Archipelago » qemu

/*

 * 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.

 */

/* define it to suppress various consistency checks (faster) */

#define NDEBUG

/* define it to use liveness analysis (better code) */

#define USE_LIVENESS_ANALYSIS

#include <assert.h>

#include <stdarg.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <inttypes.h>

#include "config.h"

#include "osdep.h"

/* Note: the long term plan is to reduce the dependancies on the QEMU

   CPU definitions. Currently they are used for qemu_ld/st

   instructions */

#define NO_CPU_IO_DEFS

#include "cpu.h"

#include "exec-all.h"

#include "tcg-op.h"

#include "elf.h"

static void patch_reloc(uint8_t *code_ptr, int type, 

                        tcg_target_long value);

TCGOpDef tcg_op_defs[] = {

#define DEF(s, n, copy_size) { #s, 0, 0, n, n, 0, copy_size },

#define DEF2(s, iargs, oargs, cargs, flags) { #s, iargs, oargs, cargs, iargs + oargs + cargs, flags, 0 },

#include "tcg-opc.h"

#undef DEF

#undef DEF2

};

TCGRegSet tcg_target_available_regs[2];

TCGRegSet tcg_target_call_clobber_regs;

/* XXX: move that inside the context */

uint16_t *gen_opc_ptr;

TCGArg *gen_opparam_ptr;

static inline void tcg_out8(TCGContext *s, uint8_t v)

{

    *s->code_ptr++ = v;

}

static inline void tcg_out16(TCGContext *s, uint16_t v)

{

    *(uint16_t *)s->code_ptr = v;

    s->code_ptr += 2;

}

static inline void tcg_out32(TCGContext *s, uint32_t v)

{

    *(uint32_t *)s->code_ptr = v;

    s->code_ptr += 4;

}

/* label relocation processing */

void tcg_out_reloc(TCGContext *s, uint8_t *code_ptr, int type, 

                   int label_index, long addend)

{

    TCGLabel *l;

    TCGRelocation *r;

    l = &s->labels[label_index];

    if (l->has_value) {

        patch_reloc(code_ptr, type, l->u.value + addend);

    } else {

        /* add a new relocation entry */

        r = tcg_malloc(sizeof(TCGRelocation));

        r->type = type;

        r->ptr = code_ptr;

        r->addend = addend;

        r->next = l->u.first_reloc;

        l->u.first_reloc = r;

    }

}

static void tcg_out_label(TCGContext *s, int label_index, 

                          tcg_target_long value)

{

    TCGLabel *l;

    TCGRelocation *r;

    l = &s->labels[label_index];

    if (l->has_value)

        tcg_abort();

    r = l->u.first_reloc;

    while (r != NULL) {

        patch_reloc(r->ptr, r->type, value + r->addend);

        r = r->next;

    }

    l->has_value = 1;

    l->u.value = value;

}

int gen_new_label(void)

{

    TCGContext *s = &tcg_ctx;

    int idx;

    TCGLabel *l;

    if (s->nb_labels >= TCG_MAX_LABELS)

        tcg_abort();

    idx = s->nb_labels++;

    l = &s->labels[idx];

    l->has_value = 0;

    l->u.first_reloc = NULL;

    return idx;

}

#include "tcg-target.c"

/* XXX: factorize */

static void pstrcpy(char *buf, int buf_size, const char *str)

{

    int c;

    char *q = buf;

    if (buf_size <= 0)

        return;

    for(;;) {

        c = *str++;

        if (c == 0 || q >= buf + buf_size - 1)

            break;

        *q++ = c;

    }

    *q = '\0';

}

#if TCG_TARGET_REG_BITS == 32

/* strcat and truncate. */

static char *pstrcat(char *buf, int buf_size, const char *s)

{

    int len;

    len = strlen(buf);

    if (len < buf_size)

        pstrcpy(buf + len, buf_size - len, s);

    return buf;

}

#endif

/* pool based memory allocation */

void *tcg_malloc_internal(TCGContext *s, int size)

{

    TCGPool *p;

    int pool_size;

    if (size > TCG_POOL_CHUNK_SIZE) {

        /* big malloc: insert a new pool (XXX: could optimize) */

        p = qemu_malloc(sizeof(TCGPool) + size);

        p->size = size;

        if (s->pool_current)

            s->pool_current->next = p;

        else

            s->pool_first = p;

        p->next = s->pool_current;

    } else {

        p = s->pool_current;

        if (!p) {

            p = s->pool_first;

            if (!p)

                goto new_pool;

        } else {

            if (!p->next) {

            new_pool:

                pool_size = TCG_POOL_CHUNK_SIZE;

                p = qemu_malloc(sizeof(TCGPool) + pool_size);

                p->size = pool_size;

                p->next = NULL;

                if (s->pool_current) 

                    s->pool_current->next = p;

                else

                    s->pool_first = p;

            } else {

                p = p->next;

            }

        }

    }

    s->pool_current = p;

    s->pool_cur = p->data + size;

    s->pool_end = p->data + p->size;

    return p->data;

}

void tcg_pool_reset(TCGContext *s)

{

    s->pool_cur = s->pool_end = NULL;

    s->pool_current = NULL;

}

/* free all the pool */

void tcg_pool_free(TCGContext *s)

{

    TCGPool *p, *p1;

    for(p = s->pool_first; p != NULL; p = p1) {

        p1 = p->next;

        qemu_free(p);

    }

    s->pool_first = NULL;

    s->pool_cur = s->pool_end = NULL;

}

void tcg_context_init(TCGContext *s)

{

    int op, total_args, n;

    TCGOpDef *def;

    TCGArgConstraint *args_ct;

    int *sorted_args;

    memset(s, 0, sizeof(*s));

    s->temps = s->static_temps;

    s->nb_globals = 0;

    /* Count total number of arguments and allocate the corresponding

       space */

    total_args = 0;

    for(op = 0; op < NB_OPS; op++) {

        def = &tcg_op_defs[op];

        n = def->nb_iargs + def->nb_oargs;

        total_args += n;

    }

    args_ct = qemu_malloc(sizeof(TCGArgConstraint) * total_args);

    sorted_args = qemu_malloc(sizeof(int) * total_args);

    for(op = 0; op < NB_OPS; op++) {

        def = &tcg_op_defs[op];

        def->args_ct = args_ct;

        def->sorted_args = sorted_args;

        n = def->nb_iargs + def->nb_oargs;

        sorted_args += n;

        args_ct += n;

    }

    tcg_target_init(s);

}

void tcg_set_frame(TCGContext *s, int reg,

                   tcg_target_long start, tcg_target_long size)

{

    s->frame_start = start;

    s->frame_end = start + size;

    s->frame_reg = reg;

}

void tcg_set_macro_func(TCGContext *s, TCGMacroFunc *func)

{

    s->macro_func = func;

}

void tcg_func_start(TCGContext *s)

{

    tcg_pool_reset(s);

    s->nb_temps = s->nb_globals;

    s->labels = tcg_malloc(sizeof(TCGLabel) * TCG_MAX_LABELS);

    s->nb_labels = 0;

    s->current_frame_offset = s->frame_start;

    gen_opc_ptr = gen_opc_buf;

    gen_opparam_ptr = gen_opparam_buf;

}

static inline void tcg_temp_alloc(TCGContext *s, int n)

{

    if (n > TCG_MAX_TEMPS)

        tcg_abort();

}

int tcg_global_reg_new(TCGType type, int reg, const char *name)

{

    TCGContext *s = &tcg_ctx;

    TCGTemp *ts;

    int idx;

#if TCG_TARGET_REG_BITS == 32

    if (type != TCG_TYPE_I32)

        tcg_abort();

#endif

    if (tcg_regset_test_reg(s->reserved_regs, reg))

        tcg_abort();

    idx = s->nb_globals;

    tcg_temp_alloc(s, s->nb_globals + 1);

    ts = &s->temps[s->nb_globals];

    ts->base_type = type;

    ts->type = type;

    ts->fixed_reg = 1;

    ts->reg = reg;

    ts->val_type = TEMP_VAL_REG;

    ts->name = name;

    s->nb_globals++;

    tcg_regset_set_reg(s->reserved_regs, reg);

    return idx;

}

int tcg_global_mem_new(TCGType type, int reg, tcg_target_long offset,

                       const char *name)

{

    TCGContext *s = &tcg_ctx;

    TCGTemp *ts;

    int idx;

    idx = s->nb_globals;

#if TCG_TARGET_REG_BITS == 32

    if (type == TCG_TYPE_I64) {

        char buf[64];

        tcg_temp_alloc(s, s->nb_globals + 1);

        ts = &s->temps[s->nb_globals];

        ts->base_type = type;

        ts->type = TCG_TYPE_I32;

        ts->fixed_reg = 0;

        ts->mem_allocated = 1;

        ts->mem_reg = reg;

#ifdef TCG_TARGET_WORDS_BIGENDIAN

        ts->mem_offset = offset + 4;

#else

        ts->mem_offset = offset;

#endif

        ts->val_type = TEMP_VAL_MEM;

        pstrcpy(buf, sizeof(buf), name);

        pstrcat(buf, sizeof(buf), "_0");

        ts->name = strdup(buf);

        ts++;

        ts->base_type = type;

        ts->type = TCG_TYPE_I32;

        ts->fixed_reg = 0;

        ts->mem_allocated = 1;

        ts->mem_reg = reg;

#ifdef TCG_TARGET_WORDS_BIGENDIAN

        ts->mem_offset = offset;

#else

        ts->mem_offset = offset + 4;

#endif

        ts->val_type = TEMP_VAL_MEM;

        pstrcpy(buf, sizeof(buf), name);

        pstrcat(buf, sizeof(buf), "_1");

        ts->name = strdup(buf);

        s->nb_globals += 2;

    } else

#endif

    {

        tcg_temp_alloc(s, s->nb_globals + 1);

        ts = &s->temps[s->nb_globals];

        ts->base_type = type;

        ts->type = type;

        ts->fixed_reg = 0;

        ts->mem_allocated = 1;

        ts->mem_reg = reg;

        ts->mem_offset = offset;

        ts->val_type = TEMP_VAL_MEM;

        ts->name = name;

        s->nb_globals++;

    }

    return idx;

}

int tcg_temp_new(TCGType type)

{

    TCGContext *s = &tcg_ctx;

    TCGTemp *ts;

    int idx;

    idx = s->nb_temps;

#if TCG_TARGET_REG_BITS == 32

    if (type == TCG_TYPE_I64) {

        tcg_temp_alloc(s, s->nb_temps + 1);

        ts = &s->temps[s->nb_temps];

        ts->base_type = type;

        ts->type = TCG_TYPE_I32;

        ts->val_type = TEMP_VAL_DEAD;

        ts->mem_allocated = 0;

        ts->name = NULL;

        ts++;

        ts->base_type = TCG_TYPE_I32;

        ts->type = TCG_TYPE_I32;

        ts->val_type = TEMP_VAL_DEAD;

        ts->mem_allocated = 0;

        ts->name = NULL;

        s->nb_temps += 2;

    } else

#endif

    {

        tcg_temp_alloc(s, s->nb_temps + 1);

        ts = &s->temps[s->nb_temps];

        ts->base_type = type;

        ts->type = type;

        ts->val_type = TEMP_VAL_DEAD;

        ts->mem_allocated = 0;

        ts->name = NULL;

        s->nb_temps++;

    }

    return idx;

}

int tcg_const_i32(int32_t val)

{

    TCGContext *s = &tcg_ctx;

    TCGTemp *ts;

    int idx;

    idx = s->nb_temps;

    tcg_temp_alloc(s, idx + 1);

    ts = &s->temps[idx];

    ts->base_type = ts->type = TCG_TYPE_I32;

    ts->val_type = TEMP_VAL_CONST;

    ts->name = NULL;

    ts->val = val;

    s->nb_temps++;

    return idx;

}

int tcg_const_i64(int64_t val)

{

    TCGContext *s = &tcg_ctx;

    TCGTemp *ts;

    int idx;

    idx = s->nb_temps;

#if TCG_TARGET_REG_BITS == 32

    tcg_temp_alloc(s, idx + 2);

    ts = &s->temps[idx];

    ts->base_type = TCG_TYPE_I64;

    ts->type = TCG_TYPE_I32;

    ts->val_type = TEMP_VAL_CONST;

    ts->name = NULL;

    ts->val = val;

    ts++;

    ts->base_type = TCG_TYPE_I32;

    ts->type = TCG_TYPE_I32;

    ts->val_type = TEMP_VAL_CONST;

    ts->name = NULL;

    ts->val = val >> 32;

    s->nb_temps += 2;

#else

    tcg_temp_alloc(s, idx + 1);

    ts = &s->temps[idx];

    ts->base_type = ts->type = TCG_TYPE_I64;

    ts->val_type = TEMP_VAL_CONST;

    ts->name = NULL;

    ts->val = val;

    s->nb_temps++;

#endif    

    return idx;

}

void tcg_register_helper(void *func, const char *name)

{

    TCGContext *s = &tcg_ctx;

    int n;

    if ((s->nb_helpers + 1) > s->allocated_helpers) {

        n = s->allocated_helpers;

        if (n == 0) {

            n = 4;

        } else {

            n *= 2;

        }

        s->helpers = realloc(s->helpers, n * sizeof(TCGHelperInfo));

        s->allocated_helpers = n;

    }

    s->helpers[s->nb_helpers].func = func;

    s->helpers[s->nb_helpers].name = name;

    s->nb_helpers++;

}

const char *tcg_helper_get_name(TCGContext *s, void *func)

{

    int i;

    for(i = 0; i < s->nb_helpers; i++) {

        if (s->helpers[i].func == func)

            return s->helpers[i].name;

    }

    return NULL;

}

static inline TCGType tcg_get_base_type(TCGContext *s, TCGArg arg)

{

    return s->temps[arg].base_type;

}

static void tcg_gen_call_internal(TCGContext *s, TCGArg func, 

                                  unsigned int flags,

                                  unsigned int nb_rets, const TCGArg *rets,

                                  unsigned int nb_params, const TCGArg *params)

{

    int i;

    *gen_opc_ptr++ = INDEX_op_call;

    *gen_opparam_ptr++ = (nb_rets << 16) | (nb_params + 1);

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

        *gen_opparam_ptr++ = rets[i];

    }

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

        *gen_opparam_ptr++ = params[i];

    }

    *gen_opparam_ptr++ = func;

    *gen_opparam_ptr++ = flags;

    /* total parameters, needed to go backward in the instruction stream */

    *gen_opparam_ptr++ = 1 + nb_rets + nb_params + 3;

}

#if TCG_TARGET_REG_BITS < 64

/* Note: we convert the 64 bit args to 32 bit */

void tcg_gen_call(TCGContext *s, TCGArg func, unsigned int flags,

                  unsigned int nb_rets, const TCGArg *rets,

                  unsigned int nb_params, const TCGArg *args1)

{

    TCGArg ret, *args2, rets_2[2], arg;

    int j, i, call_type;

    if (nb_rets == 1) {

        ret = rets[0];

        if (tcg_get_base_type(s, ret) == TCG_TYPE_I64) {

            nb_rets = 2;

            rets_2[0] = ret;

            rets_2[1] = ret + 1;

            rets = rets_2;

        }

    }

    args2 = alloca((nb_params * 2) * sizeof(TCGArg));

    j = 0;

    call_type = (flags & TCG_CALL_TYPE_MASK);

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

        arg = args1[i];

        if (tcg_get_base_type(s, arg) == TCG_TYPE_I64) {

#ifdef TCG_TARGET_I386

            /* REGPARM case: if the third parameter is 64 bit, it is

               allocated on the stack */

            if (j == 2 && call_type == TCG_CALL_TYPE_REGPARM) {

                call_type = TCG_CALL_TYPE_REGPARM_2;

                flags = (flags & ~TCG_CALL_TYPE_MASK) | call_type;

            }

            args2[j++] = arg;

            args2[j++] = arg + 1;

#else

#ifdef TCG_TARGET_WORDS_BIGENDIAN

            args2[j++] = arg + 1;

            args2[j++] = arg;

#else

            args2[j++] = arg;

            args2[j++] = arg + 1;

#endif

#endif

        } else {

            args2[j++] = arg;

        }

    }

    tcg_gen_call_internal(s, func, flags, 

                          nb_rets, rets, j, args2);

}

#else

void tcg_gen_call(TCGContext *s, TCGArg func, unsigned int flags,

                  unsigned int nb_rets, const TCGArg *rets,

                  unsigned int nb_params, const TCGArg *args1)

{

    tcg_gen_call_internal(s, func, flags, 

                          nb_rets, rets, nb_params, args1);

}

#endif

void tcg_gen_shifti_i64(TCGArg ret, TCGArg arg1, 

                        int c, int right, int arith)

{

    if (c == 0)

        return;

    if (c >= 32) {

        c -= 32;

        if (right) {

            if (arith) {

                tcg_gen_sari_i32(ret, arg1 + 1, c);

                tcg_gen_sari_i32(ret + 1, arg1 + 1, 31);

            } else {

                tcg_gen_shri_i32(ret, arg1 + 1, c);

                tcg_gen_movi_i32(ret + 1, 0);

            }

        } else {

            tcg_gen_shli_i32(ret + 1, arg1, c);

            tcg_gen_movi_i32(ret, 0);

        }

    } else {

        int t0, t1;

        t0 = tcg_temp_new(TCG_TYPE_I32);

        t1 = tcg_temp_new(TCG_TYPE_I32);

        if (right) {

            tcg_gen_shli_i32(t0, arg1 + 1, 32 - c);

            if (arith)

                tcg_gen_sari_i32(t1, arg1 + 1, c);

            else 

                tcg_gen_shri_i32(t1, arg1 + 1, c);

            tcg_gen_shri_i32(ret, arg1, c); 

            tcg_gen_or_i32(ret, ret, t0);

            tcg_gen_mov_i32(ret + 1, t1);

        } else {

            tcg_gen_shri_i32(t0, arg1, 32 - c);

            /* Note: ret can be the same as arg1, so we use t1 */

            tcg_gen_shli_i32(t1, arg1, c); 

            tcg_gen_shli_i32(ret + 1, arg1 + 1, c);

            tcg_gen_or_i32(ret + 1, ret + 1, t0);

            tcg_gen_mov_i32(ret, t1);

        }

    }

}

void tcg_reg_alloc_start(TCGContext *s)

{

    int i;

    TCGTemp *ts;

    for(i = 0; i < s->nb_globals; i++) {

        ts = &s->temps[i];

        if (ts->fixed_reg) {

            ts->val_type = TEMP_VAL_REG;

        } else {

            ts->val_type = TEMP_VAL_MEM;

        }

    }

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

        s->reg_to_temp[i] = -1;

    }

}

char *tcg_get_arg_str(TCGContext *s, char *buf, int buf_size, TCGArg arg)

{

    TCGTemp *ts;

    if (arg < s->nb_globals) {

        pstrcpy(buf, buf_size, s->temps[arg].name);

    } else {

        ts = &s->temps[arg];

        if (ts->val_type == TEMP_VAL_CONST) {

            snprintf(buf, buf_size, "$0x%" TCG_PRIlx , ts->val);

        } else {

            snprintf(buf, buf_size, "tmp%d", (int)arg - s->nb_globals);

        }

    }

    return buf;

}

void tcg_dump_ops(TCGContext *s, FILE *outfile)

{

    const uint16_t *opc_ptr;

    const TCGArg *args;

    TCGArg arg;

    int c, i, k, nb_oargs, nb_iargs, nb_cargs;

    const TCGOpDef *def;

    char buf[128];

    opc_ptr = gen_opc_buf;

    args = gen_opparam_buf;

    while (opc_ptr < gen_opc_ptr) {

        c = *opc_ptr++;

        def = &tcg_op_defs[c];

        fprintf(outfile, " %s ", def->name);

        if (c == INDEX_op_call) {

            TCGArg arg;

            /* variable number of arguments */

            arg = *args++;

            nb_oargs = arg >> 16;

            nb_iargs = arg & 0xffff;

            nb_cargs = def->nb_cargs;

        } else if (c == INDEX_op_nopn) {

            /* variable number of arguments */

            nb_cargs = *args;

            nb_oargs = 0;

            nb_iargs = 0;

        } else {

            nb_oargs = def->nb_oargs;

            nb_iargs = def->nb_iargs;

            nb_cargs = def->nb_cargs;

        }

        k = 0;

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

            if (k != 0)

                fprintf(outfile, ",");

            fprintf(outfile, "%s", tcg_get_arg_str(s, buf, sizeof(buf), args[k++]));

        }

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

            if (k != 0)

                fprintf(outfile, ",");

            /* XXX: dump helper name for call */

            fprintf(outfile, "%s", tcg_get_arg_str(s, buf, sizeof(buf), args[k++]));

        }

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

            if (k != 0)

                fprintf(outfile, ",");

            arg = args[k++];

            fprintf(outfile, "$0x%" TCG_PRIlx, arg);

        }

        fprintf(outfile, "\n");

        args += nb_iargs + nb_oargs + nb_cargs;

    }

}

/* we give more priority to constraints with less registers */

static int get_constraint_priority(const TCGOpDef *def, int k)

{

    const TCGArgConstraint *arg_ct;

    int i, n;

    arg_ct = &def->args_ct[k];

    if (arg_ct->ct & TCG_CT_ALIAS) {

        /* an alias is equivalent to a single register */

        n = 1;

    } else {

        if (!(arg_ct->ct & TCG_CT_REG))

            return 0;

        n = 0;

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

            if (tcg_regset_test_reg(arg_ct->u.regs, i))

                n++;

        }

    }

    return TCG_TARGET_NB_REGS - n + 1;

}

/* sort from highest priority to lowest */

static void sort_constraints(TCGOpDef *def, int start, int n)

{

    int i, j, p1, p2, tmp;

    for(i = 0; i < n; i++)

        def->sorted_args[start + i] = start + i;

    if (n <= 1)

        return;

    for(i = 0; i < n - 1; i++) {

        for(j = i + 1; j < n; j++) {

            p1 = get_constraint_priority(def, def->sorted_args[start + i]);

            p2 = get_constraint_priority(def, def->sorted_args[start + j]);

            if (p1 < p2) {

                tmp = def->sorted_args[start + i];

                def->sorted_args[start + i] = def->sorted_args[start + j];

                def->sorted_args[start + j] = tmp;

            }

        }

    }

}

void tcg_add_target_add_op_defs(const TCGTargetOpDef *tdefs)

{

    int op;

    TCGOpDef *def;

    const char *ct_str;

    int i, nb_args;

    for(;;) {

        if (tdefs->op < 0)

            break;

        op = tdefs->op;

        assert(op >= 0 && op < NB_OPS);

        def = &tcg_op_defs[op];

        nb_args = def->nb_iargs + def->nb_oargs;

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

            ct_str = tdefs->args_ct_str[i];

            tcg_regset_clear(def->args_ct[i].u.regs);

            def->args_ct[i].ct = 0;

            if (ct_str[0] >= '0' && ct_str[0] <= '9') {

                int oarg;

                oarg = ct_str[0] - '0';

                assert(oarg < def->nb_oargs);

                assert(def->args_ct[oarg].ct & TCG_CT_REG);

                /* TCG_CT_ALIAS is for the output arguments. The input

                   argument is tagged with TCG_CT_IALIAS for

                   informative purposes. */

                def->args_ct[i] = def->args_ct[oarg];

                def->args_ct[oarg].ct = i | TCG_CT_ALIAS;

                def->args_ct[i].ct |= TCG_CT_IALIAS;

            } else {

                for(;;) {

                    if (*ct_str == '\0')

                        break;

                    switch(*ct_str) {

                    case 'i':

                        def->args_ct[i].ct |= TCG_CT_CONST;

                        ct_str++;

                        break;

                    default:

                        if (target_parse_constraint(&def->args_ct[i], &ct_str) < 0) {

                            fprintf(stderr, "Invalid constraint '%s' for arg %d of operation '%s'\n",

                                    ct_str, i, def->name);

                            exit(1);

                        }

                    }

                }

            }

        }

        /* sort the constraints (XXX: this is just an heuristic) */

        sort_constraints(def, 0, def->nb_oargs);

        sort_constraints(def, def->nb_oargs, def->nb_iargs);

#if 0

        {

            int i;

            printf("%s: sorted=", def->name);

            for(i = 0; i < def->nb_oargs + def->nb_iargs; i++)

                printf(" %d", def->sorted_args[i]);

            printf("\n");

        }

#endif

        tdefs++;

    }

}

#ifdef USE_LIVENESS_ANALYSIS

/* set a nop for an operation using 'nb_args' */

static inline void tcg_set_nop(TCGContext *s, uint16_t *opc_ptr, 

                               TCGArg *args, int nb_args)

{

    if (nb_args == 0) {

        *opc_ptr = INDEX_op_nop;

    } else {

        *opc_ptr = INDEX_op_nopn;

        args[0] = nb_args;

        args[nb_args - 1] = nb_args;

    }

}

/* liveness analysis: end of basic block: globals are live, temps are dead */

static inline void tcg_la_bb_end(TCGContext *s, uint8_t *dead_temps)

{

    memset(dead_temps, 0, s->nb_globals);

    memset(dead_temps + s->nb_globals, 1, s->nb_temps - s->nb_globals);

}

/* Liveness analysis : update the opc_dead_iargs array to tell if a

   given input arguments is dead. Instructions updating dead

   temporaries are removed. */

void tcg_liveness_analysis(TCGContext *s)

{

    int i, op_index, op, nb_args, nb_iargs, nb_oargs, arg, nb_ops;

    TCGArg *args;

    const TCGOpDef *def;

    uint8_t *dead_temps;

    unsigned int dead_iargs;

    gen_opc_ptr++; /* skip end */

    nb_ops = gen_opc_ptr - gen_opc_buf;

    /* XXX: make it really dynamic */

    s->op_dead_iargs = tcg_malloc(OPC_BUF_SIZE * sizeof(uint16_t));

    dead_temps = tcg_malloc(s->nb_temps);

    memset(dead_temps, 1, s->nb_temps);

    args = gen_opparam_ptr;

    op_index = nb_ops - 1;

    while (op_index >= 0) {

        op = gen_opc_buf[op_index];

        def = &tcg_op_defs[op];

        switch(op) {

        case INDEX_op_call:

            nb_args = args[-1];

            args -= nb_args;

            nb_iargs = args[0] & 0xffff;

            nb_oargs = args[0] >> 16;

            args++;

            /* output args are dead */

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

                arg = args[i];

                dead_temps[arg] = 1;

            }

            /* globals are live (they may be used by the call) */

            memset(dead_temps, 0, s->nb_globals);

            /* input args are live */

            dead_iargs = 0;

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

                arg = args[i + nb_oargs];

                if (dead_temps[arg]) {

                    dead_iargs |= (1 << i);

                }

                dead_temps[arg] = 0;

            }

            s->op_dead_iargs[op_index] = dead_iargs;

            args--;

            break;

        case INDEX_op_set_label:

            args--;

            /* mark end of basic block */

            tcg_la_bb_end(s, dead_temps);

            break;

        case INDEX_op_nopn:

            nb_args = args[-1];

            args -= nb_args;

            break;

        case INDEX_op_macro_2:

            {

                int dead_args[2], macro_id;

                int saved_op_index, saved_arg_index;

                int macro_op_index, macro_arg_index;

                int macro_end_op_index, macro_end_arg_index;

                int last_nb_temps;

                nb_args = 3;

                args -= nb_args;

                dead_args[0] = dead_temps[args[0]];

                dead_args[1] = dead_temps[args[1]];

                macro_id = args[2];

                /* call the macro function which generate code

                   depending on the live outputs */

                saved_op_index = op_index;

                saved_arg_index = args - gen_opparam_buf;

                /* add a macro start instruction */

                *gen_opc_ptr++ = INDEX_op_macro_start;

                *gen_opparam_ptr++ = saved_op_index;

                *gen_opparam_ptr++ = saved_arg_index;

                macro_op_index = gen_opc_ptr - gen_opc_buf;

                macro_arg_index = gen_opparam_ptr -  gen_opparam_buf;

                last_nb_temps = s->nb_temps;

                s->macro_func(s, macro_id, dead_args);

                /* realloc temp info (XXX: make it faster) */

                if (s->nb_temps > last_nb_temps) {

                    uint8_t *new_dead_temps;

                    new_dead_temps = tcg_malloc(s->nb_temps);

                    memcpy(new_dead_temps, dead_temps, last_nb_temps);

                    memset(new_dead_temps + last_nb_temps, 1, 

                           s->nb_temps - last_nb_temps);

                    dead_temps = new_dead_temps;

                }

                macro_end_op_index = gen_opc_ptr - gen_opc_buf;

                macro_end_arg_index = gen_opparam_ptr - gen_opparam_buf;

                /* end of macro: add a goto to the next instruction */

                *gen_opc_ptr++ = INDEX_op_macro_end;

                *gen_opparam_ptr++ = op_index + 1;

                *gen_opparam_ptr++ = saved_arg_index + nb_args;

                /* modify the macro operation to be a macro_goto */

                gen_opc_buf[op_index] = INDEX_op_macro_goto;

                args[0] = macro_op_index;

                args[1] = macro_arg_index;

                args[2] = 0; /* dummy third arg to match the 

                                macro parameters */

                /* set the next instruction to the end of the macro */

                op_index = macro_end_op_index;

                args = macro_end_arg_index + gen_opparam_buf;

            }

            break;

        case INDEX_op_macro_start:

            args -= 2;

            op_index = args[0];

            args = gen_opparam_buf + args[1];

            break;

        case INDEX_op_macro_goto:

        case INDEX_op_macro_end:

            tcg_abort(); /* should never happen in liveness analysis */

        case INDEX_op_end:

            break;

            /* XXX: optimize by hardcoding common cases (e.g. triadic ops) */

        default:

            if (op > INDEX_op_end) {

                args -= def->nb_args;

                nb_iargs = def->nb_iargs;

                nb_oargs = def->nb_oargs;

                /* Test if the operation can be removed because all

                   its outputs are dead. We may add a flag to

                   explicitely tell if the op has side

                   effects. Currently we assume that if nb_oargs == 0

                   or OPF_BB_END is set, the operation has side

                   effects and cannot be removed */

                if (nb_oargs != 0 && !(def->flags & TCG_OPF_BB_END)) {

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

                        arg = args[i];

                        if (!dead_temps[arg])

                            goto do_not_remove;

                    }

                    tcg_set_nop(s, gen_opc_buf + op_index, args, def->nb_args);

#ifdef CONFIG_PROFILER

                    {

                        extern int64_t dyngen_tcg_del_op_count;

                        dyngen_tcg_del_op_count++;

                    }

#endif

                } else {

                do_not_remove:

                    /* output args are dead */

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

                        arg = args[i];

                        dead_temps[arg] = 1;

                    }

                    /* if end of basic block, update */

                    if (def->flags & TCG_OPF_BB_END) {

                        tcg_la_bb_end(s, dead_temps);

                    }

                    /* input args are live */

                    dead_iargs = 0;

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

                        arg = args[i + nb_oargs];

                        if (dead_temps[arg]) {

                            dead_iargs |= (1 << i);

                        }

                        dead_temps[arg] = 0;

                    }

                    s->op_dead_iargs[op_index] = dead_iargs;

                }

            } else {

                /* legacy dyngen operations */

                args -= def->nb_args;

                /* mark end of basic block */

                tcg_la_bb_end(s, dead_temps);

            }

            break;

        }

        op_index--;

    }

    if (args != gen_opparam_buf)

        tcg_abort();

}

#else

/* dummy liveness analysis */

void tcg_liveness_analysis(TCGContext *s)

{

    int nb_ops;

    nb_ops = gen_opc_ptr - gen_opc_buf;

    s->op_dead_iargs = tcg_malloc(nb_ops * sizeof(uint16_t));

    memset(s->op_dead_iargs, 0, nb_ops * sizeof(uint16_t));

}

#endif

#ifndef NDEBUG

static void dump_regs(TCGContext *s)

{

    TCGTemp *ts;

    int i;

    char buf[64];

    for(i = 0; i < s->nb_temps; i++) {

        ts = &s->temps[i];

        printf("  %10s: ", tcg_get_arg_str(s, buf, sizeof(buf), i));

        switch(ts->val_type) {

        case TEMP_VAL_REG:

            printf("%s", tcg_target_reg_names[ts->reg]);

            break;

        case TEMP_VAL_MEM:

            printf("%d(%s)", (int)ts->mem_offset, tcg_target_reg_names[ts->mem_reg]);

            break;

        case TEMP_VAL_CONST:

            printf("$0x%" TCG_PRIlx, ts->val);

            break;

        case TEMP_VAL_DEAD:

            printf("D");

            break;

        default:

            printf("???");

            break;

        }

        printf("\n");

    }

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

        if (s->reg_to_temp[i] >= 0) {

            printf("%s: %s\n", 

                   tcg_target_reg_names[i], 

                   tcg_get_arg_str(s, buf, sizeof(buf), s->reg_to_temp[i]));

        }

    }

}

static void check_regs(TCGContext *s)

{

    int reg, k;

    TCGTemp *ts;

    char buf[64];

    for(reg = 0; reg < TCG_TARGET_NB_REGS; reg++) {

        k = s->reg_to_temp[reg];

        if (k >= 0) {

            ts = &s->temps[k];

            if (ts->val_type != TEMP_VAL_REG ||

                ts->reg != reg) {

                printf("Inconsistency for register %s:\n", 

                       tcg_target_reg_names[reg]);

                printf("reg state:\n");

                dump_regs(s);

                tcg_abort();

            }

        }

    }

    for(k = 0; k < s->nb_temps; k++) {

        ts = &s->temps[k];

        if (ts->val_type == TEMP_VAL_REG &&

            !ts->fixed_reg &&

            s->reg_to_temp[ts->reg] != k) {

                printf("Inconsistency for temp %s:\n", 

                       tcg_get_arg_str(s, buf, sizeof(buf), k));

                printf("reg state:\n");

                dump_regs(s);

                tcg_abort();

        }

    }

}

#endif

static void temp_allocate_frame(TCGContext *s, int temp)

{

    TCGTemp *ts;

    ts = &s->temps[temp];

    s->current_frame_offset = (s->current_frame_offset + sizeof(tcg_target_long) - 1) & ~(sizeof(tcg_target_long) - 1);

    if (s->current_frame_offset + sizeof(tcg_target_long) > s->frame_end)

        abort();

    ts->mem_offset = s->current_frame_offset;

    ts->mem_reg = s->frame_reg;

    ts->mem_allocated = 1;

    s->current_frame_offset += sizeof(tcg_target_long);

}

/* free register 'reg' by spilling the corresponding temporary if necessary */

static void tcg_reg_free(TCGContext *s, int reg)

{

    TCGTemp *ts;

    int temp;

    temp = s->reg_to_temp[reg];

    if (temp != -1) {

        ts = &s->temps[temp];

        assert(ts->val_type == TEMP_VAL_REG);

        if (!ts->mem_coherent) {

            if (!ts->mem_allocated) 

                temp_allocate_frame(s, temp);

            tcg_out_st(s, reg, ts->mem_reg, ts->mem_offset);

        }

        ts->val_type = TEMP_VAL_MEM;

        s->reg_to_temp[reg] = -1;

    }

}

/* Allocate a register belonging to reg1 & ~reg2 */

static int tcg_reg_alloc(TCGContext *s, TCGRegSet reg1, TCGRegSet reg2)

{

    int i, reg;

    TCGRegSet reg_ct;

    tcg_regset_andnot(reg_ct, reg1, reg2);

    /* first try free registers */

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

        reg = tcg_target_reg_alloc_order[i];

        if (tcg_regset_test_reg(reg_ct, reg) && s->reg_to_temp[reg] == -1)

            return reg;

    }

    /* XXX: do better spill choice */

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

        reg = tcg_target_reg_alloc_order[i];

        if (tcg_regset_test_reg(reg_ct, reg)) {

            tcg_reg_free(s, reg);

            return reg;

        }

    }

    tcg_abort();

}

/* at the end of a basic block, we assume all temporaries are dead and

   all globals are stored at their canonical location */

/* XXX: optimize by handling constants in another array ? */

void tcg_reg_alloc_bb_end(TCGContext *s)

{

    TCGTemp *ts;

    int i;

    for(i = 0; i < s->nb_globals; i++) {

        ts = &s->temps[i];

        if (!ts->fixed_reg) {

            if (ts->val_type == TEMP_VAL_REG) {

                tcg_reg_free(s, ts->reg);

            }

        }

    }

    for(i = s->nb_globals; i < s->nb_temps; i++) {

        ts = &s->temps[i];

        if (ts->val_type != TEMP_VAL_CONST) {

            if (ts->val_type == TEMP_VAL_REG) {

                s->reg_to_temp[ts->reg] = -1;

            }

            ts->val_type = TEMP_VAL_DEAD;

        }

    }

}

#define IS_DEAD_IARG(n) ((dead_iargs >> (n)) & 1)

static void tcg_reg_alloc_mov(TCGContext *s, const TCGOpDef *def,

                              const TCGArg *args,

                              unsigned int dead_iargs)

{

    TCGTemp *ts, *ots;

    int reg;

    const TCGArgConstraint *arg_ct;

    ots = &s->temps[args[0]];

    ts = &s->temps[args[1]];

    arg_ct = &def->args_ct[0];

    if (ts->val_type == TEMP_VAL_REG) {

        if (IS_DEAD_IARG(0) && !ts->fixed_reg && !ots->fixed_reg) {

            /* the mov can be suppressed */

            if (ots->val_type == TEMP_VAL_REG)

                s->reg_to_temp[ots->reg] = -1;

            reg = ts->reg;

            s->reg_to_temp[reg] = -1;

            ts->val_type = TEMP_VAL_DEAD;

        } else {

            if (ots->val_type == TEMP_VAL_REG) {

                reg = ots->reg;

            } else {

                reg = tcg_reg_alloc(s, arg_ct->u.regs, s->reserved_regs);

            }

            if (ts->reg != reg) {

                tcg_out_mov(s, reg, ts->reg);

            }

        }

    } else if (ts->val_type == TEMP_VAL_MEM) {

        if (ots->val_type == TEMP_VAL_REG) {

            reg = ots->reg;

        } else {

            reg = tcg_reg_alloc(s, arg_ct->u.regs, s->reserved_regs);

        }

        tcg_out_ld(s, reg, ts->mem_reg, ts->mem_offset);

    } else if (ts->val_type == TEMP_VAL_CONST) {

        if (ots->val_type == TEMP_VAL_REG) {

            reg = ots->reg;

        } else {

            reg = tcg_reg_alloc(s, arg_ct->u.regs, s->reserved_regs);

        }

        tcg_out_movi(s, ots->type, reg, ts->val);

    } else {

        tcg_abort();

    }

    s->reg_to_temp[reg] = args[0];

    ots->reg = reg;

    ots->val_type = TEMP_VAL_REG;

    ots->mem_coherent = 0;

}

static void tcg_reg_alloc_op(TCGContext *s, 

                             const TCGOpDef *def, int opc,

                             const TCGArg *args,

                             unsigned int dead_iargs)

{

    TCGRegSet allocated_regs;

    int i, k, nb_iargs, nb_oargs, reg;

    TCGArg arg;

    const TCGArgConstraint *arg_ct;

    TCGTemp *ts;

    TCGArg new_args[TCG_MAX_OP_ARGS];

    int const_args[TCG_MAX_OP_ARGS];

    nb_oargs = def->nb_oargs;

    nb_iargs = def->nb_iargs;

    /* copy constants */

    memcpy(new_args + nb_oargs + nb_iargs, 

           args + nb_oargs + nb_iargs, 

           sizeof(TCGArg) * def->nb_cargs);

    /* satisfy input constraints */ 

    tcg_regset_set(allocated_regs, s->reserved_regs);

    for(k = 0; k < nb_iargs; k++) {

        i = def->sorted_args[nb_oargs + k];

        arg = args[i];

        arg_ct = &def->args_ct[i];

        ts = &s->temps[arg];

        if (ts->val_type == TEMP_VAL_MEM) {

            reg = tcg_reg_alloc(s, arg_ct->u.regs, allocated_regs);

            tcg_out_ld(s, reg, ts->mem_reg, ts->mem_offset);

            ts->val_type = TEMP_VAL_REG;

            ts->reg = reg;

            ts->mem_coherent = 1;

            s->reg_to_temp[reg] = arg;

        } else if (ts->val_type == TEMP_VAL_CONST) {

            if (tcg_target_const_match(ts->val, arg_ct)) {

                /* constant is OK for instruction */

                const_args[i] = 1;

                new_args[i] = ts->val;

                goto iarg_end;

            } else {

                /* need to move to a register*/

                reg = tcg_reg_alloc(s, arg_ct->u.regs, allocated_regs);

                tcg_out_movi(s, ts->type, reg, ts->val);

                goto iarg_end1;

            }

        }

        assert(ts->val_type == TEMP_VAL_REG);

        if ((arg_ct->ct & TCG_CT_IALIAS) &&

            !IS_DEAD_IARG(i - nb_oargs)) {

            /* if the input is aliased to an output and if it is

               not dead after the instruction, we must allocate

               a new register and move it */

            goto allocate_in_reg;

        }

        reg = ts->reg;

        if (tcg_regset_test_reg(arg_ct->u.regs, reg)) {

            /* nothing to do : the constraint is satisfied */

        } else {

        allocate_in_reg:

            /* allocate a new register matching the constraint 

               and move the temporary register into it */

            reg = tcg_reg_alloc(s, arg_ct->u.regs, allocated_regs);

            tcg_out_mov(s, reg, ts->reg);

        }

    iarg_end1:

        new_args[i] = reg;

        const_args[i] = 0;

        tcg_regset_set_reg(allocated_regs, reg);

    iarg_end: ;

    }

    /* mark dead temporaries and free the associated registers */

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

        arg = args[nb_oargs + i];

        if (IS_DEAD_IARG(i)) {

            ts = &s->temps[arg];

            if (ts->val_type != TEMP_VAL_CONST && !ts->fixed_reg) {

                if (ts->val_type == TEMP_VAL_REG)

                    s->reg_to_temp[ts->reg] = -1;

                ts->val_type = TEMP_VAL_DEAD;

            }

        }

    }

    /* XXX: permit generic clobber register list ? */ 

    if (def->flags & TCG_OPF_CALL_CLOBBER) {

        for(reg = 0; reg < TCG_TARGET_NB_REGS; reg++) {

            if (tcg_regset_test_reg(tcg_target_call_clobber_regs, reg)) {

                tcg_reg_free(s, reg);

            }

        }

    }

    /* satisfy the output constraints */