0.3.1/src/bintrans_i386.c

/*
 *  Copyright (C) 2004-2005  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: bintrans_i386.c,v 1.75 2005/03/22 09:12:04 debug Exp $
 *
 *  i386 specific code for dynamic binary translation.
 *  See bintrans.c for more information.  Included from bintrans.c.
 *
 *  Translated code uses the following conventions at all time:
 *
 *      esi             points to the cpu struct
 *      edi             lowest 32 bits of cpu->pc
 *      ebp             contains cpu->bintrans_instructions_executed
 */


struct cpu dummy_cpu;
struct mips_coproc dummy_coproc;
struct vth32_table dummy_vth32_table;


/*
 *  bintrans_host_cacheinvalidate()
 *
 *  Invalidate the host's instruction cache. On i386, this isn't necessary,
 *  so this is an empty function.
 */
static void bintrans_host_cacheinvalidate(unsigned char *p, size_t len)
{
        /*  Do nothing.  */
}


/*  offsetof (in stdarg.h) could possibly be used, but I'm not sure
    if it will take care of the compiler problems...  */

#define ofs_i           (((size_t)&dummy_cpu.cd.mips.bintrans_instructions_executed) - ((size_t)&dummy_cpu))
#define ofs_pc          (((size_t)&dummy_cpu.pc) - ((size_t)&dummy_cpu))
#define ofs_pc_last     (((size_t)&dummy_cpu.cd.mips.pc_last) - ((size_t)&dummy_cpu))
#define ofs_tabl0       (((size_t)&dummy_cpu.cd.mips.vaddr_to_hostaddr_table0) - ((size_t)&dummy_cpu))
#define ofs_chunks      ((size_t)&dummy_vth32_table.bintrans_chunks[0] - (size_t)&dummy_vth32_table)
#define ofs_chunkbase   ((size_t)&dummy_cpu.cd.mips.chunk_base_address - (size_t)&dummy_cpu)


static void (*bintrans_runchunk)(struct cpu *, unsigned char *);
static void (*bintrans_jump_to_32bit_pc)(struct cpu *);
static void (*bintrans_loadstore_32bit)(struct cpu *);


/*
 *  bintrans_write_quickjump():
 */
static void bintrans_write_quickjump(struct memory *mem,
        unsigned char *quickjump_code, uint32_t chunkoffset)
{
        uint32_t i386_addr;
        unsigned char *a = quickjump_code;

        i386_addr = chunkoffset + (size_t)mem->translation_code_chunk_space;
        i386_addr = i386_addr - ((size_t)a + 5);

        /*  printf("chunkoffset=%i, %08x %08x %i\n",
            chunkoffset, i386_addr, a, ofs);  */  

        *a++ = 0xe9;
        *a++ = i386_addr;
        *a++ = i386_addr >> 8;
        *a++ = i386_addr >> 16;
        *a++ = i386_addr >> 24;
}


/*
 *  bintrans_write_chunkreturn():
 */
static void bintrans_write_chunkreturn(unsigned char **addrp)
{
        unsigned char *a = *addrp;
        *a++ = 0xc3;            /*  ret  */
        *addrp = a;
}


/*
 *  bintrans_write_chunkreturn_fail():
 */
static void bintrans_write_chunkreturn_fail(unsigned char **addrp)
{
        unsigned char *a = *addrp;

        /*  81 cd 00 00 00 01    orl    $0x1000000,%ebp  */
        *a++ = 0x81; *a++ = 0xcd;
        *a++ = 0; *a++ = 0; *a++ = 0; *a++ = 0x01;      /*  TODO: not hardcoded  */

        *a++ = 0xc3;            /*  ret  */
        *addrp = a;
}


/*
 *  bintrans_write_pc_inc():
 */
static void bintrans_write_pc_inc(unsigned char **addrp)
{
        unsigned char *a = *addrp;

        /*  83 c7 04                add    $0x4,%edi  */
        *a++ = 0x83; *a++ = 0xc7; *a++ = 4;

#if 0
        if (!bintrans_32bit_only) {
                int ofs;
                /*  83 96 zz zz zz zz 00    adcl   $0x0,zz(%esi)  */
                ofs = ((size_t)&dummy_cpu.pc) - (size_t)&dummy_cpu;
                ofs += 4;
                *a++ = 0x83; *a++ = 0x96;
                *a++ = ofs & 255;
                *a++ = (ofs >> 8) & 255;
                *a++ = (ofs >> 16) & 255;
                *a++ = (ofs >> 24) & 255;
                *a++ = 0;
        }
#endif

        /*  45   inc %ebp  */
        *a++ = 0x45;

        *addrp = a;
}


/*
 *  load_pc_into_eax_edx():
 */
static void load_pc_into_eax_edx(unsigned char **addrp)
{
        unsigned char *a;
        a = *addrp;

        /*  89 f8                   mov    %edi,%eax  */
        *a++ = 0x89; *a++ = 0xf8;

#if 0
        if (bintrans_32bit_only) {
                /*  99                      cltd   */
                *a++ = 0x99;
        } else
#endif
 {
                int ofs = ((size_t)&dummy_cpu.pc) - (size_t)&dummy_cpu;
                /*  8b 96 3c 30 00 00       mov    0x303c(%esi),%edx  */
                ofs += 4;
                *a++ = 0x8b; *a++ = 0x96;
                *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
        }

        *addrp = a;
}


/*
 *  store_eax_edx_into_pc():
 */
static void store_eax_edx_into_pc(unsigned char **addrp)
{
        unsigned char *a;
        int ofs = ((size_t)&dummy_cpu.pc) - (size_t)&dummy_cpu;
        a = *addrp;

        /*  89 c7                   mov    %eax,%edi  */
        *a++ = 0x89; *a++ = 0xc7;

        /*  89 96 3c 30 00 00       mov    %edx,0x303c(%esi)  */
        ofs += 4;
        *a++ = 0x89; *a++ = 0x96;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

        *addrp = a;
}


/*
 *  load_into_eax_edx():
 *
 *  Usage:    load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);   etc.
 */
static void load_into_eax_edx(unsigned char **addrp, void *p)
{
        unsigned char *a;
        int ofs = (size_t)p - (size_t)&dummy_cpu;
        a = *addrp;

        /*  8b 86 38 30 00 00       mov    0x3038(%esi),%eax  */
        *a++ = 0x8b; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

#if 0
        if (bintrans_32bit_only) {
                /*  99                      cltd   */
                *a++ = 0x99;
        } else
#endif
 {
                /*  8b 96 3c 30 00 00       mov    0x303c(%esi),%edx  */
                ofs += 4;
                *a++ = 0x8b; *a++ = 0x96;
                *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
        }

        *addrp = a;
}


/*
 *  load_into_eax_and_sign_extend_into_edx():
 *
 *  Usage:    load_into_eax_and_sign_extend_into_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);   etc.
 */
static void load_into_eax_and_sign_extend_into_edx(unsigned char **addrp, void *p)
{
        unsigned char *a;
        int ofs = (size_t)p - (size_t)&dummy_cpu;
        a = *addrp;

        /*  8b 86 38 30 00 00       mov    0x3038(%esi),%eax  */
        *a++ = 0x8b; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

        /*  99                      cltd   */
        *a++ = 0x99;

        *addrp = a;
}


/*
 *  load_into_eax_dont_care_about_edx():
 *
 *  Usage:    load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);   etc.
 */
static void load_into_eax_dont_care_about_edx(unsigned char **addrp, void *p)
{
        unsigned char *a;
        int ofs = (size_t)p - (size_t)&dummy_cpu;
        a = *addrp;

        /*  8b 86 38 30 00 00       mov    0x3038(%esi),%eax  */
        *a++ = 0x8b; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

        *addrp = a;
}


/*
 *  store_eax_edx():
 *
 *  Usage:    store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);   etc.
 */
static void store_eax_edx(unsigned char **addrp, void *p)
{
        unsigned char *a;
        int ofs = (size_t)p - (size_t)&dummy_cpu;
        a = *addrp;

        /*  89 86 38 30 00 00       mov    %eax,0x3038(%esi)  */
        *a++ = 0x89; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

        /*  89 96 3c 30 00 00       mov    %edx,0x303c(%esi)  */
        ofs += 4;
        *a++ = 0x89; *a++ = 0x96;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

        *addrp = a;
}


/*
 *  bintrans_write_instruction__lui():
 */
static int bintrans_write_instruction__lui(unsigned char **addrp, int rt, int imm)
{
        unsigned char *a;

        a = *addrp;
        if (rt == 0)
                goto rt0;

        /*  b8 00 00 dc fe          mov    $0xfedc0000,%eax  */
        *a++ = 0xb8; *a++ = 0; *a++ = 0;
        *a++ = imm & 255; *a++ = imm >> 8;

        /*  99                      cltd   */
        *a++ = 0x99;

        store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);
        *addrp = a;

rt0:
        bintrans_write_pc_inc(addrp);
        return 1;
}


/*
 *  bintrans_write_instruction__jr():
 */
static int bintrans_write_instruction__jr(unsigned char **addrp,
        int rs, int rd, int special)
{
        unsigned char *a;
        int ofs;

        a = *addrp;

        /*
         *  Perform the jump by setting cpu->delay_slot = TO_BE_DELAYED
         *  and cpu->delay_jmpaddr = gpr[rs].
         */

        /*  c7 86 38 30 00 00 01 00 00 00    movl   $0x1,0x3038(%esi)  */
        ofs = ((size_t)&dummy_cpu.cd.mips.delay_slot) - (size_t)&dummy_cpu;
        *a++ = 0xc7; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
        *a++ = TO_BE_DELAYED; *a++ = 0; *a++ = 0; *a++ = 0;

#if 0
        if (bintrans_32bit_only)
                load_into_eax_and_sign_extend_into_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
        else
#endif
                load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);

        store_eax_edx(&a, &dummy_cpu.cd.mips.delay_jmpaddr);

        if (special == SPECIAL_JALR && rd != 0) {
                /*  gpr[rd] = retaddr    (pc + 8)  */

#if 0
                if (bintrans_32bit_only) {
                        load_pc_into_eax_edx(&a);
                        /*  83 c0 08                add    $0x8,%eax  */
                        *a++ = 0x83; *a++ = 0xc0; *a++ = 0x08;
                } else
#endif
 {
                        load_pc_into_eax_edx(&a);
                        /*  83 c0 08                add    $0x8,%eax  */
                        /*  83 d2 00                adc    $0x0,%edx  */
                        *a++ = 0x83; *a++ = 0xc0; *a++ = 0x08;
                        *a++ = 0x83; *a++ = 0xd2; *a++ = 0x00;
                }

                store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rd]);
        }

        *addrp = a;
        bintrans_write_pc_inc(addrp);
        return 1;
}


/*
 *  bintrans_write_instruction__mfmthilo():
 */
static int bintrans_write_instruction__mfmthilo(unsigned char **addrp,
        int rd, int from_flag, int hi_flag)
{
        unsigned char *a;

        a = *addrp;

        if (from_flag) {
                if (rd != 0) {
                        /*  mfhi or mflo  */
                        if (hi_flag)
                                load_into_eax_edx(&a, &dummy_cpu.cd.mips.hi);
                        else
                                load_into_eax_edx(&a, &dummy_cpu.cd.mips.lo);
                        store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rd]);
                }
        } else {
                /*  mthi or mtlo  */
                load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rd]);
                if (hi_flag)
                        store_eax_edx(&a, &dummy_cpu.cd.mips.hi);
                else
                        store_eax_edx(&a, &dummy_cpu.cd.mips.lo);
        }

        *addrp = a;
        bintrans_write_pc_inc(addrp);
        return 1;
}


/*
 *  bintrans_write_instruction__addiu_etc():
 */
static int bintrans_write_instruction__addiu_etc(unsigned char **addrp,
        int rt, int rs, int imm, int instruction_type)
{
        unsigned char *a;
        unsigned int uimm;

        /*  TODO: overflow detection for ADDI and DADDI  */
        switch (instruction_type) {
        case HI6_ADDI:
        case HI6_DADDI:
                return 0;
        }

        a = *addrp;

        if (rt == 0)
                goto rt0;

        uimm = imm & 0xffff;

        if (uimm == 0 && (instruction_type == HI6_ADDIU ||
            instruction_type == HI6_ADDI)) {
                load_into_eax_and_sign_extend_into_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
                store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);
                goto rt0;
        }

        if (uimm == 0 && (instruction_type == HI6_DADDIU ||
            instruction_type == HI6_DADDI || instruction_type == HI6_ORI)) {
                load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
                store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);
                goto rt0;
        }

#if 0
        if (bintrans_32bit_only)
                load_into_eax_and_sign_extend_into_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
        else
#endif
                load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);

        switch (instruction_type) {
        case HI6_ADDIU:
        case HI6_DADDIU:
        case HI6_ADDI:
        case HI6_DADDI:
                if (imm & 0x8000) {
                        /*  05 39 fd ff ff          add    $0xfffffd39,%eax  */
                        /*  83 d2 ff                adc    $0xffffffff,%edx  */
                        *a++ = 0x05; *a++ = uimm; *a++ = uimm >> 8; *a++ = 0xff; *a++ = 0xff;
                        if (instruction_type == HI6_DADDIU) {
                                *a++ = 0x83; *a++ = 0xd2; *a++ = 0xff;
                        }
                } else {
                        /*  05 c7 02 00 00          add    $0x2c7,%eax  */
                        /*  83 d2 00                adc    $0x0,%edx  */
                        *a++ = 0x05; *a++ = uimm; *a++ = uimm >> 8; *a++ = 0; *a++ = 0;
                        if (instruction_type == HI6_DADDIU) {
                                *a++ = 0x83; *a++ = 0xd2; *a++ = 0;
                        }
                }
                if (instruction_type == HI6_ADDIU) {
                        /*  99                      cltd   */
                        *a++ = 0x99;
                }
                break;
        case HI6_ANDI:
                /*  25 34 12 00 00          and    $0x1234,%eax  */
                /*  31 d2                   xor    %edx,%edx  */
                *a++ = 0x25; *a++ = uimm; *a++ = uimm >> 8; *a++ = 0; *a++ = 0;
                *a++ = 0x31; *a++ = 0xd2;
                break;
        case HI6_ORI:
                /*  0d 34 12 00 00          or     $0x1234,%eax  */
                *a++ = 0xd; *a++ = uimm; *a++ = uimm >> 8; *a++ = 0; *a++ = 0;
                break;
        case HI6_XORI:
                /*  35 34 12 00 00          xor    $0x1234,%eax  */
                *a++ = 0x35; *a++ = uimm; *a++ = uimm >> 8; *a++ = 0; *a++ = 0;
                break;
        case HI6_SLTIU:
                /*  set if less than, unsigned. (compare edx:eax to ecx:ebx)  */
                /*  ecx:ebx = the immediate value  */
                /*  bb dc fe ff ff          mov    $0xfffffedc,%ebx  */
                /*  b9 ff ff ff ff          mov    $0xffffffff,%ecx  */
                /*  or  */
                /*  29 c9                   sub    %ecx,%ecx  */
#if 0
                if (bintrans_32bit_only) {
                        /*  99                      cltd   */
                        *a++ = 0x99;
                }
#endif
                *a++ = 0xbb; *a++ = uimm; *a++ = uimm >> 8;
                if (uimm & 0x8000) {
                        *a++ = 0xff; *a++ = 0xff;
                        *a++ = 0xb9; *a++ = 0xff; *a++ = 0xff; *a++ = 0xff; *a++ = 0xff;
                } else {
                        *a++ = 0; *a++ = 0;
                        *a++ = 0x29; *a++ = 0xc9;
                }

                /*  if edx <= ecx and eax < ebx then 1, else 0.  */
                /*  39 ca                   cmp    %ecx,%edx  */
                /*  77 0b                   ja     <ret0>  */
                /*  39 d8                   cmp    %ebx,%eax  */
                /*  73 07                   jae    58 <ret0>  */
                *a++ = 0x39; *a++ = 0xca;
                *a++ = 0x77; *a++ = 0x0b;
                *a++ = 0x39; *a++ = 0xd8;
                *a++ = 0x73; *a++ = 0x07;

                /*  b8 01 00 00 00          mov    $0x1,%eax  */
                /*  eb 02                   jmp    <common>  */
                *a++ = 0xb8; *a++ = 1; *a++ = 0; *a++ = 0; *a++ = 0;
                *a++ = 0xeb; *a++ = 0x02;

                /*  ret0:  */
                /*  29 c0                   sub    %eax,%eax  */
                *a++ = 0x29; *a++ = 0xc0;

                /*  common:  */
                /*  99                      cltd   */
                *a++ = 0x99;
                break;
        case HI6_SLTI:
                /*  set if less than, signed. (compare edx:eax to ecx:ebx)  */
                /*  ecx:ebx = the immediate value  */
                /*  bb dc fe ff ff          mov    $0xfffffedc,%ebx  */
                /*  b9 ff ff ff ff          mov    $0xffffffff,%ecx  */
                /*  or  */
                /*  29 c9                   sub    %ecx,%ecx  */
#if 0
                if (bintrans_32bit_only) {
                        /*  99                      cltd   */
                        *a++ = 0x99;
                }
#endif
                *a++ = 0xbb; *a++ = uimm; *a++ = uimm >> 8;
                if (uimm & 0x8000) {
                        *a++ = 0xff; *a++ = 0xff;
                        *a++ = 0xb9; *a++ = 0xff; *a++ = 0xff; *a++ = 0xff; *a++ = 0xff;
                } else {
                        *a++ = 0; *a++ = 0;
                        *a++ = 0x29; *a++ = 0xc9;
                }

                /*  if edx > ecx then 0.  */
                /*  if edx < ecx then 1.  */
                /*  if eax < ebx then 1, else 0.  */
                /*  39 ca                   cmp    %ecx,%edx  */
                /*  7c 0a                   jl     <ret1>  */
                /*  7f 04                   jg     <ret0>  */
                /*  39 d8                   cmp    %ebx,%eax  */
                /*  7c 04                   jl     <ret1>  */
                *a++ = 0x39; *a++ = 0xca;
                *a++ = 0x7c; *a++ = 0x0a;
                *a++ = 0x7f; *a++ = 0x04;
                *a++ = 0x39; *a++ = 0xd8;
                *a++ = 0x7c; *a++ = 0x04;

                /*  ret0:  */
                /*  29 c0                   sub    %eax,%eax  */
                /*  eb 05                   jmp    <common>  */
                *a++ = 0x29; *a++ = 0xc0;
                *a++ = 0xeb; *a++ = 0x05;

                /*  ret1:  */
                /*  b8 01 00 00 00          mov    $0x1,%eax  */
                *a++ = 0xb8; *a++ = 1; *a++ = 0; *a++ = 0; *a++ = 0;

                /*  common:  */
                /*  99                      cltd   */
                *a++ = 0x99;
                break;
        }

        store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);

rt0:
        *addrp = a;
        bintrans_write_pc_inc(addrp);
        return 1;
}


/*
 *  bintrans_write_instruction__jal():
 */
static int bintrans_write_instruction__jal(unsigned char **addrp,
        int imm, int link)
{
        unsigned char *a;
        uint32_t subimm;
        int ofs;

        a = *addrp;

        load_pc_into_eax_edx(&a);

        if (link) {
                /*  gpr[31] = pc + 8  */
#if 0
                if (bintrans_32bit_only) {
                        /*  50             push  %eax */
                        /*  83 c0 08       add   $0x8,%eax  */
                        *a++ = 0x50;
                        *a++ = 0x83; *a++ = 0xc0; *a++ = 0x08;
                } else
#endif
 {
                        /*  50             push  %eax */
                        /*  52             push  %edx */
                        /*  83 c0 08                add    $0x8,%eax  */
                        /*  83 d2 00                adc    $0x0,%edx  */
                        *a++ = 0x50;
                        *a++ = 0x52;
                        *a++ = 0x83; *a++ = 0xc0; *a++ = 0x08;
                        *a++ = 0x83; *a++ = 0xd2; *a++ = 0x00;
                }
                store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[31]);
#if 0
                if (bintrans_32bit_only) {
                        /*  58     pop %eax  */
                        *a++ = 0x58;
                } else
#endif
 {
                        /*  5a     pop %edx  */
                        /*  58     pop %eax  */
                        *a++ = 0x5a;
                        *a++ = 0x58;
                }
        }

        /*  delay_jmpaddr = top 36 bits of pc together with lowest 28 bits of imm*4:  */
        imm *= 4;

        /*  Add 4, because the jump is from the delay slot:  */
        /*  83 c0 04                add    $0x4,%eax  */
        /*  83 d2 00                adc    $0x0,%edx  */
        *a++ = 0x83; *a++ = 0xc0; *a++ = 0x04;
        *a++ = 0x83; *a++ = 0xd2; *a++ = 0x00;

        /*  c1 e8 1c                shr    $0x1c,%eax  */
        /*  c1 e0 1c                shl    $0x1c,%eax  */
        *a++ = 0xc1; *a++ = 0xe8; *a++ = 0x1c;
        *a++ = 0xc1; *a++ = 0xe0; *a++ = 0x1c;

        subimm = imm;
        subimm &= 0x0fffffff;

        /*  0d 78 56 34 12          or     $0x12345678,%eax  */
        *a++ = 0x0d; *a++ = subimm; *a++ = subimm >> 8;
        *a++ = subimm >> 16; *a++ = subimm >> 24;

        store_eax_edx(&a, &dummy_cpu.cd.mips.delay_jmpaddr);

        /*  c7 86 38 30 00 00 01 00 00 00    movl   $0x1,0x3038(%esi)  */
        ofs = ((size_t)&dummy_cpu.cd.mips.delay_slot) - (size_t)&dummy_cpu;
        *a++ = 0xc7; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
        *a++ = TO_BE_DELAYED; *a++ = 0; *a++ = 0; *a++ = 0;

        *addrp = a;
        bintrans_write_pc_inc(addrp);
        return 1;
}


/*
 *  bintrans_write_instruction__addu_etc():
 */
static int bintrans_write_instruction__addu_etc(unsigned char **addrp,
        int rd, int rs, int rt, int sa, int instruction_type)
{
        unsigned char *a;
        int load64 = 0, do_store = 1;

        /*  TODO: Not yet  */
        switch (instruction_type) {
        case SPECIAL_MULT:
        case SPECIAL_MULTU:
        case SPECIAL_DIV:
        case SPECIAL_DIVU:
                if (rd != 0)
                        return 0;
                break;
        case SPECIAL_DSLL:
        case SPECIAL_DSLL32:
        case SPECIAL_DSRA:
        case SPECIAL_DSRA32:
        case SPECIAL_DSRL:
        case SPECIAL_DSRL32:
        case SPECIAL_MOVZ:
        case SPECIAL_MOVN:
                bintrans_write_chunkreturn_fail(addrp);
                return 0;
        }

        switch (instruction_type) {
        case SPECIAL_DADDU:
        case SPECIAL_DSUBU:
        case SPECIAL_OR:
        case SPECIAL_AND:
        case SPECIAL_NOR:
        case SPECIAL_XOR:
        case SPECIAL_DSLL:
        case SPECIAL_DSRL:
        case SPECIAL_DSRA:
        case SPECIAL_DSLL32:
        case SPECIAL_DSRL32:
        case SPECIAL_DSRA32:
        case SPECIAL_SLT:
        case SPECIAL_SLTU:
                load64 = 1;
        }

        switch (instruction_type) {
        case SPECIAL_MULT:
        case SPECIAL_MULTU:
        case SPECIAL_DIV:
        case SPECIAL_DIVU:
                break;
        default:
                if (rd == 0)
                        goto rd0;
        }

        a = *addrp;

        if ((instruction_type == SPECIAL_ADDU || instruction_type == SPECIAL_DADDU
            || instruction_type == SPECIAL_OR) && rt == 0) {
                if (load64)
                        load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
                else
                        load_into_eax_and_sign_extend_into_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
                store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rd]);
                *addrp = a;
                goto rd0;
        }

        /*  edx:eax = rs, ecx:ebx = rt  */
        if (load64) {
                load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);
                /*  89 c3                   mov    %eax,%ebx  */
                /*  89 d1                   mov    %edx,%ecx  */
                *a++ = 0x89; *a++ = 0xc3; *a++ = 0x89; *a++ = 0xd1;
                load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
        } else {
                load_into_eax_and_sign_extend_into_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);
                /*  89 c3                   mov    %eax,%ebx  */
                /*  89 d1                   mov    %edx,%ecx  */
                *a++ = 0x89; *a++ = 0xc3; *a++ = 0x89; *a++ = 0xd1;
                load_into_eax_and_sign_extend_into_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
        }

        switch (instruction_type) {
        case SPECIAL_ADDU:
                /*  01 d8                   add    %ebx,%eax  */
                /*  99                      cltd   */
                *a++ = 0x01; *a++ = 0xd8;
                *a++ = 0x99;
                break;
        case SPECIAL_DADDU:
                /*  01 d8                   add    %ebx,%eax  */
                /*  11 ca                   adc    %ecx,%edx  */
                *a++ = 0x01; *a++ = 0xd8;
                *a++ = 0x11; *a++ = 0xca;
                break;
        case SPECIAL_SUBU:
                /*  29 d8                   sub    %ebx,%eax  */
                /*  99                      cltd   */
                *a++ = 0x29; *a++ = 0xd8;
                *a++ = 0x99;
                break;
        case SPECIAL_DSUBU:
                /*  29 d8                   sub    %ebx,%eax  */
                /*  19 ca                   sbb    %ecx,%edx  */
                *a++ = 0x29; *a++ = 0xd8;
                *a++ = 0x19; *a++ = 0xca;
                break;
        case SPECIAL_AND:
                /*  21 d8                   and    %ebx,%eax  */
                /*  21 ca                   and    %ecx,%edx  */
                *a++ = 0x21; *a++ = 0xd8;
                *a++ = 0x21; *a++ = 0xca;
                break;
        case SPECIAL_OR:
                /*  09 d8                   or     %ebx,%eax  */
                /*  09 ca                   or     %ecx,%edx  */
                *a++ = 0x09; *a++ = 0xd8;
                *a++ = 0x09; *a++ = 0xca;
                break;
        case SPECIAL_NOR:
                /*  09 d8                   or     %ebx,%eax  */
                /*  09 ca                   or     %ecx,%edx  */
                /*  f7 d0                   not    %eax  */
                /*  f7 d2                   not    %edx  */
                *a++ = 0x09; *a++ = 0xd8;
                *a++ = 0x09; *a++ = 0xca;
                *a++ = 0xf7; *a++ = 0xd0;
                *a++ = 0xf7; *a++ = 0xd2;
                break;
        case SPECIAL_XOR:
                /*  31 d8                   xor    %ebx,%eax  */
                /*  31 ca                   xor    %ecx,%edx  */
                *a++ = 0x31; *a++ = 0xd8;
                *a++ = 0x31; *a++ = 0xca;
                break;
        case SPECIAL_SLL:
                /*  89 d8                   mov    %ebx,%eax  */
                /*  c1 e0 1f                shl    $0x1f,%eax  */
                /*  99                      cltd   */
                *a++ = 0x89; *a++ = 0xd8;
                if (sa == 1) {
                        *a++ = 0xd1; *a++ = 0xe0;
                } else {
                        *a++ = 0xc1; *a++ = 0xe0; *a++ = sa;
                }
                *a++ = 0x99;
                break;
        case SPECIAL_SRA:
                /*  89 d8                   mov    %ebx,%eax  */
                /*  c1 f8 1f                sar    $0x1f,%eax  */
                /*  99                      cltd   */
                *a++ = 0x89; *a++ = 0xd8;
                if (sa == 1) {
                        *a++ = 0xd1; *a++ = 0xf8;
                } else {
                        *a++ = 0xc1; *a++ = 0xf8; *a++ = sa;
                }
                *a++ = 0x99;
                break;
        case SPECIAL_SRL:
                /*  89 d8                   mov    %ebx,%eax  */
                /*  c1 e8 1f                shr    $0x1f,%eax  */
                /*  99                      cltd   */
                *a++ = 0x89; *a++ = 0xd8;
                if (sa == 1) {
                        *a++ = 0xd1; *a++ = 0xe8;
                } else {
                        *a++ = 0xc1; *a++ = 0xe8; *a++ = sa;
                }
                *a++ = 0x99;
                break;
        case SPECIAL_SLTU:
                /*  set if less than, unsigned. (compare edx:eax to ecx:ebx)  */
                /*  if edx <= ecx and eax < ebx then 1, else 0.  */
                /*  39 ca                   cmp    %ecx,%edx  */
                /*  77 0b                   ja     <ret0>  */
                /*  39 d8                   cmp    %ebx,%eax  */
                /*  73 07                   jae    58 <ret0>  */
                *a++ = 0x39; *a++ = 0xca;
                *a++ = 0x77; *a++ = 0x0b;
                *a++ = 0x39; *a++ = 0xd8;
                *a++ = 0x73; *a++ = 0x07;

                /*  b8 01 00 00 00          mov    $0x1,%eax  */
                /*  eb 02                   jmp    <common>  */
                *a++ = 0xb8; *a++ = 1; *a++ = 0; *a++ = 0; *a++ = 0;
                *a++ = 0xeb; *a++ = 0x02;

                /*  ret0:  */
                /*  29 c0                   sub    %eax,%eax  */
                *a++ = 0x29; *a++ = 0xc0;

                /*  common:  */
                /*  99                      cltd   */
                *a++ = 0x99;
                break;
        case SPECIAL_SLT:
                /*  set if less than, signed. (compare edx:eax to ecx:ebx)  */
                /*  if edx > ecx then 0.  */
                /*  if edx < ecx then 1.  */
                /*  if eax < ebx then 1, else 0.  */
                /*  39 ca                   cmp    %ecx,%edx  */
                /*  7c 0a                   jl     <ret1>  */
                /*  7f 04                   jg     <ret0>  */
                /*  39 d8                   cmp    %ebx,%eax  */
                /*  7c 04                   jl     <ret1>  */
                *a++ = 0x39; *a++ = 0xca;
                *a++ = 0x7c; *a++ = 0x0a;
                *a++ = 0x7f; *a++ = 0x04;
                *a++ = 0x39; *a++ = 0xd8;
                *a++ = 0x7c; *a++ = 0x04;

                /*  ret0:  */
                /*  29 c0                   sub    %eax,%eax  */
                /*  eb 05                   jmp    <common>  */
                *a++ = 0x29; *a++ = 0xc0;
                *a++ = 0xeb; *a++ = 0x05;

                /*  ret1:  */
                /*  b8 01 00 00 00          mov    $0x1,%eax  */
                *a++ = 0xb8; *a++ = 1; *a++ = 0; *a++ = 0; *a++ = 0;

                /*  common:  */
                /*  99                      cltd   */
                *a++ = 0x99;
                break;
        case SPECIAL_SLLV:
                /*  rd = rt << (rs&31)  (logical)     eax = ebx << (eax&31)  */
                /*  xchg ebx,eax, then we can do   eax = eax << (ebx&31)  */
                /*  93                      xchg   %eax,%ebx  */
                /*  89 d9                   mov    %ebx,%ecx  */
                /*  83 e1 1f                and    $0x1f,%ecx  */
                /*  d3 e0                   shl    %cl,%eax  */
                *a++ = 0x93;
                *a++ = 0x89; *a++ = 0xd9;
                *a++ = 0x83; *a++ = 0xe1; *a++ = 0x1f;
                *a++ = 0xd3; *a++ = 0xe0;
                /*  99                      cltd   */
                *a++ = 0x99;
                break;
        case SPECIAL_SRLV:
                /*  rd = rt >> (rs&31)  (logical)     eax = ebx >> (eax&31)  */
                /*  xchg ebx,eax, then we can do   eax = eax >> (ebx&31)  */
                /*  93                      xchg   %eax,%ebx  */
                /*  89 d9                   mov    %ebx,%ecx  */
                /*  83 e1 1f                and    $0x1f,%ecx  */
                /*  d3 e8                   shr    %cl,%eax  */
                *a++ = 0x93;
                *a++ = 0x89; *a++ = 0xd9;
                *a++ = 0x83; *a++ = 0xe1; *a++ = 0x1f;
                *a++ = 0xd3; *a++ = 0xe8;
                /*  99                      cltd   */
                *a++ = 0x99;
                break;
        case SPECIAL_SRAV:
                /*  rd = rt >> (rs&31)  (arithmetic)     eax = ebx >> (eax&31)  */
                /*  xchg ebx,eax, then we can do   eax = eax >> (ebx&31)  */
                /*  93                      xchg   %eax,%ebx  */
                /*  89 d9                   mov    %ebx,%ecx  */
                /*  83 e1 1f                and    $0x1f,%ecx  */
                /*  d3 f8                   sar    %cl,%eax  */
                *a++ = 0x93;
                *a++ = 0x89; *a++ = 0xd9;
                *a++ = 0x83; *a++ = 0xe1; *a++ = 0x1f;
                *a++ = 0xd3; *a++ = 0xf8;
                /*  99                      cltd   */
                *a++ = 0x99;
                break;
        case SPECIAL_MULT:
        case SPECIAL_MULTU:
                /*  57    push %edi  */
                *a++ = 0x57;
                if (instruction_type == SPECIAL_MULT) {
                        /*  f7 eb                   imul   %ebx  */
                        *a++ = 0xf7; *a++ = 0xeb;
                } else {
                        /*  f7 e3                   mul   %ebx  */
                        *a++ = 0xf7; *a++ = 0xe3;
                }
                /*  here: edx:eax = hi:lo  */
                /*  89 d7                   mov    %edx,%edi  */
                /*  99                      cltd   */
                *a++ = 0x89; *a++ = 0xd7;
                *a++ = 0x99;
                /*  here: edi=hi, edx:eax = sign-extended lo  */
                store_eax_edx(&a, &dummy_cpu.cd.mips.lo);
                /*  89 f8                   mov    %edi,%eax  */
                /*  99                      cltd   */
                *a++ = 0x89; *a++ = 0xf8;
                *a++ = 0x99;
                /*  here: edx:eax = sign-extended hi  */
                store_eax_edx(&a, &dummy_cpu.cd.mips.hi);
                /*  5f    pop %edi  */
                *a++ = 0x5f;
                do_store = 0;
                break;
        case SPECIAL_DIV:
        case SPECIAL_DIVU:
                /*
                 *  In:   edx:eax = rs, ecx:ebx = rt
                 *  Out:  LO = rs / rt, HI = rs % rt
                 */
                /*  Division by zero on MIPS is undefined, but on
                    i386 it causes an exception, so we'll try to
                    avoid that.  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x00;  /*  cmp $0x0,%ebx  */
                *a++ = 0x75; *a++ = 0x01;               /*  jne skip_inc  */
                *a++ = 0x43;                            /*  inc %ebx  */

                /*  57    push %edi  */
                *a++ = 0x57;
                if (instruction_type == SPECIAL_DIV) {
                        *a++ = 0x99;                    /*  cltd */
                        *a++ = 0xf7; *a++ = 0xfb;       /*  idiv %ebx  */
                } else {
                        *a++ = 0x29; *a++ = 0xd2;       /*  sub %edx,%edx  */
                        *a++ = 0xf7; *a++ = 0xf3;       /*  div %ebx  */
                }
                /*  here: edx:eax = hi:lo  */
                /*  89 d7                   mov    %edx,%edi  */
                /*  99                      cltd   */
                *a++ = 0x89; *a++ = 0xd7;
                *a++ = 0x99;
                /*  here: edi=hi, edx:eax = sign-extended lo  */
                store_eax_edx(&a, &dummy_cpu.cd.mips.lo);
                /*  89 f8                   mov    %edi,%eax  */
                /*  99                      cltd   */
                *a++ = 0x89; *a++ = 0xf8;
                *a++ = 0x99;
                /*  here: edx:eax = sign-extended hi  */
                store_eax_edx(&a, &dummy_cpu.cd.mips.hi);
                /*  5f    pop %edi  */
                *a++ = 0x5f;
                do_store = 0;
                break;
#if 0
        /*  TODO:  These are from bintrans_alpha.c. Translate them to i386.  */

        case SPECIAL_DSLL:
                *a++ = 0x21; *a++ = 0x17 + ((sa & 7) << 5); *a++ = 0x40 + (sa >> 3); *a++ = 0x48;       /*  sll t1,sa,t0  */
                break;
        case SPECIAL_DSLL32:
                sa += 32;
                *a++ = 0x21; *a++ = 0x17 + ((sa & 7) << 5); *a++ = 0x40 + (sa >> 3); *a++ = 0x48;       /*  sll t1,sa,t0  */
                break;
        case SPECIAL_DSRA:
                *a++ = 0x81; *a++ = 0x17 + ((sa & 7) << 5); *a++ = 0x40 + (sa >> 3); *a++ = 0x48;       /*  sra t1,sa,t0  */
                break;
        case SPECIAL_DSRA32:
                sa += 32;
                *a++ = 0x81; *a++ = 0x17 + ((sa & 7) << 5); *a++ = 0x40 + (sa >> 3); *a++ = 0x48;       /*  sra t1,sa,t0  */
                break;
        case SPECIAL_DSRL:
                /*  Note: bits of sa are distributed among two different bytes.  */
                *a++ = 0x81; *a++ = 0x16 + ((sa & 7) << 5); *a++ = 0x40 + (sa >> 3); *a++ = 0x48;
                break;
        case SPECIAL_DSRL32:
                /*  Note: bits of sa are distributed among two different bytes.  */
                sa += 32;
                *a++ = 0x81; *a++ = 0x16 + ((sa & 7) << 5); *a++ = 0x40 + (sa >> 3); *a++ = 0x48;
                break;
#endif
        }

        if (do_store)
                store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rd]);

        *addrp = a;
rd0:
        bintrans_write_pc_inc(addrp);
        return 1;
}


/*
 *  bintrans_write_instruction__mfc_mtc():
 */
static int bintrans_write_instruction__mfc_mtc(struct memory *mem,
        unsigned char **addrp, int coproc_nr, int flag64bit, int rt,
        int rd, int mtcflag)
{
        unsigned char *a, *failskip;
        int ofs;

        if (mtcflag && flag64bit) {
                /*  dmtc  */
                return 0;
        }

        /*
         *  NOTE: Only a few registers are readable without side effects.
         */
        if (rt == 0 && !mtcflag)
                return 0;

        if (coproc_nr >= 1)
                return 0;

        if (rd == COP0_RANDOM || rd == COP0_COUNT)
                return 0;

        a = *addrp;

        /*************************************************************
         *
         *  TODO: Check for kernel mode, or Coproc X usability bit!
         *
         *************************************************************/

        /*  8b 96 3c 30 00 00       mov    0x303c(%esi),%edx  */
        ofs = ((size_t)&dummy_cpu.cd.mips.coproc[0]) - (size_t)&dummy_cpu;
        *a++ = 0x8b; *a++ = 0x96;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

        /*  here, edx = cpu->coproc[0]  */

        if (mtcflag) {
                /*  mtc  */

                /*  TODO: This code only works for mtc0, not dmtc0  */

                /*  8b 9a 38 30 00 00       mov    0x3038(%edx),%ebx  */
                ofs = ((size_t)&dummy_coproc.reg[rd]) - (size_t)&dummy_coproc;
                *a++ = 0x8b; *a++ = 0x9a;
                *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);

                /*
                 *  Here:  eax contains the value in register rt,
                 *         ebx contains the coproc register rd value.
                 *
                 *  In the general case, only allow mtc if it does not
                 *  change the coprocessor register!
                 */

                switch (rd) {

                case COP0_INDEX:
                        break;

                case COP0_ENTRYLO0:
                case COP0_ENTRYLO1:
                        /*  TODO: Not all bits are writable!  */
                        break;

                case COP0_EPC:
                        break;

                case COP0_STATUS:
                        /*  Only allow updates to the status register if
                            the interrupt enable bits were changed, but no
                            other bits!  */
                        /*  89 c1                   mov    %eax,%ecx  */
                        /*  89 da                   mov    %ebx,%edx  */
                        /*  81 e1 00 00 e7 0f       and    $0x0fe70000,%ecx  */
                        /*  81 e2 00 00 e7 0f       and    $0x0fe70000,%edx  */
                        /*  39 ca                   cmp    %ecx,%edx  */
                        /*  74 01                   je     <ok>  */
                        *a++ = 0x89; *a++ = 0xc1;
                        *a++ = 0x89; *a++ = 0xda;
                        *a++ = 0x81; *a++ = 0xe1; *a++ = 0x00; *a++ = 0x00;
                        if (mem->bintrans_32bit_only) {
                                *a++ = 0xe7; *a++ = 0x0f;
                        } else {
                                *a++ = 0xff; *a++ = 0xff;
                        }
                        *a++ = 0x81; *a++ = 0xe2; *a++ = 0x00; *a++ = 0x00;
                        if (mem->bintrans_32bit_only) {
                                *a++ = 0xe7; *a++ = 0x0f;
                        } else {
                                *a++ = 0xff; *a++ = 0xff;
                        }
                        *a++ = 0x39; *a++ = 0xca;
                        *a++ = 0x74; failskip = a; *a++ = 0x00;
                        bintrans_write_chunkreturn_fail(&a);
                        *failskip = (size_t)a - (size_t)failskip - 1;

                        /*  Only allow the update if it would NOT cause
                            an interrupt exception:  */

                        /*  8b 96 3c 30 00 00       mov    0x303c(%esi),%edx  */
                        ofs = ((size_t)&dummy_cpu.cd.mips.coproc[0]) - (size_t)&dummy_cpu;
                        *a++ = 0x8b; *a++ = 0x96;
                        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                        /*  8b 9a 38 30 00 00       mov    0x3038(%edx),%ebx  */
                        ofs = ((size_t)&dummy_coproc.reg[COP0_CAUSE]) - (size_t)&dummy_coproc;
                        *a++ = 0x8b; *a++ = 0x9a;
                        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                        /*  21 c3                   and    %eax,%ebx  */
                        /*  81 e3 00 ff 00 00       and    $0xff00,%ebx  */
                        /*  83 fb 00                cmp    $0x0,%ebx  */
                        /*  74 01                   je     <ok>  */
                        *a++ = 0x21; *a++ = 0xc3;
                        *a++ = 0x81; *a++ = 0xe3; *a++ = 0x00;
                            *a++ = 0xff; *a++ = 0x00; *a++ = 0x00;
                        *a++ = 0x83; *a++ = 0xfb; *a++ = 0x00;
                        *a++ = 0x74; failskip = a; *a++ = 0x00;
                        bintrans_write_chunkreturn_fail(&a);
                        *failskip = (size_t)a - (size_t)failskip - 1;

                        break;

                default:
                        /*  39 d8                   cmp    %ebx,%eax  */
                        /*  74 01                   je     <ok>  */
                        *a++ = 0x39; *a++ = 0xd8;
                        *a++ = 0x74; failskip = a; *a++ = 0x00;
                        bintrans_write_chunkreturn_fail(&a);
                        *failskip = (size_t)a - (size_t)failskip - 1;
                }

                /*  8b 96 3c 30 00 00       mov    0x303c(%esi),%edx  */
                ofs = ((size_t)&dummy_cpu.cd.mips.coproc[0]) - (size_t)&dummy_cpu;
                *a++ = 0x8b; *a++ = 0x96;
                *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                /*  8d 9a 38 30 00 00       lea    0x3038(%edx),%ebx  */
                ofs = ((size_t)&dummy_coproc.reg[rd]) - (size_t)&dummy_coproc;
                *a++ = 0x8d; *a++ = 0x9a;
                *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                /*  Sign-extend eax into edx:eax, and store it in
                    coprocessor register rd:  */
                /*  99          cltd  */
                *a++ = 0x99;

                /*  89 03                   mov    %eax,(%ebx)  */
                /*  89 53 04                mov    %edx,0x4(%ebx)  */
                *a++ = 0x89; *a++ = 0x03;
                *a++ = 0x89; *a++ = 0x53; *a++ = 0x04;
        } else {
                /*  mfc  */

                /*  8b 82 38 30 00 00       mov    0x3038(%edx),%eax  */
                ofs = ((size_t)&dummy_coproc.reg[rd]) - (size_t)&dummy_coproc;
                *a++ = 0x8b; *a++ = 0x82;
                *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                if (flag64bit) {
                        /*  Load high 32 bits:  (note: edx gets overwritten)  */
                        /*  8b 92 3c 30 00 00       mov    0x303c(%edx),%edx  */
                        ofs += 4;
                        *a++ = 0x8b; *a++ = 0x92;
                        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
                } else {
                        /*  99                      cltd  */
                        *a++ = 0x99;
                }

                store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);
        }

        *addrp = a;
        bintrans_write_pc_inc(addrp);
        return 1;
}


/*
 *  bintrans_write_instruction__branch():
 */
static int bintrans_write_instruction__branch(unsigned char **addrp,
        int instruction_type, int regimm_type, int rt, int rs, int imm)
{
        unsigned char *a;
        unsigned char *skip1 = NULL, *skip2 = NULL;
        int ofs, likely = 0;

        switch (instruction_type) {
        case HI6_BEQL:
        case HI6_BNEL:
        case HI6_BLEZL:
        case HI6_BGTZL:
                likely = 1;
        }

        /*  TODO: See the Alpha backend on how these could be implemented:  */
        if (likely)
                return 0;

        a = *addrp;

        /*
         *  edx:eax = gpr[rs]; ecx:ebx = gpr[rt];
         *
         *  Compare for equality (BEQ).
         *  If the result was zero, then it means equality; perform the
         *  delayed jump. Otherwise: skip.
         */

        switch (instruction_type) {
        case HI6_BEQ:
        case HI6_BNE:
                load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);
                /*  89 c3                   mov    %eax,%ebx  */
                /*  89 d1                   mov    %edx,%ecx  */
                *a++ = 0x89; *a++ = 0xc3; *a++ = 0x89; *a++ = 0xd1;
        }
        load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);

        if (instruction_type == HI6_BEQ && rt != rs) {
                /*  If rt != rs, then skip.  */
                /*  39 c3                   cmp    %eax,%ebx  */
                /*  75 05                   jne    155 <skip>  */
                /*  39 d1                   cmp    %edx,%ecx  */
                /*  75 01                   jne    155 <skip>  */
                *a++ = 0x39; *a++ = 0xc3;
                *a++ = 0x75; skip1 = a; *a++ = 0x00;
#if 0
                if (!bintrans_32bit_only)
#endif
 {
                        *a++ = 0x39; *a++ = 0xd1;
                        *a++ = 0x75; skip2 = a; *a++ = 0x00;
                }
        }

        if (instruction_type == HI6_BNE) {
                /*  If rt != rs, then ok. Otherwise skip.  */
#if 0
                if (bintrans_32bit_only) {
                        /*  39 c3                   cmp    %eax,%ebx  */
                        /*  74 xx                   je     <skip>  */
                        *a++ = 0x39; *a++ = 0xc3;
                        *a++ = 0x74; skip2 = a; *a++ = 0x00;
                } else
#endif
 {
                        /*  39 c3                   cmp    %eax,%ebx  */
                        /*  75 06                   jne    156 <bra>  */
                        /*  39 d1                   cmp    %edx,%ecx  */
                        /*  75 02                   jne    156 <bra>  */
                        /*  eb 01                   jmp    157 <skip>  */
                        *a++ = 0x39; *a++ = 0xc3;
                        *a++ = 0x75; *a++ = 0x06;
                        *a++ = 0x39; *a++ = 0xd1;
                        *a++ = 0x75; *a++ = 0x02;
                        *a++ = 0xeb; skip2 = a; *a++ = 0x00;
                }
        }

        if (instruction_type == HI6_BLEZ) {
                /*  If both eax and edx are zero, then do the branch.  */
                /*  83 f8 00                cmp    $0x0,%eax  */
                /*  75 07                   jne    <nott>  */
                /*  83 fa 00                cmp    $0x0,%edx  */
                /*  75 02                   jne    23d <nott>  */
                /*  eb 01                   jmp    <branch>  */
                *a++ = 0x83; *a++ = 0xf8; *a++ = 0x00;
                *a++ = 0x75; *a++ = 0x07;
                *a++ = 0x83; *a++ = 0xfa; *a++ = 0x00;
                *a++ = 0x75; *a++ = 0x02;
                *a++ = 0xeb; skip1 = a; *a++ = 0x00;

                /*  If high bit of edx is set, then rs < 0.  */
                /*  f7 c2 00 00 00 80       test   $0x80000000,%edx  */
                /*  74 00                   jz     skip  */
                *a++ = 0xf7; *a++ = 0xc2; *a++ = 0; *a++ = 0; *a++ = 0; *a++ = 0x80;
                *a++ = 0x74; skip2 = a; *a++ = 0x00;

                if (skip1 != NULL)
                        *skip1 = (size_t)a - (size_t)skip1 - 1;
                skip1 = NULL;
        }
        if (instruction_type == HI6_BGTZ) {
                /*  If both eax and edx are zero, then skip the branch.  */
                /*  83 f8 00                cmp    $0x0,%eax  */
                /*  75 07                   jne    <nott>  */
                /*  83 fa 00                cmp    $0x0,%edx  */
                /*  75 02                   jne    23d <nott>  */
                /*  eb 01                   jmp    <skip>  */
                *a++ = 0x83; *a++ = 0xf8; *a++ = 0x00;
                *a++ = 0x75; *a++ = 0x07;
                *a++ = 0x83; *a++ = 0xfa; *a++ = 0x00;
                *a++ = 0x75; *a++ = 0x02;
                *a++ = 0xeb; skip1 = a; *a++ = 0x00;

                /*  If high bit of edx is set, then rs < 0.  */
                /*  f7 c2 00 00 00 80       test   $0x80000000,%edx  */
                /*  75 00                   jnz    skip  */
                *a++ = 0xf7; *a++ = 0xc2; *a++ = 0; *a++ = 0; *a++ = 0; *a++ = 0x80;
                *a++ = 0x75; skip2 = a; *a++ = 0x00;
        }
        if (instruction_type == HI6_REGIMM && regimm_type == REGIMM_BLTZ) {
                /*  If high bit of edx is set, then rs < 0.  */
                /*  f7 c2 00 00 00 80       test   $0x80000000,%edx  */
                /*  74 00                   jz     skip  */
                *a++ = 0xf7; *a++ = 0xc2; *a++ = 0; *a++ = 0; *a++ = 0; *a++ = 0x80;
                *a++ = 0x74; skip2 = a; *a++ = 0x00;
        }
        if (instruction_type == HI6_REGIMM && regimm_type == REGIMM_BGEZ) {
                /*  If high bit of edx is not set, then rs >= 0.  */
                /*  f7 c2 00 00 00 80       test   $0x80000000,%edx  */
                /*  75 00                   jnz    skip  */
                *a++ = 0xf7; *a++ = 0xc2; *a++ = 0; *a++ = 0; *a++ = 0; *a++ = 0x80;
                *a++ = 0x75; skip2 = a; *a++ = 0x00;
        }

        /*
         *  Perform the jump by setting cpu->delay_slot = TO_BE_DELAYED
         *  and cpu->delay_jmpaddr = pc + 4 + (imm << 2).
         */

        /*  c7 86 38 30 00 00 01 00 00 00    movl   $0x1,0x3038(%esi)  */
        ofs = ((size_t)&dummy_cpu.cd.mips.delay_slot) - (size_t)&dummy_cpu;
        *a++ = 0xc7; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
        *a++ = TO_BE_DELAYED; *a++ = 0; *a++ = 0; *a++ = 0;

        load_pc_into_eax_edx(&a);

        /*  05 78 56 34 12          add    $0x12345678,%eax  */
        /*  83 d2 00                adc    $0x0,%edx  */
        /*  or  */
        /*  83 d2 ff                adc    $0xffffffff,%edx  */
        imm = (imm << 2) + 4;
        *a++ = 0x05; *a++ = imm; *a++ = imm >> 8; *a++ = imm >> 16; *a++ = imm >> 24;
        if (imm >= 0) {
                *a++ = 0x83; *a++ = 0xd2; *a++ = 0x00;
        } else {
                *a++ = 0x83; *a++ = 0xd2; *a++ = 0xff;
        }
        store_eax_edx(&a, &dummy_cpu.cd.mips.delay_jmpaddr);

        if (skip1 != NULL)
                *skip1 = (size_t)a - (size_t)skip1 - 1;
        if (skip2 != NULL)
                *skip2 = (size_t)a - (size_t)skip2 - 1;

        *addrp = a;
        bintrans_write_pc_inc(addrp);
        return 1;
}


/*
 *  bintrans_write_instruction__delayedbranch():
 */
static int bintrans_write_instruction__delayedbranch(struct memory *mem,
        unsigned char **addrp, uint32_t *potential_chunk_p, uint32_t *chunks,
        int only_care_about_chunk_p, int p, int forward)
{
        unsigned char *a, *skip=NULL, *failskip;
        int ofs;
        uint32_t i386_addr;

        a = *addrp;

        if (only_care_about_chunk_p)
                goto try_chunk_p;

        /*  Skip all of this if there is no branch:  */
        ofs = ((size_t)&dummy_cpu.cd.mips.delay_slot) - (size_t)&dummy_cpu;

        /*  8b 86 38 30 00 00       mov    0x3038(%esi),%eax  */
        *a++ = 0x8b; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

        /*  83 f8 00                cmp    $0x0,%eax  */
        /*  74 01                   je     16b <skippa>  */
        *a++ = 0x83; *a++ = 0xf8; *a++ = 0x00;
        *a++ = 0x74; skip = a; *a++ = 0;

        /*
         *  Perform the jump by setting cpu->delay_slot = 0
         *  and pc = cpu->delay_jmpaddr.
         */

        /*  c7 86 38 30 00 00 00 00 00 00    movl   $0x0,0x3038(%esi)  */
        ofs = ((size_t)&dummy_cpu.cd.mips.delay_slot) - (size_t)&dummy_cpu;
        *a++ = 0xc7; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
        *a++ = 0; *a++ = 0; *a++ = 0; *a++ = 0;

        /*  REMEMBER old pc:  */
        load_pc_into_eax_edx(&a);
        /*  89 c3                   mov    %eax,%ebx  */
        /*  89 d1                   mov    %edx,%ecx  */
        *a++ = 0x89; *a++ = 0xc3;
        *a++ = 0x89; *a++ = 0xd1;
        load_into_eax_edx(&a, &dummy_cpu.cd.mips.delay_jmpaddr);
        store_eax_edx_into_pc(&a);

try_chunk_p:

        if (potential_chunk_p == NULL) {
                if (mem->bintrans_32bit_only) {
#if 1
                        /*  8b 86 78 56 34 12       mov    0x12345678(%esi),%eax  */
                        /*  ff e0                   jmp    *%eax  */
                        ofs = ((size_t)&dummy_cpu.cd.mips.bintrans_jump_to_32bit_pc) - (size_t)&dummy_cpu;
                        *a++ = 0x8b; *a++ = 0x86;
                        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
                        *a++ = 0xff; *a++ = 0xe0;

#else
                        /*  Don't execute too many instructions.  */
                        /*  81 fd f0 1f 00 00    cmpl   $0x1ff0,%ebp  */
                        /*  7c 01                jl     <okk>  */
                        /*  c3                   ret    */
                        *a++ = 0x81; *a++ = 0xfd;
                        *a++ = (N_SAFE_BINTRANS_LIMIT-1) & 255;
                        *a++ = ((N_SAFE_BINTRANS_LIMIT-1) >> 8) & 255; *a++ = 0; *a++ = 0;
                        *a++ = 0x7c; failskip = a; *a++ = 0x01;
                        bintrans_write_chunkreturn_fail(&a);
                        *failskip = (size_t)a - (size_t)failskip - 1;

                        /*
                         *  ebx = ((vaddr >> 22) & 1023) * sizeof(void *)
                         *
                         *  89 c3                   mov    %eax,%ebx
                         *  c1 eb 14                shr    $20,%ebx
                         *  81 e3 fc 0f 00 00       and    $0xffc,%ebx
                         */
                        *a++ = 0x89; *a++ = 0xc3;
                        *a++ = 0xc1; *a++ = 0xeb; *a++ = 0x14;
                        *a++ = 0x81; *a++ = 0xe3; *a++ = 0xfc; *a++ = 0x0f; *a++ = 0; *a++ = 0;

                        /*
                         *  ecx = vaddr_to_hostaddr_table0
                         *
                         *  8b 8e 34 12 00 00       mov    0x1234(%esi),%ecx
                         */
                        ofs = ((size_t)&dummy_cpu.cd.mips.vaddr_to_hostaddr_table0) - (size_t)&dummy_cpu;
                        *a++ = 0x8b; *a++ = 0x8e;
                        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                        /*
                         *  ecx = vaddr_to_hostaddr_table0[a]
                         *
                         *  8b 0c 19                mov    (%ecx,%ebx),%ecx
                         */
                        *a++ = 0x8b; *a++ = 0x0c; *a++ = 0x19;

                        /*
                         *  ebx = ((vaddr >> 12) & 1023) * sizeof(void *)
                         *
                         *  89 c3                   mov    %eax,%ebx
                         *  c1 eb 0a                shr    $10,%ebx
                         *  81 e3 fc 0f 00 00       and    $0xffc,%ebx
                         */
                        *a++ = 0x89; *a++ = 0xc3;
                        *a++ = 0xc1; *a++ = 0xeb; *a++ = 0x0a;
                        *a++ = 0x81; *a++ = 0xe3; *a++ = 0xfc; *a++ = 0x0f; *a++ = 0; *a++ = 0;

                        /*
                         *  ecx = vaddr_to_hostaddr_table0[a][b].cd.mips.chunks
                         *
                         *  8b 8c 19 56 34 12 00    mov    0x123456(%ecx,%ebx,1),%ecx
                         */
                        ofs = (size_t)&dummy_vth32_table.cd.mips.bintrans_chunks[0]
                            - (size_t)&dummy_vth32_table;

                        *a++ = 0x8b; *a++ = 0x8c;  *a++ = 0x19;
                            *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                        /*
                         *  ecx = NULL? Then return with failure.
                         *
                         *  83 f9 00                cmp    $0x0,%ecx
                         *  75 01                   jne    <okzzz>
                         */
                        *a++ = 0x83; *a++ = 0xf9; *a++ = 0x00;
                        *a++ = 0x75; fail = a; *a++ = 0x00;
                        bintrans_write_chunkreturn(&a);
                        *fail = (size_t)a - (size_t)fail - 1;

                        /*
                         *  25 fc 0f 00 00          and    $0xffc,%eax
                         *  01 c1                   add    %eax,%ecx
                         *
                         *  8b 01                   mov    (%ecx),%eax
                         *
                         *  83 f8 00                cmp    $0x0,%eax
                         *  75 01                   jne    <ok>
                         *  c3                      ret
                         */
                        *a++ = 0x25; *a++ = 0xfc; *a++ = 0x0f; *a++ = 0; *a++ = 0;
                        *a++ = 0x01; *a++ = 0xc1;

                        *a++ = 0x8b; *a++ = 0x01;

                        *a++ = 0x83; *a++ = 0xf8; *a++ = 0x00;
                        *a++ = 0x75; fail = a; *a++ = 0x01;
                        bintrans_write_chunkreturn(&a);
                        *fail = (size_t)a - (size_t)fail - 1;

                        /*  03 86 78 56 34 12       add    0x12345678(%esi),%eax  */
                        /*  ff e0                   jmp    *%eax  */
                        ofs = ((size_t)&dummy_cpu.cd.mips.chunk_base_address) - (size_t)&dummy_cpu;
                        *a++ = 0x03; *a++ = 0x86;
                        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
                        *a++ = 0xff; *a++ = 0xe0;
#endif
                } else {
                        /*  Not much we can do here if this wasn't to the same physical page...  */

                        /*  Don't execute too many instructions.  */
                        /*  81 fd f0 1f 00 00    cmpl   $0x1ff0,%ebp  */
                        /*  7c 01                jl     <okk>  */
                        /*  c3                   ret    */
                        *a++ = 0x81; *a++ = 0xfd;
                        *a++ = (N_SAFE_BINTRANS_LIMIT-1) & 255;
                        *a++ = ((N_SAFE_BINTRANS_LIMIT-1) >> 8) & 255; *a++ = 0; *a++ = 0;
                        *a++ = 0x7c; failskip = a; *a++ = 0x01;
                        bintrans_write_chunkreturn_fail(&a);
                        *failskip = (size_t)a - (size_t)failskip - 1;

                        /*
                         *  Compare the old pc (ecx:ebx) and the new pc (edx:eax). If they are on the
                         *  same virtual page (which means that they are on the same physical
                         *  page), then we can check the right chunk pointer, and if it
                         *  is non-NULL, then we can jump there.  Otherwise just return.
                         */

                        /*  Subtract 4 from the old pc first. (This is where the jump originated from.)  */
                        /*  83 eb 04                sub    $0x4,%ebx  */
                        /*  83 d9 00                sbb    $0x0,%ecx  */
                        *a++ = 0x83; *a++ = 0xeb; *a++ = 0x04;
                        *a++ = 0x83; *a++ = 0xd9; *a++ = 0x00;

                        /*  39 d1                   cmp    %edx,%ecx  */
                        /*  74 01                   je     1b9 <ok2>  */
                        /*  c3                      ret    */
                        *a++ = 0x39; *a++ = 0xd1;
                        *a++ = 0x74; *a++ = 0x01;
                        *a++ = 0xc3;

                        /*  Remember new pc:  */
                        /*  89 c1                   mov    %eax,%ecx  */
                        *a++ = 0x89; *a++ = 0xc1;

                        /*  81 e3 00 f0 ff ff       and    $0xfffff000,%ebx  */
                        /*  25 00 f0 ff ff          and    $0xfffff000,%eax  */
                        *a++ = 0x81; *a++ = 0xe3; *a++ = 0x00; *a++ = 0xf0; *a++ = 0xff; *a++ = 0xff;
                        *a++ = 0x25; *a++ = 0x00; *a++ = 0xf0; *a++ = 0xff; *a++ = 0xff;

                        /*  39 c3                   cmp    %eax,%ebx  */
                        /*  74 01                   je     <ok1>  */
                        /*  c3                      ret    */
                        *a++ = 0x39; *a++ = 0xc3;
                        *a++ = 0x74; *a++ = 0x01;
                        *a++ = 0xc3;

                        /*  81 e1 ff 0f 00 00       and    $0xfff,%ecx  */
                        *a++ = 0x81; *a++ = 0xe1; *a++ = 0xff; *a++ = 0x0f; *a++ = 0; *a++ = 0;

                        /*  8b 81 78 56 34 12       mov    0x12345678(%ecx),%eax  */
                        ofs = (size_t)chunks;
                        *a++ = 0x8b; *a++ = 0x81; *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                        /*  83 f8 00                cmp    $0x0,%eax  */
                        /*  75 01                   jne    1cd <okjump>  */
                        /*  c3                      ret    */
                        *a++ = 0x83; *a++ = 0xf8; *a++ = 0x00;
                        *a++ = 0x75; *a++ = 0x01;
                        *a++ = 0xc3;

                        /*  03 86 78 56 34 12       add    0x12345678(%esi),%eax  */
                        /*  ff e0                   jmp    *%eax  */
                        ofs = ((size_t)&dummy_cpu.cd.mips.chunk_base_address) - (size_t)&dummy_cpu;
                        *a++ = 0x03; *a++ = 0x86;
                        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
                        *a++ = 0xff; *a++ = 0xe0;
                }
        } else {
                /*
                 *  Just to make sure that we don't become too unreliant
                 *  on the main program loop, we need to return every once
                 *  in a while (interrupts etc).
                 *
                 *  Load the "nr of instructions executed" (which is an int)
                 *  and see if it is below a certain threshold. If so, then
                 *  we go on with the fast path (bintrans), otherwise we
                 *  abort by returning.
                 */
                /*  81 fd f0 1f 00 00    cmpl   $0x1ff0,%ebp  */
                /*  7c 01                jl     <okk>  */
                /*  c3                   ret    */
                if (!only_care_about_chunk_p && !forward) {
                        *a++ = 0x81; *a++ = 0xfd;
                        *a++ = (N_SAFE_BINTRANS_LIMIT-1) & 255;
                        *a++ = ((N_SAFE_BINTRANS_LIMIT-1) >> 8) & 255; *a++ = 0; *a++ = 0;
                        *a++ = 0x7c; failskip = a; *a++ = 0x01;
                        bintrans_write_chunkreturn_fail(&a);
                        *failskip = (size_t)a - (size_t)failskip - 1;
                }

                /*
                 *  potential_chunk_p points to an "uint32_t".
                 *  If this value is non-NULL, then it is a piece of i386
                 *  machine language code corresponding to the address
                 *  we're jumping to. Otherwise, those instructions haven't
                 *  been translated yet, so we have to return to the main
                 *  loop.  (Actually, we have to add cpu->chunk_base_address.)
                 *
                 *  Case 1:  The value is non-NULL already at translation
                 *           time. Then we can make a direct (fast) native
                 *           i386 jump to the code chunk.
                 *
                 *  Case 2:  The value was NULL at translation time, then we
                 *           have to check during runtime.
                 */

                /*  Case 1:  */
                /*  printf("%08x ", *potential_chunk_p);  */
                i386_addr = *potential_chunk_p +
                    (size_t)mem->translation_code_chunk_space;
                i386_addr = i386_addr - ((size_t)a + 5);
                if ((*potential_chunk_p) != 0) {
                        *a++ = 0xe9;
                        *a++ = i386_addr;
                        *a++ = i386_addr >> 8;
                        *a++ = i386_addr >> 16;
                        *a++ = i386_addr >> 24;
                } else {
                        /*  Case 2:  */

                        bintrans_register_potential_quick_jump(mem, a, p);

                        i386_addr = (size_t)potential_chunk_p;

                        /*
                         *  Load the chunk pointer into eax.
                         *  If it is NULL (zero), then skip the following jump.
                         *  Add chunk_base_address to eax, and jump to eax.
                         */

                        /*  a1 78 56 34 12          mov    0x12345678,%eax  */
                        /*  83 f8 00                cmp    $0x0,%eax  */
                        /*  75 01                   jne    <okaa>  */
                        /*  c3                      ret    */
                        *a++ = 0xa1;
                        *a++ = i386_addr; *a++ = i386_addr >> 8;
                        *a++ = i386_addr >> 16; *a++ = i386_addr >> 24;
                        *a++ = 0x83; *a++ = 0xf8; *a++ = 0x00;
                        *a++ = 0x75; *a++ = 0x01;
                        *a++ = 0xc3;

                        /*  03 86 78 56 34 12       add    0x12345678(%esi),%eax  */
                        /*  ff e0                   jmp    *%eax  */
                        ofs = ((size_t)&dummy_cpu.cd.mips.chunk_base_address) - (size_t)&dummy_cpu;
                        *a++ = 0x03; *a++ = 0x86;
                        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;
                        *a++ = 0xff; *a++ = 0xe0;
                }
        }

        if (skip != NULL)
                *skip = (size_t)a - (size_t)skip - 1;

        *addrp = a;
        return 1;
}


/*
 *  bintrans_write_instruction__loadstore():
 */
static int bintrans_write_instruction__loadstore(struct memory *mem,
        unsigned char **addrp, int rt, int imm, int rs,
        int instruction_type, int bigendian)
{
        unsigned char *a, *retfail, *generic64bit, *doloadstore,
            *okret0, *okret1, *okret2, *skip;
        int ofs, alignment, load=0, unaligned=0;

        /*  TODO: Not yet:  */
        if (instruction_type == HI6_LQ_MDMX || instruction_type == HI6_SQ)
                return 0;

        /*  TODO: Not yet:  */
        if (bigendian)
                return 0;

        switch (instruction_type) {
        case HI6_LQ_MDMX:
        case HI6_LDL:
        case HI6_LDR:
        case HI6_LD:
        case HI6_LWU:
        case HI6_LWL:
        case HI6_LWR:
        case HI6_LW:
        case HI6_LHU:
        case HI6_LH:
        case HI6_LBU:
        case HI6_LB:
                load = 1;
                if (rt == 0)
                        return 0;
        }

        switch (instruction_type) {
        case HI6_LWL:
        case HI6_LWR:
        case HI6_LDL:
        case HI6_LDR:
        case HI6_SWL:
        case HI6_SWR:
        case HI6_SDL:
        case HI6_SDR:
                unaligned = 1;
        }

        a = *addrp;

        if (mem->bintrans_32bit_only)
                load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
        else
                load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);

        if (imm & 0x8000) {
                /*  05 34 f2 ff ff          add    $0xfffff234,%eax  */
                /*  83 d2 ff                adc    $0xffffffff,%edx  */
                *a++ = 5;
                *a++ = imm; *a++ = imm >> 8; *a++ = 0xff; *a++ = 0xff;
                if (!mem->bintrans_32bit_only) {
                        *a++ = 0x83; *a++ = 0xd2; *a++ = 0xff;
                }
        } else {
                /*  05 34 12 00 00          add    $0x1234,%eax  */
                /*  83 d2 00                adc    $0x0,%edx  */
                *a++ = 5;
                *a++ = imm; *a++ = imm >> 8; *a++ = 0; *a++ = 0;
                if (!mem->bintrans_32bit_only) {
                        *a++ = 0x83; *a++ = 0xd2; *a++ = 0;
                }
        }

        alignment = 0;
        switch (instruction_type) {
        case HI6_LQ_MDMX:
        case HI6_SQ:
                alignment = 15;
                break;
        case HI6_LD:
        case HI6_LDL:
        case HI6_LDR:
        case HI6_SD:
        case HI6_SDL:
        case HI6_SDR:
                alignment = 7;
                break;
        case HI6_LW:
        case HI6_LWL:
        case HI6_LWR:
        case HI6_LWU:
        case HI6_SW:
        case HI6_SWL:
        case HI6_SWR:
                alignment = 3;
                break;
        case HI6_LH:
        case HI6_LHU:
        case HI6_SH:
                alignment = 1;
                break;
        }

        if (unaligned) {
                /*
                 *  Perform the actual load/store from an
                 *  aligned address.
                 *
                 *  83 e0 fc       and    $0xfffffffc,%eax
                 */
                *a++ = 0x83; *a++ = 0xe0; *a++ = 0xff - alignment;
        } else if (alignment > 0) {
                unsigned char *alignskip;
                /*
                 *  Check alignment:
                 *
                 *  89 c3                   mov    %eax,%ebx
                 *  83 e3 01                and    $0x1,%ebx
                 *  74 01                   jz     <ok>
                 *  c3                      ret
                 */
                *a++ = 0x89; *a++ = 0xc3;
                *a++ = 0x83; *a++ = 0xe3; *a++ = alignment;
                *a++ = 0x74; alignskip = a; *a++ = 0x00;
                bintrans_write_chunkreturn_fail(&a);
                *alignskip = (size_t)a - (size_t)alignskip - 1;
        }


        /*  Here, edx:eax = vaddr  */

        if (mem->bintrans_32bit_only) {
                /*  Call the quick lookup routine:  */
                ofs = (size_t)bintrans_loadstore_32bit;
                ofs = ofs - ((size_t)a + 5);
                *a++ = 0xe8; *a++ = ofs; *a++ = ofs >> 8;
                    *a++ = ofs >> 16; *a++ = ofs >> 24;

                /*
                 *  ecx = NULL? Then return with failure.
                 *
                 *  83 f9 00                cmp    $0x0,%ecx
                 *  75 01                   jne    <okzzz>
                 */
                *a++ = 0x83; *a++ = 0xf9; *a++ = 0x00;
                *a++ = 0x75; retfail = a; *a++ = 0x00;
                bintrans_write_chunkreturn_fail(&a);            /*  ret (and fail)  */
                *retfail = (size_t)a - (size_t)retfail - 1;

                /*
                 *  If the lowest bit is zero, and we're storing, then fail.
                 */
                if (!load) {
                        /*
                         *  f7 c1 01 00 00 00       test   $0x1,%ecx
                         *  75 01                   jne    <ok>
                         */
                        *a++ = 0xf7; *a++ = 0xc1; *a++ = 1; *a++ = 0; *a++ = 0; *a++ = 0;
                        *a++ = 0x75; retfail = a; *a++ = 0x00;
                        bintrans_write_chunkreturn_fail(&a);            /*  ret (and fail)  */
                        *retfail = (size_t)a - (size_t)retfail - 1;
                }

                /*
                 *  eax = offset within page = vaddr & 0xfff
                 *
                 *  25 ff 0f 00 00       and    $0xfff,%eax
                 */
                *a++ = 0x25; *a++ = 0xff; *a++ = 0x0f; *a++ = 0; *a++ = 0;

                /*
                 *  ecx = host address   ( = host page + offset)
                 *
                 *  83 e1 fe                and    $0xfffffffe,%ecx     clear the lowest bit
                 *  01 c1                   add    %eax,%ecx
                 */
                *a++ = 0x83; *a++ = 0xe1; *a++ = 0xfe;
                *a++ = 0x01; *a++ = 0xc1;
        } else {
                /*
                 *  If the load/store address has the top 32 bits set to
                 *  0x00000000 or 0xffffffff, then we can use the 32-bit
                 *  lookup tables:
                 *

TODO: top 33 bits!!!!!!!

                 *  83 fa 00                cmp    $0x0,%edx
                 *  74 05                   je     <ok32>
                 *  83 fa ff                cmp    $0xffffffff,%edx
                 *  75 01                   jne    <not32>
                 */
                *a++ = 0x83; *a++ = 0xfa; *a++ = 0x00;
                *a++ = 0x74; *a++ = 0x05;
                *a++ = 0x83; *a++ = 0xfa; *a++ = 0xff;
                *a++ = 0x75; generic64bit = a; *a++ = 0x01;

                /*  Call the quick lookup routine:  */
                ofs = (size_t)bintrans_loadstore_32bit;
                ofs = ofs - ((size_t)a + 5);
                *a++ = 0xe8; *a++ = ofs; *a++ = ofs >> 8;
                    *a++ = ofs >> 16; *a++ = ofs >> 24;

                /*
                 *  ecx = NULL? Then return with failure.
                 *
                 *  83 f9 00                cmp    $0x0,%ecx
                 *  75 01                   jne    <okzzz>
                 */
                *a++ = 0x83; *a++ = 0xf9; *a++ = 0x00;
                *a++ = 0x75; retfail = a; *a++ = 0x00;
                bintrans_write_chunkreturn_fail(&a);            /*  ret (and fail)  */
                *retfail = (size_t)a - (size_t)retfail - 1;

                /*
                 *  If the lowest bit is zero, and we're storing, then fail.
                 */
                if (!load) {
                        /*
                         *  f7 c1 01 00 00 00       test   $0x1,%ecx
                         *  75 01                   jne    <ok>
                         */
                        *a++ = 0xf7; *a++ = 0xc1; *a++ = 1; *a++ = 0; *a++ = 0; *a++ = 0;
                        *a++ = 0x75; retfail = a; *a++ = 0x00;
                        bintrans_write_chunkreturn_fail(&a);            /*  ret (and fail)  */
                        *retfail = (size_t)a - (size_t)retfail - 1;
                }

                /*
                 *  eax = offset within page = vaddr & 0xfff
                 *
                 *  25 ff 0f 00 00       and    $0xfff,%eax
                 */
                *a++ = 0x25; *a++ = 0xff; *a++ = 0x0f; *a++ = 0; *a++ = 0;

                /*
                 *  ecx = host address   ( = host page + offset)
                 *
                 *  83 e1 fe                and    $0xfffffffe,%ecx     clear the lowest bit
                 *  01 c1                   add    %eax,%ecx
                 */
                *a++ = 0x83; *a++ = 0xe1; *a++ = 0xfe;
                *a++ = 0x01; *a++ = 0xc1;

                *a++ = 0xeb; doloadstore = a; *a++ = 0x01;


                /*  TODO: The stuff above is so similar to the pure 32-bit
                    case that it should be factored out.  */


                *generic64bit = (size_t)a - (size_t)generic64bit - 1;

                /*
                 *  64-bit generic case:
                 */

                /*  push writeflag  */
                *a++ = 0x6a; *a++ = load? 0 : 1;

                /*  push vaddr (edx:eax)  */
                *a++ = 0x52; *a++ = 0x50;

                /*  push cpu (esi)  */
                *a++ = 0x56;

                /*  eax = points to the right function  */
                ofs = ((size_t)&dummy_cpu.cd.mips.fast_vaddr_to_hostaddr) - (size_t)&dummy_cpu;
                *a++ = 0x8b; *a++ = 0x86;
                *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

                /*  ff d0                   call   *%eax  */
                *a++ = 0xff; *a++ = 0xd0;

                /*  83 c4 08                add    $0x10,%esp  */
                *a++ = 0x83; *a++ = 0xc4; *a++ = 0x10;

                /*  If eax is NULL, then return.  */
                /*  83 f8 00                cmp    $0x0,%eax  */
                /*  75 01                   jne    1cd <okjump>  */
                /*  c3                      ret    */
                *a++ = 0x83; *a++ = 0xf8; *a++ = 0x00;
                *a++ = 0x75; retfail = a; *a++ = 0x00;
                bintrans_write_chunkreturn_fail(&a);            /*  ret (and fail)  */
                *retfail = (size_t)a - (size_t)retfail - 1;  

                /*  89 c1                   mov    %eax,%ecx  */
                *a++ = 0x89; *a++ = 0xc1;

                *doloadstore = (size_t)a - (size_t)doloadstore - 1;
        }


        if (!load) {
                if (alignment >= 7)
                        load_into_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);
                else
                        load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);
        }

        switch (instruction_type) {
        case HI6_LD:
                /*  8b 01                   mov    (%ecx),%eax  */
                /*  8b 51 04                mov    0x4(%ecx),%edx  */
                *a++ = 0x8b; *a++ = 0x01;
                *a++ = 0x8b; *a++ = 0x51; *a++ = 0x04;
                break;
        case HI6_LWU:
                /*  8b 01                   mov    (%ecx),%eax  */
                /*  31 d2                   xor    %edx,%edx  */
                *a++ = 0x8b; *a++ = 0x01;
                *a++ = 0x31; *a++ = 0xd2;
                break;
        case HI6_LW:
                /*  8b 01                   mov    (%ecx),%eax  */
                /*  99                      cltd   */
                *a++ = 0x8b; *a++ = 0x01;
                *a++ = 0x99;
                break;
        case HI6_LHU:
                /*  31 c0                   xor    %eax,%eax  */
                /*  66 8b 01                mov    (%ecx),%ax  */
                /*  99                      cltd   */
                *a++ = 0x31; *a++ = 0xc0;
                *a++ = 0x66; *a++ = 0x8b; *a++ = 0x01;
                *a++ = 0x99;
                break;
        case HI6_LH:
                /*  66 8b 01                mov    (%ecx),%ax  */
                /*  98                      cwtl   */
                /*  99                      cltd   */
                *a++ = 0x66; *a++ = 0x8b; *a++ = 0x01;
                *a++ = 0x98;
                *a++ = 0x99;
                break;
        case HI6_LBU:
                /*  31 c0                   xor    %eax,%eax  */
                /*  8a 01                   mov    (%ecx),%al  */
                /*  99                      cltd   */
                *a++ = 0x31; *a++ = 0xc0;
                *a++ = 0x8a; *a++ = 0x01;
                *a++ = 0x99;
                break;
        case HI6_LB:
                /*  8a 01                   mov    (%ecx),%al  */
                /*  66 98                   cbtw   */
                /*  98                      cwtl   */
                /*  99                      cltd   */
                *a++ = 0x8a; *a++ = 0x01;
                *a++ = 0x66; *a++ = 0x98;
                *a++ = 0x98;
                *a++ = 0x99;
                break;

        case HI6_LWL:
                load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
                /*  05 34 f2 ff ff          add    $0xfffff234,%eax  */
                *a++ = 5;
                *a++ = imm; *a++ = imm >> 8; *a++ = 0xff; *a++ = 0xff;
                /*  83 e0 03                and    $0x03,%eax  */
                *a++ = 0x83; *a++ = 0xe0; *a++ = alignment;
                /*  89 c3                   mov    %eax,%ebx  */
                *a++ = 0x89; *a++ = 0xc3;

                load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);

                /*  ALIGNED LOAD:  */
                /*  8b 11                   mov    (%ecx),%edx  */
                *a++ = 0x8b; *a++ = 0x11;

                /*
                 *  CASE 0:
                 *      memory = 0x12 0x34 0x56 0x78
                 *      register after lwl: 0x12 0x.. 0x.. 0x..
                 */
                /*  83 fb 00                cmp    $0x0,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x00;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  c1 e2 18                shl    $0x18,%edx  */
                /*  25 ff ff ff 00          and    $0xffffff,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0xc1; *a++ = 0xe2; *a++ = 0x18;
                *a++ = 0x25; *a++ = 0xff; *a++ = 0xff; *a++ = 0xff; *a++ = 0x00;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret0 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 1:
                 *      memory = 0x12 0x34 0x56 0x78
                 *      register after lwl: 0x34 0x12 0x.. 0x..
                 */
                /*  83 fb 01                cmp    $0x1,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x01;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  c1 e2 10                shl    $0x10,%edx  */
                /*  25 ff ff 00 00          and    $0xffff,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0xc1; *a++ = 0xe2; *a++ = 0x10;
                *a++ = 0x25; *a++ = 0xff; *a++ = 0xff; *a++ = 0x00; *a++ = 0x00;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret1 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 2:
                 *      memory = 0x12 0x34 0x56 0x78
                 *      register after lwl: 0x56 0x34 0x12 0x..
                 */
                /*  83 fb 02                cmp    $0x2,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x02;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  c1 e2 08                shl    $0x08,%edx  */
                /*  25 ff 00 00 00          and    $0xff,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0xc1; *a++ = 0xe2; *a++ = 0x08;
                *a++ = 0x25; *a++ = 0xff; *a++ = 0x00; *a++ = 0x00; *a++ = 0x00;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret2 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 3:
                 *      memory = 0x12 0x34 0x56 0x78
                 *      register after lwl: 0x78 0x56 0x34 0x12
                 */
                /*  89 d0                   mov    %edx,%eax  */
                *a++ = 0x89; *a++ = 0xd0;

                /*  okret:  */
                *okret0 = (size_t)a - (size_t)okret0 - 1;
                *okret1 = (size_t)a - (size_t)okret1 - 1;
                *okret2 = (size_t)a - (size_t)okret2 - 1;

                /*  99                      cltd   */
                *a++ = 0x99;
                break;

        case HI6_LWR:
                load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
                /*  05 34 f2 ff ff          add    $0xfffff234,%eax  */
                *a++ = 5;
                *a++ = imm; *a++ = imm >> 8; *a++ = 0xff; *a++ = 0xff;
                /*  83 e0 03                and    $0x03,%eax  */
                *a++ = 0x83; *a++ = 0xe0; *a++ = alignment;
                /*  89 c3                   mov    %eax,%ebx  */
                *a++ = 0x89; *a++ = 0xc3;

                load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);

                /*  ALIGNED LOAD:  */
                /*  8b 11                   mov    (%ecx),%edx  */
                *a++ = 0x8b; *a++ = 0x11;

                /*
                 *  CASE 0:
                 *      memory = 0x12 0x34 0x56 0x78
                 *      register after lwr: 0x78 0x56 0x34 0x12
                 */
                /*  83 fb 00                cmp    $0x0,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x00;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  89 d0                   mov    %edx,%eax  */
                *a++ = 0x89; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret0 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 1:
                 *      memory = 0x12 0x34 0x56 0x78
                 *      register after lwr: 0x.. 0x78 0x56 0x34
                 */
                /*  83 fb 01                cmp    $0x1,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x01;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  c1 ea 08                shr    $0x8,%edx  */
                /*  25 00 00 00 ff          and    $0xff000000,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0xc1; *a++ = 0xea; *a++ = 0x08;
                *a++ = 0x25; *a++ = 0x00; *a++ = 0x00; *a++ = 0x00; *a++ = 0xff;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret1 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 2:
                 *      memory = 0x12 0x34 0x56 0x78
                 *      register after lwr: 0x.. 0x.. 0x78 0x56
                 */
                /*  83 fb 02                cmp    $0x2,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x02;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  c1 ea 10                shr    $0x10,%edx  */
                /*  25 00 00 ff ff          and    $0xffff0000,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0xc1; *a++ = 0xea; *a++ = 0x10;
                *a++ = 0x25; *a++ = 0x00; *a++ = 0x00; *a++ = 0xff; *a++ = 0xff;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret2 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 3:
                 *      memory = 0x12 0x34 0x56 0x78
                 *      register after lwr: 0x.. 0x.. 0x.. 0x78
                 */
                /*  c1 ea 18                shr    $0x18,%edx  */
                /*  25 00 ff ff ff          and    $0xffffff00,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0xc1; *a++ = 0xea; *a++ = 0x18;
                *a++ = 0x25; *a++ = 0x00; *a++ = 0xff; *a++ = 0xff; *a++ = 0xff;
                *a++ = 0x09; *a++ = 0xd0;

                /*  okret:  */
                *okret0 = (size_t)a - (size_t)okret0 - 1;
                *okret1 = (size_t)a - (size_t)okret1 - 1;
                *okret2 = (size_t)a - (size_t)okret2 - 1;

                /*  99                      cltd   */
                *a++ = 0x99;
                break;

        case HI6_SD:
                /*  89 01                   mov    %eax,(%ecx)  */
                /*  89 51 04                mov    %edx,0x4(%ecx)  */
                *a++ = 0x89; *a++ = 0x01;
                *a++ = 0x89; *a++ = 0x51; *a++ = 0x04;
                break;
        case HI6_SW:
                /*  89 01                   mov    %eax,(%ecx)  */
                *a++ = 0x89; *a++ = 0x01;
                break;
        case HI6_SH:
                /*  66 89 01                mov    %ax,(%ecx)  */
                *a++ = 0x66; *a++ = 0x89; *a++ = 0x01;
                break;
        case HI6_SB:
                /*  88 01                   mov    %al,(%ecx)  */
                *a++ = 0x88; *a++ = 0x01;
                break;

        case HI6_SWL:
                load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
                /*  05 34 f2 ff ff          add    $0xfffff234,%eax  */
                *a++ = 5;
                *a++ = imm; *a++ = imm >> 8; *a++ = 0xff; *a++ = 0xff;
                /*  83 e0 03                and    $0x03,%eax  */
                *a++ = 0x83; *a++ = 0xe0; *a++ = alignment;
                /*  89 c3                   mov    %eax,%ebx  */
                *a++ = 0x89; *a++ = 0xc3;

                load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);

                /*  ALIGNED LOAD:  */
                /*  8b 11                   mov    (%ecx),%edx  */
                *a++ = 0x8b; *a++ = 0x11;

                /*
                 *  CASE 0:
                 *      memory (edx):   0x12 0x34 0x56 0x78
                 *      register (eax): 0x89abcdef
                 *      mem after swl:  0x89 0x.. 0x.. 0x..
                 */
                /*  83 fb 00                cmp    $0x0,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x00;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  81 e2 00 ff ff ff       and    $0xffffff00,%edx  */
                /*  c1 e8 18                shr    $0x18,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0x81; *a++ = 0xe2; *a++ = 0x00; *a++ = 0xff; *a++ = 0xff; *a++ = 0xff;
                *a++ = 0xc1; *a++ = 0xe8; *a++ = 0x18;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret0 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 1:
                 *      memory (edx):   0x12 0x34 0x56 0x78
                 *      register (eax): 0x89abcdef
                 *      mem after swl:  0xab 0x89 0x.. 0x..
                 */
                /*  83 fb 01                cmp    $0x1,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x01;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  81 e2 00 00 ff ff       and    $0xffff0000,%edx  */
                /*  c1 e8 10                shr    $0x10,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0x81; *a++ = 0xe2; *a++ = 0x00; *a++ = 0x00; *a++ = 0xff; *a++ = 0xff;
                *a++ = 0xc1; *a++ = 0xe8; *a++ = 0x10;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret1 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 2:
                 *      memory (edx):   0x12 0x34 0x56 0x78
                 *      register (eax): 0x89abcdef
                 *      mem after swl:  0xcd 0xab 0x89 0x..
                 */
                /*  83 fb 02                cmp    $0x2,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x02;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  81 e2 00 00 00 ff       and    $0xff000000,%edx  */
                /*  c1 e8 08                shr    $0x08,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0x81; *a++ = 0xe2; *a++ = 0x00; *a++ = 0x00; *a++ = 0x00; *a++ = 0xff;
                *a++ = 0xc1; *a++ = 0xe8; *a++ = 0x08;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret2 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 3:
                 *      memory (edx):   0x12 0x34 0x56 0x78
                 *      register (eax): 0x89abcdef
                 *      mem after swl:  0xef 0xcd 0xab 0x89
                 */
                /*  eax = eax :-)  */

                /*  okret:  */
                *okret0 = (size_t)a - (size_t)okret0 - 1;
                *okret1 = (size_t)a - (size_t)okret1 - 1;
                *okret2 = (size_t)a - (size_t)okret2 - 1;

                /*  Store back to memory:  */
                /*  89 01                   mov    %eax,(%ecx)  */
                *a++ = 0x89; *a++ = 0x01;
                break;

        case HI6_SWR:
                load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rs]);
                /*  05 34 f2 ff ff          add    $0xfffff234,%eax  */
                *a++ = 5;
                *a++ = imm; *a++ = imm >> 8; *a++ = 0xff; *a++ = 0xff;
                /*  83 e0 03                and    $0x03,%eax  */
                *a++ = 0x83; *a++ = 0xe0; *a++ = alignment;
                /*  89 c3                   mov    %eax,%ebx  */
                *a++ = 0x89; *a++ = 0xc3;

                load_into_eax_dont_care_about_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);

                /*  ALIGNED LOAD:  */
                /*  8b 11                   mov    (%ecx),%edx  */
                *a++ = 0x8b; *a++ = 0x11;

                /*
                 *  CASE 0:
                 *      memory (edx):   0x12 0x34 0x56 0x78
                 *      register (eax): 0x89abcdef
                 *      mem after swr:  0xef 0xcd 0xab 0x89
                 */
                /*  83 fb 00                cmp    $0x0,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x00;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  eax = eax, so do nothing  */

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret0 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 1:
                 *      memory (edx):   0x12 0x34 0x56 0x78
                 *      register (eax): 0x89abcdef
                 *      mem after swr:  0x12 0xef 0xcd 0xab
                 */
                /*  83 fb 01                cmp    $0x1,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x01;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  81 e2 ff 00 00 00       and    $0x000000ff,%edx  */
                /*  c1 e0 08                shl    $0x08,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0x81; *a++ = 0xe2; *a++ = 0xff; *a++ = 0x00; *a++ = 0x00; *a++ = 0x00;
                *a++ = 0xc1; *a++ = 0xe0; *a++ = 0x08;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret1 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 2:
                 *      memory (edx):   0x12 0x34 0x56 0x78
                 *      register (eax): 0x89abcdef
                 *      mem after swr:  0x12 0x34 0xef 0xcd
                 */
                /*  83 fb 02                cmp    $0x2,%ebx  */
                /*  75 01                   jne    <skip>  */
                *a++ = 0x83; *a++ = 0xfb; *a++ = 0x02;
                *a++ = 0x75; skip = a; *a++ = 0x01;

                /*  81 e2 ff ff 00 00       and    $0x0000ffff,%edx  */
                /*  c1 e0 10                shl    $0x10,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0x81; *a++ = 0xe2; *a++ = 0xff; *a++ = 0xff; *a++ = 0x00; *a++ = 0x00;
                *a++ = 0xc1; *a++ = 0xe0; *a++ = 0x10;
                *a++ = 0x09; *a++ = 0xd0;

                /*  eb 00                   jmp    <okret>  */
                *a++ = 0xeb; okret2 = a; *a++ = 0;

                *skip = (size_t)a - (size_t)skip - 1;

                /*
                 *  CASE 3:
                 *      memory (edx):   0x12 0x34 0x56 0x78
                 *      register (eax): 0x89abcdef
                 *      mem after swr:  0x12 0x34 0x56 0xef
                 */
                /*  81 e2 ff ff ff 00       and    $0x00ffffff,%edx  */
                /*  c1 e0 18                shl    $0x18,%eax  */
                /*  09 d0                   or     %edx,%eax  */
                *a++ = 0x81; *a++ = 0xe2; *a++ = 0xff; *a++ = 0xff; *a++ = 0xff; *a++ = 0x00;
                *a++ = 0xc1; *a++ = 0xe0; *a++ = 0x18;
                *a++ = 0x09; *a++ = 0xd0;


                /*  okret:  */
                *okret0 = (size_t)a - (size_t)okret0 - 1;
                *okret1 = (size_t)a - (size_t)okret1 - 1;
                *okret2 = (size_t)a - (size_t)okret2 - 1;

                /*  Store back to memory:  */
                /*  89 01                   mov    %eax,(%ecx)  */
                *a++ = 0x89; *a++ = 0x01;
                break;

        default:
                bintrans_write_chunkreturn_fail(&a);            /*  ret (and fail)  */
        }

        if (load && rt != 0)
                store_eax_edx(&a, &dummy_cpu.cd.mips.gpr[rt]);

        *addrp = a;
        bintrans_write_pc_inc(addrp);
        return 1;
}


/*
 *  bintrans_write_instruction__tlb_rfe_etc():
 */
static int bintrans_write_instruction__tlb_rfe_etc(unsigned char **addrp,
        int itype)
{
        unsigned char *a;
        int ofs;

        switch (itype) {
        case CALL_TLBP:
        case CALL_TLBR:
        case CALL_TLBWR:
        case CALL_TLBWI:
        case CALL_RFE:
        case CALL_ERET:
        case CALL_SYSCALL:
        case CALL_BREAK:
                break;
        default:
                return 0;
        }

        a = *addrp;

        /*  Put back PC into the cpu struct, both as pc and pc_last  */
        *a++ = 0x89; *a++ = 0xbe; *a++ = ofs_pc&255;
        *a++ = (ofs_pc>>8)&255; *a++ = (ofs_pc>>16)&255;
        *a++ = (ofs_pc>>24)&255;        /*  mov    %edi,pc(%esi)  */

        *a++ = 0x89; *a++ = 0xbe; *a++ = ofs_pc_last&255;
        *a++ = (ofs_pc_last>>8)&255; *a++ = (ofs_pc_last>>16)&255;
        *a++ = (ofs_pc_last>>24)&255;   /*  mov    %edi,pc_last(%esi)  */

        /*  ... and make sure that the high 32 bits are ALSO in pc_last:  */
        /*  8b 86 38 12 00 00       mov    0x1238(%esi),%eax  */
        ofs = ofs_pc + 4;
        *a++ = 0x8b; *a++ = 0x86; *a++ = ofs&255;
        *a++ = (ofs>>8)&255; *a++ = (ofs>>16)&255;
        *a++ = (ofs>>24)&255;   /*  mov    %edi,pc(%esi)  */

        /*  89 86 34 12 00 00       mov    %eax,0x1234(%esi)  */
        ofs = ofs_pc_last + 4;
        *a++ = 0x89; *a++ = 0x86; *a++ = ofs&255;
        *a++ = (ofs>>8)&255; *a++ = (ofs>>16)&255;
        *a++ = (ofs>>24)&255;   /*  mov    %edi,pc(%esi)  */

        switch (itype) {
        case CALL_TLBP:
        case CALL_TLBR:
                /*  push readflag  */
                *a++ = 0x6a; *a++ = (itype == CALL_TLBR);
                ofs = ((size_t)&dummy_cpu.cd.mips.bintrans_fast_tlbpr) - (size_t)&dummy_cpu;
                break;
        case CALL_TLBWR:
        case CALL_TLBWI:
                /*  push randomflag  */
                *a++ = 0x6a; *a++ = (itype == CALL_TLBWR);
                ofs = ((size_t)&dummy_cpu.cd.mips.bintrans_fast_tlbwri) - (size_t)&dummy_cpu;
                break;
        case CALL_SYSCALL:
        case CALL_BREAK:
                /*  push randomflag  */
                *a++ = 0x6a; *a++ = (itype == CALL_BREAK? EXCEPTION_BP : EXCEPTION_SYS);
                ofs = ((size_t)&dummy_cpu.cd.mips.bintrans_simple_exception) - (size_t)&dummy_cpu;
                break;
        case CALL_RFE:
                ofs = ((size_t)&dummy_cpu.cd.mips.bintrans_fast_rfe) - (size_t)&dummy_cpu;
                break;
        case CALL_ERET:
                ofs = ((size_t)&dummy_cpu.cd.mips.bintrans_fast_eret) - (size_t)&dummy_cpu;
                break;
        }

        /*  push cpu (esi)  */
        *a++ = 0x56;

        /*  eax = points to the right function  */
        *a++ = 0x8b; *a++ = 0x86;
        *a++ = ofs; *a++ = ofs >> 8; *a++ = ofs >> 16; *a++ = ofs >> 24;

        /*  ff d0                   call   *%eax  */
        *a++ = 0xff; *a++ = 0xd0;

        switch (itype) {
        case CALL_RFE:
        case CALL_ERET:
                /*  83 c4 04                add    $4,%esp  */
                *a++ = 0x83; *a++ = 0xc4; *a++ = 4;
                break;
        default:
                /*  83 c4 08                add    $8,%esp  */
                *a++ = 0x83; *a++ = 0xc4; *a++ = 8;
                break;
        }

        /*  Load PC from the cpu struct.  */
        *a++ = 0x8b; *a++ = 0xbe; *a++ = ofs_pc&255;
        *a++ = (ofs_pc>>8)&255; *a++ = (ofs_pc>>16)&255;
        *a++ = (ofs_pc>>24)&255;        /*  mov    pc(%esi),%edi  */

        *addrp = a;

        switch (itype) {
        case CALL_ERET:
        case CALL_SYSCALL:
        case CALL_BREAK:
                break;
        default:
                bintrans_write_pc_inc(addrp);
        }

        return 1;
}


/*
 *  bintrans_backend_init():
 *
 *  This is neccessary for broken GCC 2.x. (For GCC 3.x, this wouldn't be
 *  neccessary, and the old code would have worked.)
 */
static void bintrans_backend_init(void)
{ 
        int size;
        unsigned char *p;


        /*  "runchunk":  */
        size = 64;              /*  NOTE: This MUST be enough, or we fail  */
        p = (unsigned char *)mmap(NULL, size, PROT_READ | PROT_WRITE |
            PROT_EXEC, MAP_ANON | MAP_PRIVATE, -1, 0);

        /*  If mmap() failed, try malloc():  */
        if (p == NULL) {
                p = malloc(size);
                if (p == NULL) {
                        fprintf(stderr, "bintrans_backend_init():"
                            " out of memory\n");
                        exit(1);
                }
        }

        bintrans_runchunk = (void *)p;

        *p++ = 0x57;                            /*  push   %edi  */
        *p++ = 0x56;                            /*  push   %esi  */
        *p++ = 0x55;                            /*  push   %ebp  */
        *p++ = 0x53;                            /*  push   %ebx  */

        /*
         *  In all translated code, esi points to the cpu struct, and
         *  ebp is the nr of executed (translated) instructions.
         */

        /*  0=ebx, 4=ebp, 8=esi, 0xc=edi, 0x10=retaddr, 0x14=arg0, 0x18=arg1  */

        /*  mov    0x8(%esp,1),%esi  */
        *p++ = 0x8b; *p++ = 0x74; *p++ = 0x24; *p++ = 0x14;

        /*  mov    nr_instr(%esi),%ebp  */
        *p++ = 0x8b; *p++ = 0xae; *p++ = ofs_i&255; *p++ = (ofs_i>>8)&255;
        *p++ = (ofs_i>>16)&255; *p++ = (ofs_i>>24)&255;

        /*  mov    pc(%esi),%edi  */
        *p++ = 0x8b; *p++ = 0xbe; *p++ = ofs_pc&255; *p++ = (ofs_pc>>8)&255;
        *p++ = (ofs_pc>>16)&255; *p++ = (ofs_pc>>24)&255;

        /*  call  *0x18(%esp,1)  */
        *p++ = 0xff; *p++ = 0x54; *p++ = 0x24; *p++ = 0x18;

        /*  mov    %ebp,0x1234(%esi)  */
        *p++ = 0x89; *p++ = 0xae; *p++ = ofs_i&255; *p++ = (ofs_i>>8)&255;
        *p++ = (ofs_i>>16)&255; *p++ = (ofs_i>>24)&255;

        /*  mov    %edi,pc(%esi)  */
        *p++ = 0x89; *p++ = 0xbe; *p++ = ofs_pc&255; *p++ = (ofs_pc>>8)&255;
        *p++ = (ofs_pc>>16)&255; *p++ = (ofs_pc>>24)&255;

        *p++ = 0x5b;                            /*  pop    %ebx  */
        *p++ = 0x5d;                            /*  pop    %ebp  */
        *p++ = 0x5e;                            /*  pop    %esi  */
        *p++ = 0x5f;                            /*  pop    %edi  */
        *p++ = 0xc3;                            /*  ret  */


        /*  "jump_to_32bit_pc":  */
        size = 128;             /*  NOTE: This MUST be enough, or we fail  */
        p = (unsigned char *)mmap(NULL, size, PROT_READ | PROT_WRITE |
            PROT_EXEC, MAP_ANON | MAP_PRIVATE, -1, 0);

        /*  If mmap() failed, try malloc():  */
        if (p == NULL) {
                p = malloc(size);
                if (p == NULL) {
                        fprintf(stderr, "bintrans_backend_init():"
                            " out of memory\n");
                        exit(1);
                }
        }

        bintrans_jump_to_32bit_pc = (void *)p;

        /*  Don't execute too many instructions.  */
        /*  81 fd f0 1f 00 00    cmpl   $0x1ff0,%ebp  */
        /*  7c 01                jl     <okk>  */
        /*  c3                   ret    */
        *p++ = 0x81; *p++ = 0xfd; *p++ = (N_SAFE_BINTRANS_LIMIT-1) & 255;
        *p++ = ((N_SAFE_BINTRANS_LIMIT-1) >> 8) & 255; *p++ = 0; *p++ = 0;
        *p++ = 0x7c; *p++ = 0x01;
        *p++ = 0xc3;

        /*
         *  ebx = ((vaddr >> 22) & 1023) * sizeof(void *)
         *
         *  89 c3                   mov    %eax,%ebx
         *  c1 eb 14                shr    $20,%ebx
         *  81 e3 fc 0f 00 00       and    $0xffc,%ebx
         */
        *p++ = 0x89; *p++ = 0xc3;
        *p++ = 0xc1; *p++ = 0xeb; *p++ = 0x14;
        *p++ = 0x81; *p++ = 0xe3; *p++ = 0xfc; *p++ = 0x0f; *p++ = 0; *p++ = 0;

        /*
         *  ecx = vaddr_to_hostaddr_table0
         *
         *  8b 8e 34 12 00 00       mov    0x1234(%esi),%ecx
         */
        *p++ = 0x8b; *p++ = 0x8e;
        *p++ = ofs_tabl0 & 255; *p++ = (ofs_tabl0 >> 8) & 255;
        *p++ = (ofs_tabl0 >> 16) & 255; *p++ = (ofs_tabl0 >> 24) & 255;

        /*
         *  ecx = vaddr_to_hostaddr_table0[a]
         *
         *  8b 0c 19                mov    (%ecx,%ebx),%ecx
         */
        *p++ = 0x8b; *p++ = 0x0c; *p++ = 0x19;

        /*
         *  ebx = ((vaddr >> 12) & 1023) * sizeof(void *)
         *
         *  89 c3                   mov    %eax,%ebx
         *  c1 eb 0a                shr    $10,%ebx
         *  81 e3 fc 0f 00 00       and    $0xffc,%ebx
         */
        *p++ = 0x89; *p++ = 0xc3;
        *p++ = 0xc1; *p++ = 0xeb; *p++ = 0x0a;
        *p++ = 0x81; *p++ = 0xe3; *p++ = 0xfc; *p++ = 0x0f; *p++ = 0; *p++ = 0;

        /*
         *  ecx = vaddr_to_hostaddr_table0[a][b].cd.mips.chunks
         *
         *  8b 8c 19 56 34 12 00    mov    0x123456(%ecx,%ebx,1),%ecx
         */
        *p++ = 0x8b; *p++ = 0x8c; *p++ = 0x19; *p++ = ofs_chunks & 255;
        *p++ = (ofs_chunks >> 8) & 255; *p++ = (ofs_chunks >> 16) & 255;
        *p++ = (ofs_chunks >> 24) & 255;

        /*
         *  ecx = NULL? Then return with failure.
         *
         *  83 f9 00                cmp    $0x0,%ecx
         *  75 01                   jne    <okzzz>
         */
        *p++ = 0x83; *p++ = 0xf9; *p++ = 0x00;
        *p++ = 0x75; *p++ = 0x01;
        *p++ = 0xc3;            /*  TODO: failure?  */

        /*
         *  25 fc 0f 00 00          and    $0xffc,%eax
         *  01 c1                   add    %eax,%ecx
         *
         *  8b 01                   mov    (%ecx),%eax
         *
         *  83 f8 00                cmp    $0x0,%eax
         *  75 01                   jne    <ok>
         *  c3                      ret
         */
        *p++ = 0x25; *p++ = 0xfc; *p++ = 0x0f; *p++ = 0; *p++ = 0;
        *p++ = 0x01; *p++ = 0xc1;

        *p++ = 0x8b; *p++ = 0x01;

        *p++ = 0x83; *p++ = 0xf8; *p++ = 0x00;
        *p++ = 0x75; *p++ = 0x01;
        *p++ = 0xc3;            /*  TODO: failure?  */

        /*  03 86 78 56 34 12       add    0x12345678(%esi),%eax  */
        /*  ff e0                   jmp    *%eax  */
        *p++ = 0x03; *p++ = 0x86; *p++ = ofs_chunkbase & 255;
        *p++ = (ofs_chunkbase >> 8) & 255; *p++ = (ofs_chunkbase >> 16) & 255;
        *p++ = (ofs_chunkbase >> 24) & 255;
        *p++ = 0xff; *p++ = 0xe0;


        /*  "loadstore_32bit":  */
        size = 48;              /*  NOTE: This MUST be enough, or we fail  */
        p = (unsigned char *)mmap(NULL, size, PROT_READ | PROT_WRITE |
            PROT_EXEC, MAP_ANON | MAP_PRIVATE, -1, 0);

        /*  If mmap() failed, try malloc():  */
        if (p == NULL) {
                p = malloc(size);
                if (p == NULL) {
                        fprintf(stderr, "bintrans_backend_init():"
                            " out of memory\n");
                        exit(1);
                }
        }

        bintrans_loadstore_32bit = (void *)p;

        /*
         *  ebx = ((vaddr >> 22) & 1023) * sizeof(void *)
         *
         *  89 c3                   mov    %eax,%ebx
         *  c1 eb 14                shr    $20,%ebx
         *  81 e3 fc 0f 00 00       and    $0xffc,%ebx
         */
        *p++ = 0x89; *p++ = 0xc3;
        *p++ = 0xc1; *p++ = 0xeb; *p++ = 0x14;
        *p++ = 0x81; *p++ = 0xe3; *p++ = 0xfc; *p++ = 0x0f; *p++ = 0; *p++ = 0;

        /*
         *  ecx = vaddr_to_hostaddr_table0
         *
         *  8b 8e 34 12 00 00       mov    0x1234(%esi),%ecx
         */
        *p++ = 0x8b; *p++ = 0x8e; *p++ = ofs_tabl0 & 255;
        *p++ = (ofs_tabl0 >> 8) & 255;
        *p++ = (ofs_tabl0 >> 16) & 255; *p++ = (ofs_tabl0 >> 24) & 255;

        /*
         *  ecx = vaddr_to_hostaddr_table0[a]
         *
         *  8b 0c 19                mov    (%ecx,%ebx),%ecx
         */
        *p++ = 0x8b; *p++ = 0x0c; *p++ = 0x19;

        /*
         *  ebx = ((vaddr >> 12) & 1023) * sizeof(void *)
         *
         *  89 c3                   mov    %eax,%ebx
         *  c1 eb 0a                shr    $10,%ebx
         *  81 e3 fc 0f 00 00       and    $0xffc,%ebx
         */
        *p++ = 0x89; *p++ = 0xc3;
        *p++ = 0xc1; *p++ = 0xeb; *p++ = 0x0a;
        *p++ = 0x81; *p++ = 0xe3; *p++ = 0xfc; *p++ = 0x0f; *p++ = 0; *p++ = 0;

        /*
         *  ecx = vaddr_to_hostaddr_table0[a][b]
         *
         *  8b 0c 19                mov    (%ecx,%ebx,1),%ecx
         */
        *p++ = 0x8b; *p++ = 0x0c; *p++ = 0x19;

        /*  ret  */
        *p++ = 0xc3;
}
