Some formatting unifications.

[jamvm-avr32-jem.git] / src / interp / engine / interp_jem.c

/*
 * Copyright (C) 2003, 2004, 2005, 2006, 2007
 * Robert Lougher <rob@lougher.org.uk>.
 *
 * This file is part of JamVM.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2,
 * or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#define _GNU_SOURCE
#include <arpa/inet.h>
#include <math.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "jam.h"
#include "thread.h"
#include "lock.h"
#include "interp.h"

#include "interp-direct.h"

#ifdef JEM
#include <sys/syscall.h>
#include <unistd.h>
#include <sys/mman.h>

#include "arch/avr32_jem.h"
#include "interp_jem.h"

union jecr {
        struct {
                uint8_t dummy;
                uint8_t opcode;
                uint8_t op1;
                uint8_t op2;
        } s;
        uint32_t i;
};

/**
 *  Interpreter execution context
 */
struct intrp_ctx {
        /* JEM state */
        struct jem_state jem;

        /* the interpreter execution context */
        Frame *frame;
        MethodBlock *mb;
        MethodBlock *new_mb;
        ConstantPool *cp;
        Object *this;
        uintptr_t *lvars_jem;
        uintptr_t *ostack;
        uintptr_t *arg1;
        ExecEnv *ee;
};

typedef int handler_fn(struct intrp_ctx *ctx);

static void jem_opcode_rewrite(uint32_t new_opcode, char *pc, int argc, ...)
{
    int i;
    va_list vargs;

    va_start(vargs, argc);
    pc[0] = new_opcode;
    for (i = 1; i <= argc; i++)
        pc[i] = (char)va_arg(vargs, int);
    va_end(vargs);
}

#define min(x, y) ({ typeof(x) _x = (x); typeof(y) _y = (y); _x > _y ? _y : _x; })

//check if it is an valid object ref (see alloc.c)
#define OBJECT_GRAIN  8
#define IS_OBJECT(ptr) !(((uintptr_t)(ptr))&(OBJECT_GRAIN-1))

#define JEM_THROW_EXCEPTION(excep_name, message) \
({                                               \
    ctx->frame->last_pc = (CodePntr)ctx->jem.jpc;        \
    signalException(excep_name, message);        \
    jem_throwException(ctx);                     \
})

#define JEM_NULL_POINTER_CHECK(ref) \
    if (!ref) JEM_THROW_EXCEPTION("java/lang/NullPointerException", NULL);

/*********************************************
 *     JEM Trap Handlers                    **
 * *******************************************/
static int trap_debug(struct intrp_ctx *ctx)
{
#ifdef JEM_DEBUG
        struct jem_state *jem = &ctx->jem;
        union jecr jecr_u;
        int i;
        static unsigned long count;

        jecr_u.i = jem->jecr;

        jam_printf("[%lu]: Trap 0x%08x: ostack 0x%x, opcode 0x%x @ 0x%08x, "
                   "operand 1 0x%x, operand 2 0x%x. Operands:\n",
                   count++, jem->trap_pc, ctx->ostack, jecr_u.s.opcode,
                   jem->jpc, jecr_u.s.op1, jecr_u.s.op2);

        for (i = 0; i < jem->josp; i++) {
            uint32_t v;
            if (ostack_read_u32(ctx->frame->ostack, ctx->ostack, i, &v) >= 0)
                jam_printf("\tToS-%d: 0x%x\n", i, v);
        }
#endif
        return 1;
}


static int jem_throwException(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    ExecEnv *ee = ctx->ee;
    Object *excep = ee->exception;
    ee->exception = NULL;

    jem->jpc = (unsigned long)findCatchBlock(excep->class);
    jam_dprintf("Found exception handler at 0x%08x\n", jem->jpc);

    /* If we didn't find a handler, restore exception and
       return to previous invocation */

    if (!jem->jpc) {
        ee->exception = excep;
        /* Original code had a "return NULL" here, which means, end of
         * executeJava */
        return JEM_TRAP_HANDLER_FINISH;
    }

    /* If we're handling a stack overflow, reduce the stack
       back past the red zone to enable handling of further
       overflows */

    if (ee->overflow) {
        ee->overflow = FALSE;
        ee->stack_end -= STACK_RED_ZONE_SIZE;
    }

    /* Setup intepreter to run the found catch block */

    ctx->frame = ee->last_frame;
    ctx->mb = ctx->frame->mb;
    ctx->ostack = ctx->frame->ostack;
    ctx->lvars_jem = ctx->frame->lvars_jem ? ctx->frame->lvars_jem - 1 : NULL;
    if (ctx->lvars_jem) {
        uintptr_t *aobj = (uintptr_t *)*ctx->lvars_jem;
        ctx->this = JAM_OBJECT(aobj);
    } else
        ctx->this = NULL;
    ctx->cp = &(CLASS_CB(ctx->mb->class)->constant_pool);

    /* FIXME: don't know if this is correct, depends how we implement
     * exceptions */
    ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, (uint32_t)excep);

    /* Dispatch to the first bytecode */
    return 0;
}

static int opc_return(struct intrp_ctx *ctx)
{
    ExecEnv *ee = ctx->ee;

    /* Set interpreter state to previous frame */
    if (ctx->frame->prev->mb == NULL) {
       /* The previous frame is a dummy frame - this indicates
        * top of this Java invocation. */
        return 1;
    }

    ctx->frame = ctx->frame->prev;

    if (ctx->mb->access_flags & ACC_SYNCHRONIZED) {
        Object *sync_ob = ctx->mb->access_flags & ACC_STATIC ? (Object*)ctx->mb->class : ctx->this;
        objectUnlock(sync_ob);
    }

    ctx->ostack = ctx->lvars_jem - ctx->mb->max_locals + 1 - ctx->mb->args_count;
    ctx->mb = ctx->frame->mb;
    ctx->lvars_jem = ctx->frame->lvars_jem ? ctx->frame->lvars_jem - 1 : 0;
    if (ctx->lvars_jem) {
        uintptr_t *aobj = (uintptr_t *)*ctx->lvars_jem;
        ctx->this = JAM_OBJECT(aobj);
    } else
        ctx->this = NULL;
    ctx->jem.jpc = (uint32_t)ctx->frame->last_pc;
    ctx->cp = &(CLASS_CB(ctx->mb->class)->constant_pool);
    jam_dprintf("[OPC_RETURN] ostack : %08x, lvars_jem :%08x this %08x\n",
                ctx->ostack, ctx->lvars_jem, ctx->this);

    /* Pop frame */ 
    ee->last_frame = ctx->frame;

    return 0;
}

static int invokeMethod(struct intrp_ctx *ctx)
{
    ExecEnv *ee = ctx->ee;
    /* Seems like the original jamvm reused top of caller's stack for callee's
     * local variables for passing of method arguments. Our stack and
     * local variables grow in opposite directions now, so, this is impossible.
     * ctx->ostack points at the beginning of the free space above ostack.
     */
    Frame *new_frame = (Frame *)(ctx->ostack + ctx->new_mb->max_locals);
    Object *sync_ob = NULL;
    int i;
    uintptr_t *aobj;

    jam_dprintf("[invokeMethod] with args count %d\n", ctx->new_mb->args_count);
    jam_dprintf("[invokeMethod] new frame start %x\n", new_frame);

    ctx->frame->last_pc = (CodePntr)ctx->jem.jpc;
    ctx->ostack = (uintptr_t *)(new_frame + 1);

    if (ostack_overflows(ctx->ostack, ctx->new_mb->max_stack, (uintptr_t *)ee->stack_end)) {
        if (ee->overflow++) {
            /* Overflow when we're already throwing stack overflow.
               Stack extension should be enough to throw exception,
               so something's seriously gone wrong - abort the VM! */
            jam_printf("Fatal stack overflow!  Aborting VM.\n");
            exitVM(1);
        }
        ee->stack_end += STACK_RED_ZONE_SIZE;
        return JEM_THROW_EXCEPTION("java/lang/StackOverflowError", NULL);
    }

    //TODO 
    new_frame->mb = ctx->new_mb;
    //TODO: it seemed lvars is in java stack, but jos[8] should be part of java stack
    //      lvars_jem requires that the highest pointer should refer to the first local variables LV0
    //      Here still not touch the java stack, allocate lvars_jem from native heap

    new_frame->lvars_jem = (uintptr_t *)new_frame;

    if (ctx->new_mb->max_locals > 0) {

        for (i = 0; i < ctx->new_mb->args_count; i++) {
            *(new_frame->lvars_jem - 1 - i) = *(ctx->arg1 + i);
            jam_dprintf("arg[%d] = 0x%x@%p\n", i, *(ctx->arg1 + i), ctx->arg1 + i);
        }
    }
    jam_dprintf("[invokeMethod] new_frame -> lvars_jem %x\n", new_frame->lvars_jem);

    new_frame->ostack = ctx->ostack;
    new_frame->prev = ctx->frame;

    ee->last_frame = new_frame;

    if (ctx->new_mb->access_flags & ACC_SYNCHRONIZED) {
        aobj = (uintptr_t *)*ctx->arg1;
        sync_ob = ctx->new_mb->access_flags & ACC_STATIC ?
                (Object*)ctx->new_mb->class : JAM_OBJECT(aobj);
        objectLock(sync_ob);
    }

    if (ctx->new_mb->access_flags & ACC_NATIVE) {
        //FIXME: the object references in JEM are direct pointer to instance variables.
        //       While JamVM requires object references as pointers to Object type.
        jam_dprintf("[invokeMethod] invoke native method\n");
        ctx->ostack = (*(uintptr_t *(*)(Class*, MethodBlock*, uintptr_t*))
                      ctx->new_mb->native_invoker)(ctx->new_mb->class, ctx->new_mb, ctx->arg1);

        if (sync_ob)
             objectUnlock(sync_ob);

        ee->last_frame = ctx->frame;

        if (exceptionOccured0(ee)) {
            jam_dprintf("[invokeMethod] exception occured, goto throwException\n");
            return jem_throwException(ctx);
        }

        jam_dprintf("[invokeMethod] finish native method invoke, return to loop\n");
    } else {
        ctx->frame = new_frame;
        ctx->mb = ctx->new_mb;
        ctx->lvars_jem = new_frame->lvars_jem ? new_frame->lvars_jem - 1 : NULL;

        if (ctx->lvars_jem) {
            aobj = (uintptr_t *)*ctx->lvars_jem;
            ctx->this = JAM_OBJECT(aobj);
        } else
            ctx->this = NULL;

        ctx->jem.jpc = (unsigned long)ctx->mb->code & ~3;
        ctx->cp = &(CLASS_CB(ctx->mb->class)->constant_pool);

        jam_dprintf("[invokeMethod] invoke virtual method: frame %x   mb %x  "
                    "lvars %x jpc %x cp %x\n", ctx->frame, ctx->mb,
                    ctx->lvars_jem, ctx->jem.jpc, ctx->cp);
        jam_dprintf("[invokeMethod] finish virtual method invoke, return to loop\n");
     }

     return 0;
}

static int opc_invokesuper_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;

    jam_dprintf("[OPC_INVOKESUPER_QUICK] method table indx %d\n", operand->i);
    ctx->new_mb = CLASS_CB(CLASS_CB(ctx->mb->class)->super)->method_table[operand->i];
    jam_dprintf("[OPC_INVOKESUPER_QUICK] method args count %d\n", ctx->new_mb->args_count);

    // set up jem operand stack
    ctx->arg1 = ostack_address(ctx->frame->ostack, ctx->mb->max_stack,
                          ctx->ostack - ctx->frame->ostack - ctx->new_mb->args_count);
    JEM_NULL_POINTER_CHECK(*ctx->arg1);
    jam_dprintf("[OP_INVOKESUPER_QUICK] arg1 %x\n", *ctx->arg1);
    return invokeMethod(ctx);
}

static int opc_invokenonvirtual_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;

    ctx->new_mb = (MethodBlock*)operand->pntr;
    jam_dprintf("[%s] new methodblock %s (%x) with %d args\n",
               __func__, ctx->new_mb->name, ctx->new_mb, ctx->new_mb->args_count);
    ctx->arg1 = ostack_address(ctx->frame->ostack, ctx->mb->max_stack,
                          ctx->ostack - ctx->frame->ostack - ctx->new_mb->args_count);

    jam_dprintf("[%s] ctx->arg1 %x\n", __func__, *ctx->arg1);
    JEM_NULL_POINTER_CHECK(*ctx->arg1);
    return invokeMethod(ctx);
}

static int opc_invokevirtual_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Object *obj;
    ctx->arg1 = ostack_address(ctx->frame->ostack, ctx->mb->max_stack,
                        ctx->ostack - ctx->frame->ostack - INV_QUICK_ARGS(jem));
    JEM_NULL_POINTER_CHECK(*ctx->arg1);
    Class *new_class;

    //in case of "AALOAD" loads JAM obj from reference array
    obj = (Object *)*ctx->arg1;
    if (!JAM_ON_STACK || !IS_JAM_OBJECT(obj))
        obj = JAM_OBJECT((uintptr_t *)obj);

    //we should ensure ostack constains no JAM object
    *ctx->arg1 = (uintptr_t)INST_DATA(obj);

    jam_dprintf("[OPC_INVOKEVIRTUAL_QUICK] invoke on object 0x%08x (0x%08x)\n", obj, ctx->arg1);
    new_class = obj->class;
    ctx->new_mb = CLASS_CB(new_class)->method_table[INV_QUICK_IDX(jem)];
    jam_dprintf("[OPC_INVOKEVIRTUAL_QUICK] invoke method 0x%08x on class %x\n",
                ctx->new_mb, new_class);
    return invokeMethod(ctx);
}

static int opc_invokevirtual(struct intrp_ctx *ctx)
{
    int idx;
    ExecEnv *ee = ctx->ee;
    struct jem_state *jem = &ctx->jem;

    idx = jem->jecr & 0xffff;
    ctx->frame->last_pc = (CodePntr)jem->jpc;
    ctx->new_mb = resolveMethod(ctx->mb->class, idx);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    jem->operand.uu.u1 = ctx->new_mb->args_count;
    jem->operand.uu.u2 = ctx->new_mb->method_table_index;

    jam_dprintf("[OPC_INVOKEVIRTUAL] invoke 0x%08x with args count %d\n",
               ctx->new_mb,ctx->new_mb->args_count);

    return opc_invokevirtual_quick(ctx);
}

static int opc_invokespecial(struct intrp_ctx *ctx)
{
    int idx;
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;
    ExecEnv *ee = ctx->ee;

    /* INVOKESPECIAL's operands represent an index into the Constant Pool */
    idx = jem->jecr & 0xffff;

    jam_dprintf("[OPC_INVOKESPECIAL] constant pool index %d\n", idx);

    ctx->new_mb = resolveMethod(ctx->mb->class, idx);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    jam_dprintf("Resolved %s\n", ctx->new_mb->name);

    /* Check if invoking a super method... */
    if ((CLASS_CB(ctx->mb->class)->access_flags & ACC_SUPER) &&
        ((ctx->new_mb->access_flags & ACC_PRIVATE) == 0) && (ctx->new_mb->name[0] != '<')) {

        operand->i = ctx->new_mb->method_table_index;
        return opc_invokesuper_quick(ctx);
#if 0 /* FIXME: verify this whole "pc" chemistry is indeed unneeded */
        OPCODE_REWRITE(OPC_INVOKESUPER_QUICK, cache, operand);
#endif
    } else {
        operand->pntr = ctx->new_mb;
        return opc_invokenonvirtual_quick(ctx);
    }

    return 0;
}

static int opc_invokestatic_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;

    ctx->new_mb = RESOLVED_METHOD(jem);
    ctx->arg1 = ostack_address(ctx->frame->ostack, ctx->mb->max_stack,
                          ctx->ostack - ctx->frame->ostack - ctx->new_mb->args_count);
    return invokeMethod(ctx);
}

static int opc_invokestatic(struct intrp_ctx *ctx)
{
    int idx, cache;
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;
    ExecEnv *ee = ctx->ee;

    idx = jem->jecr & 0xffff;

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    ctx->new_mb = resolveMethod(ctx->mb->class, idx);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    operand->pntr = ctx->new_mb;
    return opc_invokestatic_quick(ctx);
}

static int opc_new_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;
    Class *class = (Class*)CP_INFO(ctx->cp, operand->uui.u1);
    Object *obj;

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    if ((obj = allocObject(class)) == NULL)
        return jem_throwException(ctx);
    jam_dprintf("[OPC_NEW_QUICK] push obj ref %x to stack\n", obj);
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           (uint32_t)INST_DATA(obj));
}

static int opc_new(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;
    int idx = operand->uui.u1 = jem->jecr & 0xffff;
    int opcode = operand->uui.u2 = (jem->jecr >> 16) & 0xff;
    Class *class;
    ExecEnv *ee = ctx->ee;

    jam_dprintf("[OPC_NEW] opcode: %x\n", opcode);

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    class = resolveClass(ctx->mb->class, idx, opcode == OPC_NEW);
    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    if (opcode == OPC_NEW) {
        ClassBlock *cb = CLASS_CB(class);
        if (cb->access_flags & (ACC_INTERFACE | ACC_ABSTRACT)) {
            signalException("java/lang/InstantiationError", cb->name);
            return jem_throwException(ctx);
        }
        /* rewrite opcode to OPC_NEW_QUICK (0xDD) */
        jem_opcode_rewrite(0xDD, (char*)jem->jpc - 3, 0);
    }

    return opc_new_quick(ctx);
}

static int opc_anewarray_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    ConstantPool *cp = ctx->cp;
    Class *class = RESOLVED_CLASS(jem);
    char *name = CLASS_CB(class)->name;
    int count;
    Class *array_class;
    char *ac_name;
    Object *obj;
    ExecEnv *ee = ctx->ee;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, count);
    ctx->frame->last_pc = (CodePntr)jem->jpc;

    jam_dprintf("[OPC_ANEWARRAY_QUICK] array %s size %d\n", name, count);
    if (count < 0) {
        signalException("java/lang/NegativeArraySizeException", NULL);
        return jem_throwException(ctx);
    }

    ac_name = sysMalloc(strlen(name) + 4);

    if (name[0] == '[')
        sprintf(ac_name, "[%s", name);
    else
        sprintf(ac_name, "[L%s;", name);

    array_class = findArrayClassFromClass(ac_name, ctx->mb->class);
    free(ac_name);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    if ((obj = allocArray(array_class, count, sizeof(Object*))) == NULL)
        return jem_throwException(ctx);

    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           (uint32_t)ARRAY_DATA(obj));
}

static int opc_anewarray(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;
    int idx = operand->uui.u1 = jem->jecr & 0xffff;
    int opcode = operand->uui.u2 = (jem->jecr >> 16) & 0xff;
    Class *class;
    ExecEnv *ee = ctx->ee;

    jam_dprintf("[OPC_NEW/OPC_ANEWARRAY/OPC_CHECKCAST/OPC_INSTANCEOF] opcode : %x\n", opcode);

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    //resolve the array class
    class = resolveClass(ctx->mb->class, idx, opcode == OPC_NEW);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    return opc_anewarray_quick(ctx);
}

static int opc_multianewarray_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    ConstantPool *cp = ctx->cp;
    Class *class = RESOLVED_CLASS(jem);
    int i, dim = MULTI_ARRAY_DIM(jem);
    int count;
    Object *obj;
    ExecEnv *ee = ctx->ee;

    ctx->frame->last_pc = (CodePntr)jem->jpc;

    jam_dprintf("[OPC_MULTIANEWARRAY_QUICK]: alloc %d dimensional array for class %s\n", dim, CLASS_CB(class)->name);
    for (i = 0; i < dim; i++) {
        ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, count);
        jam_dprintf("[OPC_MULTIANEWARRAY_QUICK]: elements %d for dim %d\n", count, i);
        if (count < 0) {
            signalException("java/lang/NegativeArraySizeException", NULL);
            return jem_throwException(ctx);
        }
    }

    /* counts are still stored in ostack even after we did pop them out */
    if ((obj = allocMultiArray(class, dim, (intptr_t *)ctx->ostack)) == NULL)
        return jem_throwException(ctx);

    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           (uint32_t)ARRAY_DATA(obj));
}

static int opc_multianewarray(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;
    int idx = operand->uui.u1 = jem->jecr & 0xffff;

    Class *class;
    ExecEnv *ee = ctx->ee;

    /* dimensions */
    operand->uui.u2 = *(unsigned char*)jem->jpc;
    jem->jpc++; /* skip dims */

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    /* resolve the array class */
    class = resolveClass(ctx->mb->class, idx, FALSE);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    return opc_multianewarray_quick(ctx);
}

static int opc_newarray(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    int type = (jem->jecr >> 8) & 0xff;
    int count;
    Object *obj;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, count);
    ctx->frame->last_pc = (CodePntr)jem->jpc;

    jam_dprintf("[OPC_NEWARRAY] alloc array type %d, count %d\n", type, count);
    if ((obj = allocTypeArray(type, count)) == NULL)
        return jem_throwException(ctx);

    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           (uint32_t)ARRAY_DATA(obj));
}

static int opc_putfield_quick(struct intrp_ctx *ctx)
{
    uint32_t arg;
    uint32_t obj;
    struct jem_state *jem = &ctx->jem;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, arg);
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, obj);
    jam_dprintf("[OPC_PUTFIELD_QUICK] put field %x to obj(%d) %x\n", arg,
                SINGLE_INDEX(jem), obj);

    JEM_NULL_POINTER_CHECK(obj);

    if (JAM_ON_STACK && IS_JAM_OBJECT(obj))
        obj = (uint32_t)INST_DATA((Object *)obj);

    ((uint32_t*)obj)[SINGLE_INDEX(jem)] = arg;

    return 0;
}

static int opc_putfield2_quick(struct intrp_ctx *ctx)
{
    uint64_t arg;
    uint32_t obj;
    struct jem_state *jem = &ctx->jem;

    ostack_pop_u64(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, arg);
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, obj);

    JEM_NULL_POINTER_CHECK((uintptr_t*)obj);

    if (JAM_ON_STACK && IS_JAM_OBJECT(obj))
        obj = (uint32_t)INST_DATA((Object *)obj);

    *(uint64_t *)&(((uint32_t*)obj)[SINGLE_INDEX(jem)]) = arg;
    jam_dprintf("[OPC_PUTFIELD2_QUICK] put  64 bit  %08x to obj %08x\n", arg, obj);

    return 0;
}

static int opc_putfield_quick_jem0(struct intrp_ctx *ctx)
{
    uint32_t arg;
    uintptr_t *aobj;
    struct jem_state *jem = &ctx->jem;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, arg);
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, aobj);
    jam_dprintf("[OPC_PUTFIELD_QUICK_JEM0]  field %x\n", arg);

    JEM_NULL_POINTER_CHECK(aobj);

    if (JAM_ON_STACK && arg && !IS_JAM_OBJECT(arg))
        arg = (uint32_t)JAM_OBJECT((uintptr_t *)arg);

    if (JAM_ON_STACK && IS_JAM_OBJECT(aobj))
        aobj = INST_DATA((Object *)aobj);

    aobj[SINGLE_INDEX(jem)] = arg;
    jam_dprintf("[OPC_PUTFIELD_QUICK_JEM0] put field %x to obj(%d) %x\n", arg,
                SINGLE_INDEX(jem), aobj);

    return 0;
}

static int opc_putfield_quick_jem1(struct intrp_ctx *ctx)
{
    uintptr_t *aobj, *arg;
    struct jem_state *jem = &ctx->jem;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, arg);
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, aobj);
    jam_dprintf("[OPC_PUTFIELD_QUICK_JEM1]  field %p\n", arg);

    if (JAM_ON_STACK && arg && !IS_JAM_ARRAY(arg))
        arg = (uintptr_t *)JAM_ARRAY(arg);

    if (JAM_ON_STACK && IS_JAM_OBJECT(aobj))
        aobj = INST_DATA((Object *)aobj);

    JEM_NULL_POINTER_CHECK(aobj);
    aobj[SINGLE_INDEX(jem)] = (uintptr_t)arg;
    jam_dprintf("[OPC_PUTFIELD_QUICK_JEM1] put field %p to obj(%d) %p\n", arg,
                SINGLE_INDEX(jem), aobj);

    return 0;
}

static int opc_putfield(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    int idx = jem->jecr & 0xffff;
    FieldBlock *fb;
    ExecEnv *ee = ctx->ee;

    jam_dprintf("[OPC_PUTFIELD] constant pool index %d\n", idx);

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    fb = resolveField(ctx->mb->class, idx);
    jam_dprintf("[OPC_PUTFIELD] resolve field 0x%08x, type %c\n", fb, *fb->type);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    jem->operand.i = fb->offset;
    switch (*fb->type) {
    case 'J':
    case 'D':
        /* rewrite opc_putfield to opc_putfield2_quick */
        jem_opcode_rewrite(0xD1, (char*)jem->jpc - 3, 2, fb->offset >> 8, fb->offset);
        return opc_putfield2_quick(ctx);
    case 'L':
        jem_opcode_rewrite(0xCF, (char*)jem->jpc - 3, 2, fb->offset >> 8, fb->offset);
        return opc_putfield_quick_jem0(ctx);
    case '[':
        jem_opcode_rewrite(0xCF, (char*)jem->jpc - 3, 2, fb->offset >> 8, fb->offset);
        return opc_putfield_quick_jem1(ctx);
    default:
        jem_opcode_rewrite(0xCF, (char*)jem->jpc - 3, 2, fb->offset >> 8, fb->offset);
        return opc_putfield_quick(ctx);
    }
}

static int opc_getfield2_quick(struct intrp_ctx *ctx)
{
    uint32_t *obj;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, obj);
    JEM_NULL_POINTER_CHECK(obj);

    if (JAM_ON_STACK && IS_JAM_OBJECT(obj))
        obj = (uint32_t*)INST_DATA((Object*)obj);

    jam_dprintf("[OPC_GETFIELD2_QUICK] get 64 bit field %08x from obj %08x\n",
                *(uint64_t*)(&(obj[SINGLE_INDEX(jem)])), obj);

    return ostack_push_u64(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           *(uint64_t*)(&(obj[SINGLE_INDEX(jem)])));
}

static int opc_getfield_quick(struct intrp_ctx *ctx)
{
    uintptr_t *aobj;
    struct jem_state *jem = &ctx->jem;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, aobj);
    JEM_NULL_POINTER_CHECK(aobj);

    if (JAM_ON_STACK && IS_JAM_OBJECT(aobj))
        aobj = (uint32_t*)INST_DATA((Object*)aobj);

    jam_dprintf("[OPC_GETFIELD_QUICK] get  field %08x from obj %08x\n",
                aobj[SINGLE_INDEX(jem)], aobj);
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           aobj[SINGLE_INDEX(jem)]);
}

static int opc_getfield_quick_jem0(struct intrp_ctx *ctx)
{
    uint32_t *aobj;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, aobj);
    JEM_NULL_POINTER_CHECK(aobj);

    if (JAM_ON_STACK && IS_JAM_OBJECT(aobj))
        aobj = (uint32_t*)INST_DATA((Object*)aobj);

    uint32_t value = aobj[SINGLE_INDEX(jem)];
    jam_dprintf("[OPC_GETFIELD_QUICK_JEM0] obj ref %x\n", value);
    if (value) {
        Object *ref = (Object*)value; 
        if (JAM_ON_STACK && IS_JAM_OBJECT(ref))
            //jamvm objref
            value = (uint32_t)INST_DATA(ref);
    }
    jam_dprintf("[OPC_GETFIELD_QUICK_JEM0] put obj ref %x\n", value);
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, value);

}

static int opc_getfield_quick_jem1(struct intrp_ctx *ctx)
{
    uint32_t *aobj;
    struct jem_state *jem = &ctx->jem;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, aobj);
    JEM_NULL_POINTER_CHECK(aobj);

    //"aaload" would put jamvm obj ref onto the ostack
    if (JAM_ON_STACK && IS_JAM_OBJECT(aobj))
        aobj = (uint32_t*)INST_DATA((Object*)aobj);

    uint32_t value = aobj[SINGLE_INDEX(jem)];
    jam_dprintf("[OPC_GETFIELD_QUICK_JEM1] array ref %x\n", value);
    if (value) {
        Object *ref = (Object*)value; 
        if (JAM_ON_STACK && IS_JAM_ARRAY(ref))
            value = (uint32_t)ARRAY_DATA(ref);
    }
    jam_dprintf("[OPC_GETFIELD_QUICK_JEM1] put array ref %x\n", value);
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, value);
}

static int opc_getfield(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    int idx = jem->jecr & 0xffff;
    FieldBlock *fb;
    ExecEnv *ee = ctx->ee;

    jam_dprintf("[OPC_GETFIELD] constant pool index %d\n", idx);

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    fb = resolveField(ctx->mb->class, idx);
    jam_dprintf("[OPC_GETFIELD] resolve field 0x%08x, type %c\n", fb, *fb->type);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    jem->operand.i = fb->offset;
    switch (*fb->type) {
    case 'J':
    case 'D':
        jem_opcode_rewrite(0xD0, (char*)jem->jpc - 3, 2, fb->offset >> 8, fb->offset);
        return opc_getfield2_quick(ctx);
    /*
     * Though we assume all objrefs/arrayrefs here should be JEM compliant, but
     * in case of some JNI code will set field natively, we still handle it
     * separately here.
     */
    case 'L':
        jem_opcode_rewrite(0xCE, (char*)jem->jpc - 3, 2, fb->offset >> 8, fb->offset);
        return opc_getfield_quick_jem0(ctx);
    case '[':
        jem_opcode_rewrite(0xCE, (char*)jem->jpc - 3, 2, fb->offset >> 8, fb->offset);
        return opc_getfield_quick_jem1(ctx);
    default:
        //jem_opcode_rewrite(0xCE, (char*)jem->jpc - 3, 2, (fb->offset>>8)&0xff, (fb->offset)&0xff);
        return opc_getfield_quick(ctx);
    }
}

static int opc_ldc_w_quick_jem(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    //CONSTANT_Class and CONSTANT_String are stored as object reference
    Object *cp_info = (Object*)CP_INFO(ctx->cp, DOUBLE_INDEX(jem));
    jam_dprintf("[OPC_LDC_W_QUICK_JEM] push String ref  %x to stack\n", cp_info);
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           (uint32_t)INST_DATA(cp_info));
}

static int opc_ldc_w_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    uint32_t cp_info = CP_INFO(ctx->cp, DOUBLE_INDEX(jem));
    jam_dprintf("[OPC_LDC_W_QUICK] push constant %08x to stack\n", cp_info);
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, cp_info);
}

static int opc_ldc_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    uint32_t constant = RESOLVED_CONSTANT(jem);
    jam_dprintf("[OPC_LDC_QUICK] push constant %x to stack\n", constant);
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, (uintptr_t)constant);
}

static int opc_ldc_common(struct intrp_ctx *ctx, int idx)
{
    struct jem_state *jem = &ctx->jem;
    ExecEnv *ee = ctx->ee;
    ctx->frame->last_pc = (CodePntr)jem->jpc;

    jem->operand.u = resolveSingleConstant(ctx->mb->class, idx);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    if (CP_TYPE(ctx->cp, idx) == CONSTANT_ResolvedClass) {
        jem->operand.i = idx;
        jem_opcode_rewrite(0xCC, (char*)jem->jpc - 3, 0);
        return opc_ldc_w_quick(ctx);
    } else if (CP_TYPE(ctx->cp, idx) == CONSTANT_ResolvedString) {
        jem->operand.i = idx;
        return opc_ldc_w_quick_jem(ctx);
    } else {
        jem_opcode_rewrite(0xCB, (char*)jem->jpc - 2, 0);
        return opc_ldc_quick(ctx);
    }
}

static int opc_ldc(struct intrp_ctx *ctx)
{
    int idx;
    ExecEnv *ee = ctx->ee;
    struct jem_state *jem = &ctx->jem;
                        
    idx = (jem->jecr & 0xff00) >> 8;

    jam_dprintf("[OPC_LDC] constant pool index %d\n", idx);
    return opc_ldc_common(ctx, idx);
}

static int opc_ldc_w(struct intrp_ctx *ctx)
{
    int idx;
    ExecEnv *ee = ctx->ee;
    struct jem_state *jem = &ctx->jem;

    idx = (jem->jecr & 0xffff);

    jam_dprintf("[OPC_LDC_W] constant pool index %d\n", idx);
    return opc_ldc_common(ctx, idx);
}

static int opc_monitorenter(struct intrp_ctx *ctx)
{
    Object *obj;
    uintptr_t *ptr;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, ptr);

    obj = JAM_OBJECT(ptr);
    if (!IS_OBJECT(obj))
        /* is an array ref */
        obj = JAM_ARRAY(ptr);
    jam_dprintf("[OPC_MONITORENTER] lock %x\n", obj);
    JEM_NULL_POINTER_CHECK(obj);
    objectLock(obj);
    return 0;
}

static int opc_monitorexit(struct intrp_ctx *ctx)
{
    Object *obj;
    uintptr_t *ptr;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, ptr);

    obj = JAM_OBJECT(ptr);
    if (!IS_OBJECT(obj))
        /* is an array ref */
        obj = JAM_ARRAY(ptr);
    jam_dprintf("[OPC_MONITOREXIT] unlock %x\n", obj);
    JEM_NULL_POINTER_CHECK(obj);
    objectUnlock(obj);
    return 0;
}

static int opc_getstatic_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           RESOLVED_FIELD(jem)->static_value);
}

static int opc_getstatic2_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    return ostack_push_u64(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           RESOLVED_FIELD(jem)->static_value);
}

static int opc_getstatic_quick_jem0(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    uintptr_t value = RESOLVED_FIELD(jem)->static_value;

    jam_dprintf("[OPC_GETSTATIC_QUICK_JEM0] obj ref %x\n", value);
    if (value) {
        Object *ref = (Object *)value; 
        if (!JAM_ON_STACK || IS_JAM_OBJECT(ref))
            //jamvm objref
            value = (uintptr_t)INST_DATA(ref);
    }
    jam_dprintf("[OPC_GETSTATIC_QUICK_JEM0] put obj ref %x\n", value);
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, value);
}

static int opc_getstatic_quick_jem1(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    uintptr_t value = RESOLVED_FIELD(jem)->static_value;
    jam_dprintf("[OPC_GETSTATIC_QUICK_JEM1] array ref %x\n", value);
    if (value) {
        Object *ref = (Object*)value; 
        if (!JAM_ON_STACK || IS_JAM_ARRAY(ref))
            //jamvm arrayref
            value = (uintptr_t)ARRAY_DATA(ref);
    }
    jam_dprintf("[OPC_GETSTATIC_QUICK_JEM1] put array ref %x\n", value);
    return ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, value);
}

static int opc_getstatic(struct intrp_ctx *ctx)
{
    int idx;
    FieldBlock *fb;
    Operand operand;
    ExecEnv *ee = ctx->ee;
    struct jem_state *jem = &ctx->jem;

    idx = (int)(jem->jecr & 0xffff);
    jam_dprintf("[OPC_GETSTATIC] constant pool index %d class %s\n",idx,CLASS_CB(ctx->mb->class)->name);

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    fb = resolveField(ctx->mb->class, idx);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    jam_dprintf("[OPC_GETSTATIC] get static for field %08x, type %c\n", fb, *fb->type);
    jem->operand.pntr = fb;
    switch (*fb->type) {
    case 'J':
    case 'D':
        return opc_getstatic2_quick(ctx);
    /*
     * see opc_getfield
     */
    case 'L':
        return opc_getstatic_quick_jem0(ctx);
    case '[':
        return opc_getstatic_quick_jem1(ctx);
    default:
        return opc_getstatic_quick(ctx);
    }
}

static int opc_putstatic2_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    return ostack_pop_u64(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                          *(u8*)&RESOLVED_FIELD(jem)->static_value);
}

static int opc_putstatic_quick(struct intrp_ctx *ctx)
{ 
    struct jem_state *jem = &ctx->jem;
    return ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,
                           RESOLVED_FIELD(jem)->static_value);
}

static int opc_putstatic_quick_jem0(struct intrp_ctx *ctx)
{
    uintptr_t value;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, value);

    jam_dprintf("[OPC_PUTSTATIC_QUICK_JEM0] obj %x\n", value);
    if (value && (!JAM_ON_STACK || !IS_JAM_OBJECT(value)))
        value = (uintptr_t)JAM_OBJECT((uintptr_t *)value);
    jam_dprintf("[OPC_PUTSTATIC_QUICK_JEM0] put obj %x\n", value);
    RESOLVED_FIELD(jem)->static_value = value;
    return 0;
}

static int opc_putstatic_quick_jem1(struct intrp_ctx *ctx)
{
    uintptr_t *value;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, value);

    jam_dprintf("[OPC_PUTSTATIC_QUICK_JEM1] array %p\n", value);
    if (value && (!JAM_ON_STACK || !IS_JAM_ARRAY(value)))
        value = (uintptr_t*)JAM_ARRAY(value);
    jam_dprintf("[OPC_PUTSTATIC_QUICK_JEM1] put array %p\n", value);
    RESOLVED_FIELD(jem)->static_value = (uintptr_t)value;
    return 0;
}

static int opc_putstatic(struct intrp_ctx *ctx)
{
    int idx;
    FieldBlock *fb;
    Operand operand;
    ExecEnv *ee = ctx->ee;
    struct jem_state *jem = &ctx->jem;

    idx = (int)(jem->jecr & 0xffff);

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    fb = resolveField(ctx->mb->class, idx);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    jam_dprintf("[OPC_PUTSTATIC] put static for field %08x, type %c\n", fb, *fb->type);
    jem->operand.pntr = fb;
    switch (*fb->type) {
    case 'J':
    case 'D':
        //jem_opcode_rewrite(0xD5, (char*)jem->jpc - 3);
        return opc_putstatic2_quick(ctx);
    case 'L':
        return opc_putstatic_quick_jem0(ctx);
    case '[':
        return opc_putstatic_quick_jem1(ctx);
    default:
        return opc_putstatic_quick(ctx);
    }
}

static int opc_checkcast_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    ConstantPool *cp = ctx->cp;
    Class *class = RESOLVED_CLASS(jem);
    Object *obj;
    uintptr_t *ptr;

    ostack_read_u32(ctx->frame->ostack, ctx->ostack, 0, &ptr);
    jam_dprintf("[OPC_CHECKCAST_QUICK] check cast for JEM type %x (class %s)\n", ptr, CLASS_CB(class)->name);
    if (ptr != NULL) {
#warning Does not look right!
        if (!JAM_ON_STACK || !IS_JAM_OBJECT(ptr) || !IS_JAM_ARRAY(ptr)) {
            obj = JAM_OBJECT(ptr);
            if (!IS_OBJECT(obj)) {
                jam_dprintf("[OPC_CHECKCAST_QUICK] check cast for array\n");
                //should be array ref
                obj = JAM_ARRAY(ptr);
            }
            jam_dprintf("[OPC_CHECKCAST_QUICK] check cast for object %x\n", obj);
        } else {
            obj = (Object*)ptr;
        }
        jam_dprintf("[OPC_CHECKCAST_QUICK] check class %s for obj(%s)\n", CLASS_CB(class)->name, CLASS_CB(obj->class)->name);
        if ((obj != NULL) && !isInstanceOf(class, obj->class))
            return JEM_THROW_EXCEPTION("java/lang/ClassCastException", CLASS_CB(obj->class)->name);
    }

    return 0;
}

static int opc_checkcast(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;
    int idx = operand->uui.u1 = jem->jecr & 0xffff;
    int opcode = operand->uui.u2 = (jem->jecr >> 16) & 0xff;
    Class *class;
    ExecEnv *ee = ctx->ee;

    jam_dprintf("[OPC_NEW/OPC_ANEWARRAY/OPC_CHECKCAST/OPC_INSTANCEOF] opcode : %x\n", opcode);

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    //resolve the cast class
    class = resolveClass(ctx->mb->class, idx, opcode == OPC_NEW);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    return opc_checkcast_quick(ctx);
}

static int opc_invokeinterface_quick(struct intrp_ctx *ctx)
{
    int mtbl_idx;
    ClassBlock *cb;
    Object *objref;
    int cache = ctx->jem.operand.uu.u2;

    ctx->new_mb = (MethodBlock *)CP_INFO(ctx->cp, ctx->jem.operand.uu.u1);
    ctx->arg1 = ostack_address(ctx->frame->ostack, ctx->mb->max_stack,
                          ctx->ostack - ctx->frame->ostack - ctx->new_mb->args_count);

    jam_dprintf("[OPC_INVOKEINTERFACE_QUICK] newmb %x (name %s) (args count %d)  objref(jem) %x\n",
                ctx->new_mb, ctx->new_mb->name, ctx->new_mb->args_count, ctx->arg1);

    objref = (Object *)*ctx->arg1;
#warning Does not look right!
    if (!JAM_ON_STACK || !IS_JAM_OBJECT(objref) || !IS_JAM_ARRAY(objref)) {
        objref = JAM_OBJECT((uintptr_t *)objref);
        if (!IS_OBJECT(objref))
            objref = JAM_ARRAY((uintptr_t *)*ctx->arg1);
    } else {
        //turn type in the stack to JEM type ref
        *ctx->arg1 = (uintptr_t)INST_DATA(objref);
    }
    JEM_NULL_POINTER_CHECK(objref);

    cb = CLASS_CB(objref->class);

    if ((cache >= cb->imethod_table_size) ||
               (ctx->new_mb->class != cb->imethod_table[cache].interface)) {
        for (cache = 0; (cache < cb->imethod_table_size) &&
                            (ctx->new_mb->class != cb->imethod_table[cache].interface); cache++);

        if (cache == cb->imethod_table_size)
            return JEM_THROW_EXCEPTION("java/lang/IncompatibleClassChangeError",
                              "unimplemented interface");
    }

    mtbl_idx = cb->imethod_table[cache].offsets[ctx->new_mb->method_table_index];
    jam_dprintf("[OPC_INVOKEINTERFACE_QUICK] find method at %d\n", mtbl_idx);
    ctx->new_mb = cb->method_table[mtbl_idx];
    jam_dprintf("[OPC_INVOKEINTERFACE_QUICK] invoking method at %d\n", mtbl_idx);
    return invokeMethod(ctx);
}

static int opc_invokeinterface(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;
    ExecEnv *ee = ctx->ee;

    int idx = operand->uu.u1 = jem->jecr & 0xffff;
    /*NOTES: invokeinterface opcode is supposed to take 4 operands.
     *       For JEM, two index bytes has been processed before trap,
     *       so offset jpc 4 operands for next opcode
     *FIXME: ? not know why JEM does not handle this */
    ctx->frame->last_pc = (CodePntr)(jem->jpc += 2);
    ctx-> new_mb = resolveInterfaceMethod(ctx->mb->class, idx);

    jam_dprintf("[OPC_INVOKEINTERFACE] constant pool index %d\n", idx);
    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    if (CLASS_CB(ctx->new_mb->class)->access_flags & ACC_INTERFACE) {
        operand->uu.u2 = 0;
        return opc_invokeinterface_quick(ctx);
    } else {
        operand->uu.u1 = ctx->new_mb->args_count;
        operand->uu.u2 = ctx->new_mb->method_table_index;
        return opc_invokevirtual_quick(ctx);
    }
}

static int opc_instanceof_quick(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    ConstantPool *cp = ctx->cp;
    Class *class = RESOLVED_CLASS(jem);
    Object *obj;
    uintptr_t *ptr;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, ptr);
    if (ptr != NULL) {
        obj = JAM_OBJECT(ptr);
        if (!IS_OBJECT(obj)) {
                jam_dprintf("[OPC_INSTANCEOF_QUICK] instanceof for array\n");
                //should be array ref
                obj = JAM_ARRAY(ptr);
        }

        jam_dprintf("[OPC_INSTANCEOF_QUICK] check instanceof class %s for obj(%s)\n", CLASS_CB(class)->name, CLASS_CB(obj->class)->name);
        if (obj != NULL)
            ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack,isInstanceOf(class, obj->class));
    }
    return 0;
}

static int opc_instanceof(struct intrp_ctx *ctx)
{
    struct jem_state *jem = &ctx->jem;
    Operand *operand = &jem->operand;
    int idx = operand->uui.u1 = jem->jecr & 0xffff;
    int opcode = operand->uui.u2 = (jem->jecr >> 16) & 0xff;
    Class *class;
    ExecEnv *ee = ctx->ee;

    jam_dprintf("[OPC_INSTANCEOF] opcode : %x\n", opcode);

    ctx->frame->last_pc = (CodePntr)jem->jpc;
    //resolve the cast class
    class = resolveClass(ctx->mb->class, idx, opcode == OPC_NEW);

    if (exceptionOccured0(ee))
        return jem_throwException(ctx);

    return opc_instanceof_quick(ctx);
}

static int opc_aastore(struct intrp_ctx *ctx)
{
    Object *obj;
    uintptr_t *aobj;
    int idx ;
    Object *array;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, aobj);
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, idx);
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, array);

    jam_dprintf("[OPC_AASTORE] obj %x, idx %x, array %x\n", aobj, idx, array);

    /* aobj does point to an object, but we do not know if that's an array or
     * not, and we need to know that for the arrayStoreCheck() check below */
#warning Does not look right!
    if (aobj && (!JAM_ON_STACK || !IS_JAM_OBJECT(aobj) || !IS_JAM_ARRAY(aobj))) {
        if (!IS_OBJECT(JAM_OBJECT(aobj))) {
            //in case of storing an array to another array
            obj = JAM_ARRAY(aobj);
        } else {
            obj = JAM_OBJECT(aobj);
        }
    } else
        obj = (Object *)aobj;
    array = JAM_ARRAY((uintptr_t *)array);

    jam_dprintf("[OPC_AASTORE] store obj ref %x to array %x in index %d\n", obj, array, idx);
    JEM_NULL_POINTER_CHECK(array);

    if (idx >= ARRAY_LEN(array)) {
        char buff[MAX_INT_DIGITS];
        snprintf(buff, MAX_INT_DIGITS, "%d", idx);
        JEM_THROW_EXCEPTION("java/lang/ArrayIndexOutOfBoundsException", buff);
    }

    if ((obj != NULL) && !arrayStoreCheck(array->class, obj->class))
        JEM_THROW_EXCEPTION("java/lang/ArrayStoreException", NULL);

    //FIXME: If we set JEM ref here, it is very likely that some native jamvm code would directly offset
    //       the array to get the non jamvm refs to use, which then causes segfault.
#if JAM_ON_STACK
    ((Object**)ARRAY_DATA(array))[idx] = obj;
#else
    ((uintptr_t**)ARRAY_DATA(array))[idx] = aobj;
#endif
    return 0;
}

static int do_javaExceptions(struct intrp_ctx *ctx)
{
    union jecr jecr_u;
    struct jem_state *jem = &ctx->jem;

    /* deliberate segfault */
    /* *(int *)0 = 0; */

    jecr_u.i = jem->jecr;
    /* This should not happen, because we don't use the "Java Handle" (H)
     * bit in the Status Register and we set JBCR to 0x80000000 - still
     * it does happen, but seems to be harmless so far. Just ignore. */
    if (jecr_u.s.opcode == OPC_AASTORE)
            return opc_aastore(ctx);

    return 1;
}

static int opc_afireturn(struct intrp_ctx *ctx)
{
    uint32_t val;
    int ret;
    struct jem_state *jem = &ctx->jem;

    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, val);

    jam_dprintf("[OPC_AFIRETURN] return %08x @ %p\n", val, ctx->lvars_jem);

    ret = opc_return(ctx);
    if (!ret)
        ret = ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, val);
    else
        *ctx->lvars_jem = val;

    return ret;
}

static int opc_ldreturn(struct intrp_ctx *ctx)
{
    uint64_t val;
    int ret;

    struct jem_state *jem = &ctx->jem;
    ostack_pop_u64(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, val);

    jam_dprintf("[OPC_LDRETURN] return %lld\n", val);

    ret = opc_return(ctx);

    if (!ret)
        ret = ostack_push_u64(ctx->frame->ostack, ctx->mb->max_stack,
                              ctx->ostack, val);
    else
        *(uint64_t*)ctx->lvars_jem = val;

    return ret;
}

static int opc_fcmpg(struct intrp_ctx *ctx)
{
    float v1, v2;
    int res;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v2);
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v1);
    if (v1 == v2)
        res = 0;
    else if (v1 < v2)
       res = -1;
    else if (v1 > v2)
       res = 1;
    else
       res = 1; /* isNaN */
    jam_dprintf("[OPC_FCMPG] result %d\n", res);
    ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, res);
    return 0;
}

static int opc_fcmpl(struct intrp_ctx *ctx)
{
    float v1, v2;
    int res;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v2);
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v1);
    if (v1 == v2)
        res = 0;
    else if (v1 < v2)
        res = -1;
    else if (v1 > v2)
        res = 1;
    else
        res = -1;
    jam_dprintf("[OPC_FCMPL] result %d\n", res);
    ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, res);
    return 0;
}

static int opc_i2f(struct intrp_ctx *ctx)
{
    int i;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, i);

    float f = (float)i;
    jam_dprintf("[OPC_I2F] convert to %f\n", f);
    ostack_push_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, f);
    return 0;
}

static int opc_i2d(struct intrp_ctx *ctx)
{
    return JEM_TRAP_HANDLER_FINISH;
}

static int opc_fmul(struct intrp_ctx *ctx)
{
    float v1, v2;
    float ret;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v2);
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v1);
    ret = v1 * v2;
    jam_dprintf("[OPC_FMUL] result %f\n", ret);
    ostack_push_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, ret);
    return 0;
}

static int opc_fadd(struct intrp_ctx *ctx)
{
    float v1, v2;
    float ret;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v2);
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v1);
    ret = v1 + v2;
    jam_dprintf("[OPC_FADD] result %f\n", ret);
    ostack_push_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, ret);
    return 0;
}

static int opc_fsub(struct intrp_ctx *ctx)
{
    float v1, v2;
    float ret;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v2);
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, v1);
    ret = v1 - v2;
    jam_dprintf("[OPC_FSUB] result %f\n", ret);
    ostack_push_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, ret);
    return 0;
}

static int opc_f2i(struct intrp_ctx *ctx)
{
    int res;
    float value;
    struct jem_state *jem = &ctx->jem;
    ostack_pop_f32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, value);
    jam_dprintf("[OPC_F2I] float value %f\n", value);
    if (value >= (float)INT_MAX)
        res = INT_MAX;
    else if (value <= (float)INT_MIN)
        res = INT_MIN;
    else if (value != value)
        res = 0;
    else
        res = (int)value;
    jam_dprintf("[OPC_F2I] int value %d\n", res);
    ostack_push_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, res);
    return 0;
}

static int opc_iinc(struct intrp_ctx *ctx)
{
    union jecr  jecr_u;
    jecr_u.i = ctx->jem.jecr;
    int index = (int)jecr_u.s.op1;
    int con = (int)jecr_u.s.op2;
    uintptr_t *ptr = ctx->lvars_jem;

    jam_dprintf("[OPC_IINC] add %d to local var %x at %d (%d)\n",
                con, ptr[-index], index, ctx->mb->max_locals);
    ptr[-index] = ptr[-index] + con;

    jam_dprintf("[OPC_IINC] local var is %x now\n", ptr[-index]);
    return 0;
}

static int opc_athrow(struct intrp_ctx *ctx)
{
    Object *obj;
    ostack_pop_u32(ctx->frame->ostack, ctx->mb->max_stack, ctx->ostack, obj);
    ctx->frame->last_pc = (CodePntr)ctx->jem.jpc;
    ExecEnv *ee = ctx->ee;

    JEM_NULL_POINTER_CHECK(obj);

    if (!JAM_ON_STACK || !IS_JAM_OBJECT(obj))
        obj = JAM_OBJECT((uintptr_t *)obj);

    jam_dprintf("[OPC_ATHROW] throw exception %s\n", CLASS_CB(obj->class)->name);
    ee->exception = obj;
    return jem_throwException(ctx);
}

static int do_stackOverflow(struct intrp_ctx *ctx)
{
    jam_dprintf("[TRAP] STACK OVERFLOW XXXXXXXX\n");
    trap_debug(ctx);
    return 0;
}

static int do_stackUnderflow(struct intrp_ctx *ctx)
{
    jam_dprintf("[TRAP] STACK UNDERFLOW XXXXXXXX\n");
    trap_debug(ctx);
    return 1;
}

static int do_stackOverflow1(struct intrp_ctx *ctx)
{
    jam_dprintf("[TRAP] STACK OVERFLOW1XXXXXXXX\n");
    trap_debug(ctx);
    return 1;
}

static int do_stackUnderflow1(struct intrp_ctx *ctx)
{
   jam_dprintf("[TRAP] STACK UNDERFLOW1XXXXXXXX\n");
   trap_debug(ctx);
   return 1;
}

static handler_fn *trap_handler_f[256] = {
    [OPC_INVOKEINTERFACE]               = opc_invokeinterface,
    [OPC_INVOKESPECIAL]                 = opc_invokespecial,
    [OPC_INVOKESUPER_QUICK]             = opc_invokesuper_quick,
    [OPC_INVOKENONVIRTUAL_QUICK]        = opc_invokenonvirtual_quick,
    [OPC_INVOKEVIRTUAL]                 = opc_invokevirtual,
    [OPC_INVOKEVIRTUAL_QUICK]           = opc_invokevirtual_quick,
    [OPC_INVOKESTATIC]                  = opc_invokestatic,
//    [OPC_INVOKESTATIC_QUICK]          = opc_invokestatic_quick,
    [OPC_NEW]                           = opc_new,
    [0xDD]                              = opc_new,              /* JEM: NEW_QUICK */
    [OPC_RETURN]                        = opc_return,
    [OPC_ARETURN]                       = opc_afireturn,
    [OPC_IRETURN]                       = opc_afireturn,
    [OPC_FRETURN]                       = opc_afireturn,
    [OPC_PUTFIELD]                      = opc_putfield,
//    [OPC_PUTFIELD_QUICK]              = opc_putfield_quick,
//    [OPC_PUTFIELD2_QUICK]             = opc_putfield2_quick,
//    [OPC_LDC_W_QUICK]                 = opc_ldc_w_quick,
//    [OPC_LDC_QUICK]                   = opc_ldc_quick,
    [OPC_LDC_W]                         = opc_ldc_w,
    [OPC_LDC]                           = opc_ldc,
    [OPC_MONITORENTER]                  = opc_monitorenter,
    [OPC_MONITOREXIT]                   = opc_monitorexit,
    [OPC_GETSTATIC]                     = opc_getstatic,
//    [OPC_GETSTATIC_QUICK]             = opc_getstatic_quick,
//    [OPC_GETSTATIC2_QUICK]            = opc_getstatic2_quick,
    [OPC_PUTSTATIC]                     = opc_putstatic,
    [OPC_PUTSTATIC_QUICK]               = opc_putstatic_quick,
    [OPC_PUTSTATIC2_QUICK]              = opc_putstatic2_quick,
    [OPC_ANEWARRAY]                     = opc_anewarray,
    [OPC_ANEWARRAY_QUICK]               = opc_anewarray_quick,
    [OPC_MULTIANEWARRAY]                = opc_multianewarray,
    [OPC_NEWARRAY]                      = opc_newarray,
    [OPC_CHECKCAST]                     = opc_checkcast,
    [OPC_CHECKCAST_QUICK]               = opc_checkcast_quick,
    [OPC_GETFIELD]                      = opc_getfield,
//    [OPC_GETFIELD_QUICK]              = opc_getfield_quick,
//    [OPC_GETFIELD2_QUICK]             = opc_getfield2_quick,
    [OPC_FCMPL]                         = opc_fcmpl,
    [OPC_FCMPG]                         = opc_fcmpg,
    [OPC_I2F]                           = opc_i2f,
    [OPC_I2D]                           = opc_i2d,
    [OPC_FMUL]                          = opc_fmul,
//    [OPC_FADD]                        = opc_fadd,
//    [OPC_FSUB]                        = opc_fsub,
    [OPC_F2I]                           = opc_f2i,
    [OPC_IINC]                          = opc_iinc,
    [OPC_INSTANCEOF]                    = opc_instanceof,
    [OPC_ATHROW]                        = opc_athrow,
    [OPC_LRETURN]                       = opc_ldreturn,
};

static handler_fn *exception_handler_f[] = {
        [0] = do_javaExceptions,
        [1] = do_stackOverflow,
        [2] = do_stackUnderflow,
        [3] = do_stackOverflow1,
        [4] = do_stackUnderflow1,
};

struct jem_profile {
        unsigned long time;
        unsigned int n;
};

static struct jem_profile prof[256];

/******************************/
uintptr_t *executeJava(void)
{
/**
 * load trap entries to JEM trap table set when initializing JamVM
 */
    int i;
    uint32_t jep;
    int done;
#ifdef JEM_PROFILE
    static struct timeval tv1, tv2;
#endif
    ExecEnv *ee = getExecEnv();

    /* Initialize interpreter's static environment */
    struct intrp_ctx ctx;
    struct jem_state *jem = &ctx.jem;

    ctx.ee = ee;
    ctx.frame = ee->last_frame;
    ctx.mb = ctx.frame->mb;
    /*
     * We use ostack to save overflowing Java Operand Stack elements. On a stack
     * overflow we free a half of the stack (4 elements) to avoid an immediate
     * next overflow. When entering a trap, the Operand Stack is saved in a
     * temporary array in the reverse order:
     * ATTENTION: Looks like ToS is really in r0, not in r7, as JEM manual says
     * jos[0]     = r7 (?)
     * ...
     * jos[7 - N] = rN (ToS - N)
     * ...
     * jos[7]     = r0 (ToS)
     * UPDATE (27.06.2008)
     * I think, actually, the manual is right in some way... If you access
     * registers individually _when_ JOSP == N + 1 != 0. If they are read out
     * with an ldm, you get this:
     * jos[0]     = r7 (?)
     * ...
     * jos[7 - N] = rN (ToS)
     * ...
     * jos[7]     = r0 (ToS - N)
     * on an overflow we push r3..r0, i.e., jos[4..7] to the frame stack, and
     * set saved JOSP to 4.
     */
    unsigned long jos[8];

    ctx.ostack = ctx.frame->ostack;
    ctx.cp = &(CLASS_CB(ctx.mb->class)->constant_pool);
    /* End enterpreter's static environment */
    
    //fetch the original pc before prepare direct mb
    //TODO: 
    /* I think, mb->code is indeed a copy of the original code[] array from the
     * class object. See class.c::defineClass():390 */

    if (ctx.frame->lvars_jem) {
        uintptr_t *ptr;
        ctx.lvars_jem = ctx.frame->lvars_jem - 1;
        ptr = (uintptr_t *)*ctx.lvars_jem;
        ctx.this = JAM_OBJECT(ptr);
    } else {
        /* FIXME: do not know how to set it when there're none local var */
        ctx.lvars_jem = NULL;
        ctx.this = NULL;
    }

    jam_dprintf("[executeJava] ostack %08x locals %d lvars_jem %08x\n",
                ctx.ostack, ctx.mb->max_locals, ctx.lvars_jem);
    jam_dprintf("[executeJava] execute method %s on class %s\n",
                ctx.mb->name, CLASS_CB(ctx.mb->class)->name);

#if 0
    /* Don't think we need it, at least, not in the direct.c form. There the code
     * is converted into an internal representation, which is useless for JEM */
    PREPARE_MB(ctx.mb);//see direct.c (prepare)
#endif

    jem->jpc = (unsigned long)ctx.mb->code & ~3;
    jam_dprintf("[executeJava] begin on opcode %04x (%04x)\n",
                *(char*)jem->jpc, *((char*)jem->jpc + 1));

    do {
        static int opcode;

#ifdef JEM_DEBUG
        jam_dprintf("About to enter JEM at 0x%08x, this = %p. Code:", jem->jpc, ctx.this);
        for (i = 0; i < 32 && jem->jpc + i < (unsigned long)(ctx.mb->code + ctx.mb->code_size); i++) {
                if (!(i & 0xf))
                        jam_dprintf("\n0x%04x:", i);
                jam_dprintf(" 0x%02x", ((char*)jem->jpc)[i]);
        }

        jam_dprintf("\nUp to 8 first Local Variables out of %d:\n", ctx.mb->max_locals);
        for (i = 0; i < min(8, ctx.mb->max_locals); i++)
                jam_dprintf("LVAR_%d: 0x%08x\n", i, *(ctx.lvars_jem - i), ctx.lvars_jem - i);
#endif

        /* On entry we need last Java Operand Stack depth, set it not deeper
         * than half hardware stack */
        jem->josp = min(5, ostack_depth(ctx.frame->ostack, ctx.ostack));
        jam_dprintf("Pop %d words to JEM stack from %p:%p\n", jem->josp,
                    ctx.frame->ostack, ctx.ostack);
        /* As long as we are in asm, top jem.josp stack elements belong JEM */
        for (i = 0; i < jem->josp; i++)
                ostack_pop_u32(ctx.frame->ostack, ctx.mb->max_stack, ctx.ostack,
                               jos[7 - jem->josp + 1 + i]);

#ifdef JEM_PROFILE
        if (tv1.tv_sec) {
                gettimeofday(&tv2, NULL);
                prof[opcode].time += (tv2.tv_sec - tv1.tv_sec) * 1000000 +
                        tv2.tv_usec - tv1.tv_usec;
                prof[opcode].n++;
        }
#endif

        __asm__ __volatile__(
                ".globl debug_jem_enter\n"
                "debug_jem_enter:\n"
                "       pushm   r0-r7,r10-r11\n"
                "       mov     r8, %[cp]\n"
                "       mov     r9, %[lv0]\n"
                "       mov     lr, %[jpc]\n"
                "       mov     r12, %[josp]\n"         /* Cannot use %[josp] ... */
                "       mov     r11, %[ostack]\n"
                "       pushm   r11\n"                  /* Need ostack below */
                "       ldm     r11, r0-r7\n"           /* Restore Java Operands */
                "       cp.w    r12, 0\n"               /* Test josp == 0 */
                "       breq    4f\n"
                "5:     incjosp 1\n"                    /* ... for loop counter, */
                "       sub     r12, 1\n"               /* because it can be */
                "       brne    5b\n"                   /* one of r0-r7 */
                "4:     popjc\n"                        /* Restore Local Variables */
                "       sub     r10, pc, . - trap\n"    /* These 3 instructions */
                "       retj\n"                         /* have to stay */
                "trap:  pushjc\n"                       /* together */
                "       mfsr    r11, 0x58\n"            /* JOSP */
                "       lsl     r11, 28\n"              /* Clear r11[31:3] using */
                "       lsr     r11, 28\n"              /* one register */
                "       mov     r8, r11\n"
                "       breq    2f\n"
                "3:     incjosp -1\n"
                "       sub     r11, 1\n"
                "       brne    3b\n"
                "2:     popm    r11\n"                  /* ostack */
                "       stm     r11, r0-r7\n"           /* Save Java Operands */
                "       popm    r0-r7,r10-r11\n"
                "       mov     %[tpc], r12\n"
                "       mov     %[jpc], lr\n"           /* Resume address */
                "       mfsr    %[jecr], 0x54\n"        /* JECR */
                "       mov     %[josp], r8\n"          /* JOSP */
                "       .globl debug_jem_exit\n"
                "debug_jem_exit:\n"
                : [jecr] "=r" (jem->jecr), [tpc] "=r" (jem->trap_pc),
                  [josp] "+r" (jem->josp), [jpc] "+r" (jem->jpc)
                : [cp] "r" (ctx.cp->info), [lv0] "r" (ctx.lvars_jem),
                  [ostack] "r" (jos)
                : "r8", "r9", "lr", "r12", "memory"
                );
        /*
         * trap_pc now holds trap pc, describing which trap has been entered,
         * jecr holds JECR with the trapping bytecode at bits 23..16, possibly
         *      arguments at bits 7..0 and 15..8,
         * josp holds JOSP (JOSP & 0xf),
         * jos holds stored registers r7-r0 (note order!) - Java Operand Stack
         * jpc points at the trapping opcode, in case of exceptions and stack
         *      over- and underflows, and at the next opcode, in case of a trap
         */

#ifdef JEM_PROFILE
        gettimeofday(&tv1, NULL);
#endif

        for (i = 0; i < jem->josp; i++)
                ostack_push_u32(ctx.frame->ostack, ctx.mb->max_stack, ctx.ostack,
                                jos[7 - i]);

        opcode = (jem->jecr >> 16) & 0xff;

        jep = jem->trap_pc & 0xfff;

        trap_debug(&ctx);
        if (jep < 0x280)
            done = exception_handler_f[jep >> 7](&ctx);
        else if (trap_handler_f[opcode])
            done = trap_handler_f[opcode](&ctx);
        else {
            /* Unimplemented */
            jam_printf("Unimplemented Java Opcode 0x%02x\n", opcode);
            exitVM(1);
        }

#ifdef JEM_DEBUG
        usleep(100);
#endif
    } while (done != JEM_TRAP_HANDLER_FINISH);

    return ctx.ostack;

//    DISPATCH_FIRST;

    jam_dprintf("Unknown Java Opcodes\n");
    exitVM(1);
}

#ifndef executeJava
void initialiseInterpreter(InitArgs *args) {
    initialiseDirect(args);
}
#endif

void dump_profile(void)
{
#ifdef JEM_PROFILE
        int i;

        for (i = 0; i < 256; i++)
                if (prof[i].n)
                        jam_printf("0x%x:\t%u times,\t%lu usec\n", i, prof[i].n, prof[i].time);
#endif
}

#endif //JEM