translate.c

/*
 *  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 "cpu.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(CPUM68KState, offset), #name);
#define DEFO64(name,  offset) QREG_##name = tcg_global_mem_new_i64(TCG_AREG0, offsetof(CPUM68KState, 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)(CPUM68KState *env, DisasContext *s, uint16_t insn);

#ifdef DEBUG_DISPATCH
#define DISAS_INSN(name)                                                \
    static void real_disas_##name(CPUM68KState *env, DisasContext *s,   \
                                  uint16_t insn);                       \
    static void disas_##name(CPUM68KState *env, DisasContext *s,        \
                             uint16_t insn)                             \
    {                                                                   \
        qemu_log("Dispatch " #name "\n");                               \
        real_disas_##name(s, env, insn);                                \
    }                                                                   \
    static void real_disas_##name(CPUM68KState *env, DisasContext *s,   \
                                  uint16_t insn)
#else
#define DISAS_INSN(name)                                                \
    static void disas_##name(CPUM68KState *env, DisasContext *s,        \
                             uint16_t insn)
#endif

/* 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(CPUM68KState *env, DisasContext *s)
{
    uint32_t im;
    im = ((uint32_t)cpu_lduw_code(env, s->pc)) << 16;
    s->pc += 2;
    im |= cpu_lduw_code(env, 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(CPUM68KState *env, DisasContext *s, int opsize,
                            TCGv base)
{
    uint32_t offset;
    uint16_t ext;
    TCGv add;
    TCGv tmp;
    uint32_t bd, od;

    offset = s->pc;
    ext = cpu_lduw_code(env, 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)cpu_lduw_code(env, s->pc);
                s->pc += 2;
            } else {
                bd = read_im32(env, 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 = tcg_const_i32(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 = tcg_const_i32(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)cpu_lduw_code(env, s->pc);
                    s->pc += 2;
                } else {
                    od = read_im32(env, 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(CPUM68KState *env, 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 = cpu_lduw_code(env, 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(env, s, opsize, reg);
    case 7: /* Other */
        switch (insn & 7) {
        case 0: /* Absolute short.  */
            offset = cpu_ldsw_code(env, s->pc);
            s->pc += 2;
            return tcg_const_i32(offset);
        case 1: /* Absolute long.  */
            offset = read_im32(env, s);
            return tcg_const_i32(offset);
        case 2: /* pc displacement  */
            offset = s->pc;
            offset += cpu_ldsw_code(env, s->pc);
            s->pc += 2;
            return tcg_const_i32(offset);
        case 3: /* pc index+displacement.  */
            return gen_lea_indexed(env, 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(CPUM68KState *env, 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(env, 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(CPUM68KState *env, 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(env, 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(env, 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(env, s, insn, opsize, val, addrp, what);
        case 4: /* Immediate.  */
            /* Sign extend values for consistency.  */
            switch (opsize) {
            case OS_BYTE:
                if (what == EA_LOADS) {
                    offset = cpu_ldsb_code(env, s->pc + 1);
                } else {
                    offset = cpu_ldub_code(env, s->pc + 1);
                }
                s->pc += 2;
                break;
            case OS_WORD:
                if (what == EA_LOADS) {
                    offset = cpu_ldsw_code(env, s->pc);
                } else {
                    offset = cpu_lduw_code(env, s->pc);
                }
                s->pc += 2;
                break;
            case OS_LONG:
                offset = read_im32(env, 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(cpu_env, tcg_const_i32(nr));
}

static inline void gen_addr_fault(DisasContext *s)
{
    gen_exception(s, s->insn_pc, EXCP_ADDRESS);
}

#define SRC_EA(env, result, opsize, op_sign, addrp) do {                \
        result = gen_ea(env, 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(env, insn, opsize, val, addrp) do {                     \
        TCGv ea_result = gen_ea(env, 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((tcg_target_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(env, "Illegal instruction: %04x @ %08x", insn, s->pc - 2);
}

DISAS_INSN(mulw)
{
    TCGv reg;
    TCGv tmp;
    TCGv src;
    int sign;

    sign = (insn & 0x100) != 0;
    reg = DREG(insn, 9);
    tmp = tcg_temp_new();
    if (sign)
        tcg_gen_ext16s_i32(tmp, reg);
    else
        tcg_gen_ext16u_i32(tmp, reg);
    SRC_EA(env, src, OS_WORD, sign, NULL);
    tcg_gen_mul_i32(tmp, tmp, src);
    tcg_gen_mov_i32(reg, tmp);
    /* Unlike m68k, coldfire always clears the overflow bit.  */
    gen_logic_cc(s, tmp);
}

DISAS_INSN(divw)
{
    TCGv reg;
    TCGv tmp;
    TCGv src;
    int sign;

    sign = (insn & 0x100) != 0;
    reg = DREG(insn, 9);
    if (sign) {
        tcg_gen_ext16s_i32(QREG_DIV1, reg);
    } else {
        tcg_gen_ext16u_i32(QREG_DIV1, reg);
    }
    SRC_EA(env, src, OS_WORD, sign, NULL);
    tcg_gen_mov_i32(QREG_DIV2, src);
    if (sign) {
        gen_helper_divs(cpu_env, tcg_const_i32(1));
    } else {
        gen_helper_divu(cpu_env, tcg_const_i32(1));
    }

    tmp = tcg_temp_new();
    src = tcg_temp_new();
    tcg_gen_ext16u_i32(tmp, QREG_DIV1);
    tcg_gen_shli_i32(src, QREG_DIV2, 16);
    tcg_gen_or_i32(reg, tmp, src);
    s->cc_op = CC_OP_FLAGS;
}

DISAS_INSN(divl)
{
    TCGv num;
    TCGv den;
    TCGv reg;
    uint16_t ext;

    ext = cpu_lduw_code(env, s->pc);
    s->pc += 2;
    if (ext & 0x87f8) {
        gen_exception(s, s->pc - 4, EXCP_UNSUPPORTED);
        return;
    }
    num = DREG(ext, 12);
    reg = DREG(ext, 0);
    tcg_gen_mov_i32(QREG_DIV1, num);
    SRC_EA(env, den, OS_LONG, 0, NULL);
    tcg_gen_mov_i32(QREG_DIV2, den);
    if (ext & 0x0800) {
        gen_helper_divs(cpu_env, tcg_const_i32(0));
    } else {
        gen_helper_divu(cpu_env, tcg_const_i32(0));
    }
    if ((ext & 7) == ((ext >> 12) & 7)) {
        /* div */
        tcg_gen_mov_i32 (reg, QREG_DIV1);
    } else {
        /* rem */
        tcg_gen_mov_i32 (reg, QREG_DIV2);
    }
    s->cc_op = CC_OP_FLAGS;
}

DISAS_INSN(addsub)
{
    TCGv reg;
    TCGv dest;
    TCGv src;
    TCGv tmp;
    TCGv addr;
    int add;

    add = (insn & 0x4000) != 0;
    reg = DREG(insn, 9);
    dest = tcg_temp_new();
    if (insn & 0x100) {
        SRC_EA(env, tmp, OS_LONG, 0, &addr);
        src = reg;
    } else {
        tmp = reg;
        SRC_EA(env, src, OS_LONG, 0, NULL);
    }
    if (add) {
        tcg_gen_add_i32(dest, tmp, src);
        gen_helper_xflag_lt(QREG_CC_X, dest, src);
        s->cc_op = CC_OP_ADD;
    } else {
        gen_helper_xflag_lt(QREG_CC_X, tmp, src);
        tcg_gen_sub_i32(dest, tmp, src);
        s->cc_op = CC_OP_SUB;