root/trunk/optimizer.c @ 845

#if 0
#   define XCACHE_DEBUG
#endif

#include "utils.h"
#include "optimizer.h"
/* the "vector" stack */
#include "stack.h"
#include "xcache_globals.h"

#ifdef XCACHE_DEBUG
#   include "processor.h"
#   include "const_string.h"
#   include "ext/standard/php_var.h"
#endif

#ifdef IS_CV
#   define XCACHE_IS_CV IS_CV
#else
#   define XCACHE_IS_CV 16
#endif

#ifdef ZEND_ENGINE_2_4
#   undef Z_OP_CONSTANT
/* Z_OP_CONSTANT is used before pass_two is applied */
#   define Z_OP_CONSTANT(op) op_array->literals[op.constant].constant
#endif

typedef int bbid_t;
enum {
    BBID_INVALID = -1,
};
/* {{{ basic block */
typedef struct _bb_t {
    bbid_t     id;
    zend_bool  used;

    zend_bool  alloc;
    zend_op   *opcodes;
    int        count;
    int        size;

    bbid_t     fall;
#ifdef ZEND_ENGINE_2
    bbid_t     catch;
#endif

    int        opnum; /* opnum after joining basic block */
} bb_t;
/* }}} */

/* basic blocks */
typedef xc_stack_t bbs_t;

/* op array helper functions */
static int op_array_convert_switch(zend_op_array *op_array) /* {{{ */
{
    int i;

    if (op_array->brk_cont_array == NULL) {
        return SUCCESS;
    }

    for (i = 0; i < op_array->last; i ++) {
        zend_op *opline = &op_array->opcodes[i];
        zend_brk_cont_element *jmp_to;
        zend_bool can_convert = 1;
        int array_offset, nest_levels, original_nest_levels;

        switch (opline->opcode) {
        case ZEND_BRK:
        case ZEND_CONT:
            break;

#ifdef ZEND_GOTO
        case ZEND_GOTO:
#endif
            continue;

        default:
            continue;
        }

        if (Z_OP_TYPE(opline->op2) != IS_CONST
         || Z_OP_CONSTANT(opline->op2).type != IS_LONG) {
            return FAILURE;
        }

        nest_levels = Z_OP_CONSTANT(opline->op2).value.lval;
        original_nest_levels = nest_levels;

        array_offset = Z_OP(opline->op1).opline_num;
        do {
            if (array_offset == -1) {
                /* this is a runtime error in ZE
                zend_error(E_ERROR, "Cannot break/continue %d level%s", original_nest_levels, (original_nest_levels == 1) ? "" : "s");
                */
                return FAILURE;
            }
            jmp_to = &op_array->brk_cont_array[array_offset];
            if (nest_levels > 1) {
                zend_op *brk_opline = &op_array->opcodes[jmp_to->brk];

                switch (brk_opline->opcode) {
                case ZEND_SWITCH_FREE:
                case ZEND_FREE:
                    if (!(brk_opline->extended_value & EXT_TYPE_FREE_ON_RETURN)) {
                        can_convert = 0;
                    }
                    break;
                }
            }
            array_offset = jmp_to->parent;
        } while (--nest_levels > 0);

        if (can_convert) {
            /* rewrite to jmp */
            switch (opline->opcode) {
            case ZEND_BRK:
                Z_OP(opline->op1).opline_num = jmp_to->brk;
                break;

            case ZEND_CONT:
                Z_OP(opline->op1).opline_num = jmp_to->cont;
                break;
            }
            Z_OP_TYPE(opline->op2) = IS_UNUSED;
            opline->opcode = ZEND_JMP;
        }
    }

    return SUCCESS;
}
/* }}} */
/* {{{ op_flowinfo helper func */
enum {
    XC_OPNUM_INVALID = -1,
};
typedef struct {
    int       jmpout_op1;
    int       jmpout_op2;
    int       jmpout_ext;
    zend_bool fall;
} op_flowinfo_t;
static void op_flowinfo_init(op_flowinfo_t *fi)
{
    fi->jmpout_op1 = fi->jmpout_op2 = fi->jmpout_ext = XC_OPNUM_INVALID;
    fi->fall = 0;
}
/* }}} */
static int op_get_flowinfo(op_flowinfo_t *fi, zend_op *opline) /* {{{ */
{
    op_flowinfo_init(fi);

    /* break=will fall */
    switch (opline->opcode) {
#ifdef ZEND_HANDLE_EXCEPTION
    case ZEND_HANDLE_EXCEPTION:
#endif
    case ZEND_RETURN:
    case ZEND_EXIT:
        return SUCCESS; /* no fall */

    case ZEND_JMP:
        fi->jmpout_op1 = Z_OP(opline->op1).opline_num;
        return SUCCESS; /* no fall */

    case ZEND_JMPZNZ:
        fi->jmpout_op2 = Z_OP(opline->op2).opline_num;
        fi->jmpout_ext = (int) opline->extended_value;
        return SUCCESS; /* no fall */

    case ZEND_JMPZ:
    case ZEND_JMPNZ:
    case ZEND_JMPZ_EX:
    case ZEND_JMPNZ_EX:
#ifdef ZEND_JMP_SET
    case ZEND_JMP_SET:
#endif
#ifdef ZEND_JMP_NO_CTOR
    case ZEND_JMP_NO_CTOR:
#endif
#ifdef ZEND_NEW
    case ZEND_NEW:
#endif
#ifdef ZEND_FE_RESET
    case ZEND_FE_RESET:
#endif      
    case ZEND_FE_FETCH:
        fi->jmpout_op2 = Z_OP(opline->op2).opline_num;
        break;

#ifdef ZEND_CATCH
    case ZEND_CATCH:
        fi->jmpout_ext = (int) opline->extended_value;
        break;
#endif

    default:
        return FAILURE;
    }

    fi->fall = 1;
    return SUCCESS;
}
/* }}} */
#ifdef XCACHE_DEBUG
static void op_snprint(char *buf, int size, zend_uchar op_type, znode_op *op) /* {{{ */
{
    switch (op_type) {
    case IS_CONST:
        {
            zval result;
            zval *zv = &Z_OP_CONSTANT(*op);
            TSRMLS_FETCH();

            /* TODO: update for PHP 6 */
            php_start_ob_buffer(NULL, 0, 1 TSRMLS_CC);
            php_var_export(&zv, 1 TSRMLS_CC);

            php_ob_get_buffer(&result TSRMLS_CC); 
            php_end_ob_buffer(0, 0 TSRMLS_CC);
            snprintf(buf, size, Z_STRVAL(result));
            zval_dtor(&result);
        }
        break;

    case IS_TMP_VAR:
        snprintf(buf, size, "t@%d", Z_OP(*op).var);
        break;

    case XCACHE_IS_CV:
    case IS_VAR:
        snprintf(buf, size, "v@%d", Z_OP(*op).var);
        break;

    case IS_UNUSED:
        if (Z_OP(*op).opline_num) {
            snprintf(buf, size, "u#%d", Z_OP(op).opline_num);
        }
        else {
            snprintf(buf, size, "-");
        }
        break;

    default:
        snprintf(buf, size, "%d %d", op->op_type, Z_OP(op).var);
    }
}
/* }}} */
static void op_print(int line, zend_op *first, zend_op *end) /* {{{ */
{
    zend_op *opline;
    for (opline = first; opline < end; opline ++) {
        char buf_r[20];
        char buf_1[20];
        char buf_2[20];
        op_snprint(buf_r, sizeof(buf_r), Z_OP_TYPE(opline->result), &opline->result);
        op_snprint(buf_1, sizeof(buf_1), Z_OP_TYPE(opline->op1),    &opline->op1);
        op_snprint(buf_2, sizeof(buf_2), Z_OP_TYPE(opline->op2),    &opline->op2);
        fprintf(stderr,
                "%3d %3d"
                " %-25s%-5s%-20s%-20s%5lu\r\n"
                , opline->lineno, opline - first + line
                , xc_get_opcode(opline->opcode), buf_r, buf_1, buf_2, opline->extended_value);
    }
}
/* }}} */
#endif

/*
 * basic block functions
 */

static bb_t *bb_new_ex(zend_op *opcodes, int count) /* {{{ */
{
    bb_t *bb = (bb_t *) ecalloc(sizeof(bb_t), 1);

    bb->fall       = BBID_INVALID;
#ifdef ZEND_ENGINE_2
    bb->catch      = BBID_INVALID;
#endif

    if (opcodes) {
        bb->alloc   = 0;
        bb->size    = bb->count = count;
        bb->opcodes = opcodes;
    }
    else {
        bb->alloc   = 1;
        bb->size    = bb->count = 8;
        bb->opcodes = ecalloc(sizeof(zend_op), bb->size);
    }

    return bb;
}
/* }}} */
#define bb_new() bb_new_ex(NULL, 0)
static void bb_destroy(bb_t *bb) /* {{{ */
{
    if (bb->alloc) {
        efree(bb->opcodes);
    }
    efree(bb);
}
/* }}} */
#ifdef XCACHE_DEBUG
static void bb_print(bb_t *bb, zend_op *opcodes) /* {{{ */
{
    int line = bb->opcodes - opcodes;
    op_flowinfo_t fi;
    zend_op *last = bb->opcodes + bb->count - 1;
    bbid_t catchbbid;
#ifdef ZEND_ENGINE_2
    catchbbid = BBID_INVALID;
#else
    catchbbid = bb->catch;
#endif

    op_get_flowinfo(&fi, last);

    fprintf(stderr,
            "\r\n==== #%-3d cnt:%-3d lno:%-3d"
            " %c%c"
            " op1:%-3d op2:%-3d ext:%-3d fal:%-3d cat:%-3d %s ====\r\n"
            , bb->id, bb->count, bb->alloc ? -1 : line
            , bb->used ? 'U' : ' ', bb->alloc ? 'A' : ' '
            , fi.jmpout_op1, fi.jmpout_op2, fi.jmpout_ext, bb->fall, catchbbid, xc_get_opcode(last->opcode)
            );
    op_print(line, bb->opcodes, last + 1);
}
/* }}} */
#endif

static bb_t *bbs_get(bbs_t *bbs, int n) /* {{{ */
{
    return (bb_t *) xc_stack_get(bbs, n);
}
/* }}} */
static int bbs_count(bbs_t *bbs) /* {{{ */
{
    return xc_stack_count(bbs);
}
/* }}} */
static void bbs_destroy(bbs_t *bbs) /* {{{ */
{
    bb_t *bb;
    while (bbs_count(bbs)) {
        bb = (bb_t *) xc_stack_pop(bbs);
        bb_destroy(bb);
    }
    xc_stack_destroy(bbs);
}
/* }}} */
#ifdef XCACHE_DEBUG
static void bbs_print(bbs_t *bbs, zend_op *opcodes) /* {{{ */
{
    int i;
    for (i = 0; i < xc_stack_count(bbs); i ++) {
        bb_print(bbs_get(bbs, i), opcodes);
    }
}
/* }}} */
#endif
#define bbs_init(bbs) xc_stack_init_ex(bbs, 16)
static bb_t *bbs_add_bb(bbs_t *bbs, bb_t *bb) /* {{{ */
{
    bb->id = (bbid_t) xc_stack_count(bbs);
    xc_stack_push(bbs, (void *) bb);
    return bb;
}
/* }}} */
static bb_t *bbs_new_bb_ex(bbs_t *bbs, zend_op *opcodes, int count) /* {{{ */
{
    return bbs_add_bb(bbs, bb_new_ex(opcodes, count));
}
/* }}} */
static int bbs_build_from(bbs_t *bbs, zend_op_array *op_array, int count) /* {{{ */
{
    int i, start;
    bb_t *pbb;
    bbid_t id;
    op_flowinfo_t fi;
    zend_op *opline;
    ALLOCA_FLAG(use_heap_bbids)
    ALLOCA_FLAG(use_heap_catchbbids)
    ALLOCA_FLAG(use_heap_markbbhead)
    bbid_t *bbids          = my_do_alloca(count * sizeof(bbid_t),    use_heap_bbids);
#ifdef ZEND_ENGINE_2
    bbid_t *catchbbids     = my_do_alloca(count * sizeof(bbid_t),    use_heap_catchbbids);
#endif
    zend_bool *markbbhead  = my_do_alloca(count * sizeof(zend_bool), use_heap_markbbhead);

    /* {{{ mark jmpin/jumpout */
    memset(markbbhead,  0, count * sizeof(zend_bool));

    markbbhead[0] = 1;
    for (i = 0; i < count; i ++) {
        if (op_get_flowinfo(&fi, &op_array->opcodes[i]) == SUCCESS) {
            if (fi.jmpout_op1 != XC_OPNUM_INVALID) {
                markbbhead[fi.jmpout_op1] = 1;
            }
            if (fi.jmpout_op2 != XC_OPNUM_INVALID) {
                markbbhead[fi.jmpout_op2] = 1;
            }
            if (fi.jmpout_ext != XC_OPNUM_INVALID) {
                markbbhead[fi.jmpout_ext] = 1;
            }
            if (i + 1 < count) {
                markbbhead[i + 1] = 1;
            }
        }
    }
#ifdef ZEND_ENGINE_2
    /* mark try start */
    for (i = 0; i < op_array->last_try_catch; i ++) {
        markbbhead[op_array->try_catch_array[i].try_op] = 1;
    }
#endif
    /* }}} */
    /* {{{ fill op lines with newly allocated id */
    for (i = 0; i < count; i ++) {
        bbids[i] = BBID_INVALID;
    }

    id = -1;
    for (i = 0; i < count; i ++) {
        if (markbbhead[i]) {
            id ++;
        }
        bbids[i] = id;
        TRACE("bbids[%d] = %d", i, id);
    }
    /* }}} */
#ifdef ZEND_ENGINE_2
    /* {{{ fill op lines with catch id */
    for (i = 0; i < count; i ++) {
        catchbbids[i] = BBID_INVALID;
    }

    for (i = 0; i < op_array->last_try_catch; i ++) {
        int j;
        zend_try_catch_element *e = &op_array->try_catch_array[i];
        for (j = e->try_op; j < e->catch_op; j ++) {
            catchbbids[j] = bbids[e->catch_op];
        }
    }
#ifdef XCACHE_DEBUG
    for (i = 0; i < count; i ++) {
        TRACE("catchbbids[%d] = %d", i, catchbbids[i]);
    }
#endif
    /* }}} */
#endif
    /* {{{ create basic blocks */
    start = 0;
    id = 0;
    /* loop over to deal with the last block */
    for (i = 1; i <= count; i ++) {
        if (i < count && id == bbids[i]) {
            continue;
        }

        opline = op_array->opcodes + start;
        pbb = bbs_new_bb_ex(bbs, opline, i - start);
#ifdef ZEND_ENGINE_2
        pbb->catch = catchbbids[start];
#endif

        /* last */
        opline = pbb->opcodes + pbb->count - 1;
        if (op_get_flowinfo(&fi, opline) == SUCCESS) {
            if (fi.jmpout_op1 != XC_OPNUM_INVALID) {
                Z_OP(opline->op1).opline_num = bbids[fi.jmpout_op1];
                assert(Z_OP(opline->op1).opline_num != BBID_INVALID);
            }
            if (fi.jmpout_op2 != XC_OPNUM_INVALID) {
                Z_OP(opline->op2).opline_num = bbids[fi.jmpout_op2];
                assert(Z_OP(opline->op2).opline_num != BBID_INVALID);
            }
            if (fi.jmpout_ext != XC_OPNUM_INVALID) {
                opline->extended_value = bbids[fi.jmpout_ext];
                assert(opline->extended_value != BBID_INVALID);
            }
            if (fi.fall && i + 1 < count) {
                pbb->fall = bbids[i + 1];
                TRACE("fall %d", pbb->fall);
                assert(pbb->fall != BBID_INVALID);
            }
        }
        if (i >= count) {
            break;
        }
        start = i;
        id = bbids[i];
    }
    /* }}} */

    my_free_alloca(markbbhead, use_heap_markbbhead);
#ifdef ZEND_ENGINE_2
    my_free_alloca(catchbbids, use_heap_catchbbids);
#endif
    my_free_alloca(bbids,      use_heap_bbids);
    return SUCCESS;
}
/* }}} */
static void bbs_restore_opnum(bbs_t *bbs, zend_op_array *op_array) /* {{{ */
{
    int i;
#ifdef ZEND_ENGINE_2
    bbid_t lasttrybbid;
    bbid_t lastcatchbbid;
#endif

    for (i = 0; i < bbs_count(bbs); i ++) {
        op_flowinfo_t fi;
        bb_t *bb = bbs_get(bbs, i);
        zend_op *last = bb->opcodes + bb->count - 1;

        if (op_get_flowinfo(&fi, last) == SUCCESS) {
            if (fi.jmpout_op1 != XC_OPNUM_INVALID) {
                Z_OP(last->op1).opline_num = bbs_get(bbs, fi.jmpout_op1)->opnum;
                assert(Z_OP(last->op1).opline_num != BBID_INVALID);
            }
            if (fi.jmpout_op2 != XC_OPNUM_INVALID) {
                Z_OP(last->op2).opline_num = bbs_get(bbs, fi.jmpout_op2)->opnum;
                assert(Z_OP(last->op2).opline_num != BBID_INVALID);
            }
            if (fi.jmpout_ext != XC_OPNUM_INVALID) {
                last->extended_value = bbs_get(bbs, fi.jmpout_ext)->opnum;
                assert(last->extended_value != BBID_INVALID);
            }
        }
    }

#ifdef ZEND_ENGINE_2
    lasttrybbid   = BBID_INVALID;
    lastcatchbbid = BBID_INVALID;
    op_array->last_try_catch = 0;
    for (i = 0; i < bbs_count(bbs); i ++) {
        bb_t *bb = bbs_get(bbs, i);

        if (lastcatchbbid != bb->catch) {
            if (lasttrybbid != BBID_INVALID && lastcatchbbid != BBID_INVALID) {
                int try_catch_offset = op_array->last_try_catch ++;

                op_array->try_catch_array = erealloc(op_array->try_catch_array, sizeof(zend_try_catch_element) * op_array->last_try_catch);
                op_array->try_catch_array[try_catch_offset].try_op = bbs_get(bbs, lasttrybbid)->opnum;
                op_array->try_catch_array[try_catch_offset].catch_op = bbs_get(bbs, lastcatchbbid)->opnum;
            }
            lasttrybbid   = i;
            lastcatchbbid = bb->catch;
        }
    }
    /* it is impossible to have last bb catched */
#endif
}
/* }}} */

/*
 * optimize
 */
static int xc_optimize_op_array(zend_op_array *op_array TSRMLS_DC) /* {{{ */
{
    bbs_t bbs;

    if (op_array->type != ZEND_USER_FUNCTION) {
        return 0;
    }

#ifdef XCACHE_DEBUG
#   if 0
    TRACE("optimize file: %s", op_array->filename);
    xc_dprint_zend_op_array(op_array, 0 TSRMLS_CC);
#   endif
    op_print(0, op_array->opcodes, op_array->opcodes + op_array->last);
#endif

    if (op_array_convert_switch(op_array) == SUCCESS) {
        bbs_init(&bbs);
        if (bbs_build_from(&bbs, op_array, op_array->last) == SUCCESS) {
            int i;
#ifdef XCACHE_DEBUG
            bbs_print(&bbs, op_array->opcodes);
#endif
            /* TODO: calc opnum after basic block move */
            for (i = 0; i < bbs_count(&bbs); i ++) {
                bb_t *bb = bbs_get(&bbs, i);
                bb->opnum = bb->opcodes - op_array->opcodes;
            }
            bbs_restore_opnum(&bbs, op_array);
        }
        bbs_destroy(&bbs);
    }

#ifdef XCACHE_DEBUG
#   if 0
    TRACE("%s", "after compiles");
    xc_dprint_zend_op_array(op_array, 0 TSRMLS_CC);
#   endif
    op_print(0, op_array->opcodes, op_array->opcodes + op_array->last);
#endif
    return 0;
}
/* }}} */
void xc_optimizer_op_array_handler(zend_op_array *op_array) /* {{{ */
{
    TSRMLS_FETCH();
    if (XG(optimizer)) {
        xc_optimize_op_array(op_array TSRMLS_CC);
    }
}
/* }}} */