ctrump/analyzer/deptest.c

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/* -*- coding:utf-8 -*- 
 Copyright (c) 2009, Fixstars Corp.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification, 
 are permitted provided that the following conditions are met:
 
   * Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.
 
   * Redistributions in binary form must reproduce the above copyright notice,
     this list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.
 
   * Neither the name of Fixstars Corporation nor the names of its contributors
     may be used to endorse or promote products derived from this software
     without specific prior written permission.
 
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include "ctrump/ast/ast.h"
#include "ctrump/analyzer/deptest.h"
#include "ctrump/analyzer/loop.h"
#include "ctrump/common/intmap.h"
#include "ctrump/common/abort.h"
#include "ctrump/common/varray.h"
#include <assert.h>

struct distance_vector {
    struct ctrump_loop_memory_access *store;
    struct ctrump_loop_memory_access *load;
    struct ctrump_depend_distance *vector;
};

struct dependence_info_node {
    struct ctrump_loop_memory_access *first_occur; 
    struct ctrump_varray distance_vectors; 
};


struct dependence_info {
    struct ctrump_varray nodes; /* struct ctrump_dependence_info_node */
};

static void
append_have_multiple_level(struct ctrump_varray *errors,
                           struct ctrump_loop_memory_access *ma0,
                           struct ctrump_loop_memory_access *ma1,
                           struct ctrump_mempool *tmp_alloc)
{
    struct ctrump_loop_dependence_analyze_error *e;
    VA_NEWELEM_P(errors, tmp_alloc);
    e = VA_LAST_PTR(struct ctrump_loop_dependence_analyze_error, errors);

    e->code = CTRUMP_LOOP_DEPENDENCE_ANALYZE_HAVE_MULTIPLE_LEVEL;
    e->u.have_multi_level.access0 = ma0;
    e->u.have_multi_level.access1 = ma1;
}

static void
append_have_multiple_index(struct ctrump_varray *errors,
                           struct ctrump_loop_memory_access *ma,
                           struct ctrump_mempool *tmp_alloc)
{
    struct ctrump_loop_dependence_analyze_error *e;
    VA_NEWELEM_P(errors, tmp_alloc);
    e = VA_LAST_PTR(struct ctrump_loop_dependence_analyze_error, errors);

    e->code = CTRUMP_LOOP_DEPENDENCE_ANALYZE_HAVE_MULTIPLE_INDEX;
    e->u.have_miv.access = ma;
}

static void
append_have_weak_subscript(struct ctrump_varray *errors,
                           struct ctrump_loop_subscript *sub0,
                           struct ctrump_loop_subscript *sub1,
                           struct ctrump_loop_memory_access *ma0,
                           struct ctrump_loop_memory_access *ma1,
                           struct ctrump_mempool *tmp_alloc)
{
    struct ctrump_loop_dependence_analyze_error *e;
    VA_NEWELEM_P(errors, tmp_alloc);
    e = VA_LAST_PTR(struct ctrump_loop_dependence_analyze_error, errors);

    e->code = CTRUMP_LOOP_DEPENDENCE_ANALYZE_HAVE_WEAK_SUBSCRIPT;
    e->u.have_weak.sub0 = sub0;
    e->u.have_weak.sub1 = sub1;
    e->u.have_weak.access0 = ma0;
    e->u.have_weak.access1 = ma1;
}

static void
append_have_complicated_subscript(struct ctrump_varray *errors,
                                  struct ctrump_loop_subscript *sub0,
                                  struct ctrump_loop_subscript *sub1,
                                  struct ctrump_loop_memory_access *ma0,
                                  struct ctrump_loop_memory_access *ma1,
                                  int sub_index,
                                  struct ctrump_mempool *tmp_alloc)
{
    struct ctrump_loop_dependence_analyze_error *e;
    VA_NEWELEM_P(errors, tmp_alloc);
    e = VA_LAST_PTR(struct ctrump_loop_dependence_analyze_error, errors);

    e->code = CTRUMP_LOOP_DEPENDENCE_ANALYZE_HAVE_COMPLICATED_SUBSCRIPT;
    e->u.have_complicated_subscript.sub0 = sub0;
    e->u.have_complicated_subscript.sub1 = sub1;
    e->u.have_complicated_subscript.access0 = ma0;
    e->u.have_complicated_subscript.access1 = ma1;
    e->u.have_complicated_subscript.sub_index = sub_index;
}

#define LOAD 0
#define STORE 1

static int
iv_test(struct ctrump_loop_iv *iv0,
        struct ctrump_loop_iv *iv1)
{
    /* fixme : more strictenss 
     *         care reached definition */

    return (iv0->incr == iv1->incr) && (iv0->iv_level == iv1->iv_level);
}

static int
invariant_test(struct ctrump_var *var0,
               struct ctrump_var *var1)
{
    /* fixme : care reached definition */

    return var0 == var1;
}

static void
strong_siv(struct ctrump_depend_distance *dest,
           struct ctrump_loop_subscript *x,
           struct ctrump_loop_subscript *y)
{
    dest->code = CTRUMP_DEPEND_DISTANCE_STRONG_SIV;
    dest->u.strong_siv.index0 = y->indices[0];
    dest->u.strong_siv.index1 = x->indices[0];
    dest->u.strong_siv.distance = x->offset - y->offset;
}

static int
test_index(struct ctrump_varray *errors, /* struct ctrump_loop_dependence_analyze_error */
           struct ctrump_intmap *array_map,
           struct ctrump_loop_memory_access *ma,
           struct ctrump_mempool *tmp_alloc,
           int load_store)
{
    int found;
    struct ctrump_intmap_bucket *b;
    struct ctrump_var *array_var = ma->array.var;
    struct dependence_info *ai;
    int i, n;
    struct ctrump_loop_subscript *cur_ss = ma->subscripts;

    n = ma->num_subscript;

    /* assert single index */
    for (i=0; i<n; i++) {
        if (cur_ss[i].num_index == 0) {
            /* ziv */
        } else {
            if (cur_ss[i].num_index != 1) {
                append_have_multiple_index(errors, ma, tmp_alloc);
                return 0;
            }
        }
    }

    if (load_store == STORE) {
        b = ctrump_intmap_lookup_add(array_map, &found, array_var->id);
    } else {
        b = ctrump_intmap_lookup_bucket(array_map, &found, array_var->id);
    }
    if (found) {
        int j;
        struct dependence_info *info = b->val;
        int num_node = info->nodes.nelem;
        struct dependence_info_node *nodes = info->nodes.elements;
        for (j=0; j<num_node; j++) {
            struct dependence_info_node *node = &nodes[j];
            struct ctrump_loop_memory_access *prev_ma = node->first_occur;
            struct ctrump_loop_subscript *prev_ss;
            struct ctrump_depend_distance *distvec = ctrump_mempool_alloc(tmp_alloc, sizeof(struct ctrump_depend_distance)*n);
            int cur_ns = ma->num_subscript, prev_ns = prev_ma->num_subscript;
            struct distance_vector dv;

            prev_ss = prev_ma->subscripts;

            /* test subscript */
            i = 0;
            for (i=0 ;; i++) {
                struct ctrump_loop_subscript *x, *y;
                int nl, nr;
                struct ctrump_loop_index *il, *ir;
                struct ctrump_depend_distance distance;

                if (i >= cur_ns ||
                    i >= prev_ns) {
                    if (cur_ns == prev_ns) {
                        /* have dependency */
                        goto all_strong;
                    } else {
                        append_have_multiple_level(errors, prev_ma, ma, tmp_alloc);
                        return 0;
                    }
                }

                x = &cur_ss[i];
                y = &prev_ss[i];

                /*
                 * single index vs zero index vs record member
                 *
                 *  single index <=> single index  : strong when iv incr is equal
                 *                                 : weak when iv incr is different(conservative)
                 *  single index <=> zero index    : weak always(conservative)
                 *  single index <=> record member : type error(maybe bug)
                 *
                 *  zero index   <=> zero index    : always depend when index is equal to each other
                 *                                 : always independ when index is diefferent
                 *  
                 *  zero index   <=> record member : type error(maybe bug)
                 *
                 *  record member<=> record member : always depend when tag is equal to each other
                 *                                 : always independ when tag is diefferent
                 */

                if (x->code == CTRUMP_LOOP_SUBSCRIPT_RECORD_MEMBER) {
                    if (y->code == CTRUMP_LOOP_SUBSCRIPT_RECORD_MEMBER_TERMINAL) {
                        goto always_independent;
                    }

                    assert(y->code == CTRUMP_LOOP_SUBSCRIPT_RECORD_MEMBER); /* type error : maybe bug */

                    if (x->u.record_member.member_name == y->u.record_member.member_name) {
                        distance.code = CTRUMP_DEPEND_DISTANCE_MEMBER_NAME_ZIV;
                        distance.u.member_name.member_name = x->u.record_member.member_name;
                        /* a->x = a->x */
                        goto strong_index;
                    } else {
                        /* a->x = a->y */
                        goto always_independent;
                    }
                } else if (x->code == CTRUMP_LOOP_SUBSCRIPT_RECORD_MEMBER_TERMINAL) {
                    if (y->code == CTRUMP_LOOP_SUBSCRIPT_RECORD_MEMBER) {
                        goto always_independent;
                    }

                    assert(y->code == CTRUMP_LOOP_SUBSCRIPT_RECORD_MEMBER_TERMINAL); /* type error : maybe bug */

                    if (x->u.record_member_terminal.member_name == y->u.record_member_terminal.member_name) {
                        distance.code = CTRUMP_DEPEND_DISTANCE_MEMBER_NAME_ZIV;
                        distance.u.member_name.member_name = x->u.record_member.member_name;
                        /* a->x = a->x */
                        goto strong_index;
                    } else {
                        /* a->x = a->y */
                        goto always_independent;
                    }

                } else {
#define SWAP_INDEX() do {                                       \
                        int nt = nl;                            \
                        struct ctrump_loop_index *it = il;      \
                        il = ir;                                \
                        nl = nr;                                \
                        ir = it;                                \
                        nr = nt;                                \
                    } while (0)

                    il = x->indices;
                    ir = y->indices;

                    nl = x->num_index;
                    nr = y->num_index;

                    if (nr == 1) {
                        SWAP_INDEX();
                    }

                    if (nl == 1) {
                        /*  single index <=> single index  : strong when iv incr is equal
                         *                                 : weak when iv incr is different.
                         *  single index <=> zero index    : weak always(conservative)
                         *  single index <=> record member : type error(maybe bug) */
                        if (nr == 1) {
                            if (il[0].code != ir[0].code) {
                                /* fixme : too complicated */
                                /* a[0] = a[i] + *a++; */
                                append_have_complicated_subscript(errors, y, x, prev_ma, ma, i, tmp_alloc);
                                return 0;
                            }

                            switch (il[0].code) {
                            case CTRUMP_LOOP_INDEX_INDUCTIVE:
                                if (!iv_test(&il[0].u.iv, &ir[0].u.iv)) {
                                    append_have_complicated_subscript(errors, y, x, prev_ma, ma, i, tmp_alloc);
                                    return 0;
                                }

                                strong_siv(&distance, x, y);
                                goto strong_index;

                            case CTRUMP_LOOP_INDEX_POINTER_INC:
                                /* a++; *a = *a */
                                strong_siv(&distance, x, y);
                                goto strong_index;

                            case CTRUMP_LOOP_INDEX_INVARIANT:
                                if (!invariant_test(il[0].u.invariant, ir[0].u.invariant)) {
                                    /* a[var1] = a[var2]; */
                                    /* fixme : create constraint */
                                    append_have_complicated_subscript(errors, y, x, prev_ma, ma, i, tmp_alloc);
                                    return 0;
                                }

                                /* a[var] = a[va]; */
                                if (y->offset != x->offset) {
                                    /* a[var+0] = x[var+1] always has no dependencies */
                                    goto always_independent;
                                }

                                distance.code = CTRUMP_DEPEND_DISTANCE_INVARIANT_ZIV;
                                distance.u.invariant.var = il[0].u.invariant;
                                goto strong_index;
                            }
                        } else {        /* nr == 0 */
                            append_have_weak_subscript(errors, y, x, prev_ma, ma, tmp_alloc);
                            return 0;
                        }
                    } else {            /* nl == 0 && nr == 0 */
                        if (y->offset != x->offset) {
                            goto always_independent;
                        }

                        distance.code = CTRUMP_DEPEND_DISTANCE_CONSTANT_ZIV;
                        goto strong_index;
                    }
                }
 
            strong_index:
                distvec[i] = distance;
            }

        /* have dependency */
        all_strong:
            dv.vector = distvec;
            dv.store = prev_ma;
            dv.load = ma;
            VA_PUSH_P(struct distance_vector, &node->distance_vectors, dv, tmp_alloc);
            return 1;

        always_independent:
            continue;
        }

    } else {
        if (load_store == STORE) {
            struct dependence_info_node *n;
            ai = ctrump_mempool_alloc(tmp_alloc, sizeof(*ai));
            ctrump_varray_init_pool(&ai->nodes, 4, sizeof(*n), tmp_alloc);
            VA_NEWELEM_P(&ai->nodes, tmp_alloc);
            
            n = VA_LAST_PTR(struct dependence_info_node, &ai->nodes);
            ctrump_varray_init_pool(&n->distance_vectors, 4, sizeof(struct distance_vector), tmp_alloc);
            n->first_occur = ma;
            b->val = ai;
        }
    }

    if (load_store == STORE) {
        struct dependence_info_node *n;
        ai = b->val;
        VA_NEWELEM_P(&ai->nodes, tmp_alloc);
        n = VA_LAST_PTR(struct dependence_info_node, &ai->nodes);
        ctrump_varray_init_pool(&n->distance_vectors, 4, sizeof(struct distance_vector), tmp_alloc);
        n->first_occur = ma;
        b->val = ai;
    }


    return 1;
}

static int
get_distance_vector(struct ctrump_loop_info_node *node,
                    struct ctrump_mempool *loop_alloc)
{
    struct ctrump_mempool tmp_alloc;
    struct ctrump_intmap array_map; /* array_var->id -> assert_simple_info */
    struct ctrump_varray errors;

    int have_error_in_inner = 0;
    int have_error = 0;
    int i, j, k, l, n = node->num_child, r;

    for (i=0; i<n; i++) {
        int r = get_distance_vector(node->children[i], loop_alloc);
        if (! r) have_error_in_inner = 1;
    }

    if (have_error_in_inner) {
        node->depinfo.code = CTRUMP_LOOP_DEPINFO_HAVE_ERROR_INNER;
        return 0;
    }

    ctrump_mempool_init(&tmp_alloc, 1024);
    ctrump_intmap_init_pool(&array_map, 23, &tmp_alloc);
    ctrump_varray_init_pool(&errors, 16, sizeof(struct ctrump_loop_dependence_analyze_error), &tmp_alloc);

    n = node->num_parallel_store;
    for (i=0; i<n; i++) {
        struct ctrump_loop_memory_access *ma = &node->parallel_stores[i];
        if (!test_index(&errors, &array_map, ma, &tmp_alloc, STORE)) {
            have_error = 1;
        }
    }

    n = node->num_parallel_load;
    for (i=0; i<n; i++) {
        struct ctrump_loop_memory_access *ma = &node->parallel_loads[i];
        if (!test_index(&errors, &array_map, ma, &tmp_alloc, LOAD)) {
            have_error = 1;
        }
    }

    if (have_error) {
        r = 0;
        node->depinfo.code = CTRUMP_LOOP_DEPINFO_ANALYZE_ERROR;

        node->depinfo.u.error.num_error = errors.nelem;
        node->depinfo.u.error.errors = ctrump_varray_copy(&errors, loop_alloc);
    } else {
        int num_vec_set;
        struct ctrump_intmap_iterator it;
        struct ctrump_intmap_bucket *b;
        node->depinfo.code = CTRUMP_LOOP_DEPINFO;

        num_vec_set = 0;
        /* count num_vector */
        ctrump_intmap_iterator_begin(&it, &array_map);
        while (ctrump_intmap_iterator_next(&b, &it, &array_map)) {
            struct dependence_info *info = b->val;
            int m = info->nodes.nelem;
            struct dependence_info_node *nodes = info->nodes.elements;
            for (j=0; j<m; j++) {
                struct dependence_info_node *node = &nodes[j];
                if (node->distance_vectors.nelem > 0) {
                    num_vec_set ++;
                }
            }
        }

        node->depinfo.u.dep_vector.num_vec_set = num_vec_set;
        node->depinfo.u.dep_vector.vectors = ctrump_mempool_alloc(loop_alloc,
                                                                  sizeof(struct ctrump_dependence_vector_set)*num_vec_set);

        i = 0;

        /* setup distance vector set */
        ctrump_intmap_iterator_begin(&it, &array_map);
        while (ctrump_intmap_iterator_next(&b, &it, &array_map)) {
            struct dependence_info *info = b->val;
            int m = info->nodes.nelem;
            struct dependence_info_node *nodes = info->nodes.elements;
            for (l=0; l<m; l++) {
                struct dependence_info_node *dep_node = &nodes[l];
                if (dep_node->distance_vectors.nelem > 0) {
                    int num_subscript = dep_node->first_occur->num_subscript;
                    int num_vector = dep_node->distance_vectors.nelem;
                    struct ctrump_depend_distance *vectors = ctrump_mempool_alloc(loop_alloc,
                                                                                  sizeof(struct ctrump_depend_distance)*num_subscript*num_vector);
                    struct distance_vector *dv = dep_node->distance_vectors.elements;
                    struct ctrump_loop_memory_access_pair *accesses = ctrump_mempool_alloc(loop_alloc,
                                                                                           sizeof(*accesses)*num_vector);

                    node->depinfo.u.dep_vector.vectors[i].num_subscript = num_subscript;
                    node->depinfo.u.dep_vector.vectors[i].num_vector = num_vector;
                    node->depinfo.u.dep_vector.vectors[i].distance_vectors = vectors;
                    node->depinfo.u.dep_vector.vectors[i].array_var = dep_node->first_occur->array.var;
                    node->depinfo.u.dep_vector.vectors[i].accesses = accesses;

                    for (j=0; j<num_vector; j++) {
                        struct ctrump_depend_distance *v = vectors + j*num_subscript;
                        for (k=0; k<num_subscript; k++) {
                            v[k] = dv[j].vector[k];
                        }

                        accesses[j].store = dv[j].store;
                        accesses[j].load = dv[j].load;
                    }

                    i++;
                }
            }
        }

        r = 1;
    }

    ctrump_mempool_destroy(&tmp_alloc);

    return r;
}

void
ctrump_get_loop_depinfo(struct ctrump_loop_info *loop,
                        int *id,
                        struct ctrump_mempool *loop_alloc)
{
    if (!get_distance_vector(loop->root, loop_alloc)) {
        /* failed : not simple */
        return;
    }
}

---