difference between this and an "internal native" static method
 * call on a 200MHz ARM 9 is roughly 370ns vs. 700ns.  The code here
 * "secretly replaces" the other method, so you can't avoid having two
 * implementations.  Since the DEX optimizer mode can't be known ahead
 * of time, both implementations must be correct and complete.
 *
 * The only stuff that really needs to be here are methods that
 * are high-volume or must be low-overhead, e.g. certain String/Math
 * methods and some java.util.concurrent.atomic operations.
 *
 * Normally, a class is loaded and initialized the first time a static
 * method is invoked.  This property is NOT preserved here.  If you need
 * to access a static field in a class, you must ensure initialization
 * yourself (cheap/easy way is to check the resolved-methods table, and
 * resolve the method if it hasn't been).
 *
 * DO NOT replace "synchronized" methods.  We do not support method
 * synchronization here.
 *
 * DO NOT perform any allocations or do anything that could cause a
 * garbage collection.  The method arguments are not visible to the GC
 * and will not be pinned or updated when memory blocks move.  You are
 * allowed to allocate and throw an exception so long as you only do so
 * immediately before returning.
 *
 * Remember that these functions are executing while the thread is in
 * the "RUNNING" state, not the "NATIVE" state.  If you perform a blocking
 * operation you can stall the entire VM if the GC or debugger wants to
 * suspend the thread.  Since these are arguably native implementations
 * rather than VM internals, prefer NATIVE to VMWAIT if you want to change
 * the thread state.
 *
 * Always write results to 32-bit or 64-bit fields in "pResult", e.g. do
 * not write boolean results to pResult->z.  The interpreter expects
 * 32 or 64 bits to be set.
 *
 * Inline op methods return "false" if an exception was thrown, "true" if
 * everything went well.
 *
 * DO NOT provide implementations of methods that can be overridden by a
 * subclass, as polymorphism does not work correctly.  For safety you should
 * only provide inline functions for classes/methods declared "final".
 *
 * It's best to avoid inlining the overridden version of a method.  For
 * example, String.hashCode() is inherited from Object.hashCode().  Code
 * calling String.hashCode() through an Object reference will run the
 * "slow" version, while calling it through a String reference gets
 * the inlined version.  It's best to have just one version unless there
 * are clear performance gains.
 *
 * Because the actual method is not called, debugger breakpoints on these
 * methods will not happen.  (TODO: have the code here find the original
 * method and call it when the debugger is active.)  Additional steps have
 * been taken to allow method profiling to produce correct results.
 */


/*
 * ===========================================================================
 *      org.apache.harmony.dalvik.NativeTestTarget
 * ===========================================================================
 */

/*
 * public static void emptyInlineMethod
 *
 * This exists only for benchmarks.
 */
static bool org_apache_harmony_dalvik_NativeTestTarget_emptyInlineMethod(
    u4 arg0, u4 arg1, u4 arg2, u4 arg3, JValue* pResult)
{
    // do nothing
    return true;
}


/*
 * ===========================================================================
 *      java.lang.String
 * ===========================================================================
 */

/*
 * public char charAt(int index)
 */
static bool javaLangString_charAt(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    int count, offset;
    ArrayObject* chars;

    /* null reference check on "this" */
    if (!dvmValidateObject((Object*) arg0))
        return false;

    //LOGI("String.charAt this=0x%08x index=%d\n", arg0, arg1);
    count = dvmGetFieldInt((Object*) arg0, STRING_FIELDOFF_COUNT);
    if ((s4) arg1 < 0 || (s4) arg1 >= count) {
        dvmThrowException("Ljava/lang/StringIndexOutOfBoundsException;", NULL);
        return false;
    } else {
        offset = dvmGetFieldInt((Object*) arg0, STRING_FIELDOFF_OFFSET);
        chars = (ArrayObject*)
            dvmGetFieldObject((Object*) arg0, STRING_FIELDOFF_VALUE);

        pResult->i = ((const u2*) chars->contents)[arg1 + offset];
        return true;
    }
}

#ifdef CHECK_MEMCMP16
/*
 * Utility function when we're evaluating alternative implementations.
 */
static void badMatch(StringObject* thisStrObj, StringObject* compStrObj,
    int expectResult, int newResult, const char* compareType)
{
    ArrayObject* thisArray;
    ArrayObject* compArray;
    const char* thisStr;
    const char* compStr;
    int thisOffset, compOffset, thisCount, compCount;

    thisCount =
        dvmGetFieldInt((Object*) thisStrObj, STRING_FIELDOFF_COUNT);
    compCount =
        dvmGetFieldInt((Object*) compStrObj, STRING_FIELDOFF_COUNT);
    thisOffset =
        dvmGetFieldInt((Object*) thisStrObj, STRING_FIELDOFF_OFFSET);
    compOffset =
        dvmGetFieldInt((Object*) compStrObj, STRING_FIELDOFF_OFFSET);
    thisArray = (ArrayObject*)
        dvmGetFieldObject((Object*) thisStrObj, STRING_FIELDOFF_VALUE);
    compArray = (ArrayObject*)
        dvmGetFieldObject((Object*) compStrObj, STRING_FIELDOFF_VALUE);

    thisStr = dvmCreateCstrFromString(thisStrObj);
    compStr = dvmCreateCstrFromString(compStrObj);

    LOGE("%s expected %d got %d\n", compareType, expectResult, newResult);
    LOGE(" this (o=%d l=%d) '%s'\n", thisOffset, thisCount, thisStr);
    LOGE(" comp (o=%d l=%d) '%s'\n", compOffset, compCount, compStr);
    dvmPrintHexDumpEx(ANDROID_LOG_INFO, LOG_TAG,
        ((const u2*) thisArray->contents) + thisOffset, thisCount*2,
        kHexDumpLocal);
    dvmPrintHexDumpEx(ANDROID_LOG_INFO, LOG_TAG,
        ((const u2*) compArray->contents) + compOffset, compCount*2,
        kHexDumpLocal);
    dvmAbort();
}
#endif

/*
 * public int compareTo(String s)
 */
static bool javaLangString_compareTo(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    /*
     * Null reference check on "this".  Normally this is performed during
     * the setup of the virtual method call.  We need to do it before
     * anything else.  While we're at it, check out the other string,
     * which must also be non-null.
     */
    if (!dvmValidateObject((Object*) arg0) ||
        !dvmValidateObject((Object*) arg1))
    {
        return false;
    }

    /* quick test for comparison with itself */
    if (arg0 == arg1) {
        pResult->i = 0;
        return true;
    }

    /*
     * This would be simpler and faster if we promoted StringObject to
     * a full representation, lining up the C structure fields with the
     * actual object fields.
     */
    int thisCount, thisOffset, compCount, compOffset;
    ArrayObject* thisArray;
    ArrayObject* compArray;
    const u2* thisChars;
    const u2* compChars;
    int minCount, countDiff;

    thisCount = dvmGetFieldInt((Object*) arg0, STRING_FIELDOFF_COUNT);
    compCount = dvmGetFieldInt((Object*) arg1, STRING_FIELDOFF_COUNT);
    countDiff = thisCount - compCount;
    minCount = (countDiff < 0) ? thisCount : compCount;
    thisOffset = dvmGetFieldInt((Object*) arg0, STRING_FIELDOFF_OFFSET);
    compOffset = dvmGetFieldInt((Object*) arg1, STRING_FIELDOFF_OFFSET);
    thisArray = (ArrayObject*)
        dvmGetFieldObject((Object*) arg0, STRING_FIELDOFF_VALUE);
    compArray = (ArrayObject*)
        dvmGetFieldObject((Object*) arg1, STRING_FIELDOFF_VALUE);
    thisChars = ((const u2*) thisArray->contents) + thisOffset;
    compChars = ((const u2*) compArray->contents) + compOffset;

#ifdef HAVE__MEMCMP16
    /*
     * Use assembly version, which returns the difference between the
     * characters.  The annoying part here is that 0x00e9 - 0xffff != 0x00ea,
     * because the interpreter converts the characters to 32-bit integers
     * *without* sign extension before it subtracts them (which makes some
     * sense since "char" is unsigned).  So what we get is the result of
     * 0x000000e9 - 0x0000ffff, which is 0xffff00ea.
     */
    int otherRes = __memcmp16(thisChars, compChars, minCount);
# ifdef CHECK_MEMCMP16
    int i;
    for (i = 0; i < minCount; i++) {
        if (thisChars[i] != compChars[i]) {
            pResult->i = (s4) thisChars[i] - (s4) compChars[i];
            if (pResult->i != otherRes) {
                badMatch((StringObject*) arg0, (StringObject*) arg1,
                    pResult->i, otherRes, "compareTo");
            }
            return true;
        }
    }
# endif
    if (otherRes != 0) {
        pResult->i = otherRes;
        return true;
    }

#else
    /*
     * Straightforward implementation, examining 16 bits at a time.  Compare
     * the characters that overlap, and if they're all the same then return
     * the difference in lengths.
     */
    int i;
    for (i = 0; i < minCount; i++) {
        if (thisChars[i] != compChars[i]) {
            pResult->i = (s4) thisChars[i] - (s4) compChars[i];
            return true;
        }
    }
#endif

    pResult->i = countDiff;
    return true;
}

/*
 * public boolean equals(Object anObject)
 */
static bool javaLangString_equals(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    /*
     * Null reference check on "this".
     */
    if (!dvmValidateObject((Object*) arg0))
        return false;

    /* quick test for comparison with itself */
    if (arg0 == arg1) {
        pResult->i = true;
        return true;
    }

    /*
     * See if the other object is also a String.
     *
     * str.equals(null) is expected to return false, presumably based on
     * the results of the instanceof test.
     */
    if (arg1 == 0 || ((Object*) arg0)->clazz != ((Object*) arg1)->clazz) {
        pResult->i = false;
        return true;
    }

    /*
     * This would be simpler and faster if we promoted StringObject to
     * a full representation, lining up the C structure fields with the
     * actual object fields.
     */
    int thisCount, thisOffset, compCount, compOffset;
    ArrayObject* thisArray;
    ArrayObject* compArray;
    const u2* thisChars;
    const u2* compChars;

    /* quick length check */
    thisCount = dvmGetFieldInt((Object*) arg0, STRING_FIELDOFF_COUNT);
    compCount = dvmGetFieldInt((Object*) arg1, STRING_FIELDOFF_COUNT);
    if (thisCount != compCount) {
        pResult->i = false;
        return true;
    }

    thisOffset = dvmGetFieldInt((Object*) arg0, STRING_FIELDOFF_OFFSET);
    compOffset = dvmGetFieldInt((Object*) arg1, STRING_FIELDOFF_OFFSET);
    thisArray = (ArrayObject*)
        dvmGetFieldObject((Object*) arg0, STRING_FIELDOFF_VALUE);
    compArray = (ArrayObject*)
        dvmGetFieldObject((Object*) arg1, STRING_FIELDOFF_VALUE);
    thisChars = ((const u2*) thisArray->contents) + thisOffset;
    compChars = ((const u2*) compArray->contents) + compOffset;

#ifdef HAVE__MEMCMP16
    pResult->i = (__memcmp16(thisChars, compChars, thisCount) == 0);
# ifdef CHECK_MEMCMP16
    int otherRes = (memcmp(thisChars, compChars, thisCount * 2) == 0);
    if (pResult->i != otherRes) {
        badMatch((StringObject*) arg0, (StringObject*) arg1,
            otherRes, pResult->i, "equals-1");
    }
# endif
#else
    /*
     * Straightforward implementation, examining 16 bits at a time.  The
     * direction of the loop doesn't matter, and starting at the end may
     * give us an advantage when comparing certain types of strings (e.g.
     * class names).
     *
     * We want to go forward for benchmarks against __memcmp16 so we get a
     * meaningful comparison when the strings don't match (could also test
     * with palindromes).
     */
    int i;
    //for (i = 0; i < thisCount; i++)
    for (i = thisCount-1; i >= 0; --i)
    {
        if (thisChars[i] != compChars[i]) {
            pResult->i = false;
            return true;
        }
    }
    pResult->i = true;
#endif

    return true;
}

/*
 * public int length()
 */
static bool javaLangString_length(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    //LOGI("String.length this=0x%08x pResult=%p\n", arg0, pResult);

    /* null reference check on "this" */
    if (!dvmValidateObject((Object*) arg0))
        return false;

    pResult->i = dvmGetFieldInt((Object*) arg0, STRING_FIELDOFF_COUNT);
    return true;
}

/*
 * public boolean isEmpty()
 */
static bool javaLangString_isEmpty(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    //LOGI("String.isEmpty this=0x%08x pResult=%p\n", arg0, pResult);

    /* null reference check on "this" */
    if (!dvmValidateObject((Object*) arg0))
        return false;

    pResult->i = (dvmGetFieldInt((Object*) arg0, STRING_FIELDOFF_COUNT) == 0);
    return true;
}

/*
 * Determine the index of the first character matching "ch".  The string
 * to search is described by "chars", "offset", and "count".
 *
 * The character must be <= 0xffff. Supplementary characters are handled in
 * Java.
 *
 * The "start" parameter must be clamped to [0..count].
 *
 * Returns -1 if no match is found.
 */
static inline int indexOfCommon(Object* strObj, int ch, int start)
{
    //if ((ch & 0xffff) != ch)        /* 32-bit code point */
    //    return -1;

    /* pull out the basic elements */
    ArrayObject* charArray =
        (ArrayObject*) dvmGetFieldObject(strObj, STRING_FIELDOFF_VALUE);
    const u2* chars = (const u2*) charArray->contents;
    int offset = dvmGetFieldInt(strObj, STRING_FIELDOFF_OFFSET);
    int count = dvmGetFieldInt(strObj, STRING_FIELDOFF_COUNT);
    //LOGI("String.indexOf(0x%08x, 0x%04x, %d) off=%d count=%d\n",
    //    (u4) strObj, ch, start, offset, count);

    /* factor out the offset */
    chars += offset;

    if (start < 0)
        start = 0;

#if 0
    /* 16-bit loop, simple */
    while (start < count) {
        if (chars[start] == ch)
            return start;
        start++;
    }
#else
    /* 16-bit loop, slightly better on ARM */
    const u2* ptr = chars + start;
    const u2* endPtr = chars + count;
    while (ptr < endPtr) {
        if (*ptr++ == ch)
            return (ptr-1) - chars;
    }
#endif

    return -1;
}

/*
 * public int indexOf(int c, int start)
 *
 * Scan forward through the string for a matching character.
 * The character must be <= 0xffff; this method does not handle supplementary
 * characters.
 */
static bool javaLangString_fastIndexOf_II(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    /* null reference check on "this" */
    if (!dvmValidateObject((Object*) arg0))
        return false;

    pResult->i = indexOfCommon((Object*) arg0, arg1, arg2);
    return true;
}


/*
 * ===========================================================================
 *      java.lang.Math
 * ===========================================================================
 */

typedef union {
    u4 arg;
    float ff;
} Convert32;

typedef union {
    u4 arg[2];
    s8 ll;
    double dd;
} Convert64;

/*
 * public static int abs(int)
 */
static bool javaLangMath_abs_int(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    s4 val = (s4) arg0;
    pResult->i = (val >= 0) ? val : -val;
    return true;
}

/*
 * public static long abs(long)
 */
static bool javaLangMath_abs_long(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    Convert64 convert;
    convert.arg[0] = arg0;
    convert.arg[1] = arg1;
    s8 val = convert.ll;
    pResult->j = (val >= 0) ? val : -val;
    return true;
}

/*
 * public static float abs(float)
 */
static bool javaLangMath_abs_float(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    Convert32 convert;
    /* clear the sign bit; assumes a fairly common fp representation */
    convert.arg = arg0 & 0x7fffffff;
    pResult->f = convert.ff;
    return true;
}

/*
 * public static double abs(double)
 */
static bool javaLangMath_abs_double(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    Convert64 convert;
    convert.arg[0] = arg0;
    convert.arg[1] = arg1;
    /* clear the sign bit in the (endian-dependent) high word */
    convert.ll &= 0x7fffffffffffffffULL;
    pResult->d = convert.dd;
    return true;
}

/*
 * public static int min(int)
 */
static bool javaLangMath_min_int(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    pResult->i = ((s4) arg0 < (s4) arg1) ? arg0 : arg1;
    return true;
}

/*
 * public static int max(int)
 */
static bool javaLangMath_max_int(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    pResult->i = ((s4) arg0 > (s4) arg1) ? arg0 : arg1;
    return true;
}

/*
 * public static double sqrt(double)
 *
 * With ARM VFP enabled, gcc turns this into an fsqrtd instruction, followed
 * by an fcmpd of the result against itself.  If it doesn't match (i.e.
 * it's NaN), the libm sqrt() is invoked.
 */
static bool javaLangMath_sqrt(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    Convert64 convert;
    convert.arg[0] = arg0;
    convert.arg[1] = arg1;
    pResult->d = sqrt(convert.dd);
    return true;
}

/*
 * public static double cos(double)
 */
static bool javaLangMath_cos(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    Convert64 convert;
    convert.arg[0] = arg0;
    convert.arg[1] = arg1;
    pResult->d = cos(convert.dd);
    return true;
}

/*
 * public static double sin(double)
 */
static bool javaLangMath_sin(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult)
{
    Convert64 convert;
    convert.arg[0] = arg0;
    convert.arg[1] = arg1;
    pResult->d = sin(convert.dd);
    return true;
}

/*
 * ===========================================================================
 *      java.lang.Float
 * ===========================================================================
 */

static bool javaLangFloat_floatToIntBits(u4 arg0, u4 arg1, u4 arg2, u4 arg,
    JValue* pResult)
{
    Convert32 convert;
    convert.arg = arg0;
    pResult->i = isnanf(convert.ff) ? 0x7fc00000 : arg0;
    return true;
}

static bool javaLangFloat_floatToRawIntBits(u4 arg0, u4 arg1, u4 arg2, u4 arg,
    JValue* pResult)
{
    pResult->i = arg0;
    return true;
}

static bool javaLangFloat_intBitsToFloat(u4 arg0, u4 arg1, u4 arg2, u4 arg,
    JValue* pResult)
{
    Convert32 convert;
    convert.arg = arg0;
    pResult->f = convert.ff;
    return true;
}

/*
 * ===========================================================================
 *      java.lang.Double
 * ===========================================================================
 */

static bool javaLangDouble_doubleToLongBits(u4 arg0, u4 arg1, u4 arg2, u4 arg,
    JValue* pResult)
{
    Convert64 convert;
    convert.arg[0] = arg0;
    convert.arg[1] = arg1;
    pResult->j = isnan(convert.dd) ? 0x7ff8000000000000LL : convert.ll;
    return true;
}

static bool javaLangDouble_doubleToRawLongBits(u4 arg0, u4 arg1, u4 arg2,
    u4 arg, JValue* pResult)
{
    Convert64 convert;
    convert.arg[0] = arg0;
    convert.arg[1] = arg1;
    pResult->j = convert.ll;
    return true;
}

static bool javaLangDouble_longBitsToDouble(u4 arg0, u4 arg1, u4 arg2, u4 arg,
    JValue* pResult)
{
    Convert64 convert;
    convert.arg[0] = arg0;
    convert.arg[1] = arg1;
    pResult->d = convert.dd;
    return true;
}

/*
 * ===========================================================================
 *      Infrastructure
 * ===========================================================================
 */

/*
 * Table of methods.
 *
 * The DEX optimizer uses the class/method/signature string fields to decide
 * which calls it can trample.  The interpreter just uses the function
 * pointer field.
 *
 * IMPORTANT: you must update DALVIK_VM_BUILD in DalvikVersion.h if you make
 * changes to this table.
 *
 * NOTE: If present, the JIT will also need to know about changes
 * to this table.  Update the NativeInlineOps enum in InlineNative.h and
 * the dispatch code in compiler/codegen/<target>/Codegen.c.
 */
const InlineOperation gDvmInlineOpsTable[] = {
    { org_apache_harmony_dalvik_NativeTestTarget_emptyInlineMethod,
        "Lorg/apache/harmony/dalvik/NativeTestTarget;",
        "emptyInlineMethod", "()V" },

    { javaLangString_charAt,
        "Ljava/lang/String;", "charAt", "(I)C" },
    { javaLangString_compareTo,
        "Ljava/lang/String;", "compareTo", "(Ljava/lang/String;)I" },
    { javaLangString_equals,
        "Ljava/lang/String;", "equals", "(Ljava/lang/Object;)Z" },
    { javaLangString_fastIndexOf_II,
        "Ljava/lang/String;", "fastIndexOf", "(II)I" },
    { javaLangString_isEmpty,
        "Ljava/lang/String;", "isEmpty", "()Z" },
    { javaLangString_length,
        "Ljava/lang/String;", "length", "()I" },

    { javaLangMath_abs_int,
        "Ljava/lang/Math;", "abs", "(I)I" },
    { javaLangMath_abs_long,
        "Ljava/lang/Math;", "abs", "(J)J" },
    { javaLangMath_abs_float,
        "Ljava/lang/Math;", "abs", "(F)F" },
    { javaLangMath_abs_double,
        "Ljava/lang/Math;", "abs", "(D)D" },
    { javaLangMath_min_int,
        "Ljava/lang/Math;", "min", "(II)I" },
    { javaLangMath_max_int,
        "Ljava/lang/Math;", "max", "(II)I" },
    { javaLangMath_sqrt,
        "Ljava/lang/Math;", "sqrt", "(D)D" },
    { javaLangMath_cos,
        "Ljava/lang/Math;", "cos", "(D)D" },
    { javaLangMath_sin,
        "Ljava/lang/Math;", "sin", "(D)D" },

    { javaLangFloat_floatToIntBits,
        "Ljava/lang/Float;", "floatToIntBits", "(F)I" },
    { javaLangFloat_floatToRawIntBits,
        "Ljava/lang/Float;", "floatToRawIntBits", "(F)I" },
    { javaLangFloat_intBitsToFloat,
        "Ljava/lang/Float;", "intBitsToFloat", "(I)F" },

    { javaLangDouble_doubleToLongBits,
        "Ljava/lang/Double;", "doubleToLongBits", "(D)J" },
    { javaLangDouble_doubleToRawLongBits,
        "Ljava/lang/Double;", "doubleToRawLongBits", "(D)J" },
    { javaLangDouble_longBitsToDouble,
        "Ljava/lang/Double;", "longBitsToDouble", "(J)D" },
};

/*
 * Allocate some tables.
 */
bool dvmInlineNativeStartup(void)
{
    gDvm.inlinedMethods =
        (Method**) calloc(NELEM(gDvmInlineOpsTable), sizeof(Method*));
    if (gDvm.inlinedMethods == NULL)
        return false;

    return true;
}

/*
 * Free generated tables.
 */
void dvmInlineNativeShutdown(void)
{
    free(gDvm.inlinedMethods);
}


/*
 * Get a pointer to the inlineops table.
 */
const InlineOperation* dvmGetInlineOpsTable(void)
{
    return gDvmInlineOpsTable;
}

/*
 * Get the number of entries in the inlineops table.
 */
int dvmGetInlineOpsTableLength(void)
{
    return NELEM(gDvmInlineOpsTable);
}

Method* dvmFindInlinableMethod(const char* classDescriptor,
    const char* methodName, const char* methodSignature)
{
    /*
     * Find the class.
     */
    ClassObject* clazz = dvmFindClassNoInit(classDescriptor, NULL);
    if (clazz == NULL) {
        LOGE("dvmFindInlinableMethod: can't find class '%s'",
            classDescriptor);
        dvmClearException(dvmThreadSelf());
        return NULL;
    }

    /*
     * Method could be virtual or direct.  Try both.  Don't use
     * the "hier" versions.
     */
    Method* method = dvmFindDirectMethodByDescriptor(clazz, methodName,
        methodSignature);
    if (method == NULL) {
        method = dvmFindVirtualMethodByDescriptor(clazz, methodName,
            methodSignature);
    }
    if (method == NULL) {
        LOGE("dvmFindInlinableMethod: can't find method %s.%s %s",
            clazz->descriptor, methodName, methodSignature);
        return NULL;
    }

    /*
     * Check that the method is appropriate for inlining.
     */
    if (!dvmIsFinalClass(clazz) && !dvmIsFinalMethod(method)) {
        LOGE("dvmFindInlinableMethod: can't inline non-final method %s.%s",
            clazz->descriptor, method->name);
        return NULL;
    }
    if (dvmIsSynchronizedMethod(method) ||
            dvmIsDeclaredSynchronizedMethod(method)) {
        LOGE("dvmFindInlinableMethod: can't inline synchronized method %s.%s",
            clazz->descriptor, method->name);
        return NULL;
    }

    return method;
}

/*
 * Populate the methods table on first use.  It's possible the class
 * hasn't been resolved yet, so we need to do the full "calling the
 * method for the first time" routine.  (It's probably okay to skip
 * the access checks.)
 *
 * Currently assuming that we're only inlining stuff loaded by the
 * bootstrap class loader.  This is a safe assumption for many reasons.
 */
static Method* resolveInlineNative(int opIndex)
{
    assert(opIndex >= 0 && opIndex < NELEM(gDvmInlineOpsTable));
    Method* method = gDvm.inlinedMethods[opIndex];
    if (method != NULL) {
        return method;
    }

    method = dvmFindInlinableMethod(
        gDvmInlineOpsTable[opIndex].classDescriptor,
        gDvmInlineOpsTable[opIndex].methodName,
        gDvmInlineOpsTable[opIndex].methodSignature);

    if (method == NULL) {
        /* We already reported the error. */
        return NULL;
    }

    gDvm.inlinedMethods[opIndex] = method;
    IF_LOGV() {
        char* desc = dexProtoCopyMethodDescriptor(&method->prototype);
        LOGV("Registered for profile: %s.%s %s\n",
            method->clazz->descriptor, method->name, desc);
        free(desc);
    }

    return method;
}

/*
 * Make an inline call for the "debug" interpreter, used when the debugger
 * or profiler is active.
 */
bool dvmPerformInlineOp4Dbg(u4 arg0, u4 arg1, u4 arg2, u4 arg3,
    JValue* pResult, int opIndex)
{
    Method* method = resolveInlineNative(opIndex);
    if (method == NULL) {
        return (*gDvmInlineOpsTable[opIndex].func)(arg0, arg1, arg2, arg3,
            pResult);
    }

    Thread* self = dvmThreadSelf();
    TRACE_METHOD_ENTER(self, method);
    bool result = (*gDvmInlineOpsTable[opIndex].func)(arg0, arg1, arg2, arg3,
        pResult);
    TRACE_METHOD_EXIT(self, method);
    return result;
}

/*
 * Check that we can resolve every inline native.
 */
bool dvmInlineNativeCheck(void)
{
    int op;
    for (op = 0; op < NELEM(gDvmInlineOpsTable); ++op) {
        if (resolveInlineNative(op) == NULL) {
            dvmAbort();
        }
    }
    return true;
}