/*

 * Tiny Code Generator for QEMU

 *

 * Copyright (c) 2008 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#ifndef NDEBUG

static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = {

    "%eax",

    "%ecx",

    "%edx",

    "%ebx",

    "%esp",

    "%ebp",

    "%esi",

    "%edi",

};

#endif

static const int tcg_target_reg_alloc_order[] = {

    TCG_REG_EAX,

    TCG_REG_EDX,

    TCG_REG_ECX,

    TCG_REG_EBX,

    TCG_REG_ESI,

    TCG_REG_EDI,

    TCG_REG_EBP,

};

static const int tcg_target_call_iarg_regs[3] = { TCG_REG_EAX, TCG_REG_EDX, TCG_REG_ECX };

static const int tcg_target_call_oarg_regs[2] = { TCG_REG_EAX, TCG_REG_EDX };

static uint8_t *tb_ret_addr;

static void patch_reloc(uint8_t *code_ptr, int type, 

                        tcg_target_long value, tcg_target_long addend)

{

    value += addend;

    switch(type) {

    case R_386_32:

        *(uint32_t *)code_ptr = value;

        break;

    case R_386_PC32:

        *(uint32_t *)code_ptr = value - (long)code_ptr;

        break;

    default:

        tcg_abort();

    }

}

/* maximum number of register used for input function arguments */

static inline int tcg_target_get_call_iarg_regs_count(int flags)

{

    flags &= TCG_CALL_TYPE_MASK;

    switch(flags) {

    case TCG_CALL_TYPE_STD:

        return 0;

    case TCG_CALL_TYPE_REGPARM_1:

    case TCG_CALL_TYPE_REGPARM_2:

    case TCG_CALL_TYPE_REGPARM:

        return flags - TCG_CALL_TYPE_REGPARM_1 + 1;

    default:

        tcg_abort();

    }

}

/* parse target specific constraints */

static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str)

{

    const char *ct_str;

    ct_str = *pct_str;

    switch(ct_str[0]) {

    case 'a':

        ct->ct |= TCG_CT_REG;

        tcg_regset_set_reg(ct->u.regs, TCG_REG_EAX);

        break;

    case 'b':

        ct->ct |= TCG_CT_REG;

        tcg_regset_set_reg(ct->u.regs, TCG_REG_EBX);

        break;

    case 'c':

        ct->ct |= TCG_CT_REG;

        tcg_regset_set_reg(ct->u.regs, TCG_REG_ECX);

        break;

    case 'd':

        ct->ct |= TCG_CT_REG;

        tcg_regset_set_reg(ct->u.regs, TCG_REG_EDX);

        break;

    case 'S':

        ct->ct |= TCG_CT_REG;

        tcg_regset_set_reg(ct->u.regs, TCG_REG_ESI);

        break;

    case 'D':

        ct->ct |= TCG_CT_REG;

        tcg_regset_set_reg(ct->u.regs, TCG_REG_EDI);

        break;

    case 'q':

        ct->ct |= TCG_CT_REG;

        tcg_regset_set32(ct->u.regs, 0, 0xf);

        break;

    case 'r':

        ct->ct |= TCG_CT_REG;

        tcg_regset_set32(ct->u.regs, 0, 0xff);

        break;

        /* qemu_ld/st address constraint */

    case 'L':

        ct->ct |= TCG_CT_REG;

        tcg_regset_set32(ct->u.regs, 0, 0xff);

        tcg_regset_reset_reg(ct->u.regs, TCG_REG_EAX);

        tcg_regset_reset_reg(ct->u.regs, TCG_REG_EDX);

        break;

    default:

        return -1;

    }

    ct_str++;

    *pct_str = ct_str;

    return 0;

}

/* test if a constant matches the constraint */

static inline int tcg_target_const_match(tcg_target_long val,

                                         const TCGArgConstraint *arg_ct)

{

    int ct;

    ct = arg_ct->ct;

    if (ct & TCG_CT_CONST)

        return 1;

    else

        return 0;

}

#define ARITH_ADD 0

#define ARITH_OR  1

#define ARITH_ADC 2

#define ARITH_SBB 3

#define ARITH_AND 4

#define ARITH_SUB 5

#define ARITH_XOR 6

#define ARITH_CMP 7

#define SHIFT_SHL 4

#define SHIFT_SHR 5

#define SHIFT_SAR 7

#define JCC_JMP (-1)

#define JCC_JO  0x0

#define JCC_JNO 0x1

#define JCC_JB  0x2

#define JCC_JAE 0x3

#define JCC_JE  0x4

#define JCC_JNE 0x5

#define JCC_JBE 0x6

#define JCC_JA  0x7

#define JCC_JS  0x8

#define JCC_JNS 0x9

#define JCC_JP  0xa

#define JCC_JNP 0xb

#define JCC_JL  0xc

#define JCC_JGE 0xd

#define JCC_JLE 0xe

#define JCC_JG  0xf

#define P_EXT   0x100 /* 0x0f opcode prefix */

static const uint8_t tcg_cond_to_jcc[10] = {

    [TCG_COND_EQ] = JCC_JE,

    [TCG_COND_NE] = JCC_JNE,

    [TCG_COND_LT] = JCC_JL,

    [TCG_COND_GE] = JCC_JGE,

    [TCG_COND_LE] = JCC_JLE,

    [TCG_COND_GT] = JCC_JG,

    [TCG_COND_LTU] = JCC_JB,

    [TCG_COND_GEU] = JCC_JAE,

    [TCG_COND_LEU] = JCC_JBE,

    [TCG_COND_GTU] = JCC_JA,

};

static inline void tcg_out_opc(TCGContext *s, int opc)

{

    if (opc & P_EXT)

        tcg_out8(s, 0x0f);

    tcg_out8(s, opc);

}

static inline void tcg_out_modrm(TCGContext *s, int opc, int r, int rm)

{

    tcg_out_opc(s, opc);

    tcg_out8(s, 0xc0 | (r << 3) | rm);

}

/* rm == -1 means no register index */

static inline void tcg_out_modrm_offset(TCGContext *s, int opc, int r, int rm, 

                                        int32_t offset)

{

    tcg_out_opc(s, opc);

    if (rm == -1) {

        tcg_out8(s, 0x05 | (r << 3));

        tcg_out32(s, offset);

    } else if (offset == 0 && rm != TCG_REG_EBP) {

        if (rm == TCG_REG_ESP) {

            tcg_out8(s, 0x04 | (r << 3));

            tcg_out8(s, 0x24);

        } else {

            tcg_out8(s, 0x00 | (r << 3) | rm);

        }

    } else if ((int8_t)offset == offset) {

        if (rm == TCG_REG_ESP) {

            tcg_out8(s, 0x44 | (r << 3));

            tcg_out8(s, 0x24);

        } else {

            tcg_out8(s, 0x40 | (r << 3) | rm);

        }

        tcg_out8(s, offset);

    } else {

        if (rm == TCG_REG_ESP) {

            tcg_out8(s, 0x84 | (r << 3));

            tcg_out8(s, 0x24);

        } else {

            tcg_out8(s, 0x80 | (r << 3) | rm);

        }

        tcg_out32(s, offset);

    }

}

static inline void tcg_out_mov(TCGContext *s, int ret, int arg)

{

    if (arg != ret)

        tcg_out_modrm(s, 0x8b, ret, arg);

}

static inline void tcg_out_movi(TCGContext *s, TCGType type,

                                int ret, int32_t arg)

{

    if (arg == 0) {

        /* xor r0,r0 */

        tcg_out_modrm(s, 0x01 | (ARITH_XOR << 3), ret, ret);

    } else {

        tcg_out8(s, 0xb8 + ret);

        tcg_out32(s, arg);

    }

}

static inline void tcg_out_ld(TCGContext *s, TCGType type, int ret,

                              int arg1, tcg_target_long arg2)

{

    /* movl */

    tcg_out_modrm_offset(s, 0x8b, ret, arg1, arg2);

}

static inline void tcg_out_st(TCGContext *s, TCGType type, int arg,

                              int arg1, tcg_target_long arg2)

{

    /* movl */

    tcg_out_modrm_offset(s, 0x89, arg, arg1, arg2);

}

static inline void tgen_arithi(TCGContext *s, int c, int r0, int32_t val)

{

    if (val == (int8_t)val) {

        tcg_out_modrm(s, 0x83, c, r0);

        tcg_out8(s, val);

    } else {

        tcg_out_modrm(s, 0x81, c, r0);

        tcg_out32(s, val);

    }

}

static void tcg_out_addi(TCGContext *s, int reg, tcg_target_long val)

{

    if (val != 0)

        tgen_arithi(s, ARITH_ADD, reg, val);

}

static void tcg_out_jxx(TCGContext *s, int opc, int label_index)

{

    int32_t val, val1;

    TCGLabel *l = &s->labels[label_index];

    if (l->has_value) {

        val = l->u.value - (tcg_target_long)s->code_ptr;

        val1 = val - 2;

        if ((int8_t)val1 == val1) {

            if (opc == -1)

                tcg_out8(s, 0xeb);

            else

                tcg_out8(s, 0x70 + opc);

            tcg_out8(s, val1);

        } else {

            if (opc == -1) {

                tcg_out8(s, 0xe9);

                tcg_out32(s, val - 5);

            } else {

                tcg_out8(s, 0x0f);

                tcg_out8(s, 0x80 + opc);

                tcg_out32(s, val - 6);

            }

        }

    } else {

        if (opc == -1) {

            tcg_out8(s, 0xe9);

        } else {

            tcg_out8(s, 0x0f);

            tcg_out8(s, 0x80 + opc);

        }

        tcg_out_reloc(s, s->code_ptr, R_386_PC32, label_index, -4);

        s->code_ptr += 4;

    }

}

static void tcg_out_brcond(TCGContext *s, int cond, 

                           TCGArg arg1, TCGArg arg2, int const_arg2,

                           int label_index)

{

    if (const_arg2) {

        if (arg2 == 0) {

            /* test r, r */

            tcg_out_modrm(s, 0x85, arg1, arg1);

        } else {

            tgen_arithi(s, ARITH_CMP, arg1, arg2);

        }

    } else {

        tcg_out_modrm(s, 0x01 | (ARITH_CMP << 3), arg2, arg1);

    }

    tcg_out_jxx(s, tcg_cond_to_jcc[cond], label_index);

}

/* XXX: we implement it at the target level to avoid having to

   handle cross basic blocks temporaries */

static void tcg_out_brcond2(TCGContext *s,

                            const TCGArg *args, const int *const_args)

{

    int label_next;

    label_next = gen_new_label();

    switch(args[4]) {

    case TCG_COND_EQ:

        tcg_out_brcond(s, TCG_COND_NE, args[0], args[2], const_args[2], label_next);

        tcg_out_brcond(s, TCG_COND_EQ, args[1], args[3], const_args[3], args[5]);

        break;

    case TCG_COND_NE:

        tcg_out_brcond(s, TCG_COND_NE, args[0], args[2], const_args[2], args[5]);

        tcg_out_brcond(s, TCG_COND_NE, args[1], args[3], const_args[3], args[5]);

        break;

    case TCG_COND_LT:

        tcg_out_brcond(s, TCG_COND_LT, args[1], args[3], const_args[3], args[5]);

        tcg_out_jxx(s, JCC_JNE, label_next);

        tcg_out_brcond(s, TCG_COND_LTU, args[0], args[2], const_args[2], args[5]);

        break;

    case TCG_COND_LE:

        tcg_out_brcond(s, TCG_COND_LT, args[1], args[3], const_args[3], args[5]);

        tcg_out_jxx(s, JCC_JNE, label_next);

        tcg_out_brcond(s, TCG_COND_LEU, args[0], args[2], const_args[2], args[5]);

        break;

    case TCG_COND_GT:

        tcg_out_brcond(s, TCG_COND_GT, args[1], args[3], const_args[3], args[5]);

        tcg_out_jxx(s, JCC_JNE, label_next);

        tcg_out_brcond(s, TCG_COND_GTU, args[0], args[2], const_args[2], args[5]);

        break;

    case TCG_COND_GE:

        tcg_out_brcond(s, TCG_COND_GT, args[1], args[3], const_args[3], args[5]);

        tcg_out_jxx(s, JCC_JNE, label_next);

        tcg_out_brcond(s, TCG_COND_GEU, args[0], args[2], const_args[2], args[5]);

        break;

    case TCG_COND_LTU:

        tcg_out_brcond(s, TCG_COND_LTU, args[1], args[3], const_args[3], args[5]);

        tcg_out_jxx(s, JCC_JNE, label_next);

        tcg_out_brcond(s, TCG_COND_LTU, args[0], args[2], const_args[2], args[5]);

        break;

    case TCG_COND_LEU:

        tcg_out_brcond(s, TCG_COND_LTU, args[1], args[3], const_args[3], args[5]);

        tcg_out_jxx(s, JCC_JNE, label_next);

        tcg_out_brcond(s, TCG_COND_LEU, args[0], args[2], const_args[2], args[5]);

        break;

    case TCG_COND_GTU:

        tcg_out_brcond(s, TCG_COND_GTU, args[1], args[3], const_args[3], args[5]);

        tcg_out_jxx(s, JCC_JNE, label_next);

        tcg_out_brcond(s, TCG_COND_GTU, args[0], args[2], const_args[2], args[5]);

        break;

    case TCG_COND_GEU:

        tcg_out_brcond(s, TCG_COND_GTU, args[1], args[3], const_args[3], args[5]);

        tcg_out_jxx(s, JCC_JNE, label_next);

        tcg_out_brcond(s, TCG_COND_GEU, args[0], args[2], const_args[2], args[5]);

        break;

    default:

        tcg_abort();

    }

    tcg_out_label(s, label_next, (tcg_target_long)s->code_ptr);

}

#if defined(CONFIG_SOFTMMU)

#include "../../softmmu_defs.h"

static void *qemu_ld_helpers[4] = {

    __ldb_mmu,

    __ldw_mmu,

    __ldl_mmu,

    __ldq_mmu,

};

static void *qemu_st_helpers[4] = {

    __stb_mmu,

    __stw_mmu,

    __stl_mmu,

    __stq_mmu,

};

#endif

/* XXX: qemu_ld and qemu_st could be modified to clobber only EDX and

   EAX. It will be useful once fixed registers globals are less

   common. */

static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,

                            int opc)

{

    int addr_reg, data_reg, data_reg2, r0, r1, mem_index, s_bits, bswap;

#if defined(CONFIG_SOFTMMU)

    uint8_t *label1_ptr, *label2_ptr;

#endif

#if TARGET_LONG_BITS == 64

#if defined(CONFIG_SOFTMMU)

    uint8_t *label3_ptr;

#endif

    int addr_reg2;

#endif

    data_reg = *args++;

    if (opc == 3)

        data_reg2 = *args++;

    else

        data_reg2 = 0;

    addr_reg = *args++;

#if TARGET_LONG_BITS == 64

    addr_reg2 = *args++;

#endif

    mem_index = *args;

    s_bits = opc & 3;

    r0 = TCG_REG_EAX;

    r1 = TCG_REG_EDX;

#if defined(CONFIG_SOFTMMU)

    tcg_out_mov(s, r1, addr_reg); 

    tcg_out_mov(s, r0, addr_reg); 

    tcg_out_modrm(s, 0xc1, 5, r1); /* shr $x, r1 */

    tcg_out8(s, TARGET_PAGE_BITS - CPU_TLB_ENTRY_BITS); 

    tcg_out_modrm(s, 0x81, 4, r0); /* andl $x, r0 */

    tcg_out32(s, TARGET_PAGE_MASK | ((1 << s_bits) - 1));

    tcg_out_modrm(s, 0x81, 4, r1); /* andl $x, r1 */

    tcg_out32(s, (CPU_TLB_SIZE - 1) << CPU_TLB_ENTRY_BITS);

    tcg_out_opc(s, 0x8d); /* lea offset(r1, %ebp), r1 */

    tcg_out8(s, 0x80 | (r1 << 3) | 0x04);

    tcg_out8(s, (5 << 3) | r1);

    tcg_out32(s, offsetof(CPUState, tlb_table[mem_index][0].addr_read));

    /* cmp 0(r1), r0 */

    tcg_out_modrm_offset(s, 0x3b, r0, r1, 0);

    tcg_out_mov(s, r0, addr_reg);

#if TARGET_LONG_BITS == 32

    /* je label1 */

    tcg_out8(s, 0x70 + JCC_JE);

    label1_ptr = s->code_ptr;

    s->code_ptr++;

#else

    /* jne label3 */

    tcg_out8(s, 0x70 + JCC_JNE);

    label3_ptr = s->code_ptr;

    s->code_ptr++;

    /* cmp 4(r1), addr_reg2 */

    tcg_out_modrm_offset(s, 0x3b, addr_reg2, r1, 4);

    /* je label1 */

    tcg_out8(s, 0x70 + JCC_JE);

    label1_ptr = s->code_ptr;

    s->code_ptr++;

    /* label3: */

    *label3_ptr = s->code_ptr - label3_ptr - 1;

#endif

    /* XXX: move that code at the end of the TB */

#if TARGET_LONG_BITS == 32

    tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_EDX, mem_index);

#else

    tcg_out_mov(s, TCG_REG_EDX, addr_reg2);

    tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_ECX, mem_index);

#endif

    tcg_out8(s, 0xe8);

    tcg_out32(s, (tcg_target_long)qemu_ld_helpers[s_bits] - 

              (tcg_target_long)s->code_ptr - 4);

    switch(opc) {

    case 0 | 4:

        /* movsbl */

        tcg_out_modrm(s, 0xbe | P_EXT, data_reg, TCG_REG_EAX);

        break;

    case 1 | 4:

        /* movswl */

        tcg_out_modrm(s, 0xbf | P_EXT, data_reg, TCG_REG_EAX);

        break;

    case 0:

        /* movzbl */

        tcg_out_modrm(s, 0xb6 | P_EXT, data_reg, TCG_REG_EAX);