src/cpus/cpu_arm_instr.c

/*
 *  Copyright (C) 2005  Anders Gavare.  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  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.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE   
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *
 *
 *  $Id: cpu_arm_instr.c,v 1.54 2005/11/19 18:53:07 debug Exp $
 *
 *  ARM instructions.
 *
 *  Individual functions should keep track of cpu->n_translated_instrs.
 *  (If no instruction was executed, then it should be decreased. If, say, 4
 *  instructions were combined into one function and executed, then it should
 *  be increased by 3.)
 */


#include "arm_quick_pc_to_pointers.h"

/*  #define GATHER_BDT_STATISTICS  */


#ifdef GATHER_BDT_STATISTICS
/*
 *  update_bdt_statistics():
 *
 *  Gathers statistics about load/store multiple instructions.
 *
 *  NOTE/TODO: Perhaps it would be more memory efficient to swap the high
 *  and low parts of the instruction word, so that the lllllll bits become
 *  the high bits; this would cause fewer host pages to be used. Anyway, the
 *  current implementation works on hosts with lots of RAM.
 *
 *  The resulting file, bdt_statistics.txt, should then be processed like
 *  this to give a new cpu_arm_multi.txt:
 *
 *  uniq -c bdt_statistics.txt|sort -nr|head -256|cut -f 2 > cpu_arm_multi.txt
 */
static void update_bdt_statistics(uint32_t iw)
{
        static FILE *f = NULL;
        static long long *counts;
        static char *counts_used;
        static long long n = 0;

        if (f == NULL) {
                size_t s = (1 << 24) * sizeof(long long);
                f = fopen("bdt_statistics.txt", "w");
                if (f == NULL) {
                        fprintf(stderr, "update_bdt_statistics(): :-(\n");
                        exit(1);
                }
                counts = zeroed_alloc(s);
                counts_used = zeroed_alloc(65536);
        }

        /*  Drop the s-bit: xxxx100P USWLnnnn llllllll llllllll  */
        iw = ((iw & 0x01800000) >> 1) | (iw & 0x003fffff);

        counts_used[iw & 0xffff] = 1;
        counts[iw] ++;

        n ++;
        if ((n % 500000) == 0) {
                int i;
                long long j;
                fatal("[ update_bdt_statistics(): n = %lli ]\n", (long long) n);
                fseek(f, 0, SEEK_SET);
                for (i=0; i<0x1000000; i++)
                        if (counts_used[i & 0xffff] && counts[i] != 0) {
                                /*  Recreate the opcode:  */
                                uint32_t opcode = ((i & 0x00c00000) << 1)
                                    | (i & 0x003fffff) | 0x08000000;
                                for (j=0; j<counts[i]; j++)
                                        fprintf(f, "0x%08x\n", opcode);
                        }
                fflush(f);
        }
}
#endif


/*****************************************************************************/


/*
 *  Helper definitions:
 *
 *  Each instruction is defined like this:
 *
 *      X(foo)
 *      {
 *              code for foo;
 *      }
 *      Y(foo)
 *
 *  The Y macro defines 14 copies of the instruction, one for each possible
 *  condition code. (The NV condition code is not included, and the AL code
 *  uses the main foo function.)  Y also defines an array with pointers to
 *  all of these functions.
 *
 *  If the compiler is good enough (i.e. allows long enough code sequences
 *  to be inlined), then the Y functions will be compiled as full (inlined)
 *  functions, otherwise they will simply call the X function.
 */

uint8_t condition_hi[16] = { 0,0,1,1, 0,0,0,0, 0,0,1,1, 0,0,0,0 };
uint8_t condition_ge[16] = { 1,0,1,0, 1,0,1,0, 0,1,0,1, 0,1,0,1 };
uint8_t condition_gt[16] = { 1,0,1,0, 0,0,0,0, 0,1,0,1, 0,0,0,0 };

#define Y(n) void arm_instr_ ## n ## __eq(struct cpu *cpu,              \
                        struct arm_instr_call *ic)                      \
        {  if (cpu->cd.arm.flags & ARM_F_Z)                             \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __ne(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (!(cpu->cd.arm.flags & ARM_F_Z))                          \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __cs(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (cpu->cd.arm.flags & ARM_F_C)                             \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __cc(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (!(cpu->cd.arm.flags & ARM_F_C))                          \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __mi(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (cpu->cd.arm.flags & ARM_F_N)                             \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __pl(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (!(cpu->cd.arm.flags & ARM_F_N))                          \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __vs(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (cpu->cd.arm.flags & ARM_F_V)                             \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __vc(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (!(cpu->cd.arm.flags & ARM_F_V))                          \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __hi(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (condition_hi[cpu->cd.arm.flags])                         \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __ls(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (!condition_hi[cpu->cd.arm.flags])                        \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __ge(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (condition_ge[cpu->cd.arm.flags])                         \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __lt(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (!condition_ge[cpu->cd.arm.flags])                        \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __gt(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (condition_gt[cpu->cd.arm.flags])                         \
                arm_instr_ ## n (cpu, ic);              }               \
        void arm_instr_ ## n ## __le(struct cpu *cpu,                   \
                        struct arm_instr_call *ic)                      \
        {  if (!condition_gt[cpu->cd.arm.flags])                        \
                arm_instr_ ## n (cpu, ic);              }               \
        void (*arm_cond_instr_ ## n  [16])(struct cpu *,                \
                        struct arm_instr_call *) = {                    \
                arm_instr_ ## n ## __eq, arm_instr_ ## n ## __ne,       \
                arm_instr_ ## n ## __cs, arm_instr_ ## n ## __cc,       \
                arm_instr_ ## n ## __mi, arm_instr_ ## n ## __pl,       \
                arm_instr_ ## n ## __vs, arm_instr_ ## n ## __vc,       \
                arm_instr_ ## n ## __hi, arm_instr_ ## n ## __ls,       \
                arm_instr_ ## n ## __ge, arm_instr_ ## n ## __lt,       \
                arm_instr_ ## n ## __gt, arm_instr_ ## n ## __le,       \
                arm_instr_ ## n , arm_instr_nop };

#define cond_instr(n)   ( arm_cond_instr_ ## n  [condition_code] )


/*****************************************************************************/


/*
 *  nop:  Do nothing.
 *  invalid:  Invalid instructions end up here.
 */
X(nop) { }
X(invalid) {
        uint32_t low_pc;
        low_pc = ((size_t)ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1)
            << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);

        fatal("Invalid ARM instruction: pc=0x%08x\n", (int)cpu->pc);

        cpu->running = 0;
        cpu->running_translated = 0;
        cpu->n_translated_instrs --;
        cpu->cd.arm.next_ic = &nothing_call;
}


/*
 *  b:  Branch (to a different translated page)
 *
 *  arg[0] = relative offset
 */
X(b)
{
        cpu->pc = (uint32_t)((cpu->pc & 0xfffff000) + (int32_t)ic->arg[0]);

        /*  Find the new physical page and update the translation pointers:  */
        quick_pc_to_pointers(cpu);
}
Y(b)


/*
 *  b_samepage:  Branch (to within the same translated page)
 *
 *  arg[0] = pointer to new arm_instr_call
 *  arg[1] = pointer to the next instruction.
 *
 *  NOTE: This instruction is manually inlined.
 */
X(b_samepage) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *) ic->arg[0];
}
X(b_samepage__eq) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[cpu->cd.arm.flags & ARM_F_Z? 0 : 1];
}
X(b_samepage__ne) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[cpu->cd.arm.flags & ARM_F_Z? 1 : 0];
}
X(b_samepage__cs) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[cpu->cd.arm.flags & ARM_F_C? 0 : 1];
}
X(b_samepage__cc) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[cpu->cd.arm.flags & ARM_F_C? 1 : 0];
}
X(b_samepage__mi) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[cpu->cd.arm.flags & ARM_F_N? 0 : 1];
}
X(b_samepage__pl) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[cpu->cd.arm.flags & ARM_F_N? 1 : 0];
}
X(b_samepage__vs) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[cpu->cd.arm.flags & ARM_F_V? 0 : 1];
}
X(b_samepage__vc) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[cpu->cd.arm.flags & ARM_F_V? 1 : 0];
}
X(b_samepage__hi) {
        cpu->cd.arm.next_ic = (condition_hi[cpu->cd.arm.flags])?
            (struct arm_instr_call *) ic->arg[0] :
            (struct arm_instr_call *) ic->arg[1];
}
X(b_samepage__ls) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[condition_hi[cpu->cd.arm.flags]];
}
X(b_samepage__ge) {
        cpu->cd.arm.next_ic = (condition_ge[cpu->cd.arm.flags])?
            (struct arm_instr_call *) ic->arg[0] :
            (struct arm_instr_call *) ic->arg[1];
}
X(b_samepage__lt) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[condition_ge[cpu->cd.arm.flags]];
}
X(b_samepage__gt) {
        cpu->cd.arm.next_ic = (condition_gt[cpu->cd.arm.flags])?
            (struct arm_instr_call *) ic->arg[0] :
            (struct arm_instr_call *) ic->arg[1];
}
X(b_samepage__le) {
        cpu->cd.arm.next_ic = (struct arm_instr_call *)
            ic->arg[condition_gt[cpu->cd.arm.flags]];
}
void (*arm_cond_instr_b_samepage[16])(struct cpu *,
        struct arm_instr_call *) = {
        arm_instr_b_samepage__eq, arm_instr_b_samepage__ne,
        arm_instr_b_samepage__cs, arm_instr_b_samepage__cc,
        arm_instr_b_samepage__mi, arm_instr_b_samepage__pl,
        arm_instr_b_samepage__vs, arm_instr_b_samepage__vc,
        arm_instr_b_samepage__hi, arm_instr_b_samepage__ls,
        arm_instr_b_samepage__ge, arm_instr_b_samepage__lt,
        arm_instr_b_samepage__gt, arm_instr_b_samepage__le,
        arm_instr_b_samepage, arm_instr_nop };


/*
 *  bx:  Branch, potentially exchanging Thumb/ARM encoding
 *
 *  arg[0] = ptr to rm
 */
X(bx)
{
        cpu->pc = reg(ic->arg[0]);
        if (cpu->pc & 1) {
                fatal("thumb: TODO\n");
                exit(1);
        }
        cpu->pc &= ~3;

        /*  Find the new physical page and update the translation pointers:  */
        quick_pc_to_pointers(cpu);
}
Y(bx)


/*
 *  bx_trace:  As bx, but with trace enabled, arg[0] = the link register.
 *
 *  arg[0] = ignored
 */
X(bx_trace)
{
        cpu->pc = cpu->cd.arm.r[ARM_LR];
        if (cpu->pc & 1) {
                fatal("thumb: TODO\n");
                exit(1);
        }
        cpu->pc &= ~3;

        cpu_functioncall_trace_return(cpu);

        /*  Find the new physical page and update the translation pointers:  */
        quick_pc_to_pointers(cpu);
}
Y(bx_trace)


/*
 *  bl:  Branch and Link (to a different translated page)
 *
 *  arg[0] = relative address
 */
X(bl)
{
        uint32_t pc = ((uint32_t)cpu->pc & 0xfffff000) + (int32_t)ic->arg[1];
        cpu->cd.arm.r[ARM_LR] = pc + 4;

        /*  Calculate new PC from this instruction + arg[0]  */
        cpu->pc = pc + (int32_t)ic->arg[0];

        /*  Find the new physical page and update the translation pointers:  */
        quick_pc_to_pointers(cpu);
}
Y(bl)


/*
 *  blx:  Branch and Link, potentially exchanging Thumb/ARM encoding
 *
 *  arg[0] = ptr to rm
 */
X(blx)
{
        uint32_t lr = ((uint32_t)cpu->pc & 0xfffff000) + (int32_t)ic->arg[2];
        cpu->cd.arm.r[ARM_LR] = lr;
        cpu->pc = reg(ic->arg[0]);
        if (cpu->pc & 1) {
                fatal("thumb: TODO\n");
                exit(1);
        }
        cpu->pc &= ~3;

        /*  Find the new physical page and update the translation pointers:  */
        quick_pc_to_pointers(cpu);
}
Y(blx)


/*
 *  bl_trace:  Branch and Link (to a different translated page), with trace
 *
 *  Same as for bl.
 */
X(bl_trace)
{
        uint32_t pc = ((uint32_t)cpu->pc & 0xfffff000) + (int32_t)ic->arg[1];
        cpu->cd.arm.r[ARM_LR] = pc + 4;

        /*  Calculate new PC from this instruction + arg[0]  */
        cpu->pc = pc + (int32_t)ic->arg[0];

        cpu_functioncall_trace(cpu, cpu->pc);

        /*  Find the new physical page and update the translation pointers:  */
        quick_pc_to_pointers(cpu);
}
Y(bl_trace)


/*
 *  bl_samepage:  A branch + link within the same page
 *
 *  arg[0] = pointer to new arm_instr_call
 */
X(bl_samepage)
{
        cpu->cd.arm.r[ARM_LR] =
            ((uint32_t)cpu->pc & 0xfffff000) + (int32_t)ic->arg[2];
        cpu->cd.arm.next_ic = (struct arm_instr_call *) ic->arg[0];
}
Y(bl_samepage)


/*
 *  bl_samepage_trace:  Branch and Link (to the same page), with trace
 *
 *  Same as for bl_samepage.
 */
X(bl_samepage_trace)
{
        uint32_t low_pc, lr = (cpu->pc & 0xfffff000) + ic->arg[2];

        /*  Link and branch:  */
        cpu->cd.arm.r[ARM_LR] = lr;
        cpu->cd.arm.next_ic = (struct arm_instr_call *) ic->arg[0];

        /*  Synchronize the program counter:  */
        low_pc = ((size_t)cpu->cd.arm.next_ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1)
            << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);

        /*  ... and show trace:  */
        cpu_functioncall_trace(cpu, cpu->pc);
}
Y(bl_samepage_trace)


/*
 *  clz: Count leading zeroes.
 *
 *  arg[0] = ptr to rm
 *  arg[1] = ptr to rd
 */
X(clz)
{
        uint32_t rm = reg(ic->arg[0]);
        int i = 32, n = 0, j;
        while (i>0) {
                if (rm & 0xff000000) {
                        for (j=0; j<8; j++) {
                                if (rm & 0x80000000)
                                        break;
                                n ++;
                                rm <<= 1;
                        }
                        break;
                } else {
                        rm <<= 8;
                        i -= 8;
                        n += 8;
                }
        }
        reg(ic->arg[1]) = n;
}
Y(clz)


/*
 *  mul: Multiplication
 *
 *  arg[0] = ptr to rd
 *  arg[1] = ptr to rm
 *  arg[2] = ptr to rs
 */
X(mul)
{
        reg(ic->arg[0]) = reg(ic->arg[1]) * reg(ic->arg[2]);
}
Y(mul)
X(muls)
{
        uint32_t result;
        result = reg(ic->arg[1]) * reg(ic->arg[2]);
        cpu->cd.arm.flags &= ~(ARM_F_Z | ARM_F_N);
        if (result == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (result & 0x80000000)
                cpu->cd.arm.flags |= ARM_F_N;
        reg(ic->arg[0]) = result;
}
Y(muls)


/*
 *  mla: Multiplication with addition
 *
 *  arg[0] = copy of instruction word
 */
X(mla)
{
        /*  xxxx0000 00ASdddd nnnnssss 1001mmmm (Rd,Rm,Rs[,Rn])  */
        uint32_t iw = ic->arg[0];
        int rd, rs, rn, rm;
        rd = (iw >> 16) & 15; rn = (iw >> 12) & 15,
        rs = (iw >> 8) & 15;  rm = iw & 15;
        cpu->cd.arm.r[rd] = cpu->cd.arm.r[rm] * cpu->cd.arm.r[rs]
            + cpu->cd.arm.r[rn];
}
Y(mla)
X(mlas)
{
        /*  xxxx0000 00ASdddd nnnnssss 1001mmmm (Rd,Rm,Rs[,Rn])  */
        uint32_t iw = ic->arg[0];
        int rd, rs, rn, rm;
        rd = (iw >> 16) & 15; rn = (iw >> 12) & 15,
        rs = (iw >> 8) & 15;  rm = iw & 15;
        cpu->cd.arm.r[rd] = cpu->cd.arm.r[rm] * cpu->cd.arm.r[rs]
            + cpu->cd.arm.r[rn];
        cpu->cd.arm.flags &= ~(ARM_F_Z | ARM_F_N);
        if (cpu->cd.arm.r[rd] == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (cpu->cd.arm.r[rd] & 0x80000000)
                cpu->cd.arm.flags |= ARM_F_N;
}
Y(mlas)


/*
 *  mull: Long multiplication
 *
 *  arg[0] = copy of instruction word
 */
X(mull)
{
        /*  xxxx0000 1UAShhhh llllssss 1001mmmm  */
        uint32_t iw; uint64_t tmp; int u_bit, a_bit;
        iw = ic->arg[0];
        u_bit = iw & 0x00400000; a_bit = iw & 0x00200000;
        tmp = cpu->cd.arm.r[iw & 15];
        if (u_bit)
                tmp = (int64_t)(int32_t)tmp
                    * (int64_t)(int32_t)cpu->cd.arm.r[(iw >> 8) & 15];
        else
                tmp *= (uint64_t)cpu->cd.arm.r[(iw >> 8) & 15];
        if (a_bit) {
                uint64_t x = ((uint64_t)cpu->cd.arm.r[(iw >> 16) & 15] << 32)
                    | cpu->cd.arm.r[(iw >> 12) & 15];
                x += tmp;
                cpu->cd.arm.r[(iw >> 16) & 15] = (x >> 32);
                cpu->cd.arm.r[(iw >> 12) & 15] = x;
        } else {
                cpu->cd.arm.r[(iw >> 16) & 15] = (tmp >> 32);
                cpu->cd.arm.r[(iw >> 12) & 15] = tmp;
        }
}
Y(mull)


/*
 *  mov_reg_reg:  Move a register to another.
 *
 *  arg[0] = ptr to source register
 *  arg[1] = ptr to destination register
 */
X(mov_reg_reg)
{
        reg(ic->arg[1]) = reg(ic->arg[0]);
}
Y(mov_reg_reg)


/*
 *  mov_reg_pc:  Move the PC register to a normal register.
 *
 *  arg[0] = offset compared to start of current page + 8
 *  arg[1] = ptr to destination register
 */
X(mov_reg_pc)
{
        reg(ic->arg[1]) = ((uint32_t)cpu->pc&0xfffff000) + (int32_t)ic->arg[0];
}
Y(mov_reg_pc)


/*
 *  ret_trace:  "mov pc,lr" with trace enabled
 *  ret:  "mov pc,lr" without trace enabled
 *
 *  arg[0] = ignored
 */
X(ret_trace)
{
        uint32_t old_pc, mask_within_page;
        old_pc = cpu->pc;
        mask_within_page = ((ARM_IC_ENTRIES_PER_PAGE-1)
            << ARM_INSTR_ALIGNMENT_SHIFT) |
            ((1 << ARM_INSTR_ALIGNMENT_SHIFT) - 1);

        /*  Update the PC register:  */
        cpu->pc = cpu->cd.arm.r[ARM_LR];

        cpu_functioncall_trace_return(cpu);

        /*
         *  Is this a return to code within the same page? Then there is no
         *  need to update all pointers, just next_ic.
         */
        if ((old_pc & ~mask_within_page) == (cpu->pc & ~mask_within_page)) {
                cpu->cd.arm.next_ic = cpu->cd.arm.cur_ic_page +
                    ((cpu->pc & mask_within_page) >> ARM_INSTR_ALIGNMENT_SHIFT);
        } else {
                /*  Find the new physical page and update pointers:  */
                quick_pc_to_pointers(cpu);
        }
}
Y(ret_trace)
X(ret)
{
        cpu->pc = cpu->cd.arm.r[ARM_LR];
        quick_pc_to_pointers(cpu);
}
Y(ret)


/*
 *  msr: Move to status register from a normal register or immediate value.
 *
 *  arg[0] = immediate value
 *  arg[1] = mask
 *  arg[2] = pointer to rm
 *
 *  msr_imm and msr_imm_spsr use arg[1] and arg[0].
 *  msr and msr_spsr use arg[1] and arg[2].
 */
X(msr_imm)
{
        uint32_t mask = ic->arg[1];
        int switch_register_banks = (mask & ARM_FLAG_MODE) &&
            ((cpu->cd.arm.cpsr & ARM_FLAG_MODE) !=
            (ic->arg[0] & ARM_FLAG_MODE));
        uint32_t new_value = ic->arg[0];

        cpu->cd.arm.cpsr &= 0x0fffffff;
        cpu->cd.arm.cpsr |= (cpu->cd.arm.flags << 28);

        if (switch_register_banks)
                arm_save_register_bank(cpu);

        cpu->cd.arm.cpsr &= ~mask;
        cpu->cd.arm.cpsr |= (new_value & mask);

        cpu->cd.arm.flags = cpu->cd.arm.cpsr >> 28;

        if (switch_register_banks)
                arm_load_register_bank(cpu);
}
Y(msr_imm)
X(msr)
{
        ic->arg[0] = reg(ic->arg[2]);
        instr(msr_imm)(cpu, ic);
}
Y(msr)
X(msr_imm_spsr)
{
        uint32_t mask = ic->arg[1];
        uint32_t new_value = ic->arg[0];
        switch (cpu->cd.arm.cpsr & ARM_FLAG_MODE) {
        case ARM_MODE_FIQ32:
                cpu->cd.arm.spsr_fiq &= ~mask;
                cpu->cd.arm.spsr_fiq |= (new_value & mask);
                break;
        case ARM_MODE_ABT32:
                cpu->cd.arm.spsr_abt &= ~mask;
                cpu->cd.arm.spsr_abt |= (new_value & mask);
                break;
        case ARM_MODE_UND32:
                cpu->cd.arm.spsr_und &= ~mask;
                cpu->cd.arm.spsr_und |= (new_value & mask);
                break;
        case ARM_MODE_IRQ32:
                cpu->cd.arm.spsr_irq &= ~mask;
                cpu->cd.arm.spsr_irq |= (new_value & mask);
                break;
        case ARM_MODE_SVC32:
                cpu->cd.arm.spsr_svc &= ~mask;
                cpu->cd.arm.spsr_svc |= (new_value & mask);
                break;
        default:fatal("msr_spsr: unimplemented mode %i\n",
                    cpu->cd.arm.cpsr & ARM_FLAG_MODE);
{
        /*  Synchronize the program counter:  */
        uint32_t old_pc, low_pc = ((size_t)ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1) << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);
        old_pc = cpu->pc;
        printf("msr_spsr: old pc = 0x%08x\n", old_pc);
}
                exit(1);
        }
}
Y(msr_imm_spsr)
X(msr_spsr)
{
        ic->arg[0] = reg(ic->arg[2]);
        instr(msr_imm_spsr)(cpu, ic);
}
Y(msr_spsr)


/*
 *  mrs: Move from status/flag register to a normal register.
 *
 *  arg[0] = pointer to rd
 */
X(mrs)
{
        cpu->cd.arm.cpsr &= 0x0fffffff;
        cpu->cd.arm.cpsr |= (cpu->cd.arm.flags << 28);
        reg(ic->arg[0]) = cpu->cd.arm.cpsr;
}
Y(mrs)


/*
 *  mrs: Move from saved status/flag register to a normal register.
 *
 *  arg[0] = pointer to rd
 */
X(mrs_spsr)
{
        switch (cpu->cd.arm.cpsr & ARM_FLAG_MODE) {
        case ARM_MODE_FIQ32: reg(ic->arg[0]) = cpu->cd.arm.spsr_fiq; break;
        case ARM_MODE_ABT32: reg(ic->arg[0]) = cpu->cd.arm.spsr_abt; break;
        case ARM_MODE_UND32: reg(ic->arg[0]) = cpu->cd.arm.spsr_und; break;
        case ARM_MODE_IRQ32: reg(ic->arg[0]) = cpu->cd.arm.spsr_irq; break;
        case ARM_MODE_SVC32: reg(ic->arg[0]) = cpu->cd.arm.spsr_svc; break;
        case ARM_MODE_USR32:
        case ARM_MODE_SYS32: reg(ic->arg[0]) = 0; break;
        default:fatal("mrs_spsr: unimplemented mode %i\n",
                    cpu->cd.arm.cpsr & ARM_FLAG_MODE);
                exit(1);
        }
}
Y(mrs_spsr)


/*
 *  mcr_mrc:  Coprocessor move
 *  cdp:      Coprocessor operation
 *
 *  arg[0] = copy of the instruction word
 */
X(mcr_mrc) {
        uint32_t low_pc = ((size_t)ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1) << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);
        arm_mcr_mrc(cpu, ic->arg[0]);
}
Y(mcr_mrc)
X(cdp) {
        uint32_t low_pc = ((size_t)ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1) << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);
        arm_cdp(cpu, ic->arg[0]);
}
Y(cdp)


/*
 *  openfirmware:
 */
X(openfirmware)
{
        /*  TODO: sync pc?  */
        of_emul(cpu);
        cpu->pc = cpu->cd.arm.r[ARM_LR];
        if (cpu->machine->show_trace_tree)
                cpu_functioncall_trace_return(cpu);
        quick_pc_to_pointers(cpu);
}


/*
 *  reboot:
 */
X(reboot)
{
        cpu->running = 0;
        cpu->running_translated = 0;
        cpu->n_translated_instrs --;
        cpu->cd.arm.next_ic = &nothing_call;
}


/*
 *  swi_useremul: Syscall.
 *
 *  arg[0] = swi number
 */
X(swi_useremul)
{
        /*  Synchronize the program counter:  */
        uint32_t old_pc, low_pc = ((size_t)ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1)
            << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);
        old_pc = cpu->pc;

        useremul_syscall(cpu, ic->arg[0]);

        if (!cpu->running) {
                cpu->running_translated = 0;
                cpu->n_translated_instrs --;
                cpu->cd.arm.next_ic = &nothing_call;
        } else if (cpu->pc != old_pc) {
                /*  PC was changed by the SWI call. Find the new physical
                    page and update the translation pointers:  */
                quick_pc_to_pointers(cpu);
        }
}
Y(swi_useremul)


/*
 *  swi:  Software interrupt.
 */
X(swi)
{
        /*  Synchronize the program counter first:  */
        cpu->pc &= 0xfffff000;
        cpu->pc += ic->arg[0];
        arm_exception(cpu, ARM_EXCEPTION_SWI);
}
Y(swi)


/*
 *  und:  Undefined instruction.
 */
X(und)
{
        /*  Synchronize the program counter first:  */
        cpu->pc &= 0xfffff000;
        cpu->pc += ic->arg[0];
        arm_exception(cpu, ARM_EXCEPTION_UND);
}
Y(und)


/*
 *  swp, swpb:  Swap (word or byte).
 *
 *  arg[0] = ptr to rd
 *  arg[1] = ptr to rm
 *  arg[2] = ptr to rn
 */
X(swp)
{
        uint32_t addr = reg(ic->arg[2]), data, data2;
        unsigned char d[4];

        /*  Synchronize the program counter:  */
        uint32_t low_pc = ((size_t)ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1) << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);

        if (!cpu->memory_rw(cpu, cpu->mem, addr, d, sizeof(d), MEM_READ,
            CACHE_DATA)) {
                fatal("swp: load failed\n");
                return;
        }
        data = d[0] + (d[1] << 8) + (d[2] << 16) + (d[3] << 24);
        data2 = reg(ic->arg[1]);
        d[0] = data2; d[1] = data2 >> 8; d[2] = data2 >> 16; d[3] = data2 >> 24;
        if (!cpu->memory_rw(cpu, cpu->mem, addr, d, sizeof(d), MEM_WRITE,
            CACHE_DATA)) {
                fatal("swp: store failed\n");
                return;
        }
        reg(ic->arg[0]) = data;
}
Y(swp)
X(swpb)
{
        uint32_t addr = reg(ic->arg[2]), data;
        unsigned char d[1];

        /*  Synchronize the program counter:  */
        uint32_t low_pc = ((size_t)ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1) << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);

        if (!cpu->memory_rw(cpu, cpu->mem, addr, d, sizeof(d), MEM_READ,
            CACHE_DATA)) {
                fatal("swp: load failed\n");
                return;
        }
        data = d[0];
        d[0] = reg(ic->arg[1]);
        if (!cpu->memory_rw(cpu, cpu->mem, addr, d, sizeof(d), MEM_WRITE,
            CACHE_DATA)) {
                fatal("swp: store failed\n");
                return;
        }
        reg(ic->arg[0]) = data;
}
Y(swpb)


extern void (*arm_load_store_instr[1024])(struct cpu *,
        struct arm_instr_call *);
X(store_w1_word_u1_p0_imm);
X(store_w0_byte_u1_p0_imm);
X(store_w0_word_u1_p0_imm);
X(store_w0_word_u1_p1_imm);
X(load_w1_word_u1_p0_imm);
X(load_w0_word_u1_p0_imm);
X(load_w0_byte_u1_p1_imm);
X(load_w0_byte_u1_p1_reg);
X(load_w1_byte_u1_p1_imm);

extern void (*arm_load_store_instr_pc[1024])(struct cpu *,
        struct arm_instr_call *);

extern void (*arm_load_store_instr_3[2048])(struct cpu *,
        struct arm_instr_call *);

extern void (*arm_load_store_instr_3_pc[2048])(struct cpu *,
        struct arm_instr_call *);

extern uint32_t (*arm_r[8192])(struct cpu *, struct arm_instr_call *);
extern void arm_r_r3_t0_c0(void);

extern void (*arm_dpi_instr[2 * 2 * 2 * 16 * 16])(struct cpu *,
        struct arm_instr_call *);
extern void (*arm_dpi_instr_regshort[2 * 16 * 16])(struct cpu *,
        struct arm_instr_call *);
X(cmps);
X(teqs);
X(tsts);
X(sub);
X(add);
X(subs);
X(eor_regshort);
X(cmps_regshort);


#include "cpu_arm_instr_misc.c"


/*
 *  bdt_load:  Block Data Transfer, Load
 *
 *  arg[0] = pointer to uint32_t in host memory, pointing to the base register
 *  arg[1] = 32-bit instruction word. Most bits are read from this.
 */
X(bdt_load)
{
        unsigned char data[4];
        uint32_t *np = (uint32_t *)ic->arg[0];
        uint32_t addr = *np, low_pc;
        unsigned char *page;
        uint32_t iw = ic->arg[1];  /*  xxxx100P USWLnnnn llllllll llllllll  */
        int p_bit = iw & 0x01000000;
        int u_bit = iw & 0x00800000;
        int s_bit = iw & 0x00400000;
        int w_bit = iw & 0x00200000;
        int i, return_flag = 0;
        uint32_t new_values[16];

#ifdef GATHER_BDT_STATISTICS
        if (!s_bit)
                update_bdt_statistics(iw);
#endif

        /*  Synchronize the program counter:  */
        low_pc = ((size_t)ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1) << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);

        if (s_bit) {
                /*  Load to USR registers:  */
                if ((cpu->cd.arm.cpsr & ARM_FLAG_MODE) == ARM_MODE_USR32) {
                        fatal("[ bdt_load: s-bit: in usermode? ]\n");
                        s_bit = 0;
                }
                if (iw & 0x8000) {
                        s_bit = 0;
                        return_flag = 1;
                }
        }

        for (i=(u_bit? 0 : 15); i>=0 && i<=15; i+=(u_bit? 1 : -1)) {
                uint32_t value;

                if (!((iw >> i) & 1)) {
                        /*  Skip register i:  */
                        continue;
                }

                if (p_bit) {
                        if (u_bit)
                                addr += sizeof(uint32_t);
                        else
                                addr -= sizeof(uint32_t);
                }

                page = cpu->cd.arm.host_load[addr >> 12];
                if (page != NULL) {
                        uint32_t *p32 = (uint32_t *) page;
                        value = p32[(addr & 0xfff) >> 2];
                        /*  Change byte order of value if
                            host and emulated endianness differ:  */
#ifdef HOST_LITTLE_ENDIAN
                        if (cpu->byte_order == EMUL_BIG_ENDIAN)
#else
                        if (cpu->byte_order == EMUL_LITTLE_ENDIAN)
#endif
                                value = ((value & 0xff) << 24) |
                                    ((value & 0xff00) << 8) |
                                    ((value & 0xff0000) >> 8) |
                                    ((value & 0xff000000) >> 24);
                } else {
                        if (!cpu->memory_rw(cpu, cpu->mem, addr, data,
                            sizeof(data), MEM_READ, CACHE_DATA)) {
                                /*  load failed  */
                                return;
                        }
                        if (cpu->byte_order == EMUL_LITTLE_ENDIAN) {
                                value = data[0] +
                                    (data[1] << 8) + (data[2] << 16)
                                    + (data[3] << 24);
                        } else {
                                value = data[3] +
                                    (data[2] << 8) + (data[1] << 16)
                                    + (data[0] << 24);
                        }
                }

                new_values[i] = value;

                if (!p_bit) {
                        if (u_bit)
                                addr += sizeof(uint32_t);
                        else
                                addr -= sizeof(uint32_t);
                }
        }

        for (i=(u_bit? 0 : 15); i>=0 && i<=15; i+=(u_bit? 1 : -1)) {
                if (!((iw >> i) & 1)) {
                        /*  Skip register i:  */
                        continue;
                }

                if (!s_bit) {
                        cpu->cd.arm.r[i] = new_values[i];
                } else {
                        switch (cpu->cd.arm.cpsr & ARM_FLAG_MODE) {
                        case ARM_MODE_USR32:
                        case ARM_MODE_SYS32:
                                cpu->cd.arm.r[i] = new_values[i];
                                break;
                        case ARM_MODE_FIQ32:
                                if (i >= 8 && i <= 14)
                                        cpu->cd.arm.default_r8_r14[i-8] =
                                            new_values[i];
                                else
                                        cpu->cd.arm.r[i] = new_values[i];
                                break;
                        case ARM_MODE_SVC32:
                        case ARM_MODE_ABT32:
                        case ARM_MODE_UND32:
                        case ARM_MODE_IRQ32:
                                if (i >= 13 && i <= 14)
                                        cpu->cd.arm.default_r8_r14[i-8] =
                                            new_values[i];
                                else
                                        cpu->cd.arm.r[i] = new_values[i];
                                break;
                        }
                }
        }

        if (w_bit)
                *np = addr;

        if (return_flag) {
                uint32_t new_cpsr;
                int switch_register_banks;

                switch (cpu->cd.arm.cpsr & ARM_FLAG_MODE) {
                case ARM_MODE_FIQ32:
                        new_cpsr = cpu->cd.arm.spsr_fiq; break;
                case ARM_MODE_ABT32:
                        new_cpsr = cpu->cd.arm.spsr_abt; break;
                case ARM_MODE_UND32:
                        new_cpsr = cpu->cd.arm.spsr_und; break;
                case ARM_MODE_IRQ32:
                        new_cpsr = cpu->cd.arm.spsr_irq; break;
                case ARM_MODE_SVC32:
                        new_cpsr = cpu->cd.arm.spsr_svc; break;
                default:fatal("bdt_load: unimplemented mode %i\n",
                            cpu->cd.arm.cpsr & ARM_FLAG_MODE);
                        exit(1);
                }

                switch_register_banks = (cpu->cd.arm.cpsr & ARM_FLAG_MODE) !=
                    (new_cpsr & ARM_FLAG_MODE);

                if (switch_register_banks)
                        arm_save_register_bank(cpu);

                cpu->cd.arm.cpsr = new_cpsr;
                cpu->cd.arm.flags = cpu->cd.arm.cpsr >> 28;

                if (switch_register_banks)
                        arm_load_register_bank(cpu);
        }

        /*  NOTE: Special case: Loading the PC  */
        if (iw & 0x8000) {
                cpu->pc = cpu->cd.arm.r[ARM_PC] & 0xfffffffc;
                if (cpu->machine->show_trace_tree)
                        cpu_functioncall_trace_return(cpu);
                /*  TODO: There is no need to update the
                    pointers if this is a return to the
                    same page!  */
                /*  Find the new physical page and update the
                    translation pointers:  */
                quick_pc_to_pointers(cpu);
        }
}
Y(bdt_load)


/*
 *  bdt_store:  Block Data Transfer, Store
 *
 *  arg[0] = pointer to uint32_t in host memory, pointing to the base register
 *  arg[1] = 32-bit instruction word. Most bits are read from this.
 */
X(bdt_store)
{
        unsigned char data[4];
        uint32_t *np = (uint32_t *)ic->arg[0];
        uint32_t low_pc, value, addr = *np;
        uint32_t iw = ic->arg[1];  /*  xxxx100P USWLnnnn llllllll llllllll  */
        unsigned char *page;
        int p_bit = iw & 0x01000000;
        int u_bit = iw & 0x00800000;
        int s_bit = iw & 0x00400000;
        int w_bit = iw & 0x00200000;
        int i;

#ifdef GATHER_BDT_STATISTICS
        if (!s_bit)
                update_bdt_statistics(iw);
#endif

        /*  Synchronize the program counter:  */
        low_pc = ((size_t)ic - (size_t)
            cpu->cd.arm.cur_ic_page) / sizeof(struct arm_instr_call);
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1) << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);

        for (i=(u_bit? 0 : 15); i>=0 && i<=15; i+=(u_bit? 1 : -1)) {
                if (!((iw >> i) & 1)) {
                        /*  Skip register i:  */
                        continue;
                }

                value = cpu->cd.arm.r[i];

                if (s_bit) {
                        switch (cpu->cd.arm.cpsr & ARM_FLAG_MODE) {
                        case ARM_MODE_FIQ32:
                                if (i >= 8 && i <= 14)
                                        value = cpu->cd.arm.default_r8_r14[i-8];
                                break;
                        case ARM_MODE_ABT32:
                        case ARM_MODE_UND32:
                        case ARM_MODE_IRQ32:
                        case ARM_MODE_SVC32:
                                if (i >= 13 && i <= 14)
                                        value = cpu->cd.arm.default_r8_r14[i-8];
                                break;
                        case ARM_MODE_USR32:
                        case ARM_MODE_SYS32:
                                break;
                        }
                }

                /*  NOTE/TODO: 8 vs 12 on some ARMs  */
                if (i == ARM_PC)
                        value = cpu->pc + 12;

                if (p_bit) {
                        if (u_bit)
                                addr += sizeof(uint32_t);
                        else
                                addr -= sizeof(uint32_t);
                }

                page = cpu->cd.arm.host_store[addr >> 12];
                if (page != NULL) {
                        uint32_t *p32 = (uint32_t *) page;
                        /*  Change byte order of value if
                            host and emulated endianness differ:  */
#ifdef HOST_LITTLE_ENDIAN
                        if (cpu->byte_order == EMUL_BIG_ENDIAN)
#else
                        if (cpu->byte_order == EMUL_LITTLE_ENDIAN)
#endif
                                value = ((value & 0xff) << 24) |
                                    ((value & 0xff00) << 8) |
                                    ((value & 0xff0000) >> 8) |
                                    ((value & 0xff000000) >> 24);
                        p32[(addr & 0xfff) >> 2] = value;
                } else {
                        if (cpu->byte_order == EMUL_LITTLE_ENDIAN) {
                                data[0] = value;
                                data[1] = value >> 8;
                                data[2] = value >> 16;
                                data[3] = value >> 24;
                        } else {
                                data[0] = value >> 24;
                                data[1] = value >> 16;
                                data[2] = value >> 8;
                                data[3] = value;
                        }
                        if (!cpu->memory_rw(cpu, cpu->mem, addr, data,
                            sizeof(data), MEM_WRITE, CACHE_DATA)) {
                                /*  store failed  */
                                return;
                        }
                }

                if (!p_bit) {
                        if (u_bit)
                                addr += sizeof(uint32_t);
                        else
                                addr -= sizeof(uint32_t);
                }
        }

        if (w_bit)
                *np = addr;
}
Y(bdt_store)


/*  Various load/store multiple instructions:  */
uint32_t *multi_opcode[256];
void (**multi_opcode_f[256])(struct cpu *, struct arm_instr_call *);
X(multi_0x08b15018);
X(multi_0x08ac000c__ge);
X(multi_0x08a05018);


/*****************************************************************************/


/*
 *  netbsd_memset:
 *
 *  The core of a NetBSD/arm memset.
 *
 *  f01bc420:  e25XX080     subs    rX,rX,#0x80
 *  f01bc424:  a8ac000c     stmgeia ip!,{r2,r3}   (16 of these)
 *  ..
 *  f01bc464:  caffffed     bgt     0xf01bc420      <memset+0x38>
 */
X(netbsd_memset)
{
        unsigned char *page;
        uint32_t addr;

        do {
                addr = cpu->cd.arm.r[ARM_IP];

                instr(subs)(cpu, ic);

                if (((cpu->cd.arm.flags & ARM_F_N)?1:0) !=
                    ((cpu->cd.arm.flags & ARM_F_V)?1:0)) {
                        cpu->n_translated_instrs += 16;
                        /*  Skip the store multiples:  */
                        cpu->cd.arm.next_ic = &ic[17];
                        return;
                }

                /*  Crossing a page boundary? Then continue non-combined.  */
                if ((addr & 0xfff) + 128 > 0x1000)
                        return;

                /*  R2/R3 non-zero? Not allowed here.  */
                if (cpu->cd.arm.r[2] != 0 || cpu->cd.arm.r[3] != 0)
                        return;

                /*  printf("addr = 0x%08x\n", addr);  */

                page = cpu->cd.arm.host_store[addr >> 12];
                /*  No page translation? Continue non-combined.  */
                if (page == NULL)
                        return;

                /*  Clear:  */
                memset(page + (addr & 0xfff), 0, 128);
                cpu->cd.arm.r[ARM_IP] = addr + 128;
                cpu->n_translated_instrs += 16;

                /*  Branch back if greater:  */
                cpu->n_translated_instrs += 1;
        } while (((cpu->cd.arm.flags & ARM_F_N)?1:0) ==
            ((cpu->cd.arm.flags & ARM_F_V)?1:0) &&
            !(cpu->cd.arm.flags & ARM_F_Z));

        /*  Continue at the instruction after the bgt:  */
        cpu->cd.arm.next_ic = &ic[18];
}


/*
 *  netbsd_memcpy:
 *
 *  The core of a NetBSD/arm memcpy.
 *
 *  f01bc530:  e8b15018     ldmia   r1!,{r3,r4,ip,lr}
 *  f01bc534:  e8a05018     stmia   r0!,{r3,r4,ip,lr}
 *  f01bc538:  e8b15018     ldmia   r1!,{r3,r4,ip,lr}
 *  f01bc53c:  e8a05018     stmia   r0!,{r3,r4,ip,lr}
 *  f01bc540:  e2522020     subs    r2,r2,#0x20
 *  f01bc544:  aafffff9     bge     0xf01bc530
 */
X(netbsd_memcpy)
{
        unsigned char *page_0, *page_1;
        uint32_t addr_r0, addr_r1;

        do {
                addr_r0 = cpu->cd.arm.r[0];
                addr_r1 = cpu->cd.arm.r[1];

                /*  printf("addr_r0 = %08x  r1 = %08x\n", addr_r0, addr_r1);  */

                /*  Crossing a page boundary? Then continue non-combined.  */
                if ((addr_r0 & 0xfff) + 32 > 0x1000 ||
                    (addr_r1 & 0xfff) + 32 > 0x1000) {
                        instr(multi_0x08b15018)(cpu, ic);
                        return;
                }

                page_0 = cpu->cd.arm.host_store[addr_r0 >> 12];
                page_1 = cpu->cd.arm.host_store[addr_r1 >> 12];

                /*  No page translations? Continue non-combined.  */
                if (page_0 == NULL || page_1 == NULL) {
                        instr(multi_0x08b15018)(cpu, ic);
                        return;
                }

                memcpy(page_0 + (addr_r0 & 0xfff),
                    page_1 + (addr_r1 & 0xfff), 32);
                cpu->cd.arm.r[0] = addr_r0 + 32;
                cpu->cd.arm.r[1] = addr_r1 + 32;

                cpu->n_translated_instrs += 4;

                instr(subs)(cpu, ic + 4);
                cpu->n_translated_instrs ++;

                /*  Loop while greater or equal:  */
                cpu->n_translated_instrs ++;
        } while (((cpu->cd.arm.flags & ARM_F_N)?1:0) ==
            ((cpu->cd.arm.flags & ARM_F_V)?1:0));

        /*  Continue at the instruction after the bge:  */
        cpu->cd.arm.next_ic = &ic[6];
        cpu->n_translated_instrs --;
}


/*
 *  netbsd_cacheclean:
 *
 *  The core of a NetBSD/arm cache clean routine, variant 1:
 *
 *  f015f88c:  e4902020     ldr     r2,[r0],#32
 *  f015f890:  e2511020     subs    r1,r1,#0x20
 *  f015f894:  1afffffc     bne     0xf015f88c
 *  f015f898:  ee070f9a     mcr     15,0,r0,cr7,cr10,4
 */
X(netbsd_cacheclean)
{
        uint32_t r1 = cpu->cd.arm.r[1];
        cpu->n_translated_instrs += ((r1 >> 5) * 3);
        cpu->cd.arm.r[0] += r1;
        cpu->cd.arm.r[1] = 0;
        cpu->cd.arm.next_ic = &ic[4];
}


/*
 *  netbsd_cacheclean2:
 *
 *  The core of a NetBSD/arm cache clean routine, variant 2:
 *
 *  f015f93c:  ee070f3a     mcr     15,0,r0,cr7,cr10,1
 *  f015f940:  ee070f36     mcr     15,0,r0,cr7,cr6,1
 *  f015f944:  e2800020     add     r0,r0,#0x20
 *  f015f948:  e2511020     subs    r1,r1,#0x20
 *  f015f94c:  8afffffa     bhi     0xf015f93c
 */
X(netbsd_cacheclean2)
{
        cpu->n_translated_instrs += ((cpu->cd.arm.r[1] >> 5) * 5) - 1;
        cpu->cd.arm.next_ic = &ic[5];
}


/*
 *  netbsd_scanc:
 *
 *  f01bccbc:  e5d13000     ldrb    r3,[r1]
 *  f01bccc0:  e7d23003     ldrb    r3,[r2,r3]
 *  f01bccc4:  e113000c     tsts    r3,ip
 */
X(netbsd_scanc)
{
        unsigned char *page = cpu->cd.arm.host_load[cpu->cd.arm.r[1] >> 12];
        uint32_t t;

        if (page == NULL) {
                instr(load_w0_byte_u1_p1_imm)(cpu, ic);
                return;
        }

        t = page[cpu->cd.arm.r[1] & 0xfff];
        t += cpu->cd.arm.r[2];
        page = cpu->cd.arm.host_load[t >> 12];

        if (page == NULL) {
                instr(load_w0_byte_u1_p1_imm)(cpu, ic);
                return;
        }

        cpu->cd.arm.r[3] = page[t & 0xfff];

        t = cpu->cd.arm.r[3] & cpu->cd.arm.r[ARM_IP];
        cpu->cd.arm.flags &= ~(ARM_F_Z | ARM_F_N);
        if (t == 0)
                cpu->cd.arm.flags |= ARM_F_Z;

        cpu->n_translated_instrs += 2;
        cpu->cd.arm.next_ic = &ic[3];
}


/*
 *  strlen:
 *
 *  S: e5f03001   ldrb  rY,[rX,#1]!
 *     e3530000   cmps  rY,#0
 *     1afffffc   bne   S
 */
X(strlen)
{
        unsigned int n_loops = 0;
        uint32_t rY, rX = reg(ic[0].arg[0]);
        unsigned char *p;

        do {
                rX ++;
                p = cpu->cd.arm.host_load[rX >> 12];
                if (p == NULL) {
                        cpu->n_translated_instrs += (n_loops * 3);
                        instr(load_w1_byte_u1_p1_imm)(cpu, ic);
                        return;
                }

                rY = reg(ic[0].arg[2]) = p[rX & 0xfff]; /*  load  */
                reg(ic[0].arg[0]) = rX;                 /*  writeback  */
                n_loops ++;

                /*  Compare rY to zero:  */
                cpu->cd.arm.flags = ARM_F_C;
                if (rY == 0)
                        cpu->cd.arm.flags |= ARM_F_Z;
        } while (rY != 0);

        cpu->n_translated_instrs += (n_loops * 3) - 1;
        cpu->cd.arm.next_ic = &ic[3];
}


/*
 *  xchg:
 *
 *  e02YX00X     eor     rX,rY,rX
 *  e02XY00Y     eor     rY,rX,rY
 *  e02YX00X     eor     rX,rY,rX
 */
X(xchg)
{
        uint32_t tmp = reg(ic[0].arg[0]);
        cpu->n_translated_instrs += 2;
        cpu->cd.arm.next_ic = &ic[3];
        reg(ic[0].arg[0]) = reg(ic[1].arg[0]);
        reg(ic[1].arg[0]) = tmp;
}


/*
 *  netbsd_copyin:
 *
 *  e4b0a004     ldrt    sl,[r0],#4
 *  e4b0b004     ldrt    fp,[r0],#4
 *  e4b06004     ldrt    r6,[r0],#4
 *  e4b07004     ldrt    r7,[r0],#4
 *  e4b08004     ldrt    r8,[r0],#4
 *  e4b09004     ldrt    r9,[r0],#4
 */
X(netbsd_copyin)
{
        uint32_t r0 = cpu->cd.arm.r[0], ofs = (r0 & 0xffc), index = r0 >> 12;
        unsigned char *p = cpu->cd.arm.host_load[index];
        uint32_t *p32 = (uint32_t *) p, *q32;
        int ok = cpu->cd.arm.is_userpage[index >> 5] & (1 << (index & 31));

        if (ofs > 0x1000 - 6*4 || !ok || p == NULL) {
                instr(load_w1_word_u1_p0_imm)(cpu, ic);
                return;
        }
        q32 = &cpu->cd.arm.r[6];
        ofs >>= 2;
        q32[0] = p32[ofs+2];
        q32[1] = p32[ofs+3];
        q32[2] = p32[ofs+4];
        q32[3] = p32[ofs+5];
        q32[4] = p32[ofs+0];
        q32[5] = p32[ofs+1];
        cpu->cd.arm.r[0] = r0 + 24;
        cpu->n_translated_instrs += 5;
        cpu->cd.arm.next_ic = &ic[6];
}


/*
 *  netbsd_copyout:
 *
 *  e4a18004     strt    r8,[r1],#4
 *  e4a19004     strt    r9,[r1],#4
 *  e4a1a004     strt    sl,[r1],#4
 *  e4a1b004     strt    fp,[r1],#4
 *  e4a16004     strt    r6,[r1],#4
 *  e4a17004     strt    r7,[r1],#4
 */
X(netbsd_copyout)
{
        uint32_t r1 = cpu->cd.arm.r[1], ofs = (r1 & 0xffc), index = r1 >> 12;
        unsigned char *p = cpu->cd.arm.host_store[index];
        uint32_t *p32 = (uint32_t *) p, *q32;
        int ok = cpu->cd.arm.is_userpage[index >> 5] & (1 << (index & 31));

        if (ofs > 0x1000 - 6*4 || !ok || p == NULL) {
                instr(store_w1_word_u1_p0_imm)(cpu, ic);
                return;
        }
        q32 = &cpu->cd.arm.r[6];
        ofs >>= 2;
        p32[ofs  ] = q32[2];
        p32[ofs+1] = q32[3];
        p32[ofs+2] = q32[4];
        p32[ofs+3] = q32[5];
        p32[ofs+4] = q32[0];
        p32[ofs+5] = q32[1];
        cpu->cd.arm.r[1] = r1 + 24;
        cpu->n_translated_instrs += 5;
        cpu->cd.arm.next_ic = &ic[6];
}


/*
 *  cmps by 0, followed by beq (inside the same page):
 */
X(cmps0_beq_samepage)
{
        uint32_t a = reg(ic->arg[0]);
        cpu->n_translated_instrs ++;
        if (a == 0) {
                cpu->cd.arm.flags = ARM_F_Z | ARM_F_C;
        } else {
                /*  Semi-ugly hack which sets the negative-bit if a < 0:  */
                cpu->cd.arm.flags = ARM_F_C | ((a >> 28) & 8);
        }
        if (a == 0)
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
        else
                cpu->cd.arm.next_ic = &ic[2];
}


/*
 *  cmps followed by beq (inside the same page):
 */
X(cmps_beq_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if (((int32_t)a >= 0 && (int32_t)b < 0 && (int32_t)c < 0) ||
            ((int32_t)a < 0 && (int32_t)b >= 0 && (int32_t)c >= 0))
                cpu->cd.arm.flags |= ARM_F_V;
        if (c == 0) {
                cpu->cd.arm.flags |= ARM_F_Z;
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
        } else {
                cpu->cd.arm.next_ic = &ic[2];
                if (c & 0x80000000)
                        cpu->cd.arm.flags |= ARM_F_N;
        }
}


/*
 *  cmps followed by beq (not the same page):
 */
X(cmps_0_beq)
{
        uint32_t a = reg(ic->arg[0]);
        cpu->n_translated_instrs ++;
        if (a == 0) {
                cpu->cd.arm.flags = ARM_F_Z | ARM_F_C;
                cpu->pc = (uint32_t)(((uint32_t)cpu->pc & 0xfffff000)
                    + (int32_t)ic[1].arg[0]);
                quick_pc_to_pointers(cpu);
        } else {
                /*  Semi-ugly hack which sets the negative-bit if a < 0:  */
                cpu->cd.arm.flags = ARM_F_C | ((a >> 28) & 8);
                cpu->cd.arm.next_ic = &ic[2];
        }
}
X(cmps_pos_beq)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if ((int32_t)a < 0 && (int32_t)c >= 0)
                cpu->cd.arm.flags |= ARM_F_V;
        if (c == 0) {
                cpu->cd.arm.flags |= ARM_F_Z;
                cpu->pc = (uint32_t)(((uint32_t)cpu->pc & 0xfffff000)
                    + (int32_t)ic[1].arg[0]);
                quick_pc_to_pointers(cpu);
        } else {
                cpu->cd.arm.next_ic = &ic[2];
                if (c & 0x80000000)
                        cpu->cd.arm.flags |= ARM_F_N;
        }
}
X(cmps_neg_beq)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if ((int32_t)a >= 0 && (int32_t)c < 0)
                cpu->cd.arm.flags |= ARM_F_V;
        if (c == 0) {
                cpu->cd.arm.flags |= ARM_F_Z;
                cpu->pc = (uint32_t)(((uint32_t)cpu->pc & 0xfffff000)
                    + (int32_t)ic[1].arg[0]);
                quick_pc_to_pointers(cpu);
        } else {
                cpu->cd.arm.next_ic = &ic[2];
                if (c & 0x80000000)
                        cpu->cd.arm.flags |= ARM_F_N;
        }
}


/*
 *  cmps by 0, followed by bne (inside the same page):
 */
X(cmps0_bne_samepage)
{
        uint32_t a = reg(ic->arg[0]);
        cpu->n_translated_instrs ++;
        if (a == 0) {
                cpu->cd.arm.flags = ARM_F_Z | ARM_F_C;
        } else {
                /*  Semi-ugly hack which sets the negative-bit if a < 0:  */
                cpu->cd.arm.flags = ARM_F_C | ((a >> 28) & 8);
        }
        if (a == 0)
                cpu->cd.arm.next_ic = &ic[2];
        else
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
}


/*
 *  cmps followed by bne (inside the same page):
 */
X(cmps_bne_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if (((int32_t)a >= 0 && (int32_t)b < 0 && (int32_t)c < 0) ||
            ((int32_t)a < 0 && (int32_t)b >= 0 && (int32_t)c >= 0))
                cpu->cd.arm.flags |= ARM_F_V;
        if (c == 0) {
                cpu->cd.arm.flags |= ARM_F_Z;
                cpu->cd.arm.next_ic = &ic[2];
        } else {
                if (c & 0x80000000)
                        cpu->cd.arm.flags |= ARM_F_N;
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
        }
}


/*
 *  cmps followed by bcc (inside the same page):
 */
X(cmps_bcc_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if (c & 0x80000000)
                cpu->cd.arm.flags |= ARM_F_N;
        else if (c == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (((int32_t)a >= 0 && (int32_t)b < 0 && (int32_t)c < 0) ||
            ((int32_t)a < 0 && (int32_t)b >= 0 && (int32_t)c >= 0))
                cpu->cd.arm.flags |= ARM_F_V;
        if (a >= b)
                cpu->cd.arm.next_ic = &ic[2];
        else
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
}


/*
 *  cmps (reg) followed by bcc (inside the same page):
 */
X(cmps_reg_bcc_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = reg(ic->arg[1]), c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if (c & 0x80000000)
                cpu->cd.arm.flags |= ARM_F_N;
        else if (c == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (((int32_t)a >= 0 && (int32_t)b < 0 && (int32_t)c < 0) ||
            ((int32_t)a < 0 && (int32_t)b >= 0 && (int32_t)c >= 0))
                cpu->cd.arm.flags |= ARM_F_V;
        if (a >= b)
                cpu->cd.arm.next_ic = &ic[2];
        else
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
}


/*
 *  cmps followed by bhi (inside the same page):
 */
X(cmps_bhi_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if (c & 0x80000000)
                cpu->cd.arm.flags |= ARM_F_N;
        else if (c == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (((int32_t)a >= 0 && (int32_t)b < 0 && (int32_t)c < 0) ||
            ((int32_t)a < 0 && (int32_t)b >= 0 && (int32_t)c >= 0))
                cpu->cd.arm.flags |= ARM_F_V;
        if (a > b)
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
        else
                cpu->cd.arm.next_ic = &ic[2];
}


/*
 *  cmps (reg) followed by bhi (inside the same page):
 */
X(cmps_reg_bhi_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = reg(ic->arg[1]), c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if (c & 0x80000000)
                cpu->cd.arm.flags |= ARM_F_N;
        else if (c == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (((int32_t)a >= 0 && (int32_t)b < 0 && (int32_t)c < 0) ||
            ((int32_t)a < 0 && (int32_t)b >= 0 && (int32_t)c >= 0))
                cpu->cd.arm.flags |= ARM_F_V;
        if (a > b)
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
        else
                cpu->cd.arm.next_ic = &ic[2];
}


/*
 *  cmps followed by bgt (inside the same page):
 */
X(cmps_bgt_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if (c & 0x80000000)
                cpu->cd.arm.flags |= ARM_F_N;
        else if (c == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (((int32_t)a >= 0 && (int32_t)b < 0 && (int32_t)c < 0) ||
            ((int32_t)a < 0 && (int32_t)b >= 0 && (int32_t)c >= 0))
                cpu->cd.arm.flags |= ARM_F_V;
        if ((int32_t)a > (int32_t)b)
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
        else
                cpu->cd.arm.next_ic = &ic[2];
}


/*
 *  cmps followed by ble (inside the same page):
 */
X(cmps_ble_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a - b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags = ((uint32_t)a >= (uint32_t)b)? ARM_F_C : 0;
        if (c & 0x80000000)
                cpu->cd.arm.flags |= ARM_F_N;
        else if (c == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (((int32_t)a >= 0 && (int32_t)b < 0 && (int32_t)c < 0) ||
            ((int32_t)a < 0 && (int32_t)b >= 0 && (int32_t)c >= 0))
                cpu->cd.arm.flags |= ARM_F_V;
        if ((int32_t)a <= (int32_t)b)
                cpu->cd.arm.next_ic = (struct arm_instr_call *) ic[1].arg[0];
        else
                cpu->cd.arm.next_ic = &ic[2];
}


/*
 *  teqs followed by beq (inside the same page):
 */
X(teqs_beq_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a ^ b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags &= ~(ARM_F_Z | ARM_F_N);
        if (c == 0) {
                cpu->cd.arm.flags |= ARM_F_Z;
                cpu->cd.arm.next_ic = (struct arm_instr_call *)
                    ic[1].arg[0];
        } else {
                if (c & 0x80000000)
                        cpu->cd.arm.flags |= ARM_F_N;
                cpu->cd.arm.next_ic = &ic[2];
        }
}


/*
 *  tsts followed by beq (inside the same page):
 *  (arg[1] must not have its highest bit set))
 */
X(tsts_lo_beq_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a & b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags &= ~(ARM_F_Z | ARM_F_N);
        if (c == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (c == 0)
                cpu->cd.arm.next_ic = (struct arm_instr_call *)
                    ic[1].arg[0];
        else
                cpu->cd.arm.next_ic = &ic[2];
}


/*
 *  teqs followed by bne (inside the same page):
 */
X(teqs_bne_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a ^ b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags &= ~(ARM_F_Z | ARM_F_N);
        if (c == 0) {
                cpu->cd.arm.flags |= ARM_F_Z;
        } else {
                if (c & 0x80000000)
                        cpu->cd.arm.flags |= ARM_F_N;
        }
        if (c == 0)
                cpu->cd.arm.next_ic = &ic[2];
        else
                cpu->cd.arm.next_ic = (struct arm_instr_call *)
                    ic[1].arg[0];
}


/*
 *  tsts followed by bne (inside the same page):
 *  (arg[1] must not have its highest bit set))
 */
X(tsts_lo_bne_samepage)
{
        uint32_t a = reg(ic->arg[0]), b = ic->arg[1], c = a & b;
        cpu->n_translated_instrs ++;
        cpu->cd.arm.flags &= ~(ARM_F_Z | ARM_F_N);
        if (c == 0)
                cpu->cd.arm.flags |= ARM_F_Z;
        if (c == 0)
                cpu->cd.arm.next_ic = &ic[2];
        else
                cpu->cd.arm.next_ic = (struct arm_instr_call *)
                    ic[1].arg[0];
}


/*****************************************************************************/


X(end_of_page)
{
        /*  Update the PC:  (offset 0, but on the next page)  */
        cpu->pc &= ~((ARM_IC_ENTRIES_PER_PAGE-1) << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc += (ARM_IC_ENTRIES_PER_PAGE << ARM_INSTR_ALIGNMENT_SHIFT);

        /*  Find the new physical page and update the translation pointers:  */
        quick_pc_to_pointers(cpu);

        /*  end_of_page doesn't count as an executed instruction:  */
        cpu->n_translated_instrs --;
}


/*****************************************************************************/


/*
 *  arm_combine_netbsd_memset():
 *
 *  Check for the core of a NetBSD/arm memset; large memsets use a sequence
 *  of 16 store-multiple instructions, each storing 2 registers at a time.
 */
void arm_combine_netbsd_memset(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
#ifdef HOST_LITTLE_ENDIAN
        int n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);

        if (n_back >= 17) {
                int i;
                for (i=-16; i<=-1; i++)
                        if (ic[i].f != instr(multi_0x08ac000c__ge))
                                return;
                if (ic[-17].f == instr(subs) &&
                    ic[-17].arg[0]==ic[-17].arg[2] && ic[-17].arg[1] == 128 &&
                    ic[ 0].f == instr(b_samepage__gt) &&
                    ic[ 0].arg[0] == (size_t)&ic[-17]) {
                        ic[-17].f = instr(netbsd_memset);
                        combined;
                }
        }
#endif
}


/*
 *  arm_combine_netbsd_memcpy():
 *
 *  Check for the core of a NetBSD/arm memcpy; large memcpys use a
 *  sequence of ldmia instructions.
 */
void arm_combine_netbsd_memcpy(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
#ifdef HOST_LITTLE_ENDIAN
        int n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);

        if (n_back >= 5) {
                if (ic[-5].f==instr(multi_0x08b15018) &&
                    ic[-4].f==instr(multi_0x08a05018) &&
                    ic[-3].f==instr(multi_0x08b15018) &&
                    ic[-2].f==instr(multi_0x08a05018) &&
                    ic[-1].f == instr(subs) &&
                    ic[-1].arg[0]==ic[-1].arg[2] && ic[-1].arg[1] == 0x20 &&
                    ic[ 0].f == instr(b_samepage__ge) &&
                    ic[ 0].arg[0] == (size_t)&ic[-5]) {
                        ic[-5].f = instr(netbsd_memcpy);
                        combined;
                }
        }
#endif
}


/*
 *  arm_combine_netbsd_cacheclean():
 *
 *  Check for the core of a NetBSD/arm cache clean. (There are two variants.)
 */
void arm_combine_netbsd_cacheclean(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
        int n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);

        if (n_back >= 3) {
                if (ic[-3].f==instr(load_w0_word_u1_p0_imm) &&
                    ic[-2].f == instr(subs) &&
                    ic[-2].arg[0]==ic[-2].arg[2] && ic[-2].arg[1] == 0x20 &&
                    ic[-1].f == instr(b_samepage__ne) &&
                    ic[-1].arg[0] == (size_t)&ic[-3]) {
                        ic[-3].f = instr(netbsd_cacheclean);
                        combined;
                }
        }
}


/*
 *  arm_combine_netbsd_cacheclean2():
 *
 *  Check for the core of a NetBSD/arm cache clean. (Second variant.)
 */
void arm_combine_netbsd_cacheclean2(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
        int n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);

        if (n_back >= 4) {
                if (ic[-4].f == instr(mcr_mrc) && ic[-4].arg[0] == 0xee070f3a &&
                    ic[-3].f == instr(mcr_mrc) && ic[-3].arg[0] == 0xee070f36 &&
                    ic[-2].f == instr(add) &&
                    ic[-2].arg[0]==ic[-2].arg[2] && ic[-2].arg[1] == 0x20 &&
                    ic[-1].f == instr(subs) &&
                    ic[-1].arg[0]==ic[-1].arg[2] && ic[-1].arg[1] == 0x20) {
                        ic[-4].f = instr(netbsd_cacheclean2);
                        combined;
                }
        }
}


/*
 *  arm_combine_netbsd_scanc():
 */
void arm_combine_netbsd_scanc(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
        int n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);

        if (n_back < 2)
                return;

        if (ic[-2].f == instr(load_w0_byte_u1_p1_imm) &&
            ic[-2].arg[0] == (size_t)(&cpu->cd.arm.r[1]) &&
            ic[-2].arg[1] == 0 &&
            ic[-2].arg[2] == (size_t)(&cpu->cd.arm.r[3]) &&
            ic[-1].f == instr(load_w0_byte_u1_p1_reg) &&
            ic[-1].arg[0] == (size_t)(&cpu->cd.arm.r[2]) &&
            ic[-1].arg[1] == (size_t)arm_r_r3_t0_c0 &&
            ic[-1].arg[2] == (size_t)(&cpu->cd.arm.r[3])) {
                ic[-2].f = instr(netbsd_scanc);
                combined;
        }
}


/*
 *  arm_combine_strlen():
 */
void arm_combine_strlen(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
        int n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);

        if (n_back < 2)
                return;

        if (ic[-2].f == instr(load_w1_byte_u1_p1_imm) &&
            ic[-2].arg[1] == 1 &&
            ic[-2].arg[2] == (size_t)(&cpu->cd.arm.r[3]) &&
            ic[-1].f == instr(cmps) &&
            ic[-1].arg[0] == (size_t)(&cpu->cd.arm.r[3]) &&
            ic[-1].arg[1] == 0) {
                ic[-2].f = instr(strlen);
                combined;
        }
}


/*
 *  arm_combine_xchg():
 */
void arm_combine_xchg(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
        int n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);
        size_t a, b;

        if (n_back < 2)
                return;

        a = ic[-2].arg[0]; b = ic[-1].arg[0];

        if (ic[-2].f == instr(eor_regshort) &&
            ic[-1].f == instr(eor_regshort) &&
            ic[-2].arg[0] == a && ic[-2].arg[1] == b && ic[-2].arg[2] == b &&
            ic[-1].arg[0] == b && ic[-1].arg[1] == a && ic[-1].arg[2] == a &&
            ic[ 0].arg[0] == a && ic[ 0].arg[1] == b && ic[ 0].arg[2] == b) {
                ic[-2].f = instr(xchg);
                combined;
        }
}


/*
 *  arm_combine_netbsd_copyin():
 */
void arm_combine_netbsd_copyin(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
#ifdef HOST_LITTLE_ENDIAN
        int i, n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);

        if (n_back < 5)
                return;

        for (i=-5; i<0; i++) {
                if (ic[i].f != instr(load_w1_word_u1_p0_imm) ||
                    ic[i].arg[0] != (size_t)(&cpu->cd.arm.r[0]) ||
                    ic[i].arg[1] != 4)
                        return;
        }

        if (ic[-5].arg[2] == (size_t)(&cpu->cd.arm.r[10]) &&
            ic[-4].arg[2] == (size_t)(&cpu->cd.arm.r[11]) &&
            ic[-3].arg[2] == (size_t)(&cpu->cd.arm.r[6]) &&
            ic[-2].arg[2] == (size_t)(&cpu->cd.arm.r[7]) &&
            ic[-1].arg[2] == (size_t)(&cpu->cd.arm.r[8])) {
                ic[-5].f = instr(netbsd_copyin);
                combined;
        }
#endif
}


/*
 *  arm_combine_netbsd_copyout():
 */
void arm_combine_netbsd_copyout(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
#ifdef HOST_LITTLE_ENDIAN
        int i, n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);

        if (n_back < 5)
                return;

        for (i=-5; i<0; i++) {
                if (ic[i].f != instr(store_w1_word_u1_p0_imm) ||
                    ic[i].arg[0] != (size_t)(&cpu->cd.arm.r[1]) ||
                    ic[i].arg[1] != 4)
                        return;
        }

        if (ic[-5].arg[2] == (size_t)(&cpu->cd.arm.r[8]) &&
            ic[-4].arg[2] == (size_t)(&cpu->cd.arm.r[9]) &&
            ic[-3].arg[2] == (size_t)(&cpu->cd.arm.r[10]) &&
            ic[-2].arg[2] == (size_t)(&cpu->cd.arm.r[11]) &&
            ic[-1].arg[2] == (size_t)(&cpu->cd.arm.r[6])) {
                ic[-5].f = instr(netbsd_copyout);
                combined;
        }
#endif
}


/*
 *  arm_combine_cmps_b():
 */
void arm_combine_cmps_b(struct cpu *cpu,
        struct arm_instr_call *ic, int low_addr)
{
        int n_back = (low_addr >> ARM_INSTR_ALIGNMENT_SHIFT)
            & (ARM_IC_ENTRIES_PER_PAGE-1);
        if (n_back < 1)
                return;
        if (ic[0].f == instr(b__eq)) {
                if (ic[-1].f == instr(cmps)) {
                        if (ic[-1].arg[1] == 0)
                                ic[-1].f = instr(cmps_0_beq);
                        else if (ic[-1].arg[1] & 0x80000000)
                                ic[-1].f = instr(cmps_neg_beq);
                        else
                                ic[-1].f = instr(cmps_pos_beq);
                        combined;
                }
                return;
        }
        if (ic[0].f == instr(b_samepage__eq)) {
                if (ic[-1].f == instr(cmps)) {
                        if (ic[-1].arg[1] == 0)
                                ic[-1].f = instr(cmps0_beq_samepage);
                        else
                                ic[-1].f = instr(cmps_beq_samepage);
                        combined;
                }
                if (ic[-1].f == instr(tsts) &&
                    !(ic[-1].arg[1] & 0x80000000)) {
                        ic[-1].f = instr(tsts_lo_beq_samepage);
                        combined;
                }
                if (ic[-1].f == instr(teqs)) {
                        ic[-1].f = instr(teqs_beq_samepage);
                        combined;
                }
                return;
        }
        if (ic[0].f == instr(b_samepage__ne)) {
                if (ic[-1].f == instr(cmps)) {
                        if (ic[-1].arg[1] == 0)
                                ic[-1].f = instr(cmps0_bne_samepage);
                        else
                                ic[-1].f = instr(cmps_bne_samepage);
                        combined;
                }
                if (ic[-1].f == instr(tsts) &&
                    !(ic[-1].arg[1] & 0x80000000)) {
                        ic[-1].f = instr(tsts_lo_bne_samepage);
                        combined;
                }
                if (ic[-1].f == instr(teqs)) {
                        ic[-1].f = instr(teqs_bne_samepage);
                        combined;
                }
                return;
        }
        if (ic[0].f == instr(b_samepage__cc)) {
                if (ic[-1].f == instr(cmps)) {
                        ic[-1].f = instr(cmps_bcc_samepage);
                        combined;
                }
                if (ic[-1].f == instr(cmps_regshort)) {
                        ic[-1].f = instr(cmps_reg_bcc_samepage);
                        combined;
                }
                return;
        }
        if (ic[0].f == instr(b_samepage__hi)) {
                if (ic[-1].f == instr(cmps)) {
                        ic[-1].f = instr(cmps_bhi_samepage);
                        combined;
                }
                if (ic[-1].f == instr(cmps_regshort)) {
                        ic[-1].f = instr(cmps_reg_bhi_samepage);
                        combined;
                }
                return;
        }
        if (ic[0].f == instr(b_samepage__gt)) {
                if (ic[-1].f == instr(cmps)) {
                        ic[-1].f = instr(cmps_bgt_samepage);
                        combined;
                }
                return;
        }
        if (ic[0].f == instr(b_samepage__le)) {
                if (ic[-1].f == instr(cmps)) {
                        ic[-1].f = instr(cmps_ble_samepage);
                        combined;
                }
                return;
        }
}


/*****************************************************************************/


static void arm_switch_clear(struct arm_instr_call *ic, int rd,
        int condition_code)
{
        switch (rd) {
        case  0: ic->f = cond_instr(clear_r0); break;
        case  1: ic->f = cond_instr(clear_r1); break;
        case  2: ic->f = cond_instr(clear_r2); break;
        case  3: ic->f = cond_instr(clear_r3); break;
        case  4: ic->f = cond_instr(clear_r4); break;
        case  5: ic->f = cond_instr(clear_r5); break;
        case  6: ic->f = cond_instr(clear_r6); break;
        case  7: ic->f = cond_instr(clear_r7); break;
        case  8: ic->f = cond_instr(clear_r8); break;
        case  9: ic->f = cond_instr(clear_r9); break;
        case 10: ic->f = cond_instr(clear_r10); break;
        case 11: ic->f = cond_instr(clear_r11); break;
        case 12: ic->f = cond_instr(clear_r12); break;
        case 13: ic->f = cond_instr(clear_r13); break;
        case 14: ic->f = cond_instr(clear_r14); break;
        }
}


static void arm_switch_mov1(struct arm_instr_call *ic, int rd,
        int condition_code)
{
        switch (rd) {
        case  0: ic->f = cond_instr(mov1_r0); break;
        case  1: ic->f = cond_instr(mov1_r1); break;
        case  2: ic->f = cond_instr(mov1_r2); break;
        case  3: ic->f = cond_instr(mov1_r3); break;
        case  4: ic->f = cond_instr(mov1_r4); break;
        case  5: ic->f = cond_instr(mov1_r5); break;
        case  6: ic->f = cond_instr(mov1_r6); break;
        case  7: ic->f = cond_instr(mov1_r7); break;
        case  8: ic->f = cond_instr(mov1_r8); break;
        case  9: ic->f = cond_instr(mov1_r9); break;
        case 10: ic->f = cond_instr(mov1_r10); break;
        case 11: ic->f = cond_instr(mov1_r11); break;
        case 12: ic->f = cond_instr(mov1_r12); break;
        case 13: ic->f = cond_instr(mov1_r13); break;
        case 14: ic->f = cond_instr(mov1_r14); break;
        }
}


static void arm_switch_add1(struct arm_instr_call *ic, int rd,
        int condition_code)
{
        switch (rd) {
        case  0: ic->f = cond_instr(add1_r0); break;
        case  1: ic->f = cond_instr(add1_r1); break;
        case  2: ic->f = cond_instr(add1_r2); break;
        case  3: ic->f = cond_instr(add1_r3); break;
        case  4: ic->f = cond_instr(add1_r4); break;
        case  5: ic->f = cond_instr(add1_r5); break;
        case  6: ic->f = cond_instr(add1_r6); break;
        case  7: ic->f = cond_instr(add1_r7); break;
        case  8: ic->f = cond_instr(add1_r8); break;
        case  9: ic->f = cond_instr(add1_r9); break;
        case 10: ic->f = cond_instr(add1_r10); break;
        case 11: ic->f = cond_instr(add1_r11); break;
        case 12: ic->f = cond_instr(add1_r12); break;
        case 13: ic->f = cond_instr(add1_r13); break;
        case 14: ic->f = cond_instr(add1_r14); break;
        }
}


/*****************************************************************************/


/*
 *  arm_instr_to_be_translated():
 *
 *  Translate an instruction word into an arm_instr_call. ic is filled in with
 *  valid data for the translated instruction, or a "nothing" instruction if
 *  there was a translation failure. The newly translated instruction is then
 *  executed.
 */
X(to_be_translated)
{
        uint32_t addr, low_pc, iword, imm = 0;
        unsigned char *page;
        unsigned char ib[4];
        int condition_code, main_opcode, secondary_opcode, s_bit, rn, rd, r8;
        int p_bit, u_bit, w_bit, l_bit, regform, rm, c, t, any_pc_reg;
        void (*samepage_function)(struct cpu *, struct arm_instr_call *);

        /*  Figure out the address of the instruction:  */
        low_pc = ((size_t)ic - (size_t)cpu->cd.arm.cur_ic_page)
            / sizeof(struct arm_instr_call);
        addr = cpu->pc & ~((ARM_IC_ENTRIES_PER_PAGE-1) <<
            ARM_INSTR_ALIGNMENT_SHIFT);
        addr += (low_pc << ARM_INSTR_ALIGNMENT_SHIFT);
        cpu->pc = addr;
        addr &= ~((1 << ARM_INSTR_ALIGNMENT_SHIFT) - 1);

        /*  Read the instruction word from memory:  */
        page = cpu->cd.arm.host_load[addr >> 12];
        if (page != NULL) {
                /*  fatal("TRANSLATION HIT! 0x%08x\n", addr);  */
                memcpy(ib, page + (addr & 0xfff), sizeof(ib));
        } else {
                /*  fatal("TRANSLATION MISS! 0x%08x\n", addr);  */
                if (!cpu->memory_rw(cpu, cpu->mem, addr, &ib[0],
                    sizeof(ib), MEM_READ, CACHE_INSTRUCTION)) {
                        fatal("to_be_translated(): "
                            "read failed: TODO\n");
                        return;
                }
        }

        if (cpu->byte_order == EMUL_LITTLE_ENDIAN)
                iword = ib[0] + (ib[1]<<8) + (ib[2]<<16) + (ib[3]<<24);
        else
                iword = ib[3] + (ib[2]<<8) + (ib[1]<<16) + (ib[0]<<24);


#define DYNTRANS_TO_BE_TRANSLATED_HEAD
#include "cpu_dyntrans.c"
#undef  DYNTRANS_TO_BE_TRANSLATED_HEAD


        /*  The idea of taking bits 27..24 was found here:
            http://armphetamine.sourceforge.net/oldinfo.html  */
        condition_code = iword >> 28;
        main_opcode = (iword >> 24) & 15;
        secondary_opcode = (iword >> 21) & 15;
        u_bit = iword & 0x00800000;
        w_bit = iword & 0x00200000;
        s_bit = l_bit = iword & 0x00100000;
        rn    = (iword >> 16) & 15;
        rd    = (iword >> 12) & 15;
        r8    = (iword >> 8) & 15;
        c     = (iword >> 7) & 31;
        t     = (iword >> 4) & 7;
        rm    = iword & 15;

        if (condition_code == 0xf) {
                if ((iword & 0xfc70f000) == 0xf450f000) {
                        /*  Preload:  TODO.  Treat as NOP for now.  */
                        ic->f = instr(nop);
                        goto okay;
                }

                fatal("TODO: ARM condition code 0x%x\n",
                    condition_code);
                goto bad;
        }


        /*
         *  Translate the instruction:
         */

        switch (main_opcode) {

        case 0x0:
        case 0x1:
        case 0x2:
        case 0x3:
                /*  Check special cases first:  */
                if ((iword & 0x0fc000f0) == 0x00000090) {
                        /*
                         *  Multiplication:
                         *  xxxx0000 00ASdddd nnnnssss 1001mmmm (Rd,Rm,Rs[,Rn])
                         */
                        if (iword & 0x00200000) {
                                if (s_bit)
                                        ic->f = cond_instr(mlas);
                                else
                                        ic->f = cond_instr(mla);
                                ic->arg[0] = iword;
                        } else {
                                if (s_bit)
                                        ic->f = cond_instr(muls);
                                else
                                        ic->f = cond_instr(mul);
                                /*  NOTE: rn means rd in this case:  */
                                ic->arg[0] = (size_t)(&cpu->cd.arm.r[rn]);
                                ic->arg[1] = (size_t)(&cpu->cd.arm.r[rm]);
                                ic->arg[2] = (size_t)(&cpu->cd.arm.r[r8]);
                        }
                        break;
                }
                if ((iword & 0x0f8000f0) == 0x00800090) {
                        /*  Long multiplication:  */
                        if (s_bit) {
                                fatal("TODO: sbit mull\n");
                                goto bad;
                        }
                        ic->f = cond_instr(mull);
                        ic->arg[0] = iword;
                        break;
                }
                if ((iword & 0x0f900ff0) == 0x01000050) {
                        fatal("TODO: q{,d}{add,sub}\n");
                        goto bad;
                }
                if ((iword & 0x0ff000d0) == 0x01200010) {
                        /*  bx or blx  */
                        if (iword & 0x20)
                                ic->f = cond_instr(blx);
                        else {
                                if (cpu->machine->show_trace_tree &&
                                    rm == ARM_LR)
                                        ic->f = cond_instr(bx_trace);
                                else
                                        ic->f = cond_instr(bx);
                        }
                        ic->arg[0] = (size_t)(&cpu->cd.arm.r[rm]);
                        break;
                }
                if ((iword & 0x0fb00ff0) == 0x1000090) {
                        if (iword & 0x00400000)
                                ic->f = cond_instr(swpb);
                        else
                                ic->f = cond_instr(swp);
                        ic->arg[0] = (size_t)(&cpu->cd.arm.r[rd]);
                        ic->arg[1] = (size_t)(&cpu->cd.arm.r[rm]);
                        ic->arg[2] = (size_t)(&cpu->cd.arm.r[rn]);
                        break;
                }
                if ((iword & 0x0fff0ff0) == 0x016f0f10) {
                        ic->f = cond_instr(clz);
                        ic->arg[0] = (size_t)(&cpu->cd.arm.r[rm]);
                        ic->arg[1] = (size_t)(&cpu->cd.arm.r[rd]);
                        break;
                }
                if ((iword & 0x0ff00090) == 0x01000080) {
                        /*  TODO: smlaXX  */
                        goto bad;
                }
                if ((iword & 0x0ff00090) == 0x01400080) {
                        /*  TODO: smlalY  */
                        goto bad;
                }
                if ((iword & 0x0ff000b0) == 0x01200080) {
                        /*  TODO: smlawY  */
                        goto bad;
                }
                if ((iword & 0x0ff0f090) == 0x01600080) {
                        /*  TODO: smulXY  */
                        goto bad;
                }
                if ((iword & 0x0ff0f0b0) == 0x012000a0) {
                        /*  TODO: smulwY  */
                        goto bad;
                }
                if ((iword & 0x0fb0fff0) == 0x0120f000 ||
                    (iword & 0x0fb0f000) == 0x0320f000) {
                        /*  msr: move to [S|C]PSR from a register or
                            immediate value  */
                        if (rm == ARM_PC) {
                                fatal("msr PC?\n");
                                goto bad;
                        }
                        if (iword & 0x02000000) {
                                if (iword & 0x00400000)
                                        ic->f = cond_instr(msr_imm_spsr);
                                else
                                        ic->f = cond_instr(msr_imm);
                        } else {
                                if (iword & 0x00400000)
                                        ic->f = cond_instr(msr_spsr);
                                else
                                        ic->f = cond_instr(msr);
                        }
                        imm = iword & 0xff;
                        while (r8-- > 0)
                                imm = (imm >> 2) | ((imm & 3) << 30);
                        ic->arg[0] = imm;
                        ic->arg[2] = (size_t)(&cpu->cd.arm.r[rm]);
                        switch ((iword >> 16) & 15) {
                        case 1: ic->arg[1] = 0x000000ff; break;
                        case 8: ic->arg[1] = 0xff000000; break;
                        case 9: ic->arg[1] = 0xff0000ff; break;
                        default:fatal("unimpl a: msr regform\n");
                                goto bad;
                        }
                        break;
                }
                if ((iword & 0x0fbf0fff) == 0x010f0000) {
                        /*  mrs: move from CPSR/SPSR to a register:  */
                        if (rd == ARM_PC) {
                                fatal("mrs PC?\n");
                                goto bad;
                        }
                        if (iword & 0x00400000)
                                ic->f = cond_instr(mrs_spsr);
                        else
                                ic->f = cond_instr(mrs);
                        ic->arg[0] = (size_t)(&cpu->cd.arm.r[rd]);
                        break;
                }
                if ((iword & 0x0e000090) == 0x00000090) {
                        int imm = ((iword >> 4) & 0xf0) | (iword & 0xf);
                        int regform = !(iword & 0x00400000);
                        p_bit = main_opcode & 1;
                        ic->arg[0] = (size_t)(&cpu->cd.arm.r[rn]);
                        ic->arg[2] = (size_t)(&cpu->cd.arm.r[rd]);
                        if (rd == ARM_PC || rn == ARM_PC) {
                                ic->f = arm_load_store_instr_3_pc[
                                    condition_code + (l_bit? 16 : 0)
                                    + (iword & 0x40? 32 : 0)
                                    + (w_bit? 64 : 0)
                                    + (iword & 0x20? 128 : 0)
                                    + (u_bit? 256 : 0) + (p_bit? 512 : 0)
                                    + (regform? 1024 : 0)];
                                if (rn == ARM_PC)
                                        ic->arg[0] = (size_t)
                                            (&cpu->cd.arm.tmp_pc);
                                if (!l_bit && rd == ARM_PC)
                                        ic->arg[2] = (size_t)
                                            (&cpu->cd.arm.tmp_pc);
                        } else
                                ic->f = arm_load_store_instr_3[
                                    condition_code + (l_bit? 16 : 0)
                                    + (iword & 0x40? 32 : 0)
                                    + (w_bit? 64 : 0)
                                    + (iword & 0x20? 128 : 0)
                                    + (u_bit? 256 : 0) + (p_bit? 512 : 0)
                                    + (regform? 1024 : 0)];
                        if (regform)
                                ic->arg[1] = (size_t)(void *)arm_r[iword & 0xf];
                        else
                                ic->arg[1] = imm;
                        break;
                }

                if (iword & 0x80 && !(main_opcode & 2) && iword & 0x10) {
                        fatal("reg form blah blah\n");
                        goto bad;
                }

                /*  "mov pc,lr":  */
                if ((iword & 0x0fffffff) == 0x01a0f00e) {
                        if (cpu->machine->show_trace_tree)
                                ic->f = cond_instr(ret_trace);
                        else
                                ic->f = cond_instr(ret);
                        break;
                }

                /*  "mov reg,reg" or "mov reg,pc":  */
                if ((iword & 0x0fff0ff0) == 0x01a00000 && rd != ARM_PC) {
                        if (rm != ARM_PC) {
                                ic->f = cond_instr(mov_reg_reg);
                                ic->arg[0] = (size_t)(&cpu->cd.arm.r[rm]);
                        } else {
                                ic->f = cond_instr(mov_reg_pc);
                                ic->arg[0] = (addr & 0xfff) + 8;
                        }
                        ic->arg[1] = (size_t)(&cpu->cd.arm.r[rd]);
                        break;
                }

                /*  "mov reg,#0":  */
                if ((iword & 0x0fff0fff) == 0x03a00000 && rd != ARM_PC) {
                        arm_switch_clear(ic, rd, condition_code);
                        break;
                }

                /*  "mov reg,#1":  */
                if ((iword & 0x0fff0fff) == 0x03a00001 && rd != ARM_PC) {
                        arm_switch_mov1(ic, rd, condition_code);
                        break;
                }

                /*  "add reg,reg,#1":  */
                if ((iword & 0x0ff00fff) == 0x02800001 && rd != ARM_PC
                    && rn == rd) {
                        arm_switch_add1(ic, rd, condition_code);
                        break;
                }

                /*
                 *  Generic Data Processing Instructions:
                 */
                if ((main_opcode & 2) == 0)
                        regform = 1;
                else
                        regform = 0;

                if (regform) {
                        /*  0x1000 signifies Carry bit update on rotation,
                            which is not necessary for add,adc,sub,sbc,
                            rsb,rsc,cmp, or cmn, because they update the
                            Carry bit manually anyway.  */
                        int q = 0x1000;
                        if (s_bit == 0)
                                q = 0;
                        if ((secondary_opcode >= 2 && secondary_opcode <= 7)
                            || secondary_opcode==0xa || secondary_opcode==0xb)
                                q = 0;
                        ic->arg[1] = (size_t)(void *)arm_r[(iword & 0xfff) + q];
                } else {
                        imm = iword & 0xff;
                        while (r8-- > 0)
                                imm = (imm >> 2) | ((imm & 3) << 30);
                        ic->arg[1] = imm;
                }

                /*  mvn #imm ==> mov #~imm  */
                if (secondary_opcode == 0xf && !regform) {
                        secondary_opcode = 0xd;
                        ic->arg[1] = ~ic->arg[1];
                }

                ic->arg[0] = (size_t)(&cpu->cd.arm.r[rn]);
                ic->arg[2] = (size_t)(&cpu->cd.arm.r[rd]);
                any_pc_reg = 0;
                if (rn == ARM_PC || rd == ARM_PC)
                        any_pc_reg = 1;

                if (!any_pc_reg && regform && (iword & 0xfff) < ARM_PC) {
                        ic->arg[1] = (size_t)(&cpu->cd.arm.r[rm]);
                        ic->f = arm_dpi_instr_regshort[condition_code +
                            16 * secondary_opcode + (s_bit? 256 : 0)];
                } else
                        ic->f = arm_dpi_instr[condition_code +
                            16 * secondary_opcode + (s_bit? 256 : 0) +
                            (any_pc_reg? 512 : 0) + (regform? 1024 : 0)];

                if (ic->f == instr(eor_regshort))
                        cpu->cd.arm.combination_check = arm_combine_xchg;
                if (iword == 0xe113000c)
                        cpu->cd.arm.combination_check =
                            arm_combine_netbsd_scanc;
                break;

        case 0x4:       /*  Load and store...  */
        case 0x5:       /*  xxxx010P UBWLnnnn ddddoooo oooooooo  Immediate  */
        case 0x6:       /*  xxxx011P UBWLnnnn ddddcccc ctt0mmmm  Register  */
        case 0x7:
                ic->arg[0] = (size_t)(&cpu->cd.arm.r[rn]);
                ic->arg[2] = (size_t)(&cpu->cd.arm.r[rd]);
                if (rd == ARM_PC || rn == ARM_PC) {
                        ic->f = arm_load_store_instr_pc[((iword >> 16)
                            & 0x3f0) + condition_code];
                        if (rn == ARM_PC)
                                ic->arg[0] = (size_t)(&cpu->cd.arm.tmp_pc);
                        if (!l_bit && rd == ARM_PC)
                                ic->arg[2] = (size_t)(&cpu->cd.arm.tmp_pc);
                } else {
                        ic->f = arm_load_store_instr[((iword >> 16) &
                            0x3f0) + condition_code];
                }
                imm = iword & 0xfff;
                if (main_opcode < 6)
                        ic->arg[1] = imm;
                else
                        ic->arg[1] = (size_t)(void *)arm_r[iword & 0xfff];
                if ((iword & 0x0e000010) == 0x06000010) {
                        fatal("Not a Load/store TODO\n");
                        goto bad;
                }
                /*  Special case: pc-relative load within the same page:  */
                if (rn == ARM_PC && rd != ARM_PC && main_opcode < 6) {
                        int ofs = (addr & 0xfff) + 8, max = 0xffc;
                        int b_bit = iword & 0x00400000;
                        if (b_bit)
                                max = 0xfff;
                        if (u_bit)
                                ofs += (iword & 0xfff);
                        else
                                ofs -= (iword & 0xfff);
                        /*  NOTE/TODO: This assumes 4KB pages,
                            it will not work with 1KB pages.  */
                        if (ofs >= 0 && ofs <= max) {
                                unsigned char *p;
                                unsigned char c[4];
                                int len = b_bit? 1 : 4;
                                uint32_t x, a = (addr & 0xfffff000) | ofs;
                                /*  ic->f = cond_instr(mov);  */
                                ic->f = arm_dpi_instr[condition_code + 16*0xd];
                                ic->arg[2] = (size_t)(&cpu->cd.arm.r[rd]);
                                p = cpu->cd.arm.host_load[a >> 12];
                                if (p != NULL) {
                                        memcpy(c, p + (a & 0xfff), len);
                                } else {
                                        if (!cpu->memory_rw(cpu, cpu->mem, a,
                                            c, len, MEM_READ, CACHE_DATA)) {
                                                fatal("to_be_translated(): "
                                                    "read failed X: TODO\n");
                                                goto bad;
                                        }
                                }
                                if (cpu->byte_order == EMUL_LITTLE_ENDIAN)
                                        x = c[0] + (c[1]<<8) +
                                            (c[2]<<16) + (c[3]<<24);
                                else
                                        x = c[3] + (c[2]<<8) +
                                            (c[1]<<16) + (c[0]<<24);
                                if (b_bit)
                                        x = c[0];
                                ic->arg[1] = x;
                        }
                }
                if (iword == 0xe4b09004)
                        cpu->cd.arm.combination_check =
                            arm_combine_netbsd_copyin;
                if (iword == 0xe4a17004)
                        cpu->cd.arm.combination_check =
                            arm_combine_netbsd_copyout;
                break;

        case 0x8:       /*  Multiple load/store...  (Block data transfer)  */
        case 0x9:       /*  xxxx100P USWLnnnn llllllll llllllll  */
                ic->arg[0] = (size_t)(&cpu->cd.arm.r[rn]);
                ic->arg[1] = (size_t)iword;
                /*  Generic case:  */
                if (l_bit)
                        ic->f = cond_instr(bdt_load);
                else
                        ic->f = cond_instr(bdt_store);
#if defined(HOST_LITTLE_ENDIAN) && !defined(GATHER_BDT_STATISTICS)
                /*
                 *  Check for availability of optimized implementation:
                 *  xxxx100P USWLnnnn llllllll llllllll
                 *           ^  ^ ^ ^        ^  ^ ^ ^   (0x00950154)
                 *  These bits are used to select which list to scan, and then
                 *  the list is scanned linearly.
                 *
                 *  The optimized functions do not support show_trace_tree,
                 *  but it's ok to use the unoptimized version in that case.
                 */
                if (!cpu->machine->show_trace_tree) {
                        int i = 0, j = iword;
                        j = ((j & 0x00800000) >> 16) | ((j & 0x00100000) >> 14)
                          | ((j & 0x00040000) >> 13) | ((j & 0x00010000) >> 12)
                          | ((j & 0x00000100) >>  5) | ((j & 0x00000040) >>  4)
                          | ((j & 0x00000010) >>  3) | ((j & 0x00000004) >>  2);
                        while (multi_opcode[j][i] != 0) {
                                if ((iword & 0x0fffffff) ==
                                    multi_opcode[j][i]) {
                                        ic->f = multi_opcode_f[j]
                                            [i*16 + condition_code];
                                        break;
                                }
                                i ++;
                        }
                }
#endif
                if (rn == ARM_PC) {
                        fatal("TODO: bdt with PC as base\n");
                        goto bad;
                }
                break;

        case 0xa:                                       /*  B: branch  */
        case 0xb:                                       /*  BL: branch+link  */
                if (main_opcode == 0x0a) {
                        ic->f = cond_instr(b);
                        samepage_function = cond_instr(b_samepage);
                        if (iword == 0xcaffffed)
                                cpu->cd.arm.combination_check =
                                    arm_combine_netbsd_memset;
                        if (iword == 0xaafffff9)
                                cpu->cd.arm.combination_check =
                                    arm_combine_netbsd_memcpy;
                } else {
                        if (cpu->machine->show_trace_tree) {
                                ic->f = cond_instr(bl_trace);
                                samepage_function =
                                    cond_instr(bl_samepage_trace);
                        } else {
                                ic->f = cond_instr(bl);
                                samepage_function = cond_instr(bl_samepage);
                        }
                }

                /*  arg 1 = offset of current instruction  */
                /*  arg 2 = offset of the following instruction  */
                ic->arg[1] = addr & 0xffc;
                ic->arg[2] = (addr & 0xffc) + 4;

                ic->arg[0] = (iword & 0x00ffffff) << 2;
                /*  Sign-extend:  */
                if (ic->arg[0] & 0x02000000)
                        ic->arg[0] |= 0xfc000000;
                /*
                 *  Branches are calculated as PC + 8 + offset.
                 */
                ic->arg[0] = (int32_t)(ic->arg[0] + 8);

                /*
                 *  Special case: branch within the same page:
                 *
                 *  arg[0] = addr of the arm_instr_call of the target
                 *  arg[1] = addr of the next arm_instr_call.
                 */
                {
                        uint32_t mask_within_page =
                            ((ARM_IC_ENTRIES_PER_PAGE-1) <<
                            ARM_INSTR_ALIGNMENT_SHIFT) |
                            ((1 << ARM_INSTR_ALIGNMENT_SHIFT) - 1);
                        uint32_t old_pc = addr;
                        uint32_t new_pc = old_pc + (int32_t)ic->arg[0];
                        if ((old_pc & ~mask_within_page) ==
                            (new_pc & ~mask_within_page)) {
                                ic->f = samepage_function;
                                ic->arg[0] = (size_t) (
                                    cpu->cd.arm.cur_ic_page +
                                    ((new_pc & mask_within_page) >>
                                    ARM_INSTR_ALIGNMENT_SHIFT));
                                ic->arg[1] = (size_t) (
                                    cpu->cd.arm.cur_ic_page +
                                    (((addr & mask_within_page) + 4) >>
                                    ARM_INSTR_ALIGNMENT_SHIFT));
                        } else if (main_opcode == 0x0a) {
                                /*  Special hack for a plain "b":  */
                                ic->arg[0] += ic->arg[1];
                        }
                }

                if (main_opcode == 0xa && (condition_code <= 1
                    || condition_code == 3 || condition_code == 8
                    || condition_code == 12 || condition_code == 13))
                        cpu->cd.arm.combination_check = arm_combine_cmps_b;

                if (iword == 0x1afffffc)
                        cpu->cd.arm.combination_check = arm_combine_strlen;

                /*  Hm. Does this really increase performance?  */
                if (iword == 0x8afffffa)
                        cpu->cd.arm.combination_check =
                            arm_combine_netbsd_cacheclean2;
                break;

        case 0xc:
        case 0xd:
                /*
                 *  xxxx1100 0100nnnn ddddcccc oooommmm    MCRR c,op,Rd,Rn,CRm
                 *  xxxx1100 0101nnnn ddddcccc oooommmm    MRRC c,op,Rd,Rn,CRm
                 */
                if ((iword & 0x0fe00000) == 0x0c400000) {
                        fatal("MCRR/MRRC: TODO\n");
                        goto bad;
                }

                /*
                 *  TODO: LDC/STC
                 *
                 *  For now, treat as Undefined instructions. This causes e.g.
                 *  Linux/ARM to emulate these instructions (floating point).
                 */
                ic->f = cond_instr(und);
                ic->arg[0] = addr & 0xfff;
                break;

        case 0xe:
                if (iword & 0x10) {
                        /*  xxxx1110 oooLNNNN ddddpppp qqq1MMMM  MCR/MRC  */
                        ic->arg[0] = iword;
                        ic->f = cond_instr(mcr_mrc);
                } else {
                        /*  xxxx1110 oooonnnn ddddpppp qqq0mmmm  CDP  */
                        ic->arg[0] = iword;
                        ic->f = cond_instr(cdp);
                }
                if (iword == 0xee070f9a)
                        cpu->cd.arm.combination_check =
                            arm_combine_netbsd_cacheclean;
                break;

        case 0xf:
                /*  SWI:  */
                /*  Default handler:  */
                ic->f = cond_instr(swi);
                ic->arg[0] = addr & 0xfff;
                if (iword == 0xef8c64eb) {
                        /*  Hack for rebooting a machine:  */
                        ic->f = instr(reboot);
                } else if (iword == 0xef8c64be) {
                        /*  Hack for openfirmware prom emulation:  */
                        ic->f = instr(openfirmware);
                } else if (cpu->machine->userland_emul != NULL) {
                        if ((iword & 0x00f00000) == 0x00a00000) {
                                ic->arg[0] = iword & 0x00ffffff;
                                ic->f = cond_instr(swi_useremul);
                        } else {
                                fatal("Bad userland SWI?\n");
                                goto bad;
                        }
                }
                break;

        default:goto bad;
        }

okay:

#define DYNTRANS_TO_BE_TRANSLATED_TAIL
#include "cpu_dyntrans.c" 
#undef  DYNTRANS_TO_BE_TRANSLATED_TAIL
}
