root/trunk/optimizer.c @ 316

#if 0
#define DEBUG
#endif

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

#ifdef DEBUG
#   include "processor.h"
#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     jmpout_op1;
    bbid_t     jmpout_op2;
    bbid_t     jmpout_ext;
    bbid_t     fall;
} bb_t;
/* }}} */

/* basic blocks */
typedef xc_stack_t bbs_t;

/* oparray help 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;
        int array_offset, nest_levels, original_nest_levels;

        if (opline->opcode != ZEND_BRK && opline->opcode != ZEND_CONT) {
            continue;
        }
        if (opline->op2.op_type != IS_CONST
         || opline->op2.u.constant.type != IS_LONG) {
            return FAILURE;
        }

        nest_levels = opline->op2.u.constant.value.lval;
        original_nest_levels = nest_levels;

        array_offset = opline->op1.u.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:
                    break;
                case ZEND_FREE:
                    break;
                }
            }
            array_offset = jmp_to->parent;
        } while (--nest_levels > 0);

        /* rewrite to jmp */
        if (opline->opcode == ZEND_BRK) {
            opline->op1.u.opline_num = jmp_to->brk;
        }
        else {
            opline->op1.u.opline_num = jmp_to->cont;
        }
        opline->op2.op_type = IS_UNUSED;
        opline->opcode = ZEND_JMP;
    }

    if (op_array->brk_cont_array != NULL) {
        efree(op_array->brk_cont_array);
        op_array->brk_cont_array = NULL;
    }
    op_array->last_brk_cont = 0;
    return SUCCESS;
}
/* }}} */
static int op_get_jmpout(int *jmpout_op1, int *jmpout_op2, int *jmpout_ext, zend_bool *fall, zend_op *opline) /* {{{ */
{
    /* break=will fall */
    switch (opline->opcode) {
    case ZEND_RETURN:
    case ZEND_EXIT:
        return SUCCESS; /* no fall */

    case ZEND_JMP:
        *jmpout_op1 = opline->op1.u.opline_num;
        return SUCCESS; /* no fall */

    case ZEND_JMPZNZ:
        *jmpout_ext = opline->extended_value;
        *jmpout_op2 = opline->op2.u.opline_num;
        break;

    case ZEND_JMPZ:
    case ZEND_JMPNZ:
    case ZEND_JMPZ_EX:
    case ZEND_JMPNZ_EX:
#ifndef ZEND_ENGINE_2_1
        /* Pre-PHP 5.1 only */
    case ZEND_JMP_NO_CTOR:
#else       
    case ZEND_NEW:
    case ZEND_FE_RESET:
#endif      
    case ZEND_FE_FETCH:
        *jmpout_op2 = opline->op2.u.opline_num;
        break;

    default:
        return FAILURE;
    }

    *fall = 1;
    return SUCCESS;
}
/* }}} */

/*
 * 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->jmpout_op1 = BBID_INVALID;
    bb->jmpout_op2 = BBID_INVALID;
    bb->jmpout_ext = BBID_INVALID;
    bb->fall       = BBID_INVALID;

    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 DEBUG
static void bb_print(bb_t *bb, zend_op *opcodes) /* {{{ */
{
    fprintf(stderr,
            "%3d %3d %3d"
            " %c%c"
            " %3d %3d %3d %3d\r\n"
            , bb->id, bb->count, bb->opcodes - opcodes
            , bb->used ? 'U' : ' ', bb->alloc ? 'A' : ' '
            , bb->jmpout_op1, bb->jmpout_op2, bb->jmpout_ext, bb->fall
            );
}
/* }}} */
#endif

#define bbs_get(bbs, n) xc_stack_get(bbs, n)
static void bbs_destroy(bbs_t *bbs) /* {{{ */
{
    bb_t *bb;
    while (xc_stack_count(bbs)) {
        bb = (bb_t *) xc_stack_pop(bbs);
        bb_destroy(bb);
    }
    xc_stack_destroy(bbs);
}
/* }}} */
#ifdef 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 *opcodes, int count) /* {{{ */
{
    int i, prev;
    bb_t *pbb;
    bbid_t id;
    int jmpout_op1, jmpout_op2, jmpout_ext;
    zend_bool fall;
    bbid_t *bbids          = do_alloca(count * sizeof(bbid_t));
    zend_bool *markjmpins  = do_alloca(count * sizeof(zend_bool));
    zend_bool *markjmpouts = do_alloca(count * sizeof(zend_bool));

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

    for (i = 0; i < count; i ++) {
        jmpout_op1 = jmpout_op2 = jmpout_ext = -1;
        fall = 0;
        if (op_get_jmpout(&jmpout_op1, &jmpout_op2, &jmpout_ext, &fall, &opcodes[i]) == SUCCESS) {
            markjmpouts[i] = 1;

            if (jmpout_op1 != -1) {
                markjmpins[jmpout_op1] = 1;
            }
            if (jmpout_op2 != -1) {
                markjmpins[jmpout_op2] = 1;
            }
            if (jmpout_ext != -1) {
                markjmpins[jmpout_ext] = 1;
            }
        }
    }
    /* }}} */
    /* {{{ fill opcodes with newly allocated id */
    for (i = 0; i < count; i ++) {
        bbids[i] = BBID_INVALID;
    }

    prev = 0;
    id = 0;
    for (i = 1; i < count; i ++) {
        if (markjmpins[i] || markjmpouts[i - 1]) {
            for (; prev < i; prev ++) {
                bbids[prev] = id;
            }
            id ++;
            prev = i;
        }
    }

    if (prev < count) {
        for (; prev < i; prev ++) {
            bbids[prev] = id;
        }
    }
    /* }}} */
    /* {{{ create basic blocks */
    prev = 0;
    id = 0;
    for (i = 1; i < count; i ++) {
        if (id == bbids[i]) {
            continue;
        }
        id = bbids[i];

        pbb = bbs_new_bb_ex(bbs, opcodes + prev, i - prev);
        jmpout_op1 = jmpout_op2 = jmpout_ext = -1;
        fall = 0;
        if (op_get_jmpout(&jmpout_op1, &jmpout_op2, &jmpout_ext, &fall, &opcodes[prev]) == SUCCESS) {
            if (jmpout_op1 != -1) {
                pbb->jmpout_op1 = bbids[jmpout_op1];
                assert(pbb->jmpout_op1 != BBID_INVALID);
            }
            if (jmpout_op2 != -1) {
                pbb->jmpout_op2 = bbids[jmpout_op2];
                assert(pbb->jmpout_op2 != BBID_INVALID);
            }
            if (jmpout_ext != -1) {
                pbb->jmpout_ext = bbids[jmpout_ext];
                assert(pbb->jmpout_ext != BBID_INVALID);
            }
            if (fall && i + 1 < count) {
                pbb->fall = bbids[i + 1];
                assert(pbb->fall != BBID_INVALID);
            }
        }
        prev = i + 1;
    }
    assert(prev == count);
    /* }}} */

    free_alloca(bbids);
    free_alloca(markjmpins);
    free_alloca(markjmpouts);
    return SUCCESS;
}
/* }}} */

/*
 * 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;
    }
    xc_undo_pass_two(op_array TSRMLS_CC);
#ifdef DEBUG
#   if 0
    TRACE("optimize file: %s", op_array->filename);
    xc_dprint_zend_op_array(op_array, 0 TSRMLS_CC);
#   endif
#endif

    if (op_array_convert_switch(op_array) == SUCCESS) {
        bbs_init(&bbs);
        if (bbs_build_from(&bbs, op_array->opcodes, op_array->last) == SUCCESS) {
#ifdef DEBUG
            bbs_print(&bbs, op_array->opcodes);
#endif
        }
        bbs_destroy(&bbs);
    }

#ifdef DEBUG
#   if 0
    TRACE("%s", "after compiles");
    xc_dprint_zend_op_array(op_array, 0 TSRMLS_CC);
#   endif
#endif
    xc_redo_pass_two(op_array TSRMLS_CC);
    return 0;
}
/* }}} */
void xc_optimize(zend_op_array *op_array TSRMLS_DC) /* {{{ */
{
    xc_compile_result_t cr;

    if (!op_array) {
        return;
    }

    xc_compile_result_init_cur(&cr, op_array TSRMLS_CC);

    xc_apply_op_array(&cr, (apply_func_t) xc_undo_pass_two TSRMLS_CC);
    xc_apply_op_array(&cr, (apply_func_t) xc_optimize_op_array TSRMLS_CC);
    xc_apply_op_array(&cr, (apply_func_t) xc_redo_pass_two TSRMLS_CC);

    xc_compile_result_free(&cr);
}
/* }}} */