source: trunk/optimizer.c @ 308

#if 1
#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     follow;
} 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(bb_t *bb, zend_op *opcodes, zend_op *opline) /* {{{ */
{
    /* break=have follow */
    switch (opline->opcode) {
    case ZEND_RETURN:
    case ZEND_EXIT:
        break;

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

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

    default:
        return FAILURE;
    }

    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->follow     = 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);
}
/* }}} */
#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);
    }
}
/* }}} */
#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 bb, *pbb;
    zend_bool *markjmpins  = do_alloca(count);
    zend_bool *markjmpouts = do_alloca(count);

    memset(markjmpins,  0, sizeof(zend_bool));
    memset(markjmpouts, 0, sizeof(zend_bool));

    for (i = 0; i < count; i ++) {
        /* BBID_INVALID=invalidate line 
         * bb.jmpout_op1 bb.jmpout_op2 bb.jmpout_ext bb.follow means opline number here, not basicblock id
         */
        bb.jmpout_op1 = bb.jmpout_op2 = BBID_INVALID;
        bb.jmpout_ext = bb.follow     = BBID_INVALID;
        if (op_get_jmpout(&bb, opcodes, &opcodes[i]) == SUCCESS) {
            markjmpouts[i] = 1;

            if (bb.jmpout_op1 != BBID_INVALID) {
                markjmpins[bb.jmpout_op1] = 1;
            }
            if (bb.jmpout_op2 != BBID_INVALID) {
                markjmpins[bb.jmpout_op2] = 1;
            }
            if (bb.jmpout_ext != BBID_INVALID) {
                markjmpins[bb.jmpout_ext] = 1;
            }

            if (i < count && bb.follow != BBID_INVALID) {
                markjmpins[i + 1] = 1;
            }
        }
    }

    prev = 0;
    for (i = 1; i < count; i ++) {
        if (markjmpins[i]) {
            pbb = bbs_new_bb_ex(bbs, opcodes + prev, i - prev);
            op_get_jmpout(pbb, opcodes, &opcodes[prev]);
            prev = i;
        }
    }

    if (prev != count - 1) {
        pbb = bbs_new_bb_ex(bbs, opcodes + prev, count - prev);
    }

    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
    TRACE("optimize file: %s", op_array->filename);
    xc_dprint_zend_op_array(op_array, 0 TSRMLS_CC);
#endif

    if (op_array_convert_switch(op_array)) {
        bbs_init(&bbs);
        if (bbs_build_from(&bbs, op_array->opcodes, op_array->last)) {
        }
        bbs_destroy(&bbs);
    }

#ifdef DEBUG
    TRACE("%s", "after compiles");
    xc_dprint_zend_op_array(op_array, 0 TSRMLS_CC);
#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;

    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);
}
/* }}} */