Archipelago » qemu

/*

 *  m68k translation

 *

 *  Copyright (c) 2005-2007 CodeSourcery

 *  Written by Paul Brook

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

#include <stdarg.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <inttypes.h>

#include "config.h"

#include "cpu.h"

#include "exec-all.h"

#include "disas.h"

#include "tcg-op.h"

#include "qemu-log.h"

#include "helpers.h"

#define GEN_HELPER 1

#include "helpers.h"

//#define DEBUG_DISPATCH 1

/* Fake floating point.  */

#define tcg_gen_mov_f64 tcg_gen_mov_i64

#define tcg_gen_qemu_ldf64 tcg_gen_qemu_ld64

#define tcg_gen_qemu_stf64 tcg_gen_qemu_st64

#define DEFO32(name, offset) static TCGv QREG_##name;

#define DEFO64(name, offset) static TCGv_i64 QREG_##name;

#define DEFF64(name, offset) static TCGv_i64 QREG_##name;

#include "qregs.def"

#undef DEFO32

#undef DEFO64

#undef DEFF64

static TCGv_ptr cpu_env;

static char cpu_reg_names[3*8*3 + 5*4];

static TCGv cpu_dregs[8];

static TCGv cpu_aregs[8];

static TCGv_i64 cpu_fregs[8];

static TCGv_i64 cpu_macc[4];

#define DREG(insn, pos) cpu_dregs[((insn) >> (pos)) & 7]

#define AREG(insn, pos) cpu_aregs[((insn) >> (pos)) & 7]

#define FREG(insn, pos) cpu_fregs[((insn) >> (pos)) & 7]

#define MACREG(acc) cpu_macc[acc]

#define QREG_SP cpu_aregs[7]

static TCGv NULL_QREG;

#define IS_NULL_QREG(t) (TCGV_EQUAL(t, NULL_QREG))

/* Used to distinguish stores from bad addressing modes.  */

static TCGv store_dummy;

#include "gen-icount.h"

void m68k_tcg_init(void)

{

    char *p;

    int i;

#define DEFO32(name,  offset) QREG_##name = tcg_global_mem_new_i32(TCG_AREG0, offsetof(CPUState, offset), #name);

#define DEFO64(name,  offset) QREG_##name = tcg_global_mem_new_i64(TCG_AREG0, offsetof(CPUState, offset), #name);

#define DEFF64(name,  offset) DEFO64(name, offset)

#include "qregs.def"

#undef DEFO32

#undef DEFO64

#undef DEFF64

    cpu_env = tcg_global_reg_new_ptr(TCG_AREG0, "env");

    p = cpu_reg_names;

    for (i = 0; i < 8; i++) {

        sprintf(p, "D%d", i);

        cpu_dregs[i] = tcg_global_mem_new(TCG_AREG0,

                                          offsetof(CPUM68KState, dregs[i]), p);

        p += 3;

        sprintf(p, "A%d", i);

        cpu_aregs[i] = tcg_global_mem_new(TCG_AREG0,

                                          offsetof(CPUM68KState, aregs[i]), p);

        p += 3;

        sprintf(p, "F%d", i);

        cpu_fregs[i] = tcg_global_mem_new_i64(TCG_AREG0,

                                          offsetof(CPUM68KState, fregs[i]), p);

        p += 3;

    }

    for (i = 0; i < 4; i++) {

        sprintf(p, "ACC%d", i);

        cpu_macc[i] = tcg_global_mem_new_i64(TCG_AREG0,

                                         offsetof(CPUM68KState, macc[i]), p);

        p += 5;

    }

    NULL_QREG = tcg_global_mem_new(TCG_AREG0, -4, "NULL");

    store_dummy = tcg_global_mem_new(TCG_AREG0, -8, "NULL");

#define GEN_HELPER 2

#include "helpers.h"

}

static inline void qemu_assert(int cond, const char *msg)

{

    if (!cond) {

        fprintf (stderr, "badness: %s\n", msg);

        abort();

    }

}

/* internal defines */

typedef struct DisasContext {

    CPUM68KState *env;

    target_ulong insn_pc; /* Start of the current instruction.  */

    target_ulong pc;

    int is_jmp;

    int cc_op;

    int user;

    uint32_t fpcr;

    struct TranslationBlock *tb;

    int singlestep_enabled;

    int is_mem;

    TCGv_i64 mactmp;

    int done_mac;

} DisasContext;

#define DISAS_JUMP_NEXT 4

#if defined(CONFIG_USER_ONLY)

#define IS_USER(s) 1

#else

#define IS_USER(s) s->user

#endif

/* XXX: move that elsewhere */

/* ??? Fix exceptions.  */

static void *gen_throws_exception;

#define gen_last_qop NULL

#define OS_BYTE 0

#define OS_WORD 1

#define OS_LONG 2

#define OS_SINGLE 4

#define OS_DOUBLE 5

typedef void (*disas_proc)(DisasContext *, uint16_t);

#ifdef DEBUG_DISPATCH

#define DISAS_INSN(name) \

  static void real_disas_##name (DisasContext *s, uint16_t insn); \

  static void disas_##name (DisasContext *s, uint16_t insn) { \

    qemu_log("Dispatch " #name "\n"); \

    real_disas_##name(s, insn); } \

  static void real_disas_##name (DisasContext *s, uint16_t insn)

#else

#define DISAS_INSN(name) \

  static void disas_##name (DisasContext *s, uint16_t insn)

#endif

/* FIXME: Remove this.  */

#define gen_im32(val) tcg_const_i32(val)

/* Generate a load from the specified address.  Narrow values are

   sign extended to full register width.  */

static inline TCGv gen_load(DisasContext * s, int opsize, TCGv addr, int sign)

{

    TCGv tmp;

    int index = IS_USER(s);

    s->is_mem = 1;

    tmp = tcg_temp_new_i32();

    switch(opsize) {

    case OS_BYTE:

        if (sign)

            tcg_gen_qemu_ld8s(tmp, addr, index);

        else

            tcg_gen_qemu_ld8u(tmp, addr, index);

        break;

    case OS_WORD:

        if (sign)

            tcg_gen_qemu_ld16s(tmp, addr, index);

        else

            tcg_gen_qemu_ld16u(tmp, addr, index);

        break;

    case OS_LONG:

    case OS_SINGLE:

        tcg_gen_qemu_ld32u(tmp, addr, index);

        break;

    default:

        qemu_assert(0, "bad load size");

    }

    gen_throws_exception = gen_last_qop;

    return tmp;

}

static inline TCGv_i64 gen_load64(DisasContext * s, TCGv addr)

{

    TCGv_i64 tmp;

    int index = IS_USER(s);

    s->is_mem = 1;

    tmp = tcg_temp_new_i64();

    tcg_gen_qemu_ldf64(tmp, addr, index);

    gen_throws_exception = gen_last_qop;

    return tmp;

}

/* Generate a store.  */

static inline void gen_store(DisasContext *s, int opsize, TCGv addr, TCGv val)

{

    int index = IS_USER(s);

    s->is_mem = 1;

    switch(opsize) {

    case OS_BYTE:

        tcg_gen_qemu_st8(val, addr, index);

        break;

    case OS_WORD:

        tcg_gen_qemu_st16(val, addr, index);

        break;

    case OS_LONG:

    case OS_SINGLE:

        tcg_gen_qemu_st32(val, addr, index);

        break;

    default:

        qemu_assert(0, "bad store size");

    }

    gen_throws_exception = gen_last_qop;

}

static inline void gen_store64(DisasContext *s, TCGv addr, TCGv_i64 val)

{

    int index = IS_USER(s);

    s->is_mem = 1;

    tcg_gen_qemu_stf64(val, addr, index);

    gen_throws_exception = gen_last_qop;

}

typedef enum {

    EA_STORE,

    EA_LOADU,

    EA_LOADS

} ea_what;

/* Generate an unsigned load if VAL is 0 a signed load if val is -1,

   otherwise generate a store.  */

static TCGv gen_ldst(DisasContext *s, int opsize, TCGv addr, TCGv val,

                     ea_what what)

{

    if (what == EA_STORE) {

        gen_store(s, opsize, addr, val);

        return store_dummy;

    } else {

        return gen_load(s, opsize, addr, what == EA_LOADS);

    }

}

/* Read a 32-bit immediate constant.  */

static inline uint32_t read_im32(DisasContext *s)

{

    uint32_t im;

    im = ((uint32_t)lduw_code(s->pc)) << 16;

    s->pc += 2;

    im |= lduw_code(s->pc);

    s->pc += 2;

    return im;

}

/* Calculate and address index.  */

static TCGv gen_addr_index(uint16_t ext, TCGv tmp)

{

    TCGv add;

    int scale;

    add = (ext & 0x8000) ? AREG(ext, 12) : DREG(ext, 12);

    if ((ext & 0x800) == 0) {

        tcg_gen_ext16s_i32(tmp, add);

        add = tmp;

    }

    scale = (ext >> 9) & 3;

    if (scale != 0) {

        tcg_gen_shli_i32(tmp, add, scale);

        add = tmp;

    }

    return add;

}

/* Handle a base + index + displacement effective addresss.

   A NULL_QREG base means pc-relative.  */

static TCGv gen_lea_indexed(DisasContext *s, int opsize, TCGv base)

{

    uint32_t offset;

    uint16_t ext;

    TCGv add;

    TCGv tmp;

    uint32_t bd, od;

    offset = s->pc;

    ext = lduw_code(s->pc);

    s->pc += 2;

    if ((ext & 0x800) == 0 && !m68k_feature(s->env, M68K_FEATURE_WORD_INDEX))

        return NULL_QREG;

    if (ext & 0x100) {

        /* full extension word format */

        if (!m68k_feature(s->env, M68K_FEATURE_EXT_FULL))

            return NULL_QREG;

        if ((ext & 0x30) > 0x10) {

            /* base displacement */

            if ((ext & 0x30) == 0x20) {

                bd = (int16_t)lduw_code(s->pc);

                s->pc += 2;

            } else {

                bd = read_im32(s);

            }

        } else {

            bd = 0;

        }

        tmp = tcg_temp_new();

        if ((ext & 0x44) == 0) {

            /* pre-index */

            add = gen_addr_index(ext, tmp);

        } else {

            add = NULL_QREG;

        }

        if ((ext & 0x80) == 0) {

            /* base not suppressed */

            if (IS_NULL_QREG(base)) {

                base = gen_im32(offset + bd);

                bd = 0;

            }

            if (!IS_NULL_QREG(add)) {

                tcg_gen_add_i32(tmp, add, base);

                add = tmp;

            } else {

                add = base;

            }

        }

        if (!IS_NULL_QREG(add)) {

            if (bd != 0) {

                tcg_gen_addi_i32(tmp, add, bd);

                add = tmp;

            }

        } else {

            add = gen_im32(bd);

        }

        if ((ext & 3) != 0) {

            /* memory indirect */

            base = gen_load(s, OS_LONG, add, 0);

            if ((ext & 0x44) == 4) {

                add = gen_addr_index(ext, tmp);

                tcg_gen_add_i32(tmp, add, base);

                add = tmp;

            } else {

                add = base;

            }

            if ((ext & 3) > 1) {

                /* outer displacement */

                if ((ext & 3) == 2) {

                    od = (int16_t)lduw_code(s->pc);

                    s->pc += 2;

                } else {

                    od = read_im32(s);

                }

            } else {

                od = 0;

            }

            if (od != 0) {

                tcg_gen_addi_i32(tmp, add, od);

                add = tmp;

            }

        }

    } else {

        /* brief extension word format */

        tmp = tcg_temp_new();

        add = gen_addr_index(ext, tmp);

        if (!IS_NULL_QREG(base)) {

            tcg_gen_add_i32(tmp, add, base);

            if ((int8_t)ext)

                tcg_gen_addi_i32(tmp, tmp, (int8_t)ext);

        } else {

            tcg_gen_addi_i32(tmp, add, offset + (int8_t)ext);

        }

        add = tmp;

    }

    return add;

}

/* Update the CPU env CC_OP state.  */

static inline void gen_flush_cc_op(DisasContext *s)

{

    if (s->cc_op != CC_OP_DYNAMIC)

        tcg_gen_movi_i32(QREG_CC_OP, s->cc_op);

}

/* Evaluate all the CC flags.  */

static inline void gen_flush_flags(DisasContext *s)

{

    if (s->cc_op == CC_OP_FLAGS)

        return;

    gen_flush_cc_op(s);

    gen_helper_flush_flags(cpu_env, QREG_CC_OP);

    s->cc_op = CC_OP_FLAGS;

}

static void gen_logic_cc(DisasContext *s, TCGv val)

{

    tcg_gen_mov_i32(QREG_CC_DEST, val);

    s->cc_op = CC_OP_LOGIC;

}

static void gen_update_cc_add(TCGv dest, TCGv src)

{

    tcg_gen_mov_i32(QREG_CC_DEST, dest);

    tcg_gen_mov_i32(QREG_CC_SRC, src);

}

static inline int opsize_bytes(int opsize)

{

    switch (opsize) {

    case OS_BYTE: return 1;

    case OS_WORD: return 2;

    case OS_LONG: return 4;

    case OS_SINGLE: return 4;

    case OS_DOUBLE: return 8;

    default:

        qemu_assert(0, "bad operand size");

        return 0;

    }

}

/* Assign value to a register.  If the width is less than the register width

   only the low part of the register is set.  */

static void gen_partset_reg(int opsize, TCGv reg, TCGv val)

{

    TCGv tmp;

    switch (opsize) {

    case OS_BYTE:

        tcg_gen_andi_i32(reg, reg, 0xffffff00);

        tmp = tcg_temp_new();

        tcg_gen_ext8u_i32(tmp, val);

        tcg_gen_or_i32(reg, reg, tmp);

        break;

    case OS_WORD:

        tcg_gen_andi_i32(reg, reg, 0xffff0000);

        tmp = tcg_temp_new();

        tcg_gen_ext16u_i32(tmp, val);

        tcg_gen_or_i32(reg, reg, tmp);

        break;

    case OS_LONG:

    case OS_SINGLE:

        tcg_gen_mov_i32(reg, val);

        break;

    default:

        qemu_assert(0, "Bad operand size");

        break;

    }

}

/* Sign or zero extend a value.  */

static inline TCGv gen_extend(TCGv val, int opsize, int sign)

{

    TCGv tmp;

    switch (opsize) {

    case OS_BYTE:

        tmp = tcg_temp_new();

        if (sign)

            tcg_gen_ext8s_i32(tmp, val);

        else

            tcg_gen_ext8u_i32(tmp, val);

        break;

    case OS_WORD:

        tmp = tcg_temp_new();

        if (sign)

            tcg_gen_ext16s_i32(tmp, val);

        else

            tcg_gen_ext16u_i32(tmp, val);

        break;

    case OS_LONG:

    case OS_SINGLE:

        tmp = val;

        break;

    default:

        qemu_assert(0, "Bad operand size");

    }

    return tmp;

}

/* Generate code for an "effective address".  Does not adjust the base

   register for autoincrement addressing modes.  */

static TCGv gen_lea(DisasContext *s, uint16_t insn, int opsize)

{

    TCGv reg;

    TCGv tmp;

    uint16_t ext;

    uint32_t offset;

    switch ((insn >> 3) & 7) {

    case 0: /* Data register direct.  */

    case 1: /* Address register direct.  */

        return NULL_QREG;

    case 2: /* Indirect register */

    case 3: /* Indirect postincrement.  */

        return AREG(insn, 0);

    case 4: /* Indirect predecrememnt.  */

        reg = AREG(insn, 0);

        tmp = tcg_temp_new();

        tcg_gen_subi_i32(tmp, reg, opsize_bytes(opsize));

        return tmp;

    case 5: /* Indirect displacement.  */

        reg = AREG(insn, 0);

        tmp = tcg_temp_new();

        ext = lduw_code(s->pc);

        s->pc += 2;

        tcg_gen_addi_i32(tmp, reg, (int16_t)ext);

        return tmp;

    case 6: /* Indirect index + displacement.  */

        reg = AREG(insn, 0);

        return gen_lea_indexed(s, opsize, reg);

    case 7: /* Other */

        switch (insn & 7) {

        case 0: /* Absolute short.  */

            offset = ldsw_code(s->pc);

            s->pc += 2;

            return gen_im32(offset);

        case 1: /* Absolute long.  */

            offset = read_im32(s);

            return gen_im32(offset);

        case 2: /* pc displacement  */

            tmp = tcg_temp_new();

            offset = s->pc;

            offset += ldsw_code(s->pc);

            s->pc += 2;

            return gen_im32(offset);

        case 3: /* pc index+displacement.  */

            return gen_lea_indexed(s, opsize, NULL_QREG);

        case 4: /* Immediate.  */

        default:

            return NULL_QREG;

        }

    }

    /* Should never happen.  */

    return NULL_QREG;

}

/* Helper function for gen_ea. Reuse the computed address between the

   for read/write operands.  */

static inline TCGv gen_ea_once(DisasContext *s, uint16_t insn, int opsize,

                              TCGv val, TCGv *addrp, ea_what what)

{

    TCGv tmp;

    if (addrp && what == EA_STORE) {

        tmp = *addrp;

    } else {

        tmp = gen_lea(s, insn, opsize);

        if (IS_NULL_QREG(tmp))

            return tmp;

        if (addrp)

            *addrp = tmp;

    }

    return gen_ldst(s, opsize, tmp, val, what);

}

/* Generate code to load/store a value ito/from an EA.  If VAL > 0 this is

   a write otherwise it is a read (0 == sign extend, -1 == zero extend).

   ADDRP is non-null for readwrite operands.  */

static TCGv gen_ea(DisasContext *s, uint16_t insn, int opsize, TCGv val,

                   TCGv *addrp, ea_what what)

{

    TCGv reg;

    TCGv result;

    uint32_t offset;

    switch ((insn >> 3) & 7) {

    case 0: /* Data register direct.  */

        reg = DREG(insn, 0);

        if (what == EA_STORE) {

            gen_partset_reg(opsize, reg, val);

            return store_dummy;

        } else {

            return gen_extend(reg, opsize, what == EA_LOADS);

        }

    case 1: /* Address register direct.  */

        reg = AREG(insn, 0);

        if (what == EA_STORE) {

            tcg_gen_mov_i32(reg, val);

            return store_dummy;

        } else {

            return gen_extend(reg, opsize, what == EA_LOADS);

        }

    case 2: /* Indirect register */

        reg = AREG(insn, 0);

        return gen_ldst(s, opsize, reg, val, what);

    case 3: /* Indirect postincrement.  */

        reg = AREG(insn, 0);

        result = gen_ldst(s, opsize, reg, val, what);

        /* ??? This is not exception safe.  The instruction may still

           fault after this point.  */

        if (what == EA_STORE || !addrp)

            tcg_gen_addi_i32(reg, reg, opsize_bytes(opsize));

        return result;

    case 4: /* Indirect predecrememnt.  */

        {

            TCGv tmp;

            if (addrp && what == EA_STORE) {

                tmp = *addrp;

            } else {

                tmp = gen_lea(s, insn, opsize);

                if (IS_NULL_QREG(tmp))

                    return tmp;

                if (addrp)

                    *addrp = tmp;

            }

            result = gen_ldst(s, opsize, tmp, val, what);

            /* ??? This is not exception safe.  The instruction may still

               fault after this point.  */

            if (what == EA_STORE || !addrp) {

                reg = AREG(insn, 0);

                tcg_gen_mov_i32(reg, tmp);

            }

        }

        return result;

    case 5: /* Indirect displacement.  */

    case 6: /* Indirect index + displacement.  */

        return gen_ea_once(s, insn, opsize, val, addrp, what);

    case 7: /* Other */

        switch (insn & 7) {

        case 0: /* Absolute short.  */

        case 1: /* Absolute long.  */

        case 2: /* pc displacement  */

        case 3: /* pc index+displacement.  */

            return gen_ea_once(s, insn, opsize, val, addrp, what);

        case 4: /* Immediate.  */

            /* Sign extend values for consistency.  */

            switch (opsize) {

            case OS_BYTE:

                if (what == EA_LOADS)

                    offset = ldsb_code(s->pc + 1);

                else

                    offset = ldub_code(s->pc + 1);

                s->pc += 2;

                break;

            case OS_WORD:

                if (what == EA_LOADS)

                    offset = ldsw_code(s->pc);

                else

                    offset = lduw_code(s->pc);

                s->pc += 2;

                break;

            case OS_LONG:

                offset = read_im32(s);

                break;

            default:

                qemu_assert(0, "Bad immediate operand");

            }

            return tcg_const_i32(offset);

        default:

            return NULL_QREG;

        }

    }

    /* Should never happen.  */

    return NULL_QREG;

}

/* This generates a conditional branch, clobbering all temporaries.  */

static void gen_jmpcc(DisasContext *s, int cond, int l1)

{

    TCGv tmp;

    /* TODO: Optimize compare/branch pairs rather than always flushing

       flag state to CC_OP_FLAGS.  */

    gen_flush_flags(s);

    switch (cond) {

    case 0: /* T */

        tcg_gen_br(l1);

        break;

    case 1: /* F */

        break;

    case 2: /* HI (!C && !Z) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_C | CCF_Z);

        tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, 0, l1);

        break;

    case 3: /* LS (C || Z) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_C | CCF_Z);

        tcg_gen_brcondi_i32(TCG_COND_NE, tmp, 0, l1);

        break;

    case 4: /* CC (!C) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_C);

        tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, 0, l1);

        break;

    case 5: /* CS (C) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_C);

        tcg_gen_brcondi_i32(TCG_COND_NE, tmp, 0, l1);

        break;

    case 6: /* NE (!Z) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_Z);

        tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, 0, l1);

        break;

    case 7: /* EQ (Z) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_Z);

        tcg_gen_brcondi_i32(TCG_COND_NE, tmp, 0, l1);

        break;

    case 8: /* VC (!V) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_V);

        tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, 0, l1);

        break;

    case 9: /* VS (V) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_V);

        tcg_gen_brcondi_i32(TCG_COND_NE, tmp, 0, l1);

        break;

    case 10: /* PL (!N) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_N);

        tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, 0, l1);

        break;

    case 11: /* MI (N) */

        tmp = tcg_temp_new();

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_N);

        tcg_gen_brcondi_i32(TCG_COND_NE, tmp, 0, l1);

        break;

    case 12: /* GE (!(N ^ V)) */

        tmp = tcg_temp_new();

        assert(CCF_V == (CCF_N >> 2));

        tcg_gen_shri_i32(tmp, QREG_CC_DEST, 2);

        tcg_gen_xor_i32(tmp, tmp, QREG_CC_DEST);

        tcg_gen_andi_i32(tmp, tmp, CCF_V);

        tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, 0, l1);

        break;

    case 13: /* LT (N ^ V) */

        tmp = tcg_temp_new();

        assert(CCF_V == (CCF_N >> 2));

        tcg_gen_shri_i32(tmp, QREG_CC_DEST, 2);

        tcg_gen_xor_i32(tmp, tmp, QREG_CC_DEST);

        tcg_gen_andi_i32(tmp, tmp, CCF_V);

        tcg_gen_brcondi_i32(TCG_COND_NE, tmp, 0, l1);

        break;

    case 14: /* GT (!(Z || (N ^ V))) */

        tmp = tcg_temp_new();

        assert(CCF_V == (CCF_N >> 2));

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_N);

        tcg_gen_shri_i32(tmp, tmp, 2);

        tcg_gen_xor_i32(tmp, tmp, QREG_CC_DEST);

        tcg_gen_andi_i32(tmp, tmp, CCF_V | CCF_Z);

        tcg_gen_brcondi_i32(TCG_COND_EQ, tmp, 0, l1);

        break;

    case 15: /* LE (Z || (N ^ V)) */

        tmp = tcg_temp_new();

        assert(CCF_V == (CCF_N >> 2));

        tcg_gen_andi_i32(tmp, QREG_CC_DEST, CCF_N);

        tcg_gen_shri_i32(tmp, tmp, 2);

        tcg_gen_xor_i32(tmp, tmp, QREG_CC_DEST);

        tcg_gen_andi_i32(tmp, tmp, CCF_V | CCF_Z);

        tcg_gen_brcondi_i32(TCG_COND_NE, tmp, 0, l1);

        break;

    default:

        /* Should ever happen.  */

        abort();

    }

}

DISAS_INSN(scc)

{

    int l1;

    int cond;

    TCGv reg;

    l1 = gen_new_label();

    cond = (insn >> 8) & 0xf;

    reg = DREG(insn, 0);

    tcg_gen_andi_i32(reg, reg, 0xffffff00);

    /* This is safe because we modify the reg directly, with no other values

       live.  */

    gen_jmpcc(s, cond ^ 1, l1);

    tcg_gen_ori_i32(reg, reg, 0xff);

    gen_set_label(l1);

}

/* Force a TB lookup after an instruction that changes the CPU state.  */

static void gen_lookup_tb(DisasContext *s)

{

    gen_flush_cc_op(s);

    tcg_gen_movi_i32(QREG_PC, s->pc);

    s->is_jmp = DISAS_UPDATE;

}

/* Generate a jump to an immediate address.  */

static void gen_jmp_im(DisasContext *s, uint32_t dest)

{

    gen_flush_cc_op(s);

    tcg_gen_movi_i32(QREG_PC, dest);

    s->is_jmp = DISAS_JUMP;

}

/* Generate a jump to the address in qreg DEST.  */

static void gen_jmp(DisasContext *s, TCGv dest)

{

    gen_flush_cc_op(s);

    tcg_gen_mov_i32(QREG_PC, dest);

    s->is_jmp = DISAS_JUMP;

}

static void gen_exception(DisasContext *s, uint32_t where, int nr)

{

    gen_flush_cc_op(s);

    gen_jmp_im(s, where);

    gen_helper_raise_exception(tcg_const_i32(nr));

}

static inline void gen_addr_fault(DisasContext *s)

{

    gen_exception(s, s->insn_pc, EXCP_ADDRESS);

}

#define SRC_EA(result, opsize, op_sign, addrp) do { \

    result = gen_ea(s, insn, opsize, NULL_QREG, addrp, op_sign ? EA_LOADS : EA_LOADU); \

    if (IS_NULL_QREG(result)) { \

        gen_addr_fault(s); \

        return; \

    } \

    } while (0)

#define DEST_EA(insn, opsize, val, addrp) do { \

    TCGv ea_result = gen_ea(s, insn, opsize, val, addrp, EA_STORE); \

    if (IS_NULL_QREG(ea_result)) { \

        gen_addr_fault(s); \

        return; \

    } \

    } while (0)

/* Generate a jump to an immediate address.  */

static void gen_jmp_tb(DisasContext *s, int n, uint32_t dest)

{

    TranslationBlock *tb;

    tb = s->tb;

    if (unlikely(s->singlestep_enabled)) {

        gen_exception(s, dest, EXCP_DEBUG);

    } else if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK) ||

               (s->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)) {

        tcg_gen_goto_tb(n);

        tcg_gen_movi_i32(QREG_PC, dest);

        tcg_gen_exit_tb((long)tb + n);

    } else {

        gen_jmp_im(s, dest);

        tcg_gen_exit_tb(0);

    }

    s->is_jmp = DISAS_TB_JUMP;

}

DISAS_INSN(undef_mac)

{

    gen_exception(s, s->pc - 2, EXCP_LINEA);

}

DISAS_INSN(undef_fpu)

{

    gen_exception(s, s->pc - 2, EXCP_LINEF);

}

DISAS_INSN(undef)

{

    gen_exception(s, s->pc - 2, EXCP_UNSUPPORTED);

    cpu_abort(cpu_single_env, "Illegal instruction: %04x @ %08x",

              insn, s->pc - 2);