root/ext/opcache/Optimizer/block_pass.c

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DEFINITIONS

This source file includes following definitions.
  1. zend_get_persistent_constant
  2. print_block
  3. find_code_blocks
  4. replace_source
  5. del_source
  6. delete_code_block
  7. zend_access_path
  8. zend_rebuild_access_path
  9. strip_nop
  10. zend_optimize_block
  11. assemble_code_blocks
  12. zend_jmp_optimization
  13. zend_t_usage
  14. zend_block_optimization

#define DEBUG_BLOCKPASS 0

/* Checks if a constant (like "true") may be replaced by its value */
static int zend_get_persistent_constant(char *name, uint name_len, zval *result, int copy TSRMLS_DC ELS_DC)
{
        zend_constant *c;
        char *lookup_name;
        int retval = 1;
        ALLOCA_FLAG(use_heap);

        if (zend_hash_find(EG(zend_constants), name, name_len + 1, (void **) &c) == FAILURE) {
                lookup_name = DO_ALLOCA(name_len + 1);
                memcpy(lookup_name, name, name_len + 1);
                zend_str_tolower(lookup_name, name_len);

                if (zend_hash_find(EG(zend_constants), lookup_name, name_len + 1, (void **) &c) == SUCCESS) {
                        if (!(c->flags & CONST_CT_SUBST) || (c->flags & CONST_CS)) {
                                retval = 0;
                        }
                } else {
                        retval = 0;
                }
                FREE_ALLOCA(lookup_name);
        }

        if (retval) {
                if (c->flags & CONST_PERSISTENT) {
                        *result = c->value;
                        if (copy) {
                                zval_copy_ctor(result);
                        }
                } else {
                        retval = 0;
                }
        }

        return retval;
}

#if DEBUG_BLOCKPASS
# define BLOCK_REF(b) b?op_array->opcodes-b->start_opline:-1

static inline void print_block(zend_code_block *block, zend_op *opcodes, char *txt)
{
        fprintf(stderr, "%sBlock: %d-%d (%d)", txt, block->start_opline - opcodes, block->start_opline - opcodes + block->len - 1, block->len);
        if (!block->access) {
                fprintf(stderr, " unused");
        }
        if (block->op1_to) {
                fprintf(stderr, " 1: %d", block->op1_to->start_opline - opcodes);
        }
        if (block->op2_to) {
                fprintf(stderr, " 2: %d", block->op2_to->start_opline - opcodes);
        }
        if (block->ext_to) {
                fprintf(stderr, " e: %d", block->ext_to->start_opline - opcodes);
        }
        if (block->follow_to) {
                fprintf(stderr, " f: %d", block->follow_to->start_opline - opcodes);
        }

        if (block->sources) {
                zend_block_source *bs = block->sources;
                fprintf(stderr, " s:");
                while (bs) {
                        fprintf(stderr, " %d", bs->from->start_opline - opcodes);
                        bs = bs->next;
                }
        }

        fprintf(stderr, "\n");
        fflush(stderr);
}
#else
#define print_block(a,b,c)
#endif

#define START_BLOCK_OP(opno) blocks[opno].start_opline = &op_array->opcodes[opno]; blocks[opno].start_opline_no = opno; blocks[opno].access = 1

/* find code blocks in op_array
   code block is a set of opcodes with single flow of control, i.e. without jmps,
   branches, etc. */
static int find_code_blocks(zend_op_array *op_array, zend_cfg *cfg)
{
        zend_op *opline;
        zend_op *end = op_array->opcodes + op_array->last;
        zend_code_block *blocks, *cur_block;
        zend_uint opno = 0;

        memset(cfg, 0, sizeof(zend_cfg));
        blocks = cfg->blocks = ecalloc(op_array->last + 2, sizeof(zend_code_block));
        opline = op_array->opcodes;
        blocks[0].start_opline = opline;
        blocks[0].start_opline_no = 0;
        while (opline < end) {
                switch((unsigned)opline->opcode) {
                        case ZEND_BRK:
                        case ZEND_CONT:
#if ZEND_EXTENSION_API_NO >= PHP_5_3_X_API_NO
                        case ZEND_GOTO:
#endif
                                /* would not optimize non-optimized BRK/CONTs - we cannot
                                 really know where it jumps, so these optimizations are
                                too dangerous */
                                efree(blocks);
                                return 0;
#if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
                        case ZEND_FAST_CALL:
                                START_BLOCK_OP(ZEND_OP1(opline).opline_num);
                                if (opline->extended_value) {
                                        START_BLOCK_OP(ZEND_OP2(opline).opline_num);
                                }
                                START_BLOCK_OP(opno + 1);
                                break;
                        case ZEND_FAST_RET:
                                if (opline->extended_value) {
                                        START_BLOCK_OP(ZEND_OP2(opline).opline_num);
                                }
                                START_BLOCK_OP(opno + 1);
                                break;
#endif
                        case ZEND_JMP:
                                START_BLOCK_OP(ZEND_OP1(opline).opline_num);
                                /* break missing intentionally */
                        case ZEND_RETURN:
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                        case ZEND_RETURN_BY_REF:
#endif
#if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
                        case ZEND_GENERATOR_RETURN:
#endif
                        case ZEND_EXIT:
                        case ZEND_THROW:
                                /* start new block from this+1 */
                                START_BLOCK_OP(opno + 1);
                                break;
                                /* TODO: if conditional jmp depends on constant,
                                                 don't start block that won't be executed */
                        case ZEND_CATCH:
                                START_BLOCK_OP(opline->extended_value);
                                START_BLOCK_OP(opno + 1);
                                break;
                        case ZEND_JMPZNZ:
                                START_BLOCK_OP(opline->extended_value);
                        case ZEND_JMPZ:
                        case ZEND_JMPNZ:
                        case ZEND_JMPZ_EX:
                        case ZEND_JMPNZ_EX:
                        case ZEND_FE_RESET:
                        case ZEND_NEW:
#if ZEND_EXTENSION_API_NO >= PHP_5_3_X_API_NO
                        case ZEND_JMP_SET:
#endif
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                        case ZEND_JMP_SET_VAR:
#endif
                                START_BLOCK_OP(ZEND_OP2(opline).opline_num);
                                START_BLOCK_OP(opno + 1);
                                break;
                        case ZEND_FE_FETCH:
                                START_BLOCK_OP(ZEND_OP2(opline).opline_num);
                                START_BLOCK_OP(opno + 2);
                                break;
                }
                opno++;
                opline++;
        }

        /* first find block start points */
        if (op_array->last_try_catch) {
                int i;
                cfg->try = ecalloc(op_array->last_try_catch, sizeof(zend_code_block *));
                cfg->catch = ecalloc(op_array->last_try_catch, sizeof(zend_code_block *));
                for (i = 0; i< op_array->last_try_catch; i++) {
                        cfg->try[i] = &blocks[op_array->try_catch_array[i].try_op];
                        cfg->catch[i] = &blocks[op_array->try_catch_array[i].catch_op];
                        START_BLOCK_OP(op_array->try_catch_array[i].try_op);
                        START_BLOCK_OP(op_array->try_catch_array[i].catch_op);
                        blocks[op_array->try_catch_array[i].try_op].protected = 1;
                }
        }
        /* Currently, we don't optimize op_arrays with BRK/CONT/GOTO opcodes,
         * but, we have to keep brk_cont_array to avoid memory leaks during
         * exception handling */
        if (op_array->last_brk_cont) {
                int i, j;

                j = 0;
                for (i = 0; i< op_array->last_brk_cont; i++) {
                        if (op_array->brk_cont_array[i].start >= 0 &&
                            (op_array->opcodes[op_array->brk_cont_array[i].brk].opcode == ZEND_FREE ||
                             op_array->opcodes[op_array->brk_cont_array[i].brk].opcode == ZEND_SWITCH_FREE)) {
                                int parent = op_array->brk_cont_array[i].parent;

                                while (parent >= 0 &&
                                       op_array->brk_cont_array[parent].start < 0 &&
                                       op_array->opcodes[op_array->brk_cont_array[parent].brk].opcode != ZEND_FREE &&
                                       op_array->opcodes[op_array->brk_cont_array[parent].brk].opcode != ZEND_SWITCH_FREE) {
                                        parent = op_array->brk_cont_array[parent].parent;
                                }
                                op_array->brk_cont_array[i].parent = parent;
                                j++;
                        }
                }
                if (j) {
                        cfg->loop_start = ecalloc(op_array->last_brk_cont, sizeof(zend_code_block *));
                        cfg->loop_cont  = ecalloc(op_array->last_brk_cont, sizeof(zend_code_block *));
                        cfg->loop_brk   = ecalloc(op_array->last_brk_cont, sizeof(zend_code_block *));
                        j = 0;
                        for (i = 0; i< op_array->last_brk_cont; i++) {
                                if (op_array->brk_cont_array[i].start >= 0 &&
                                    (op_array->opcodes[op_array->brk_cont_array[i].brk].opcode == ZEND_FREE ||
                                     op_array->opcodes[op_array->brk_cont_array[i].brk].opcode == ZEND_SWITCH_FREE)) {
                                        if (i != j) {
                                                op_array->brk_cont_array[j] = op_array->brk_cont_array[i];
                                        }
                                        cfg->loop_start[j] = &blocks[op_array->brk_cont_array[j].start];
                                        cfg->loop_cont[j]  = &blocks[op_array->brk_cont_array[j].cont];
                                        cfg->loop_brk[j]   = &blocks[op_array->brk_cont_array[j].brk];
                                        START_BLOCK_OP(op_array->brk_cont_array[j].start);
                                        START_BLOCK_OP(op_array->brk_cont_array[j].cont);
                                        START_BLOCK_OP(op_array->brk_cont_array[j].brk);
                                        blocks[op_array->brk_cont_array[j].start].protected = 1;
                                        blocks[op_array->brk_cont_array[j].brk].protected = 1;
                                        j++;
                                }
                        }
                        op_array->last_brk_cont = j;
                } else {
                        efree(op_array->brk_cont_array);
                        op_array->brk_cont_array = NULL;
                        op_array->last_brk_cont = 0;
                }
        }

        /* Build CFG (Control Flow Graph) */
        cur_block = blocks;
        for (opno = 1; opno < op_array->last; opno++) {
                if (blocks[opno].start_opline) {
                        /* found new block start */
                        cur_block->len = blocks[opno].start_opline - cur_block->start_opline;
                        cur_block->next = &blocks[opno];
                        /* what is the last OP of previous block? */
                        opline = blocks[opno].start_opline - 1;
                        if (opline->opcode == ZEND_OP_DATA) {
                                opline--;
                        }
                        switch((unsigned)opline->opcode) {
                                case ZEND_RETURN:
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                                case ZEND_RETURN_BY_REF:
#endif
#if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
                                case ZEND_GENERATOR_RETURN:
#endif
                                case ZEND_EXIT:
                                case ZEND_THROW:
                                        break;
#if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
                                case ZEND_FAST_CALL:
                                        if (opline->extended_value) {
                                                cur_block->op2_to = &blocks[ZEND_OP2(opline).opline_num];
                                        }
                                        cur_block->op1_to = &blocks[ZEND_OP1(opline).opline_num];
                                        break;
                                case ZEND_FAST_RET:
                                        if (opline->extended_value) {
                                                cur_block->op2_to = &blocks[ZEND_OP2(opline).opline_num];
                                        }
                                        break;
#endif
                                case ZEND_JMP:
                                        cur_block->op1_to = &blocks[ZEND_OP1(opline).opline_num];
                                        break;
                                case ZEND_JMPZNZ:
                                        cur_block->op2_to = &blocks[ZEND_OP2(opline).opline_num];
                                        cur_block->ext_to = &blocks[opline->extended_value];
                                        break;
                                case ZEND_CATCH:
                                        cur_block->ext_to = &blocks[opline->extended_value];
                                        cur_block->follow_to = &blocks[opno];
                                        break;
                                case ZEND_JMPZ:
                                case ZEND_JMPNZ:
                                case ZEND_JMPZ_EX:
                                case ZEND_JMPNZ_EX:
                                case ZEND_FE_RESET:
                                case ZEND_NEW:
#if ZEND_EXTENSION_API_NO >= PHP_5_3_X_API_NO
                                case ZEND_JMP_SET:
#endif
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                                case ZEND_JMP_SET_VAR:
#endif
                                case ZEND_FE_FETCH:
                                        cur_block->op2_to = &blocks[ZEND_OP2(opline).opline_num];
                                        /* break missing intentionally */
                                default:
                                        /* next block follows this */
                                        cur_block->follow_to = &blocks[opno];
                                        break;
                        }
                        print_block(cur_block, op_array->opcodes, "");
                        cur_block = cur_block->next;
                }
        }
        cur_block->len = end - cur_block->start_opline;
        cur_block->next = &blocks[op_array->last + 1];
        print_block(cur_block, op_array->opcodes, "");

        return 1;
}

/* CFG back references management */

#define ADD_SOURCE(fromb, tob) { \
        zend_block_source *__s = tob->sources; \
    while (__s && __s->from != fromb) __s = __s->next; \
        if (__s == NULL) { \
                zend_block_source *__t = emalloc(sizeof(zend_block_source)); \
                __t->next = tob->sources; \
                tob->sources = __t; \
                __t->from = fromb; \
        } \
}

#define DEL_SOURCE(cs) { \
        zend_block_source *__ns = (*cs)->next; \
        efree(*cs); \
        *cs = __ns; \
}


static inline void replace_source(zend_block_source *list, zend_code_block *old, zend_code_block *new)
{
        /* replace all references to 'old' in 'list' with 'new' */
        zend_block_source **cs;
        int found = 0;

        for (cs = &list; *cs; cs = &((*cs)->next)) {
                if ((*cs)->from == new) {
                        if (found) {
                                DEL_SOURCE(cs);
                        } else {
                                found = 1;
                        }
                }

                if ((*cs)->from == old) {
                        if (found) {
                                DEL_SOURCE(cs);
                        } else {
                                (*cs)->from = new;
                                found = 1;
                        }
                }
        }
}

static inline void del_source(zend_code_block *from, zend_code_block *to)
{
        /* delete source 'from' from 'to'-s sources list */
        zend_block_source **cs = &to->sources;

        if (to->sources == NULL) {
                to->access = 0;
                return;
        }

        while (*cs) {
                if ((*cs)->from == from) {
                        DEL_SOURCE(cs);
                        break;
                }
                cs = &((*cs)->next);
        }

        if (to->sources == NULL) {
                /* 'to' has no more sources - it's unused, will be stripped */
                to->access = 0;
                return;
        }

        if (!to->protected && to->sources->next == NULL) {
                /* source to only one block */
                zend_code_block *from_block = to->sources->from;

                if (from_block->access && from_block->follow_to == to &&
                    from_block->op1_to == NULL &&
                    from_block->op2_to == NULL &&
                    from_block->ext_to == NULL) {
                        /* this block follows it's only predecessor - we can join them */
                        zend_op *new_to = from_block->start_opline + from_block->len;
                        if (new_to != to->start_opline) {
                                /* move block to new location */
                                memmove(new_to, to->start_opline, sizeof(zend_op)*to->len);
                        }
                        /* join blocks' lengths */
                        from_block->len += to->len;
                        /* move 'to'`s references to 'from' */
                        to->start_opline = NULL;
                        to->access = 0;
                        efree(to->sources);
                        to->sources = NULL;
                        from_block->follow_to = to->follow_to;
                        if (to->op1_to) {
                                from_block->op1_to = to->op1_to;
                                replace_source(to->op1_to->sources, to, from_block);
                        }
                        if (to->op2_to) {
                                from_block->op2_to = to->op2_to;
                                replace_source(to->op2_to->sources, to, from_block);
                        }
                        if (to->ext_to) {
                                from_block->ext_to = to->ext_to;
                                replace_source(to->ext_to->sources, to, from_block);
                        }
                        if (to->follow_to) {
                                replace_source(to->follow_to->sources, to, from_block);
                        }
                        /* remove "to" from list */
                }
        }
}

static void delete_code_block(zend_code_block *block)
{
        if (block->protected) {
                return;
        }
        if (block->follow_to) {
                zend_block_source *bs = block->sources;
                while (bs) {
                        zend_code_block *from_block = bs->from;
                        zend_code_block *to = block->follow_to;
                        if (from_block->op1_to == block) {
                                from_block->op1_to = to;
                                ADD_SOURCE(from_block, to);
                        }
                        if (from_block->op2_to == block) {
                                from_block->op2_to = to;
                                ADD_SOURCE(from_block, to);
                        }
                        if (from_block->ext_to == block) {
                                from_block->ext_to = to;
                                ADD_SOURCE(from_block, to);
                        }
                        if (from_block->follow_to == block) {
                                from_block->follow_to = to;
                                ADD_SOURCE(from_block, to);
                        }
                        bs = bs->next;
                }
        }
        block->access = 0;
}

static void zend_access_path(zend_code_block *block)
{
        if (block->access) {
                return;
        }

        block->access = 1;
        if (block->op1_to) {
                zend_access_path(block->op1_to);
                ADD_SOURCE(block, block->op1_to);
        }
        if (block->op2_to) {
                zend_access_path(block->op2_to);
                ADD_SOURCE(block, block->op2_to);
        }
        if (block->ext_to) {
                zend_access_path(block->ext_to);
                ADD_SOURCE(block, block->ext_to);
        }
        if (block->follow_to) {
                zend_access_path(block->follow_to);
                ADD_SOURCE(block, block->follow_to);
        }
}

/* Traverse CFG, mark reachable basic blocks and build back references */
static void zend_rebuild_access_path(zend_cfg *cfg, zend_op_array *op_array, int find_start)
{
        zend_code_block *blocks = cfg->blocks;
        zend_code_block *start = find_start? NULL : blocks;
        zend_code_block *b;

        /* Mark all blocks as unaccessible and destroy back references */
        b = blocks;
        while (b != NULL) {
                zend_block_source *cs;
                if (!start && b->access) {
                        start = b;
                }
                b->access = 0;
                cs = b->sources;
                while (cs) {
                        zend_block_source *n = cs->next;
                        efree(cs);
                        cs = n;
                }
                b->sources = NULL;
                b = b->next;
        }

        /* Walk thorough all paths */
        zend_access_path(start);

        /* Add brk/cont paths */
        if (op_array->last_brk_cont) {
                int i;
                for (i=0; i< op_array->last_brk_cont; i++) {
                        zend_access_path(cfg->loop_start[i]);
                        zend_access_path(cfg->loop_cont[i]);
                        zend_access_path(cfg->loop_brk[i]);
                }
        }

        /* Add exception paths */
        if (op_array->last_try_catch) {
                int i;
                for (i=0; i< op_array->last_try_catch; i++) {
                        if (!cfg->catch[i]->access) {
                                zend_access_path(cfg->catch[i]);
                        }
                }
        }
}

/* Data dependencies macros */

#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO

# define VAR_NUM_EX(op) ((op ## _type & (IS_TMP_VAR|IS_VAR))?VAR_NUM((op).var):(op).var)

# define VAR_SOURCE(op) Tsource[VAR_NUM(op.var)]
# define SET_VAR_SOURCE(opline) Tsource[VAR_NUM(opline->result.var)] = opline

# define VAR_UNSET(op) do { if (op ## _type & (IS_TMP_VAR|IS_VAR)) {VAR_SOURCE(op) = NULL;}} while (0)

#else

# define VAR_NUM_EX(op) ((op).op_type == IS_TMP_VAR || (op).op_type == IS_VAR? VAR_NUM((op).u.var) : (op).u.var)

# define VAR_SOURCE(op) Tsource[VAR_NUM(op.u.var)]
# define SET_VAR_SOURCE(opline) Tsource[VAR_NUM(ZEND_RESULT(opline).var)] = opline

# define VAR_UNSET(op) do { if ((op).op_type == IS_TMP_VAR || (op).op_type == IS_VAR) {VAR_SOURCE(op) = NULL;}} while (0)

#endif

#define convert_to_string_safe(v) \
        if (Z_TYPE_P((v)) == IS_NULL) { \
                ZVAL_STRINGL((v), "", 0, 1); \
        } else { \
                convert_to_string((v)); \
        }

static void strip_nop(zend_code_block *block)
{
        zend_op *opline = block->start_opline;
        zend_op *end, *new_end;

        /* remove leading NOPs */
        while (block->len > 0 && block->start_opline->opcode == ZEND_NOP) {
                if (block->len == 1) {
                        /* this block is all NOPs, join with following block */
                        if (block->follow_to) {
                                delete_code_block(block);
                        }
                        return;
                }
                block->start_opline++;
                block->start_opline_no++;
                block->len--;
        }

        /* strip the inside NOPs */
        opline = new_end = block->start_opline;
        end = opline + block->len;

        while (opline < end) {
                zend_op *src;
                int len = 0;

                while (opline < end && opline->opcode == ZEND_NOP) {
                        opline++;
                }
                src = opline;

                while (opline < end && opline->opcode != ZEND_NOP) {
                        opline++;
                }
                len = opline - src;

                /* move up non-NOP opcodes */
                memmove(new_end, src, len*sizeof(zend_op));

                new_end += len;
        }
        block->len = new_end - block->start_opline;
}

static void zend_optimize_block(zend_code_block *block, zend_op_array *op_array, char *used_ext TSRMLS_DC)
{
        zend_op *opline = block->start_opline;
        zend_op *end, *last_op = NULL;
        zend_op **Tsource = NULL;

        print_block(block, op_array->opcodes, "Opt ");

        /* remove leading NOPs */
        while (block->len > 0 && block->start_opline->opcode == ZEND_NOP) {
                if (block->len == 1) {
                        /* this block is all NOPs, join with following block */
                        if (block->follow_to) {
                                delete_code_block(block);
                        }
                        return;
                }
                block->start_opline++;
                block->start_opline_no++;
                block->len--;
        }

        /* we track data dependencies only insight a single basic block */
        if (op_array->T) {
                Tsource = ecalloc(op_array->T, sizeof(zend_op *));
        }
        opline = block->start_opline;
        end = opline + block->len;
        while ((op_array->T) && (opline < end)) {
                /* strip X = QM_ASSIGN(const) */
                if (ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                        VAR_SOURCE(opline->op1) &&
                        VAR_SOURCE(opline->op1)->opcode == ZEND_QM_ASSIGN &&
                        ZEND_OP1_TYPE(VAR_SOURCE(opline->op1)) == IS_CONST &&
                        opline->opcode != ZEND_CASE &&         /* CASE _always_ expects variable */
                        opline->opcode != ZEND_FETCH_DIM_TMP_VAR &&   /* in 5.1, FETCH_DIM_TMP_VAR expects T */
                        opline->opcode != ZEND_FE_RESET &&
                        opline->opcode != ZEND_FREE
                        ) {
                        zend_op *src = VAR_SOURCE(opline->op1);
                        zval c = ZEND_OP1_LITERAL(src);
                        VAR_UNSET(opline->op1);
                        zval_copy_ctor(&c);
                        update_op1_const(op_array, opline, &c TSRMLS_CC);
                        literal_dtor(&ZEND_OP1_LITERAL(src));
                        MAKE_NOP(src);
                }

                /* T = QM_ASSIGN(C), F(T) => NOP, F(C) */
                if (ZEND_OP2_TYPE(opline) == IS_TMP_VAR &&
                        VAR_SOURCE(opline->op2) &&
                        VAR_SOURCE(opline->op2)->opcode == ZEND_QM_ASSIGN &&
                        ZEND_OP1_TYPE(VAR_SOURCE(opline->op2)) == IS_CONST) {
                        zend_op *src = VAR_SOURCE(opline->op2);
                        zval c = ZEND_OP1_LITERAL(src);
                        VAR_UNSET(opline->op2);
                        zval_copy_ctor(&c);
                        update_op2_const(op_array, opline, &c TSRMLS_CC);
                        literal_dtor(&ZEND_OP1_LITERAL(src));
                        MAKE_NOP(src);
                }

                /* T = PRINT(X), F(T) => ECHO(X), F(1) */
                if (ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                        VAR_SOURCE(opline->op1) &&
                        VAR_SOURCE(opline->op1)->opcode == ZEND_PRINT &&
                        opline->opcode != ZEND_CASE && opline->opcode != ZEND_FREE) {
                        ZEND_OP1_TYPE(opline) = IS_CONST;
                        LITERAL_LONG(opline->op1, 1);
                }

                if (ZEND_OP2_TYPE(opline) == IS_TMP_VAR &&
                        VAR_SOURCE(opline->op2) &&
                        VAR_SOURCE(opline->op2)->opcode == ZEND_PRINT) {
                        ZEND_OP2_TYPE(opline) = IS_CONST;
                        LITERAL_LONG(opline->op2, 1);
                }

                /* T = CAST(X, String), ECHO(T) => NOP, ECHO(X) */
                if ((opline->opcode == ZEND_ECHO || opline->opcode == ZEND_PRINT) &&
                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                        VAR_SOURCE(opline->op1) &&
                        VAR_SOURCE(opline->op1)->opcode == ZEND_CAST &&
                        VAR_SOURCE(opline->op1)->extended_value == IS_STRING) {
                        zend_op *src = VAR_SOURCE(opline->op1);
                        COPY_NODE(opline->op1, src->op1);
                        MAKE_NOP(src);
                }

                /* T = PRINT(X), FREE(T) => ECHO(X) */
                if (opline->opcode == ZEND_FREE &&
                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                        VAR_SOURCE(opline->op1)) {
                        zend_op *src = VAR_SOURCE(opline->op1);
                        if (src->opcode == ZEND_PRINT) {
                                src->opcode = ZEND_ECHO;
                                ZEND_RESULT_TYPE(src) = IS_UNUSED;
                                MAKE_NOP(opline);
                        }
                }

       /* T = BOOL(X), FREE(T) => NOP */
                if (opline->opcode == ZEND_FREE &&
                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                        VAR_SOURCE(opline->op1)) {
                        zend_op *src = VAR_SOURCE(opline->op1);
                        if (src->opcode == ZEND_BOOL) {
                                if (ZEND_OP1_TYPE(src) == IS_CONST) {
                                        literal_dtor(&ZEND_OP1_LITERAL(src));
                                }
                                MAKE_NOP(src);
                                MAKE_NOP(opline);
                        }
                }

#if 0
                /* pre-evaluate functions:
                   constant(x)
                   defined(x)
                   function_exists(x)
                   extension_loaded(x)
                   BAD: interacts badly with Accelerator
                */
                if((ZEND_OP1_TYPE(opline) & IS_VAR) &&
                   VAR_SOURCE(opline->op1) && VAR_SOURCE(opline->op1)->opcode == ZEND_DO_CF_FCALL &&
                   VAR_SOURCE(opline->op1)->extended_value == 1) {
                        zend_op *fcall = VAR_SOURCE(opline->op1);
                        zend_op *sv = fcall-1;
                        if(sv >= block->start_opline && sv->opcode == ZEND_SEND_VAL &&
                           ZEND_OP1_TYPE(sv) == IS_CONST && Z_TYPE(OPLINE_OP1_LITERAL(sv)) == IS_STRING &&
                           Z_LVAL(OPLINE_OP2_LITERAL(sv)) == 1
                           ) {
                                zval *arg = &OPLINE_OP1_LITERAL(sv);
                                char *fname = FUNCTION_CACHE->funcs[Z_LVAL(ZEND_OP1_LITERAL(fcall))].function_name;
                                int flen = FUNCTION_CACHE->funcs[Z_LVAL(ZEND_OP1_LITERAL(fcall))].name_len;
                                if(flen == sizeof("defined")-1 && zend_binary_strcasecmp(fname, flen, "defined", sizeof("defined")-1) == 0) {
                                        zval c;
                                        if(zend_get_persistent_constant(Z_STRVAL_P(arg), Z_STRLEN_P(arg), &c, 0 TSRMLS_CC ELS_CC) != 0) {
                                                literal_dtor(arg);
                                                MAKE_NOP(sv);
                                                MAKE_NOP(fcall);
                                                LITERAL_BOOL(opline->op1, 1);
                                                ZEND_OP1_TYPE(opline) = IS_CONST;
                                        }
                                } else if((flen == sizeof("function_exists")-1 && zend_binary_strcasecmp(fname, flen, "function_exists", sizeof("function_exists")-1) == 0) ||
                                                  (flen == sizeof("is_callable")-1 && zend_binary_strcasecmp(fname, flen, "is_callable", sizeof("is_callable")-1) == 0)
                                                  ) {
                                        zend_function *function;
                                        if(zend_hash_find(EG(function_table), Z_STRVAL_P(arg), Z_STRLEN_P(arg)+1, (void **)&function) == SUCCESS) {
                                                literal_dtor(arg);
                                                MAKE_NOP(sv);
                                                MAKE_NOP(fcall);
                                                LITERAL_BOOL(opline->op1, 1);
                                                ZEND_OP1_TYPE(opline) = IS_CONST;
                                        }
                                } else if(flen == sizeof("constant")-1 && zend_binary_strcasecmp(fname, flen, "constant", sizeof("constant")-1) == 0) {
                                        zval c;
                                        if(zend_get_persistent_constant(Z_STRVAL_P(arg), Z_STRLEN_P(arg), &c, 1 TSRMLS_CC ELS_CC) != 0) {
                                                literal_dtor(arg);
                                                MAKE_NOP(sv);
                                                MAKE_NOP(fcall);
                                                ZEND_OP1_LITERAL(opline) = zend_optimizer_add_literal(op_array, &c TSRMLS_CC);
                                                /* no copy ctor - get already copied it */
                                                ZEND_OP1_TYPE(opline) = IS_CONST;
                                        }
                                } else if(flen == sizeof("extension_loaded")-1 && zend_binary_strcasecmp(fname, flen, "extension_loaded", sizeof("extension_loaded")-1) == 0) {
                                        if(zend_hash_exists(&module_registry, Z_STRVAL_P(arg), Z_STRLEN_P(arg)+1)) {
                                                literal_dtor(arg);
                                                MAKE_NOP(sv);
                                                MAKE_NOP(fcall);
                                                LITERAL_BOOL(opline->op1, 1);
                                                ZEND_OP1_TYPE(opline) = IS_CONST;
                                        }
                                }
                        }
                }
#endif

        /* IS_EQ(TRUE, X)      => BOOL(X)
         * IS_EQ(FALSE, X)     => BOOL_NOT(X)
         * IS_NOT_EQ(TRUE, X)  => BOOL_NOT(X)
         * IS_NOT_EQ(FALSE, X) => BOOL(X)
         */
                if (opline->opcode == ZEND_IS_EQUAL ||
                        opline->opcode == ZEND_IS_NOT_EQUAL) {
                        if (ZEND_OP1_TYPE(opline) == IS_CONST &&
                                Z_TYPE(ZEND_OP1_LITERAL(opline)) == IS_BOOL) {
                                opline->opcode =
                                        ((opline->opcode == ZEND_IS_EQUAL) == Z_LVAL(ZEND_OP1_LITERAL(opline)))?
                                        ZEND_BOOL : ZEND_BOOL_NOT;
                                COPY_NODE(opline->op1, opline->op2);
                                SET_UNUSED(opline->op2);
                        } else if (ZEND_OP2_TYPE(opline) == IS_CONST &&
                                           Z_TYPE(ZEND_OP2_LITERAL(opline)) == IS_BOOL) {
                                opline->opcode =
                                        ((opline->opcode == ZEND_IS_EQUAL) == Z_LVAL(ZEND_OP2_LITERAL(opline)))?
                                        ZEND_BOOL : ZEND_BOOL_NOT;
                                SET_UNUSED(opline->op2);
                        }
                }

                if ((opline->opcode == ZEND_BOOL ||
                        opline->opcode == ZEND_BOOL_NOT ||
                        opline->opcode == ZEND_JMPZ ||
                        opline->opcode == ZEND_JMPNZ ||
                        opline->opcode == ZEND_JMPZNZ) &&
                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                        VAR_SOURCE(opline->op1) != NULL &&
                        !used_ext[VAR_NUM(ZEND_OP1(opline).var)] &&
                        VAR_SOURCE(opline->op1)->opcode == ZEND_BOOL_NOT) {
                        /* T = BOOL_NOT(X) + JMPZ(T) -> NOP, JMPNZ(X) */
                        zend_op *src = VAR_SOURCE(opline->op1);

                        COPY_NODE(opline->op1, src->op1);

                        switch (opline->opcode) {
                                case ZEND_BOOL:
                                        /* T = BOOL_NOT(X) + BOOL(T) -> NOP, BOOL_NOT(X) */
                                        opline->opcode = ZEND_BOOL_NOT;
                                        break;
                                case ZEND_BOOL_NOT:
                                        /* T = BOOL_NOT(X) + BOOL_BOOL(T) -> NOP, BOOL(X) */
                                        opline->opcode = ZEND_BOOL;
                                        break;
                                case ZEND_JMPZ:
                                        /* T = BOOL_NOT(X) + JMPZ(T,L) -> NOP, JMPNZ(X,L) */
                                        opline->opcode = ZEND_JMPNZ;
                                        break;
                                case ZEND_JMPNZ:
                                        /* T = BOOL_NOT(X) + JMPNZ(T,L) -> NOP, JMPZ(X,L) */
                                        opline->opcode = ZEND_JMPZ;
                                        break;
                                case ZEND_JMPZNZ:
                                {
                                        /* T = BOOL_NOT(X) + JMPZNZ(T,L1,L2) -> NOP, JMPZNZ(X,L2,L1) */
                                        int op_t;
                                        zend_code_block *op_b;

                                        op_t = opline->extended_value;
                                        opline->extended_value = ZEND_OP2(opline).opline_num;
                                        ZEND_OP2(opline).opline_num = op_t;

                                        op_b = block->ext_to;
                                        block->ext_to = block->op2_to;
                                        block->op2_to = op_b;
                                }
                                break;
                        }

                        VAR_UNSET(opline->op1);
                        MAKE_NOP(src);
                        continue;
                } else
#if 0
                /* T = BOOL_NOT(X) + T = JMPZ_EX(T, X) -> T = BOOL_NOT(X), JMPNZ(X) */
                if(0 && (opline->opcode == ZEND_JMPZ_EX ||
                        opline->opcode == ZEND_JMPNZ_EX) &&
                   ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                   VAR_SOURCE(opline->op1) != NULL &&
                   VAR_SOURCE(opline->op1)->opcode == ZEND_BOOL_NOT &&
                   ZEND_OP1(opline).var == ZEND_RESULT(opline).var
                   ) {
                        zend_op *src = VAR_SOURCE(opline->op1);
                        if(opline->opcode == ZEND_JMPZ_EX) {
                                opline->opcode = ZEND_JMPNZ;
                        } else {
                                opline->opcode = ZEND_JMPZ;
                        }
                        COPY_NODE(opline->op1, src->op1);
                        SET_UNUSED(opline->result);
                        continue;
                } else
#endif
                /* T = BOOL(X) + JMPZ(T) -> NOP, JMPZ(X) */
                if ((opline->opcode == ZEND_BOOL ||
                        opline->opcode == ZEND_BOOL_NOT ||
                        opline->opcode == ZEND_JMPZ ||
                        opline->opcode == ZEND_JMPZ_EX ||
                        opline->opcode == ZEND_JMPNZ_EX ||
                        opline->opcode == ZEND_JMPNZ ||
                        opline->opcode == ZEND_JMPZNZ) &&
                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                        VAR_SOURCE(opline->op1) != NULL &&
                        (!used_ext[VAR_NUM(ZEND_OP1(opline).var)] ||
                        (ZEND_RESULT_TYPE(opline) == IS_TMP_VAR &&
                         ZEND_RESULT(opline).var == ZEND_OP1(opline).var)) &&
                        (VAR_SOURCE(opline->op1)->opcode == ZEND_BOOL ||
                        VAR_SOURCE(opline->op1)->opcode == ZEND_QM_ASSIGN)) {
                        zend_op *src = VAR_SOURCE(opline->op1);
                        COPY_NODE(opline->op1, src->op1);

                        VAR_UNSET(opline->op1);
                        MAKE_NOP(src);
                        continue;
                } else if (last_op && opline->opcode == ZEND_ECHO &&
                                  last_op->opcode == ZEND_ECHO &&
                                  ZEND_OP1_TYPE(opline) == IS_CONST &&
                                  Z_TYPE(ZEND_OP1_LITERAL(opline)) != IS_DOUBLE &&
                                  ZEND_OP1_TYPE(last_op) == IS_CONST &&
                                  Z_TYPE(ZEND_OP1_LITERAL(last_op)) != IS_DOUBLE) {
                        /* compress consecutive ECHO's.
                         * Float to string conversion may be affected by current
                         * locale setting.
                         */
                        int l;

                        if (Z_TYPE(ZEND_OP1_LITERAL(opline)) != IS_STRING) {
                                convert_to_string_safe(&ZEND_OP1_LITERAL(opline));
                        }
                        if (Z_TYPE(ZEND_OP1_LITERAL(last_op)) != IS_STRING) {
                                convert_to_string_safe(&ZEND_OP1_LITERAL(last_op));
                        }
                        l = Z_STRLEN(ZEND_OP1_LITERAL(opline)) + Z_STRLEN(ZEND_OP1_LITERAL(last_op));
                        if (IS_INTERNED(Z_STRVAL(ZEND_OP1_LITERAL(last_op)))) {
                                char *tmp = emalloc(l + 1);
                                memcpy(tmp, Z_STRVAL(ZEND_OP1_LITERAL(last_op)), l + 1);
                                Z_STRVAL(ZEND_OP1_LITERAL(last_op)) = tmp;
                        } else {
                                Z_STRVAL(ZEND_OP1_LITERAL(last_op)) = erealloc(Z_STRVAL(ZEND_OP1_LITERAL(last_op)), l + 1);
                        }
                        memcpy(Z_STRVAL(ZEND_OP1_LITERAL(last_op))+Z_STRLEN(ZEND_OP1_LITERAL(last_op)), Z_STRVAL(ZEND_OP1_LITERAL(opline)), Z_STRLEN(ZEND_OP1_LITERAL(opline)));
                        Z_STRVAL(ZEND_OP1_LITERAL(last_op))[l] = '\0';
                        zval_dtor(&ZEND_OP1_LITERAL(opline));
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                        Z_STRVAL(ZEND_OP1_LITERAL(opline)) = (char*)zend_new_interned_string(Z_STRVAL(ZEND_OP1_LITERAL(last_op)), l + 1, 1 TSRMLS_CC);
                        Z_TYPE(ZEND_OP1_LITERAL(last_op)) = IS_NULL;
#else
                        Z_STRVAL(ZEND_OP1_LITERAL(opline)) = Z_STRVAL(ZEND_OP1_LITERAL(last_op));
#endif
                        Z_STRLEN(ZEND_OP1_LITERAL(opline)) = l;
                        MAKE_NOP(last_op);
                } else if (opline->opcode == ZEND_CONCAT &&
                                  ZEND_OP2_TYPE(opline) == IS_CONST &&
                                  ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                                  VAR_SOURCE(opline->op1) &&
                                  (VAR_SOURCE(opline->op1)->opcode == ZEND_CONCAT ||
                                   VAR_SOURCE(opline->op1)->opcode == ZEND_ADD_STRING) &&
                                  ZEND_OP2_TYPE(VAR_SOURCE(opline->op1)) == IS_CONST &&
                                  ZEND_RESULT(VAR_SOURCE(opline->op1)).var == ZEND_OP1(opline).var) {
                        /* compress consecutive CONCATs */
                        zend_op *src = VAR_SOURCE(opline->op1);
                        int l;

                        if (Z_TYPE(ZEND_OP2_LITERAL(opline)) != IS_STRING) {
                                convert_to_string_safe(&ZEND_OP2_LITERAL(opline));
                        }
                        if (Z_TYPE(ZEND_OP2_LITERAL(src)) != IS_STRING) {
                                convert_to_string_safe(&ZEND_OP2_LITERAL(src));
                        }

                        VAR_UNSET(opline->op1);
                        if (ZEND_OP1_TYPE(src) == IS_UNUSED) {
                                /* 5.3 may use IS_UNUSED as first argument to ZEND_ADD_... */
                                opline->opcode = ZEND_ADD_STRING;
                        }
                        COPY_NODE(opline->op1, src->op1);
                        l = Z_STRLEN(ZEND_OP2_LITERAL(opline)) + Z_STRLEN(ZEND_OP2_LITERAL(src));
                        if (IS_INTERNED(Z_STRVAL(ZEND_OP2_LITERAL(src)))) {
                                char *tmp = emalloc(l + 1);
                                memcpy(tmp, Z_STRVAL(ZEND_OP2_LITERAL(src)), l + 1);
                                Z_STRVAL(ZEND_OP2_LITERAL(src)) = tmp;
                        } else {
                                Z_STRVAL(ZEND_OP2_LITERAL(src)) = erealloc(Z_STRVAL(ZEND_OP2_LITERAL(src)), l + 1);
                        }
                        memcpy(Z_STRVAL(ZEND_OP2_LITERAL(src))+Z_STRLEN(ZEND_OP2_LITERAL(src)), Z_STRVAL(ZEND_OP2_LITERAL(opline)), Z_STRLEN(ZEND_OP2_LITERAL(opline)));
                        Z_STRVAL(ZEND_OP2_LITERAL(src))[l] = '\0';
                        if (!IS_INTERNED(Z_STRVAL(ZEND_OP2_LITERAL(opline)))) {
                                efree(Z_STRVAL(ZEND_OP2_LITERAL(opline)));
                        }
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                        Z_STRVAL(ZEND_OP2_LITERAL(opline)) = (char*)zend_new_interned_string(Z_STRVAL(ZEND_OP2_LITERAL(src)), l + 1, 1 TSRMLS_CC);
                        Z_TYPE(ZEND_OP2_LITERAL(src)) = IS_NULL;
#else
                        Z_STRVAL(ZEND_OP2_LITERAL(opline)) = Z_STRVAL(ZEND_OP2_LITERAL(src));
#endif
                        Z_STRLEN(ZEND_OP2_LITERAL(opline)) = l;
                        MAKE_NOP(src);
                } else if ((opline->opcode == ZEND_ADD_STRING || opline->opcode == ZEND_ADD_VAR) && ZEND_OP1_TYPE(opline) == IS_CONST) {
                        /* convert ADD_STRING(C1, C2) to CONCAT(C1, C2) */
                        opline->opcode = ZEND_CONCAT;
                        continue;
                } else if (opline->opcode == ZEND_ADD_CHAR && ZEND_OP1_TYPE(opline) == IS_CONST && ZEND_OP2_TYPE(opline) == IS_CONST) {
            /* convert ADD_CHAR(C1, C2) to CONCAT(C1, C2) */
                        char c = (char)Z_LVAL(ZEND_OP2_LITERAL(opline));
                        ZVAL_STRINGL(&ZEND_OP2_LITERAL(opline), &c, 1, 1);
                        opline->opcode = ZEND_CONCAT;
                        continue;
                } else if ((opline->opcode == ZEND_ADD ||
                                        opline->opcode == ZEND_SUB ||
                                        opline->opcode == ZEND_MUL ||
                                        opline->opcode == ZEND_DIV ||
                                        opline->opcode == ZEND_MOD ||
                                        opline->opcode == ZEND_SL ||
                                        opline->opcode == ZEND_SR ||
                                        opline->opcode == ZEND_CONCAT ||
                                        opline->opcode == ZEND_IS_EQUAL ||
                                        opline->opcode == ZEND_IS_NOT_EQUAL ||
                                        opline->opcode == ZEND_IS_SMALLER ||
                                        opline->opcode == ZEND_IS_SMALLER_OR_EQUAL ||
                                        opline->opcode == ZEND_IS_IDENTICAL ||
                                        opline->opcode == ZEND_IS_NOT_IDENTICAL ||
                                        opline->opcode == ZEND_BOOL_XOR ||
                                        opline->opcode == ZEND_BW_OR ||
                                        opline->opcode == ZEND_BW_AND ||
                                        opline->opcode == ZEND_BW_XOR) &&
                                        ZEND_OP1_TYPE(opline)==IS_CONST &&
                                        ZEND_OP2_TYPE(opline)==IS_CONST) {
                        /* evaluate constant expressions */
                        int (*binary_op)(zval *result, zval *op1, zval *op2 TSRMLS_DC) = get_binary_op(opline->opcode);
                        zval result;
                        int er;

            if ((opline->opcode == ZEND_DIV || opline->opcode == ZEND_MOD) &&
                ((Z_TYPE(ZEND_OP2_LITERAL(opline)) == IS_LONG &&
                  Z_LVAL(ZEND_OP2_LITERAL(opline)) == 0) ||
                 (Z_TYPE(ZEND_OP2_LITERAL(opline)) == IS_DOUBLE &&
                  Z_DVAL(ZEND_OP2_LITERAL(opline)) == 0.0))) {
                                if (RESULT_USED(opline)) {
                                        SET_VAR_SOURCE(opline);
                                }
                opline++;
                                continue;
                        }
                        er = EG(error_reporting);
                        EG(error_reporting) = 0;
                        if (binary_op(&result, &ZEND_OP1_LITERAL(opline), &ZEND_OP2_LITERAL(opline) TSRMLS_CC) == SUCCESS) {
                                PZ_SET_REFCOUNT_P(&result, 1);
                                PZ_UNSET_ISREF_P(&result);

                                literal_dtor(&ZEND_OP1_LITERAL(opline));
                                literal_dtor(&ZEND_OP2_LITERAL(opline));
                                opline->opcode = ZEND_QM_ASSIGN;
                                SET_UNUSED(opline->op2);
                                update_op1_const(op_array, opline, &result TSRMLS_CC);
                        }
                        EG(error_reporting) = er;
                } else if ((opline->opcode == ZEND_BOOL ||
                                        opline->opcode == ZEND_BOOL_NOT ||
                                        opline->opcode == ZEND_BW_NOT) && ZEND_OP1_TYPE(opline) == IS_CONST) {
                        /* evaluate constant unary ops */
                        unary_op_type unary_op = get_unary_op(opline->opcode);
                        zval result;

                        if (unary_op) {
#if ZEND_EXTENSION_API_NO < PHP_5_3_X_API_NO
                                unary_op(&result, &ZEND_OP1_LITERAL(opline));
#else
                                unary_op(&result, &ZEND_OP1_LITERAL(opline) TSRMLS_CC);
#endif
                                literal_dtor(&ZEND_OP1_LITERAL(opline));
                        } else {
                                /* BOOL */
                                result = ZEND_OP1_LITERAL(opline);
                                convert_to_boolean(&result);
                                Z_TYPE(ZEND_OP1_LITERAL(opline)) = IS_NULL;
                        }
                        PZ_SET_REFCOUNT_P(&result, 1);
                        PZ_UNSET_ISREF_P(&result);
                        opline->opcode = ZEND_QM_ASSIGN;
                        update_op1_const(op_array, opline, &result TSRMLS_CC);
                } else if ((opline->opcode == ZEND_RETURN || opline->opcode == ZEND_EXIT) &&
                                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                                        VAR_SOURCE(opline->op1) &&
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_QM_ASSIGN) {
                        /* T = QM_ASSIGN(X), RETURN(T) to RETURN(X) */
                        zend_op *src = VAR_SOURCE(opline->op1);
                        VAR_UNSET(opline->op1);
                        COPY_NODE(opline->op1, src->op1);
                        MAKE_NOP(src);
                } else if ((opline->opcode == ZEND_ADD_STRING ||
                                        opline->opcode == ZEND_ADD_CHAR) &&
                                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                                        VAR_SOURCE(opline->op1) &&
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_INIT_STRING) {
                        /* convert T = INIT_STRING(), T = ADD_STRING(T, X) to T = QM_ASSIGN(X) */
                        /* CHECKME: Remove ZEND_ADD_VAR optimization, since some conversions -
                           namely, BOOL(false)->string - don't allocate memory but use empty_string
                           and ADD_CHAR fails */
                        zend_op *src = VAR_SOURCE(opline->op1);
                        VAR_UNSET(opline->op1);
                        COPY_NODE(opline->op1, opline->op2);
                        if (opline->opcode == ZEND_ADD_CHAR) {
                                char c = (char)Z_LVAL(ZEND_OP2_LITERAL(opline));
                                ZVAL_STRINGL(&ZEND_OP1_LITERAL(opline), &c, 1, 1);
                        }
                        SET_UNUSED(opline->op2);
                        MAKE_NOP(src);
                        opline->opcode = ZEND_QM_ASSIGN;
                } else if ((opline->opcode == ZEND_ADD_STRING ||
                                        opline->opcode == ZEND_ADD_CHAR ||
                                        opline->opcode == ZEND_ADD_VAR ||
                                        opline->opcode == ZEND_CONCAT) &&
                                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                                        VAR_SOURCE(opline->op1) &&
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_CONCAT &&
                                        ZEND_OP2_TYPE(VAR_SOURCE(opline->op1)) == IS_CONST &&
                                        Z_TYPE(ZEND_OP2_LITERAL(VAR_SOURCE(opline->op1))) == IS_STRING &&
                                        Z_STRLEN(ZEND_OP2_LITERAL(VAR_SOURCE(opline->op1))) == 0) {
                        /* convert T = CONCAT(X,''), T = ADD_STRING(T, Y) to T = CONCAT(X,Y) */
                        zend_op *src = VAR_SOURCE(opline->op1);
                        VAR_UNSET(opline->op1);
                        COPY_NODE(opline->op1, src->op1);
                        if (opline->opcode == ZEND_ADD_CHAR) {
                                char c = (char)Z_LVAL(ZEND_OP2_LITERAL(opline));
                                ZVAL_STRINGL(&ZEND_OP2_LITERAL(opline), &c, 1, 1);
                        }
                        opline->opcode = ZEND_CONCAT;
                        literal_dtor(&ZEND_OP2_LITERAL(src)); /* will take care of empty_string too */
                        MAKE_NOP(src);
                } else if (opline->opcode == ZEND_ADD_VAR &&
                                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                                        VAR_SOURCE(opline->op1) &&
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_INIT_STRING) {
                        /* convert T = INIT_STRING(), T = ADD_VAR(T, X) to T = CAST(STRING, X) */
                        zend_op *src = VAR_SOURCE(opline->op1);
                        VAR_UNSET(opline->op1);
                        COPY_NODE(opline->op1, opline->op2);
                        SET_UNUSED(opline->op2);
                        MAKE_NOP(src);
                        opline->opcode = ZEND_CAST;
                        opline->extended_value = IS_STRING;
                } else if ((opline->opcode == ZEND_ADD_STRING ||
                                        opline->opcode == ZEND_ADD_CHAR ||
                                        opline->opcode == ZEND_ADD_VAR ||
                                        opline->opcode == ZEND_CONCAT) &&
                                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                                        VAR_SOURCE(opline->op1) &&
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_CAST &&
                                        VAR_SOURCE(opline->op1)->extended_value == IS_STRING) {
                        /* convert T1 = CAST(STRING, X), T2 = CONCAT(T1, Y) to T2 = CONCAT(X,Y) */
                        zend_op *src = VAR_SOURCE(opline->op1);
                        VAR_UNSET(opline->op1);
                        COPY_NODE(opline->op1, src->op1);
                        if (opline->opcode == ZEND_ADD_CHAR) {
                                char c = (char)Z_LVAL(ZEND_OP2_LITERAL(opline));
                                ZVAL_STRINGL(&ZEND_OP2_LITERAL(opline), &c, 1, 1);
                        }
                        opline->opcode = ZEND_CONCAT;
                        MAKE_NOP(src);
                } else if (opline->opcode == ZEND_QM_ASSIGN &&
                                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                                        ZEND_RESULT_TYPE(opline) == IS_TMP_VAR &&
                                        ZEND_OP1(opline).var == ZEND_RESULT(opline).var) {
                        /* strip T = QM_ASSIGN(T) */
                        MAKE_NOP(opline);
                } else if (opline->opcode == ZEND_BOOL &&
                                        ZEND_OP1_TYPE(opline) == IS_TMP_VAR &&
                                        VAR_SOURCE(opline->op1) &&
                                        (VAR_SOURCE(opline->op1)->opcode == ZEND_IS_EQUAL ||
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_IS_NOT_EQUAL ||
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_IS_SMALLER ||
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_IS_SMALLER_OR_EQUAL ||
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_BOOL ||
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_IS_IDENTICAL ||
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_IS_NOT_IDENTICAL ||
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_ISSET_ISEMPTY_VAR ||
                                        VAR_SOURCE(opline->op1)->opcode == ZEND_ISSET_ISEMPTY_DIM_OBJ) &&
                                        !used_ext[VAR_NUM(ZEND_OP1(opline).var)]) {
                        /* T = IS_SMALLER(X, Y), T1 = BOOL(T) => T = IS_SMALLER(X, Y), T1 = QM_ASSIGN(T) */
                        zend_op *src = VAR_SOURCE(opline->op1);
                        COPY_NODE(src->result, opline->result);
                        SET_VAR_SOURCE(src);
                        MAKE_NOP(opline);
                }
                /* get variable source */
                if (RESULT_USED(opline)) {
                        SET_VAR_SOURCE(opline);
                }
                if (opline->opcode != ZEND_NOP) {
                        last_op = opline;
                }
                opline++;
        }

        strip_nop(block);

        if (op_array->T) {
                efree(Tsource);
        }
}

/* Rebuild plain (optimized) op_array from CFG */
static void assemble_code_blocks(zend_cfg *cfg, zend_op_array *op_array)
{
        zend_code_block *blocks = cfg->blocks;
        zend_op *new_opcodes = emalloc(op_array->last * sizeof(zend_op));
        zend_op *opline = new_opcodes;
        zend_code_block *cur_block = blocks;

        /* Copy code of reachable blocks into a single buffer */
        while (cur_block) {
                if (cur_block->access) {
                        memcpy(opline, cur_block->start_opline, cur_block->len * sizeof(zend_op));
                        cur_block->start_opline = opline;
                        opline += cur_block->len;
                        if ((opline - 1)->opcode == ZEND_JMP) {
                                zend_code_block *next;
                                next = cur_block->next;
                                while (next && !next->access) {
                                        next = next->next;
                                }
                                if (next && next == cur_block->op1_to) {
                                        /* JMP to the next block - strip it */
                                        cur_block->follow_to = cur_block->op1_to;
                                        cur_block->op1_to = NULL;
                                        MAKE_NOP((opline - 1));
                                        opline--;
                                        cur_block->len--;
                                }
                        }
                } else {
                        /* this block will not be used, delete all constants there */
                        zend_op *_opl;
                        zend_op *end = cur_block->start_opline + cur_block->len;
                        for (_opl = cur_block->start_opline; _opl && _opl < end; _opl++) {
                                if (ZEND_OP1_TYPE(_opl) == IS_CONST) {
                                        literal_dtor(&ZEND_OP1_LITERAL(_opl));
                                }
                                if (ZEND_OP2_TYPE(_opl) == IS_CONST) {
                                        literal_dtor(&ZEND_OP2_LITERAL(_opl));
                                }
                        }
                }
                cur_block = cur_block->next;
        }

        if ((opline-1)->opcode == ZEND_THROW) {
                /* if we finished with THROW, we need to add space between THROW and HANDLE to not confuse
                   zend_throw_internal */
                MAKE_NOP(opline);
                opline->lineno = opline[-1].lineno;
                opline++;
        }
#if ZEND_EXTENSION_API_NO < PHP_5_3_X_API_NO
        MAKE_NOP(opline);
        opline->opcode = ZEND_HANDLE_EXCEPTION;
        opline->lineno = opline[-1].lineno;
        opline++;
#endif

        op_array->last = opline-new_opcodes;

        /* adjust exception jump targets */
        if (op_array->last_try_catch) {
                int i, j;
                for (i = 0, j = 0; i< op_array->last_try_catch; i++) {
                        if (cfg->try[i]->access) {
                                op_array->try_catch_array[j].try_op = cfg->try[i]->start_opline - new_opcodes;
                                op_array->try_catch_array[j].catch_op = cfg->catch[i]->start_opline - new_opcodes;
                                j++;
                        }
                }
                op_array->last_try_catch = j;
                efree(cfg->try);
                efree(cfg->catch);
        }

        /* adjust loop jump targets */
        if (op_array->last_brk_cont) {
                int i;
                for (i = 0; i< op_array->last_brk_cont; i++) {
                        op_array->brk_cont_array[i].start = cfg->loop_start[i]->start_opline - new_opcodes;
                        op_array->brk_cont_array[i].cont = cfg->loop_cont[i]->start_opline - new_opcodes;
                        op_array->brk_cont_array[i].brk = cfg->loop_brk[i]->start_opline - new_opcodes;
                }
                efree(cfg->loop_start);
                efree(cfg->loop_cont);
                efree(cfg->loop_brk);
        }

    /* adjust jump targets */
        for (cur_block = blocks; cur_block; cur_block = cur_block->next) {
                if (!cur_block->access) {
                        continue;
                }
                opline = cur_block->start_opline + cur_block->len - 1;
                if (opline->opcode == ZEND_OP_DATA) {
                        opline--;
                }
                if (cur_block->op1_to) {
                        ZEND_OP1(opline).opline_num = cur_block->op1_to->start_opline - new_opcodes;
                }
                if (cur_block->op2_to) {
                        ZEND_OP2(opline).opline_num = cur_block->op2_to->start_opline - new_opcodes;
                }
                if (cur_block->ext_to) {
                        opline->extended_value = cur_block->ext_to->start_opline - new_opcodes;
                }
                print_block(cur_block, new_opcodes, "Out ");
        }
        efree(op_array->opcodes);
        op_array->opcodes = erealloc(new_opcodes, op_array->last * sizeof(zend_op));

#if ZEND_EXTENSION_API_NO >= PHP_5_3_X_API_NO
        /* adjust early binding list */
        if (op_array->early_binding != (zend_uint)-1) {
                zend_uint *opline_num = &op_array->early_binding;
                zend_op *end;

                opline = op_array->opcodes;
                end = opline + op_array->last;
                while (opline < end) {
                        if (opline->opcode == ZEND_DECLARE_INHERITED_CLASS_DELAYED) {
                                *opline_num = opline - op_array->opcodes;
                                opline_num = &ZEND_RESULT(opline).opline_num;
                        }
                        ++opline;
                }
                *opline_num = -1;
        }
#endif
}

static void zend_jmp_optimization(zend_code_block *block, zend_op_array *op_array, zend_code_block *blocks TSRMLS_DC)
{
        /* last_op is the last opcode of the current block */
        zend_op *last_op = (block->start_opline + block->len - 1);

        if (!block->len) {
                return;
        }
        switch (last_op->opcode) {
                case ZEND_JMP:
                        {
                                zend_op *target = block->op1_to->start_opline;
                                zend_code_block *next = block->next;

                                while (next && !next->access) {
                                        /* find used one */
                                        next = next->next;
                                }

                                /* JMP(next) -> NOP */
                                if (block->op1_to == next) {
                                        block->follow_to = block->op1_to;
                                        block->op1_to = NULL;
                                        MAKE_NOP(last_op);
                                        block->len--;
                                        if (block->len == 0) {
                                                /* this block is nothing but NOP now */
                                                delete_code_block(block);
                                        }
                                        break;
                                }

                                if (((target->opcode == ZEND_JMP &&
                                        block->op1_to != block->op1_to->op1_to) ||
                                        target->opcode == ZEND_JMPZNZ) &&
                                        !block->op1_to->protected) {
                                        /* JMP L, L: JMP L1 -> JMP L1 */
                                        /* JMP L, L: JMPZNZ L1,L2 -> JMPZNZ L1,L2 */
                                        *last_op = *target;
#if ZEND_EXTENSION_API_NO < PHP_5_4_X_API_NO
                                        if (ZEND_OP1_TYPE(last_op) == IS_CONST) {
                                                zval_copy_ctor(&ZEND_OP1_LITERAL(last_op));
                                        }
#else
                                        if (ZEND_OP1_TYPE(last_op) == IS_CONST) {
                                                zval zv = ZEND_OP1_LITERAL(last_op);
                                                zval_copy_ctor(&zv);
                                                last_op->op1.constant = zend_optimizer_add_literal(op_array, &zv TSRMLS_CC);
                                        }
#endif
                                        del_source(block, block->op1_to);
                                        if (block->op1_to->op2_to) {
                                                block->op2_to = block->op1_to->op2_to;
                                                ADD_SOURCE(block, block->op2_to);
                                        }
                                        if (block->op1_to->ext_to) {
                                                block->ext_to = block->op1_to->ext_to;
                                                ADD_SOURCE(block, block->ext_to);
                                        }
                                        if (block->op1_to->op1_to) {
                                                block->op1_to = block->op1_to->op1_to;
                                                ADD_SOURCE(block, block->op1_to);
                                        } else {
                                                block->op1_to = NULL;
                                        }
                                } else if (target->opcode == ZEND_RETURN ||
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                                          target->opcode == ZEND_RETURN_BY_REF ||
#endif
#if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
                          target->opcode == ZEND_FAST_RET ||
#endif
                                      target->opcode == ZEND_EXIT) {
                                        /* JMP L, L: RETURN to immediate RETURN */
                                        *last_op = *target;
#if ZEND_EXTENSION_API_NO < PHP_5_4_X_API_NO
                                        if (ZEND_OP1_TYPE(last_op) == IS_CONST) {
                                                zval_copy_ctor(&ZEND_OP1_LITERAL(last_op));
                                        }
#else
                                        if (ZEND_OP1_TYPE(last_op) == IS_CONST) {
                                                zval zv = ZEND_OP1_LITERAL(last_op);
                                                zval_copy_ctor(&zv);
                                                last_op->op1.constant = zend_optimizer_add_literal(op_array, &zv TSRMLS_CC);
                                        }
#endif
                                        del_source(block, block->op1_to);
                                        block->op1_to = NULL;
#if 0
                                /* Temporarily disabled - see bug #0025274 */
                                } else if (0&& block->op1_to != block &&
                                   block->op1_to != blocks &&
                                                   op_array->last_try_catch == 0 &&
                                           target->opcode != ZEND_FREE &&
                                           target->opcode != ZEND_SWITCH_FREE) {
                                    /* Block Reordering (saves one JMP on each "for" loop iteration)
                                     * It is disabled for some cases (ZEND_FREE/ZEND_SWITCH_FREE)
                                     * which may break register allocation.
                     */
                                        zend_bool can_reorder = 0;
                                        zend_block_source *cs = block->op1_to->sources;

                                        /* the "target" block doesn't had any followed block */
                                        while(cs) {
                                                if (cs->from->follow_to == block->op1_to) {
                                                        can_reorder = 0;
                                                        break;
                                                }
                                                cs = cs->next;
                                        }
                                        if (can_reorder) {
                                                next = block->op1_to;
                                                /* the "target" block is not followed by current "block" */
                                                while (next->follow_to != NULL) {
                                                        if (next->follow_to == block) {
                                                                can_reorder = 0;
                                                                break;
                                                        }
                                                        next = next->follow_to;
                                                }
                                                if (can_reorder) {
                                                        zend_code_block *prev = blocks;

                                                        while (prev->next != block->op1_to) {
                                                                prev = prev->next;
                                                        }
                                                        prev->next = next->next;
                                                        next->next = block->next;
                                                        block->next = block->op1_to;

                                                        block->follow_to = block->op1_to;
                                                        block->op1_to = NULL;
                                                        MAKE_NOP(last_op);
                                                        block->len--;
                                                        if(block->len == 0) {
                                                                /* this block is nothing but NOP now */
                                                                delete_code_block(block);
                                                        }
                                                        break;
                                                }
                                        }
#endif
                                }
                        }
                        break;

                case ZEND_JMPZ:
                case ZEND_JMPNZ:
                        /* constant conditional JMPs */
                        if (ZEND_OP1_TYPE(last_op) == IS_CONST) {
                                int should_jmp = zend_is_true(&ZEND_OP1_LITERAL(last_op));
                                if (last_op->opcode == ZEND_JMPZ) {
                                        should_jmp = !should_jmp;
                                }
                                literal_dtor(&ZEND_OP1_LITERAL(last_op));
                                ZEND_OP1_TYPE(last_op) = IS_UNUSED;
                                if (should_jmp) {
                                        /* JMPNZ(true) -> JMP */
                                        last_op->opcode = ZEND_JMP;
                                        COPY_NODE(last_op->op1, last_op->op2);
                                        block->op1_to = block->op2_to;
                                        del_source(block, block->follow_to);
                                        block->op2_to = NULL;
                                        block->follow_to = NULL;
                                } else {
                                        /* JMPNZ(false) -> NOP */
                                        MAKE_NOP(last_op);
                                        del_source(block, block->op2_to);
                                        block->op2_to = NULL;
                                }
                                break;
                        }

                        if (block->op2_to) {
                                zend_uchar same_type = ZEND_OP1_TYPE(last_op);
                                zend_uint same_var = VAR_NUM_EX(last_op->op1);
                                zend_op *target;
                                zend_op *target_end;
                                zend_code_block *target_block = block->op2_to;;

next_target:
                                target = target_block->start_opline;
                                target_end = target_block->start_opline + target_block->len;
                                while (target < target_end && target->opcode == ZEND_NOP) {
                                        target++;
                                }

                                /* next block is only NOP's */
                                if (target == target_end) {
                                        target_block = target_block->follow_to;
                                        goto next_target;
                                } else if (target->opcode == INV_COND(last_op->opcode) &&
                                        /* JMPZ(X, L), L: JMPNZ(X, L2) -> JMPZ(X, L+1) */
                                   (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                   same_type == ZEND_OP1_TYPE(target) &&
                                   same_var == VAR_NUM_EX(target->op1) &&
                                   target_block->follow_to &&
                                   !target_block->protected
                                   ) {
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->follow_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target->opcode == INV_COND_EX(last_op->opcode) &&
                                                        (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                same_type == ZEND_OP1_TYPE(target) &&
                                                same_var == VAR_NUM_EX(target->op1) &&
                                                        target_block->follow_to &&
                                                        !target_block->protected) {
                                        /* JMPZ(X, L), L: X = JMPNZ_EX(X, L2) -> JMPZ(X, L+1) */
                                        last_op->opcode += 3;
                                        last_op->result = target->result;
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->follow_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target_block->op2_to &&
                                                   target->opcode == last_op->opcode &&
                                                   (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                   same_type == ZEND_OP1_TYPE(target) &&
                                                   same_var == VAR_NUM_EX(target->op1) &&
                                                   !target_block->protected) {
                                        /* JMPZ(X, L), L: JMPZ(X, L2) -> JMPZ(X, L2) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->op2_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target_block->op1_to &&
                                                        target->opcode == ZEND_JMP &&
                                                        !target_block->protected) {
                                        /* JMPZ(X, L), L: JMP(L2) -> JMPZ(X, L2) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->op1_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target_block->op2_to &&
                                                        target_block->ext_to &&
                                                        target->opcode == ZEND_JMPZNZ &&
                                                        (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                same_type == ZEND_OP1_TYPE(target) &&
                                                same_var == VAR_NUM_EX(target->op1) &&
                                                        !target_block->protected) {
                                        /* JMPZ(X, L), L: JMPZNZ(X, L2, L3) -> JMPZ(X, L2) */
                                        del_source(block, block->op2_to);
                                        if (last_op->opcode == ZEND_JMPZ) {
                                                block->op2_to = target_block->op2_to;
                                        } else {
                                                block->op2_to = target_block->ext_to;
                                        }
                                        ADD_SOURCE(block, block->op2_to);
                                }
                        }

                        if (block->follow_to &&
                            (last_op->opcode == ZEND_JMPZ || last_op->opcode == ZEND_JMPNZ)) {
                                zend_op *target;
                                zend_op *target_end;

                                while (1) {
                                        target = block->follow_to->start_opline;
                                        target_end = block->follow_to->start_opline + block->follow_to->len;
                                        while (target < target_end && target->opcode == ZEND_NOP) {
                                                target++;
                                        }

                                        /* next block is only NOP's */
                                        if (target == target_end && ! block->follow_to->protected) {
                                                del_source(block, block->follow_to);
                                                block->follow_to = block->follow_to->follow_to;
                                                ADD_SOURCE(block, block->follow_to);
                                        } else {
                                                break;
                                        }
                                }
                                /* JMPZ(X,L1), JMP(L2) -> JMPZNZ(X,L1,L2) */
                                if (target->opcode == ZEND_JMP &&
                                        block->follow_to->op1_to &&
                                        !block->follow_to->protected) {
                                        del_source(block, block->follow_to);
                                        if (last_op->opcode == ZEND_JMPZ) {
                                                block->ext_to = block->follow_to->op1_to;
                                                ADD_SOURCE(block, block->ext_to);
                                        } else {
                                                block->ext_to = block->op2_to;
                                                block->op2_to = block->follow_to->op1_to;
                                                ADD_SOURCE(block, block->op2_to);
                                        }
                                        block->follow_to = NULL;
                                        last_op->opcode = ZEND_JMPZNZ;
                                }
                        }
                        break;

                case ZEND_JMPNZ_EX:
                case ZEND_JMPZ_EX:
                        /* constant conditional JMPs */
                        if (ZEND_OP1_TYPE(last_op) == IS_CONST) {
                                int should_jmp = zend_is_true(&ZEND_OP1_LITERAL(last_op));
                                if (last_op->opcode == ZEND_JMPZ_EX) {
                                        should_jmp = !should_jmp;
                                }
                                if (!should_jmp) {
                                        /* T = JMPZ_EX(true,L)   -> T = QM_ASSIGN(true)
                                         * T = JMPNZ_EX(false,L) -> T = QM_ASSIGN(false)
                                         */
                                        last_op->opcode = ZEND_QM_ASSIGN;
                                        SET_UNUSED(last_op->op2);
                                        del_source(block, block->op2_to);
                                        block->op2_to = NULL;
                                }
                                break;
                        }

                        if (block->op2_to) {
                                zend_op *target, *target_end;
                                char *same_t=NULL;
                                zend_code_block *target_block;
                                int var_num = 0;
                                if (op_array->T >= (zend_uint)op_array->last_var) {
                                        var_num = op_array->T;
                                } else {
                                        var_num = op_array->last_var;
                                }
                                if (var_num <= 0) {
                                        return;
                                }
                                same_t = ecalloc(var_num, sizeof(char));
                                if (same_t == NULL) {
                                        return;
                                }
                                same_t[VAR_NUM_EX(last_op->op1)] |= ZEND_OP1_TYPE(last_op);
                                same_t[VAR_NUM_EX(last_op->result)] |= ZEND_RESULT_TYPE(last_op);
                                target_block = block->op2_to;
next_target_ex:
                                target = target_block->start_opline;
                                target_end = target_block->start_opline + target_block->len;
                                while (target < target_end && target->opcode == ZEND_NOP) {
                                        target++;
                                }
                                /* next block is only NOP's */
                                if (target == target_end) {
                                        target_block = target_block->follow_to;
                                        goto next_target_ex;
                                } else if (target_block->op2_to &&
                                                   target->opcode == last_op->opcode-3 &&
                                                   (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                   (same_t[VAR_NUM_EX(target->op1)] & ZEND_OP1_TYPE(target)) != 0 &&
                                                   !target_block->protected) {
                                        /* T = JMPZ_EX(X, L1), L1: JMPZ({X|T}, L2) -> T = JMPZ_EX(X, L2) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->op2_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target_block->op2_to &&
                                                   target->opcode == INV_EX_COND(last_op->opcode) &&
                                                   (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                   (same_t[VAR_NUM_EX(target->op1)] & ZEND_OP1_TYPE(target)) != 0 &&
                                                   !target_block->protected) {
                                        /* T = JMPZ_EX(X, L1), L1: JMPNZ({X|T1}, L2) -> T = JMPZ_EX(X, L1+1) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->follow_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target_block->op2_to &&
                                                   target->opcode == INV_EX_COND_EX(last_op->opcode) &&
                                               (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                   (same_t[VAR_NUM_EX(target->op1)] & ZEND_OP1_TYPE(target)) != 0 &&
                                                   (same_t[VAR_NUM_EX(target->result)] & ZEND_RESULT_TYPE(target)) != 0 &&
                                                   !target_block->protected) {
                                        /* T = JMPZ_EX(X, L1), L1: T = JMPNZ_EX(T, L2) -> T = JMPZ_EX(X, L1+1) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->follow_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target_block->op2_to &&
                                                   target->opcode == last_op->opcode &&
                                                   (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                   (same_t[VAR_NUM_EX(target->op1)] & ZEND_OP1_TYPE(target)) != 0 &&
                                                   (same_t[VAR_NUM_EX(target->result)] & ZEND_RESULT_TYPE(target)) != 0 &&
                                                   !target_block->protected) {
                                        /* T = JMPZ_EX(X, L1), L1: T = JMPZ({X|T}, L2) -> T = JMPZ_EX(X, L2) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->op2_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target_block->op1_to &&
                                                   target->opcode == ZEND_JMP &&
                                                   !target_block->protected) {
                                        /* T = JMPZ_EX(X, L), L: JMP(L2) -> T = JMPZ(X, L2) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->op1_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target_block->op2_to &&
                                                   target_block->ext_to &&
                                                   target->opcode == ZEND_JMPZNZ &&
                                                   (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                   (same_t[VAR_NUM_EX(target->op1)] & ZEND_OP1_TYPE(target)) != 0 &&
                                                   !target_block->protected) {
                                        /* T = JMPZ_EX(X, L), L: JMPZNZ({X|T}, L2, L3) -> T = JMPZ_EX(X, L2) */
                                        del_source(block, block->op2_to);
                                        if (last_op->opcode == ZEND_JMPZ_EX) {
                                                block->op2_to = target_block->op2_to;
                                        } else {
                                                block->op2_to = target_block->ext_to;
                                        }
                                        ADD_SOURCE(block, block->op2_to);
                                }
                                if (same_t != NULL) {
                                        efree(same_t);
                                }
                        }
                        break;

                case ZEND_JMPZNZ: {
                        zend_code_block *next = block->next;

                        while (next && !next->access) {
                                /* find first accessed one */
                                next = next->next;
                        }

                        if (ZEND_OP1_TYPE(last_op) == IS_CONST) {
                                if (!zend_is_true(&ZEND_OP1_LITERAL(last_op))) {
                                        /* JMPZNZ(false,L1,L2) -> JMP(L1) */
                                        zend_code_block *todel;

                                        literal_dtor(&ZEND_OP1_LITERAL(last_op));
                                        last_op->opcode = ZEND_JMP;
                                        SET_UNUSED(last_op->op1);
                                        SET_UNUSED(last_op->op2);
                                        block->op1_to = block->op2_to;
                                        todel = block->ext_to;
                                        block->op2_to = NULL;
                                        block->ext_to = NULL;
                                        del_source(block, todel);
                                } else {
                                        /* JMPZNZ(true,L1,L2) -> JMP(L2) */
                                        zend_code_block *todel;

                                        literal_dtor(&ZEND_OP1_LITERAL(last_op));
                                        last_op->opcode = ZEND_JMP;
                                        SET_UNUSED(last_op->op1);
                                        SET_UNUSED(last_op->op2);
                                        block->op1_to = block->ext_to;
                                        todel =  block->op2_to;
                                        block->op2_to = NULL;
                                        block->ext_to = NULL;
                                        del_source(block, todel);
                                }
                        } else if (block->op2_to == block->ext_to) {
                                /* both goto the same one - it's JMP */
                                if (!(last_op->op1_type & (IS_VAR|IS_TMP_VAR))) {
                                        /* JMPZNZ(?,L,L) -> JMP(L) */
                                        last_op->opcode = ZEND_JMP;
                                        SET_UNUSED(last_op->op1);
                                        SET_UNUSED(last_op->op2);
                                        block->op1_to = block->op2_to;
                                        block->op2_to = NULL;
                                        block->ext_to = NULL;
                                }
                        } else if (block->op2_to == next) {
                                /* jumping to next on Z - can follow to it and jump only on NZ */
                                /* JMPZNZ(X,L1,L2) L1: -> JMPNZ(X,L2) */
                                last_op->opcode = ZEND_JMPNZ;
                                block->op2_to = block->ext_to;
                                block->follow_to = next;
                                block->ext_to = NULL;
                                /* no need to add source - it's block->op2_to */
                        } else if (block->ext_to == next) {
                                /* jumping to next on NZ - can follow to it and jump only on Z */
                                /* JMPZNZ(X,L1,L2) L2: -> JMPZ(X,L1) */
                                last_op->opcode = ZEND_JMPZ;
                                block->follow_to = next;
                                block->ext_to = NULL;
                                /* no need to add source - it's block->ext_to */
                        }

                        if (last_op->opcode == ZEND_JMPZNZ && block->op2_to) {
                                zend_uchar same_type = ZEND_OP1_TYPE(last_op);
                                zend_uchar same_var = VAR_NUM_EX(last_op->op1);
                                zend_op *target;
                                zend_op *target_end;
                                zend_code_block *target_block = block->op2_to;

next_target_znz:
                                target = target_block->start_opline;
                                target_end = target_block->start_opline + target_block->len;
                                while (target < target_end && target->opcode == ZEND_NOP) {
                                        target++;
                                }
                                /* next block is only NOP's */
                                if (target == target_end) {
                                        target_block = target_block->follow_to;
                                        goto next_target_znz;
                                } else if (target_block->op2_to &&
                                                   (target->opcode == ZEND_JMPZ || target->opcode == ZEND_JMPZNZ) &&
                                                   (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                   same_type == ZEND_OP1_TYPE(target) &&
                                                   same_var == VAR_NUM_EX(target->op1) &&
                                                   !target_block->protected) {
                                    /* JMPZNZ(X, L1, L2), L1: JMPZ(X, L3) -> JMPZNZ(X, L3, L2) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->op2_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target->opcode == ZEND_JMPNZ &&
                                                   (ZEND_OP1_TYPE(target) & (IS_TMP_VAR|IS_CV)) &&
                                                   same_type == ZEND_OP1_TYPE(target) &&
                                                   same_var == VAR_NUM_EX(target->op1) &&
                                                   target_block->follow_to &&
                                                   !target_block->protected) {
                    /* JMPZNZ(X, L1, L2), L1: X = JMPNZ(X, L3) -> JMPZNZ(X, L1+1, L2) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->follow_to;
                                        ADD_SOURCE(block, block->op2_to);
                                } else if (target_block->op1_to &&
                                               target->opcode == ZEND_JMP &&
                                               !target_block->protected) {
                    /* JMPZNZ(X, L1, L2), L1: JMP(L3) -> JMPZNZ(X, L3, L2) */
                                        del_source(block, block->op2_to);
                                        block->op2_to = target_block->op1_to;
                                        ADD_SOURCE(block, block->op2_to);
                                }
                        }
                        break;
                }
        }
}

/* Global data dependencies */

#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO

# define T_USAGE(op) do { \
                if ((op ## _type & (IS_VAR | IS_TMP_VAR)) && \
                   !defined_here[VAR_NUM(op.var)] && !used_ext[VAR_NUM(op.var)]) {      \
                        used_ext[VAR_NUM(op.var)] = 1;                                                                  \
                } \
        } while (0)

# define NEVER_USED(op) ((op ## _type & (IS_VAR | IS_TMP_VAR)) && !usage[VAR_NUM(op.var)]) /* !used_ext[op.var] && */
# define RES_NEVER_USED(opline) (opline->result_type == IS_UNUSED || NEVER_USED(opline->result))

#else

# define T_USAGE(op) do { \
                if ((op.op_type == IS_VAR || op.op_type == IS_TMP_VAR) && \
                   !defined_here[VAR_NUM(op.u.var)] && !used_ext[VAR_NUM(op.u.var)]) {  \
                        used_ext[VAR_NUM(op.u.var)] = 1;                                                                        \
                } \
        } while (0)

# define NEVER_USED(op) ((op.op_type == IS_VAR || op.op_type == IS_TMP_VAR) && !usage[VAR_NUM(op.u.var)]) /* !used_ext[op.u.var] && */
# define RES_NEVER_USED(opline) (ZEND_RESULT_TYPE(opline) == IS_UNUSED || NEVER_USED(opline->result))

#endif

/* Find a set of variables which are used outside of the block where they are
 * defined. We won't apply some optimization patterns for such variables. */
static void zend_t_usage(zend_code_block *block, zend_op_array *op_array, char *used_ext)
{
        zend_code_block *next_block = block->next;
        char *usage;
        char *defined_here;

        if (op_array->T == 0) {
                /* shortcut - if no Ts, nothing to do */
                return;
        }

        usage = ecalloc(op_array->T, 1);
        defined_here = emalloc(op_array->T);

        while (next_block) {
                zend_op *opline = next_block->start_opline;
                zend_op *end = opline + next_block->len;

                if (!next_block->access) {
                        next_block = next_block->next;
                        continue;
                }
                memset(defined_here, 0, op_array->T);

                while (opline<end) {
                        T_USAGE(opline->op1);
                        T_USAGE(opline->op2);

                        if (RESULT_USED(opline)) {
                                if (!defined_here[VAR_NUM(ZEND_RESULT(opline).var)] && !used_ext[VAR_NUM(ZEND_RESULT(opline).var)] &&
                                    (opline->opcode == ZEND_RECV || opline->opcode == ZEND_RECV_INIT ||
#if ZEND_EXTENSION_API_NO > PHP_5_5_X_API_NO
                                     opline->opcode == ZEND_RECV_VARIADIC ||
#endif
                                        (opline->opcode == ZEND_OP_DATA && ZEND_RESULT_TYPE(opline) == IS_TMP_VAR) ||
                                        opline->opcode == ZEND_ADD_ARRAY_ELEMENT)) {
                                        /* these opcodes use the result as argument */
                                        used_ext[VAR_NUM(ZEND_RESULT(opline).var)] = 1;
                                }
                                defined_here[VAR_NUM(ZEND_RESULT(opline).var)] = 1;
                        }
                        opline++;
                }
                next_block = next_block->next;
        }

#if DEBUG_BLOCKPASS
        {
                int i;
                for (i = 0; i< op_array->T; i++) {
                        fprintf(stderr, "T%d: %c\n", i, used_ext[i] + '0');
                }
        }
#endif

        while (block) {
                zend_op *opline = block->start_opline + block->len - 1;

                if (!block->access) {
                        block = block->next;
                        continue;
                }

                memcpy(usage, used_ext, op_array->T);

                while (opline >= block->start_opline) {
                        /* usage checks */
                        if (RES_NEVER_USED(opline)) {
                                switch (opline->opcode) {
                                        case ZEND_ASSIGN_ADD:
                                        case ZEND_ASSIGN_SUB:
                                        case ZEND_ASSIGN_MUL:
                                        case ZEND_ASSIGN_DIV:
                                        case ZEND_ASSIGN_MOD:
                                        case ZEND_ASSIGN_SL:
                                        case ZEND_ASSIGN_SR:
                                        case ZEND_ASSIGN_CONCAT:
                                        case ZEND_ASSIGN_BW_OR:
                                        case ZEND_ASSIGN_BW_AND:
                                        case ZEND_ASSIGN_BW_XOR:
                                        case ZEND_PRE_INC:
                                        case ZEND_PRE_DEC:
                                        case ZEND_POST_INC:
                                        case ZEND_POST_DEC:
                                        case ZEND_ASSIGN:
                                        case ZEND_ASSIGN_REF:
                                        case ZEND_DO_FCALL:
                                        case ZEND_DO_FCALL_BY_NAME:
                                                if (ZEND_RESULT_TYPE(opline) == IS_VAR) {
#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                                                        ZEND_RESULT_TYPE(opline) |= EXT_TYPE_UNUSED;
#else
                                                        ZEND_RESULT(opline).EA.type |= EXT_TYPE_UNUSED;
#endif
                                                }
                                                break;
                                        case ZEND_QM_ASSIGN:
                                        case ZEND_BOOL:
                                        case ZEND_BOOL_NOT:
                                                if (ZEND_OP1_TYPE(opline) == IS_CONST) {
                                                        literal_dtor(&ZEND_OP1_LITERAL(opline));
                                                }
                                                MAKE_NOP(opline);
                                                break;
                                        case ZEND_PRINT:
                                                opline->opcode = ZEND_ECHO;
                                                ZEND_RESULT_TYPE(opline) = IS_UNUSED;
                                                break;
                                        case ZEND_JMPZ_EX:
                                        case ZEND_JMPNZ_EX:
                                                opline->opcode -= 3;
                                                SET_UNUSED(opline->result);
                                                break;
                                }
                        }

                        if (opline->opcode == ZEND_RECV ||
                opline->opcode == ZEND_RECV_INIT ||
#if ZEND_EXTENSION_API_NO > PHP_5_5_X_API_NO
                opline->opcode == ZEND_RECV_VARIADIC ||
#endif
                opline->opcode == ZEND_ADD_ARRAY_ELEMENT) {
                                if (ZEND_OP1_TYPE(opline) == IS_VAR || ZEND_OP1_TYPE(opline) == IS_TMP_VAR) {
                                        usage[VAR_NUM(ZEND_RESULT(opline).var)] = 1;
                                }
                        } else {
                                if (RESULT_USED(opline)) {
                                        usage[VAR_NUM(ZEND_RESULT(opline).var)] = 0;
                                }
                        }

                        if (ZEND_OP1_TYPE(opline) == IS_VAR || ZEND_OP1_TYPE(opline) == IS_TMP_VAR) {
                                usage[VAR_NUM(ZEND_OP1(opline).var)] = 1;
                        }
                        if (ZEND_OP2_TYPE(opline) == IS_VAR || ZEND_OP2_TYPE(opline) == IS_TMP_VAR) {
                                usage[VAR_NUM(ZEND_OP2(opline).var)] = 1;
                        }


#if ZEND_EXTENSION_API_NO > PHP_5_3_X_API_NO
                        if ((ZEND_RESULT_TYPE(opline) & IS_VAR) &&
                (ZEND_RESULT_TYPE(opline) & EXT_TYPE_UNUSED) &&
                usage[VAR_NUM(ZEND_RESULT(opline).var)]) {
                                ZEND_RESULT_TYPE(opline) &= ~EXT_TYPE_UNUSED;
                        }
#else
                        if (ZEND_RESULT_TYPE(opline) == IS_VAR &&
                            usage[VAR_NUM(ZEND_RESULT(opline).var)] &&
                            (ZEND_RESULT(opline).EA.type & EXT_TYPE_UNUSED) != 0) {
                                ZEND_RESULT(opline).EA.type &= ~EXT_TYPE_UNUSED;
                        }
#endif

                        opline--;
                }
                block = block->next;
        } /* end blocks */

        efree(defined_here);
        efree(usage);
}

#define PASSES 3

static void zend_block_optimization(zend_op_array *op_array TSRMLS_DC)
{
        zend_cfg cfg;
        zend_code_block *cur_block;
        int pass;
        char *usage;

#if DEBUG_BLOCKPASS
        fprintf(stderr, "File %s func %s\n", op_array->filename, op_array->function_name? op_array->function_name : "main");
        fflush(stderr);
#endif

#if ZEND_EXTENSION_API_NO > PHP_5_4_X_API_NO
        if (op_array->has_finally_block) {
                return;
        }
#endif

    /* Build CFG */
        if (!find_code_blocks(op_array, &cfg)) {
                return;
        }

        zend_rebuild_access_path(&cfg, op_array, 0);
        /* full rebuild here to produce correct sources! */
        usage = emalloc(op_array->T);
        for (pass = 0; pass < PASSES; pass++) {
                /* Compute data dependencies */
                memset(usage, 0, op_array->T);
                zend_t_usage(cfg.blocks, op_array, usage);

                /* optimize each basic block separately */
                for (cur_block = cfg.blocks; cur_block; cur_block = cur_block->next) {
                        if (!cur_block->access) {
                                continue;
                        }
                        zend_optimize_block(cur_block, op_array, usage TSRMLS_CC);
                }

                /* Jump optimization for each block */
                for (cur_block = cfg.blocks; cur_block; cur_block = cur_block->next) {
                        if (!cur_block->access) {
                                continue;
                        }
                        zend_jmp_optimization(cur_block, op_array, cfg.blocks TSRMLS_CC);
                }

                /* Eliminate unreachable basic blocks */
                zend_rebuild_access_path(&cfg, op_array, 1);
        }

        memset(usage, 0, op_array->T);
        zend_t_usage(cfg.blocks, op_array, usage);
        assemble_code_blocks(&cfg, op_array);
        efree(usage);

        /* Destroy CFG */
        for (cur_block = cfg.blocks; cur_block; cur_block = cur_block->next) {
                zend_block_source *cs = cur_block->sources;
                while (cs) {
                        zend_block_source *n = cs->next;
                        efree(cs);
                        cs = n;
                }
        }
        efree(cfg.blocks);
}

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