Archipelago » qemu

/*

 *  Xilinx MicroBlaze emulation for qemu: main translation routines.

 *

 *  Copyright (c) 2009 Edgar E. Iglesias.

 *

 * 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

 * Lesser 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 <assert.h>

#include "cpu.h"

#include "exec-all.h"

#include "disas.h"

#include "tcg-op.h"

#include "helper.h"

#include "microblaze-decode.h"

#include "qemu-common.h"

#define GEN_HELPER 1

#include "helper.h"

#define SIM_COMPAT 0

#define DISAS_GNU 1

#define DISAS_MB 1

#if DISAS_MB && !SIM_COMPAT

#  define LOG_DIS(...) qemu_log_mask(CPU_LOG_TB_IN_ASM, ## __VA_ARGS__)

#else

#  define LOG_DIS(...) do { } while (0)

#endif

#define D(x)

#define EXTRACT_FIELD(src, start, end) \

            (((src) >> start) & ((1 << (end - start + 1)) - 1))

static TCGv env_debug;

static TCGv_ptr cpu_env;

static TCGv cpu_R[32];

static TCGv cpu_SR[18];

static TCGv env_imm;

static TCGv env_btaken;

static TCGv env_btarget;

static TCGv env_iflags;

#include "gen-icount.h"

/* This is the state at translation time.  */

typedef struct DisasContext {

    CPUState *env;

    target_ulong pc, ppc;

    target_ulong cache_pc;

    /* Decoder.  */

    int type_b;

    uint32_t ir;

    uint8_t opcode;

    uint8_t rd, ra, rb;

    uint16_t imm;

    unsigned int cpustate_changed;

    unsigned int delayed_branch;

    unsigned int tb_flags, synced_flags; /* tb dependent flags.  */

    unsigned int clear_imm;

    int is_jmp;

#define JMP_NOJMP    0

#define JMP_DIRECT   1

#define JMP_INDIRECT 2

    unsigned int jmp;

    uint32_t jmp_pc;

    int abort_at_next_insn;

    int nr_nops;

    struct TranslationBlock *tb;

    int singlestep_enabled;

} DisasContext;

const static char *regnames[] =

{

    "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",

    "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",

    "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",

    "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",

};

const static char *special_regnames[] =

{

    "rpc", "rmsr", "sr2", "sr3", "sr4", "sr5", "sr6", "sr7",

    "sr8", "sr9", "sr10", "sr11", "sr12", "sr13", "sr14", "sr15",

    "sr16", "sr17", "sr18"

};

/* Sign extend at translation time.  */

static inline int sign_extend(unsigned int val, unsigned int width)

{

        int sval;

        /* LSL.  */

        val <<= 31 - width;

        sval = val;

        /* ASR.  */

        sval >>= 31 - width;

        return sval;

}

static inline void t_sync_flags(DisasContext *dc)

{

    /* Synch the tb dependant flags between translator and runtime.  */

    if (dc->tb_flags != dc->synced_flags) {

        tcg_gen_movi_tl(env_iflags, dc->tb_flags);

        dc->synced_flags = dc->tb_flags;

    }

}

static inline void t_gen_raise_exception(DisasContext *dc, uint32_t index)

{

    TCGv_i32 tmp = tcg_const_i32(index);

    t_sync_flags(dc);

    tcg_gen_movi_tl(cpu_SR[SR_PC], dc->pc);

    gen_helper_raise_exception(tmp);

    tcg_temp_free_i32(tmp);

    dc->is_jmp = DISAS_UPDATE;

}

static void gen_goto_tb(DisasContext *dc, int n, target_ulong dest)

{

    TranslationBlock *tb;

    tb = dc->tb;

    if ((tb->pc & TARGET_PAGE_MASK) == (dest & TARGET_PAGE_MASK)) {

        tcg_gen_goto_tb(n);

        tcg_gen_movi_tl(cpu_SR[SR_PC], dest);

        tcg_gen_exit_tb((long)tb + n);

    } else {

        tcg_gen_movi_tl(cpu_SR[SR_PC], dest);

        tcg_gen_exit_tb(0);

    }

}

static inline TCGv *dec_alu_op_b(DisasContext *dc)

{

    if (dc->type_b) {

        if (dc->tb_flags & IMM_FLAG)

            tcg_gen_ori_tl(env_imm, env_imm, dc->imm);

        else

            tcg_gen_movi_tl(env_imm, (int32_t)((int16_t)dc->imm));

        return &env_imm;

    } else

        return &cpu_R[dc->rb];

}

static void dec_add(DisasContext *dc)

{

    unsigned int k, c;

    k = dc->opcode & 4;

    c = dc->opcode & 2;

    LOG_DIS("add%s%s%s r%d r%d r%d\n",

            dc->type_b ? "i" : "", k ? "k" : "", c ? "c" : "",

            dc->rd, dc->ra, dc->rb);

    if (k && !c && dc->rd)

        tcg_gen_add_tl(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)));

    else if (dc->rd)

        gen_helper_addkc(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)),

                         tcg_const_tl(k), tcg_const_tl(c));

    else {

        TCGv d = tcg_temp_new();

        gen_helper_addkc(d, cpu_R[dc->ra], *(dec_alu_op_b(dc)),

                         tcg_const_tl(k), tcg_const_tl(c));

        tcg_temp_free(d);

    }

}

static void dec_sub(DisasContext *dc)

{

    unsigned int u, cmp, k, c;

    u = dc->imm & 2;

    k = dc->opcode & 4;

    c = dc->opcode & 2;

    cmp = (dc->imm & 1) && (!dc->type_b) && k;

    if (cmp) {

        LOG_DIS("cmp%s r%d, r%d ir=%x\n", u ? "u" : "", dc->rd, dc->ra, dc->ir);

        if (dc->rd) {

            if (u)

                gen_helper_cmpu(cpu_R[dc->rd], cpu_R[dc->ra], cpu_R[dc->rb]);

            else

                gen_helper_cmp(cpu_R[dc->rd], cpu_R[dc->ra], cpu_R[dc->rb]);

        }

    } else {

        LOG_DIS("sub%s%s r%d, r%d r%d\n",

                 k ? "k" : "",  c ? "c" : "", dc->rd, dc->ra, dc->rb);

        if (!k || c) {

            TCGv t;

            t = tcg_temp_new();

            if (dc->rd)

                gen_helper_subkc(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)),

                                 tcg_const_tl(k), tcg_const_tl(c));

            else

                gen_helper_subkc(t, cpu_R[dc->ra], *(dec_alu_op_b(dc)),

                                 tcg_const_tl(k), tcg_const_tl(c));

            tcg_temp_free(t);

        }

        else if (dc->rd)

            tcg_gen_sub_tl(cpu_R[dc->rd], *(dec_alu_op_b(dc)), cpu_R[dc->ra]);

    }

}

static void dec_pattern(DisasContext *dc)

{

    unsigned int mode;

    int l1;

    mode = dc->opcode & 3;

    switch (mode) {

        case 0:

            /* pcmpbf.  */

            LOG_DIS("pcmpbf r%d r%d r%d\n", dc->rd, dc->ra, dc->rb);

            if (dc->rd)

                gen_helper_pcmpbf(cpu_R[dc->rd], cpu_R[dc->ra], cpu_R[dc->rb]);

            break;

        case 2:

            LOG_DIS("pcmpeq r%d r%d r%d\n", dc->rd, dc->ra, dc->rb);

            if (dc->rd) {

                TCGv t0 = tcg_temp_local_new();

                l1 = gen_new_label();

                tcg_gen_movi_tl(t0, 1);

                tcg_gen_brcond_tl(TCG_COND_EQ,

                                  cpu_R[dc->ra], cpu_R[dc->rb], l1);

                tcg_gen_movi_tl(t0, 0);

                gen_set_label(l1);

                tcg_gen_mov_tl(cpu_R[dc->rd], t0);

                tcg_temp_free(t0);

            }

            break;

        case 3:

            LOG_DIS("pcmpne r%d r%d r%d\n", dc->rd, dc->ra, dc->rb);

            l1 = gen_new_label();

            if (dc->rd) {

                TCGv t0 = tcg_temp_local_new();

                tcg_gen_movi_tl(t0, 1);

                tcg_gen_brcond_tl(TCG_COND_NE,

                                  cpu_R[dc->ra], cpu_R[dc->rb], l1);

                tcg_gen_movi_tl(t0, 0);

                gen_set_label(l1);

                tcg_gen_mov_tl(cpu_R[dc->rd], t0);

                tcg_temp_free(t0);

            }

            break;

        default:

            cpu_abort(dc->env,

                      "unsupported pattern insn opcode=%x\n", dc->opcode);

            break;

    }

}

static void dec_and(DisasContext *dc)

{

    unsigned int not;

    if (!dc->type_b && (dc->imm & (1 << 10))) {

        dec_pattern(dc);

        return;

    }

    not = dc->opcode & (1 << 1);

    LOG_DIS("and%s\n", not ? "n" : "");

    if (!dc->rd)

        return;

    if (not) {

        TCGv t = tcg_temp_new();

        tcg_gen_not_tl(t, *(dec_alu_op_b(dc)));

        tcg_gen_and_tl(cpu_R[dc->rd], cpu_R[dc->ra], t);

        tcg_temp_free(t);

    } else

        tcg_gen_and_tl(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)));

}

static void dec_or(DisasContext *dc)

{

    if (!dc->type_b && (dc->imm & (1 << 10))) {

        dec_pattern(dc);

        return;

    }

    LOG_DIS("or r%d r%d r%d imm=%x\n", dc->rd, dc->ra, dc->rb, dc->imm);

    if (dc->rd)

        tcg_gen_or_tl(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)));

}

static void dec_xor(DisasContext *dc)

{

    if (!dc->type_b && (dc->imm & (1 << 10))) {

        dec_pattern(dc);

        return;

    }

    LOG_DIS("xor r%d\n", dc->rd);

    if (dc->rd)

        tcg_gen_xor_tl(cpu_R[dc->rd], cpu_R[dc->ra], *(dec_alu_op_b(dc)));

}

static void read_carry(DisasContext *dc, TCGv d)

{

    tcg_gen_shri_tl(d, cpu_SR[SR_MSR], 31);

}

static void write_carry(DisasContext *dc, TCGv v)

{

    TCGv t0 = tcg_temp_new();

    tcg_gen_shli_tl(t0, v, 31);

    tcg_gen_sari_tl(t0, t0, 31);

    tcg_gen_mov_tl(env_debug, t0);

    tcg_gen_andi_tl(t0, t0, (MSR_C | MSR_CC));

    tcg_gen_andi_tl(cpu_SR[SR_MSR], cpu_SR[SR_MSR],

                    ~(MSR_C | MSR_CC));

    tcg_gen_or_tl(cpu_SR[SR_MSR], cpu_SR[SR_MSR], t0);

    tcg_temp_free(t0);

}

static inline void msr_read(DisasContext *dc, TCGv d)

{

    tcg_gen_mov_tl(d, cpu_SR[SR_MSR]);

}

static inline void msr_write(DisasContext *dc, TCGv v)

{

    dc->cpustate_changed = 1;

    tcg_gen_mov_tl(cpu_SR[SR_MSR], v);

    /* PVR, we have a processor version register.  */

    tcg_gen_ori_tl(cpu_SR[SR_MSR], cpu_SR[SR_MSR], (1 << 10));

}

static void dec_msr(DisasContext *dc)

{

    TCGv t0, t1;

    unsigned int sr, to, rn;

    sr = dc->imm & ((1 << 14) - 1);

    to = dc->imm & (1 << 14);

    dc->type_b = 1;

    if (to)

        dc->cpustate_changed = 1;

    /* msrclr and msrset.  */

    if (!(dc->imm & (1 << 15))) {

        unsigned int clr = dc->ir & (1 << 16);

        LOG_DIS("msr%s r%d imm=%x\n", clr ? "clr" : "set",

                dc->rd, dc->imm);

        if (dc->rd)

            msr_read(dc, cpu_R[dc->rd]);

        t0 = tcg_temp_new();

        t1 = tcg_temp_new();

        msr_read(dc, t0);

        tcg_gen_mov_tl(t1, *(dec_alu_op_b(dc)));

        if (clr) {

            tcg_gen_not_tl(t1, t1);

            tcg_gen_and_tl(t0, t0, t1);

        } else

            tcg_gen_or_tl(t0, t0, t1);

        msr_write(dc, t0);

        tcg_temp_free(t0);

        tcg_temp_free(t1);

        tcg_gen_movi_tl(cpu_SR[SR_PC], dc->pc + 4);

        dc->is_jmp = DISAS_UPDATE;

        return;

    }

#if !defined(CONFIG_USER_ONLY)

    /* Catch read/writes to the mmu block.  */

    if ((sr & ~0xff) == 0x1000) {

        sr &= 7;

        LOG_DIS("m%ss sr%d r%d imm=%x\n", to ? "t" : "f", sr, dc->ra, dc->imm);

        if (to)

            gen_helper_mmu_write(tcg_const_tl(sr), cpu_R[dc->ra]);

        else

            gen_helper_mmu_read(cpu_R[dc->rd], tcg_const_tl(sr));

        return;

    }

#endif

    if (to) {

        LOG_DIS("m%ss sr%x r%d imm=%x\n", to ? "t" : "f", sr, dc->ra, dc->imm);

        switch (sr) {

            case 0:

                break;

            case 1:

                msr_write(dc, cpu_R[dc->ra]);

                break;

            case 0x3:

                tcg_gen_mov_tl(cpu_SR[SR_EAR], cpu_R[dc->ra]);

                break;

            case 0x5:

                tcg_gen_mov_tl(cpu_SR[SR_ESR], cpu_R[dc->ra]);

                break;

            case 0x7:

                /* Ignored at the moment.  */

                break;

            default:

                cpu_abort(dc->env, "unknown mts reg %x\n", sr);

                break;

        }

    } else {

        LOG_DIS("m%ss r%d sr%x imm=%x\n", to ? "t" : "f", dc->rd, sr, dc->imm);

        switch (sr) {

            case 0:

                tcg_gen_movi_tl(cpu_R[dc->rd], dc->pc);

                break;

            case 1:

                msr_read(dc, cpu_R[dc->rd]);

                break;

            case 0x3:

                tcg_gen_mov_tl(cpu_R[dc->rd], cpu_SR[SR_EAR]);

                break;

            case 0x5:

                tcg_gen_mov_tl(cpu_R[dc->rd], cpu_SR[SR_ESR]);

                break;

             case 0x7:

                tcg_gen_movi_tl(cpu_R[dc->rd], 0);

                break;

            case 0xb:

                tcg_gen_mov_tl(cpu_R[dc->rd], cpu_SR[SR_BTR]);

                break;

            case 0x2000:

            case 0x2001:

            case 0x2002:

            case 0x2003:

            case 0x2004:

            case 0x2005:

            case 0x2006:

            case 0x2007:

            case 0x2008:

            case 0x2009:

            case 0x200a:

            case 0x200b:

            case 0x200c:

                rn = sr & 0xf;

                tcg_gen_ld_tl(cpu_R[dc->rd],

                              cpu_env, offsetof(CPUState, pvr.regs[rn]));

                break;

            default:

                cpu_abort(dc->env, "unknown mfs reg %x\n", sr);

                break;

        }

    }

}

/* 64-bit signed mul, lower result in d and upper in d2.  */

static void t_gen_muls(TCGv d, TCGv d2, TCGv a, TCGv b)

{

    TCGv_i64 t0, t1;

    t0 = tcg_temp_new_i64();

    t1 = tcg_temp_new_i64();

    tcg_gen_ext_i32_i64(t0, a);

    tcg_gen_ext_i32_i64(t1, b);

    tcg_gen_mul_i64(t0, t0, t1);

    tcg_gen_trunc_i64_i32(d, t0);

    tcg_gen_shri_i64(t0, t0, 32);

    tcg_gen_trunc_i64_i32(d2, t0);

    tcg_temp_free_i64(t0);

    tcg_temp_free_i64(t1);

}

/* 64-bit unsigned muls, lower result in d and upper in d2.  */

static void t_gen_mulu(TCGv d, TCGv d2, TCGv a, TCGv b)

{

    TCGv_i64 t0, t1;

    t0 = tcg_temp_new_i64();

    t1 = tcg_temp_new_i64();

    tcg_gen_extu_i32_i64(t0, a);

    tcg_gen_extu_i32_i64(t1, b);

    tcg_gen_mul_i64(t0, t0, t1);

    tcg_gen_trunc_i64_i32(d, t0);

    tcg_gen_shri_i64(t0, t0, 32);

    tcg_gen_trunc_i64_i32(d2, t0);

    tcg_temp_free_i64(t0);

    tcg_temp_free_i64(t1);

}

/* Multiplier unit.  */

static void dec_mul(DisasContext *dc)

{

    TCGv d[2];

    unsigned int subcode;

    subcode = dc->imm & 3;

    d[0] = tcg_temp_new();

    d[1] = tcg_temp_new();

    if (dc->type_b) {

        LOG_DIS("muli r%d r%d %x\n", dc->rd, dc->ra, dc->imm);

        t_gen_mulu(cpu_R[dc->rd], d[1], cpu_R[dc->ra], *(dec_alu_op_b(dc)));

        goto done;

    }

    switch (subcode) {

        case 0:

            LOG_DIS("mul r%d r%d r%d\n", dc->rd, dc->ra, dc->rb);

            t_gen_mulu(cpu_R[dc->rd], d[1], cpu_R[dc->ra], cpu_R[dc->rb]);

            break;

        case 1:

            LOG_DIS("mulh r%d r%d r%d\n", dc->rd, dc->ra, dc->rb);

            t_gen_muls(d[0], cpu_R[dc->rd], cpu_R[dc->ra], cpu_R[dc->rb]);

            break;

        case 2:

            LOG_DIS("mulhsu r%d r%d r%d\n", dc->rd, dc->ra, dc->rb);

            t_gen_muls(d[0], cpu_R[dc->rd], cpu_R[dc->ra], cpu_R[dc->rb]);

            break;

        case 3:

            LOG_DIS("mulhu r%d r%d r%d\n", dc->rd, dc->ra, dc->rb);

            t_gen_mulu(d[0], cpu_R[dc->rd], cpu_R[dc->ra], cpu_R[dc->rb]);

            break;

        default:

            cpu_abort(dc->env, "unknown MUL insn %x\n", subcode);

            break;

    }

done:

    tcg_temp_free(d[0]);

    tcg_temp_free(d[1]);

}

/* Div unit.  */

static void dec_div(DisasContext *dc)

{

    unsigned int u;

    u = dc->imm & 2; 

    LOG_DIS("div\n");

    /* FIXME: support div by zero exceptions.  */

    if (u)

        gen_helper_divu(cpu_R[dc->rd], *(dec_alu_op_b(dc)), cpu_R[dc->ra]);

    else

        gen_helper_divs(cpu_R[dc->rd], *(dec_alu_op_b(dc)), cpu_R[dc->ra]);

    if (!dc->rd)

        tcg_gen_movi_tl(cpu_R[dc->rd], 0);

}

static void dec_barrel(DisasContext *dc)

{

    TCGv t0;

    unsigned int s, t;

    s = dc->imm & (1 << 10);

    t = dc->imm & (1 << 9);

    LOG_DIS("bs%s%s r%d r%d r%d\n",

            s ? "l" : "r", t ? "a" : "l", dc->rd, dc->ra, dc->rb);

    t0 = tcg_temp_new();

    tcg_gen_mov_tl(t0, *(dec_alu_op_b(dc)));

    tcg_gen_andi_tl(t0, t0, 31);

    if (s)

        tcg_gen_shl_tl(cpu_R[dc->rd], cpu_R[dc->ra], t0);

    else {

        if (t)

            tcg_gen_sar_tl(cpu_R[dc->rd], cpu_R[dc->ra], t0);

        else

            tcg_gen_shr_tl(cpu_R[dc->rd], cpu_R[dc->ra], t0);

    }

}

static void dec_bit(DisasContext *dc)

{

    TCGv t0, t1;

    unsigned int op;

    op = dc->ir & ((1 << 8) - 1);

    switch (op) {

        case 0x21:

            /* src.  */

            t0 = tcg_temp_new();

            LOG_DIS("src r%d r%d\n", dc->rd, dc->ra);

            tcg_gen_andi_tl(t0, cpu_R[dc->ra], 1);

            if (dc->rd) {

                t1 = tcg_temp_new();

                read_carry(dc, t1);

                tcg_gen_shli_tl(t1, t1, 31);

                tcg_gen_shri_tl(cpu_R[dc->rd], cpu_R[dc->ra], 1);

                tcg_gen_or_tl(cpu_R[dc->rd], cpu_R[dc->rd], t1);

                tcg_temp_free(t1);

            }

            /* Update carry.  */

            write_carry(dc, t0);

            tcg_temp_free(t0);

            break;

        case 0x1:

        case 0x41:

            /* srl.  */

            t0 = tcg_temp_new();

            LOG_DIS("srl r%d r%d\n", dc->rd, dc->ra);

            /* Update carry.  */

            tcg_gen_andi_tl(t0, cpu_R[dc->ra], 1);

            write_carry(dc, t0);

            tcg_temp_free(t0);

            if (dc->rd) {

                if (op == 0x41)

                    tcg_gen_shri_tl(cpu_R[dc->rd], cpu_R[dc->ra], 1);

                else

                    tcg_gen_sari_tl(cpu_R[dc->rd], cpu_R[dc->ra], 1);

            }

            break;

        case 0x60:

            LOG_DIS("ext8s r%d r%d\n", dc->rd, dc->ra);

            tcg_gen_ext8s_i32(cpu_R[dc->rd], cpu_R[dc->ra]);

            break;

        case 0x61:

            LOG_DIS("ext16s r%d r%d\n", dc->rd, dc->ra);

            tcg_gen_ext16s_i32(cpu_R[dc->rd], cpu_R[dc->ra]);

            break;

        case 0x64:

            /* wdc.  */

            LOG_DIS("wdc r%d\n", dc->ra);

            break;

        case 0x68:

            /* wic.  */

            LOG_DIS("wic r%d\n", dc->ra);

            break;

        default:

            cpu_abort(dc->env, "unknown bit oc=%x op=%x rd=%d ra=%d rb=%d\n",

                     dc->pc, op, dc->rd, dc->ra, dc->rb);

            break;

    }

}

static inline void sync_jmpstate(DisasContext *dc)

{

    if (dc->jmp == JMP_DIRECT) {

            dc->jmp = JMP_INDIRECT;

            tcg_gen_movi_tl(env_btaken, 1);

            tcg_gen_movi_tl(env_btarget, dc->jmp_pc);

    }

}

static void dec_imm(DisasContext *dc)

{

    LOG_DIS("imm %x\n", dc->imm << 16);

    tcg_gen_movi_tl(env_imm, (dc->imm << 16));

    dc->tb_flags |= IMM_FLAG;

    dc->clear_imm = 0;

}

static inline void gen_load(DisasContext *dc, TCGv dst, TCGv addr,

                            unsigned int size)

{

    int mem_index = cpu_mmu_index(dc->env);

    if (size == 1) {

        tcg_gen_qemu_ld8u(dst, addr, mem_index);

    } else if (size == 2) {

        tcg_gen_qemu_ld16u(dst, addr, mem_index);

    } else if (size == 4) {

        tcg_gen_qemu_ld32u(dst, addr, mem_index);

    } else

        cpu_abort(dc->env, "Incorrect load size %d\n", size);

}

static inline TCGv *compute_ldst_addr(DisasContext *dc, TCGv *t)

{

    unsigned int extimm = dc->tb_flags & IMM_FLAG;

    /* Treat the fast cases first.  */

    if (!dc->type_b) {

        *t = tcg_temp_new();

        tcg_gen_add_tl(*t, cpu_R[dc->ra], cpu_R[dc->rb]);

        return t;

    }

    /* Immediate.  */

    if (!extimm) {

        if (dc->imm == 0) {

            return &cpu_R[dc->ra];

        }

        *t = tcg_temp_new();

        tcg_gen_movi_tl(*t, (int32_t)((int16_t)dc->imm));

        tcg_gen_add_tl(*t, cpu_R[dc->ra], *t);

    } else {

        *t = tcg_temp_new();

        tcg_gen_add_tl(*t, cpu_R[dc->ra], *(dec_alu_op_b(dc)));

    }

    return t;

}

static void dec_load(DisasContext *dc)

{

    TCGv t, *addr;

    unsigned int size;

    size = 1 << (dc->opcode & 3);

    LOG_DIS("l %x %d\n", dc->opcode, size);

    t_sync_flags(dc);

    addr = compute_ldst_addr(dc, &t);

    /* If we get a fault on a dslot, the jmpstate better be in sync.  */

    sync_jmpstate(dc);

    if (dc->rd)

        gen_load(dc, cpu_R[dc->rd], *addr, size);

    else {

        gen_load(dc, env_imm, *addr, size);

    }

    if (addr == &t)

        tcg_temp_free(t);

}

static void gen_store(DisasContext *dc, TCGv addr, TCGv val,

                      unsigned int size)

{

    int mem_index = cpu_mmu_index(dc->env);

    if (size == 1)

        tcg_gen_qemu_st8(val, addr, mem_index);

    else if (size == 2) {

        tcg_gen_qemu_st16(val, addr, mem_index);

    } else if (size == 4) {

        tcg_gen_qemu_st32(val, addr, mem_index);

    } else

        cpu_abort(dc->env, "Incorrect store size %d\n", size);

}

static void dec_store(DisasContext *dc)

{

    TCGv t, *addr;

    unsigned int size;

    size = 1 << (dc->opcode & 3);

    LOG_DIS("s%d%s\n", size, dc->type_b ? "i" : "");

    t_sync_flags(dc);

    /* If we get a fault on a dslot, the jmpstate better be in sync.  */

    sync_jmpstate(dc);

    addr = compute_ldst_addr(dc, &t);

    gen_store(dc, *addr, cpu_R[dc->rd], size);

    if (addr == &t)

        tcg_temp_free(t);

}

static inline void eval_cc(DisasContext *dc, unsigned int cc,

                           TCGv d, TCGv a, TCGv b)

{

    int l1;

    switch (cc) {

        case CC_EQ:

            l1 = gen_new_label();

            tcg_gen_movi_tl(env_btaken, 1);

            tcg_gen_brcond_tl(TCG_COND_EQ, a, b, l1);

            tcg_gen_movi_tl(env_btaken, 0);

            gen_set_label(l1);

            break;

        case CC_NE:

            l1 = gen_new_label();

            tcg_gen_movi_tl(env_btaken, 1);

            tcg_gen_brcond_tl(TCG_COND_NE, a, b, l1);

            tcg_gen_movi_tl(env_btaken, 0);

            gen_set_label(l1);

            break;

        case CC_LT:

            l1 = gen_new_label();

            tcg_gen_movi_tl(env_btaken, 1);

            tcg_gen_brcond_tl(TCG_COND_LT, a, b, l1);

            tcg_gen_movi_tl(env_btaken, 0);

            gen_set_label(l1);

            break;

        case CC_LE:

            l1 = gen_new_label();

            tcg_gen_movi_tl(env_btaken, 1);

            tcg_gen_brcond_tl(TCG_COND_LE, a, b, l1);

            tcg_gen_movi_tl(env_btaken, 0);

            gen_set_label(l1);

            break;

        case CC_GE:

            l1 = gen_new_label();

            tcg_gen_movi_tl(env_btaken, 1);

            tcg_gen_brcond_tl(TCG_COND_GE, a, b, l1);

            tcg_gen_movi_tl(env_btaken, 0);

            gen_set_label(l1);

            break;

        case CC_GT:

            l1 = gen_new_label();

            tcg_gen_movi_tl(env_btaken, 1);

            tcg_gen_brcond_tl(TCG_COND_GT, a, b, l1);

            tcg_gen_movi_tl(env_btaken, 0);

            gen_set_label(l1);

            break;

        default:

            cpu_abort(dc->env, "Unknown condition code %x.\n", cc);

            break;

    }

}

static void eval_cond_jmp(DisasContext *dc, TCGv pc_true, TCGv pc_false)

{

    int l1;

    l1 = gen_new_label();

    /* Conditional jmp.  */

    tcg_gen_mov_tl(cpu_SR[SR_PC], pc_false);

    tcg_gen_brcondi_tl(TCG_COND_EQ, env_btaken, 0, l1);

    tcg_gen_mov_tl(cpu_SR[SR_PC], pc_true);

    gen_set_label(l1);

}

static void dec_bcc(DisasContext *dc)

{

    unsigned int cc;

    unsigned int dslot;

    cc = EXTRACT_FIELD(dc->ir, 21, 23);

    dslot = dc->ir & (1 << 25);

    LOG_DIS("bcc%s r%d %x\n", dslot ? "d" : "", dc->ra, dc->imm);