/* * Copyright 2013 Ecole Normale Superieure * * Use of this software is governed by the MIT license * * Written by Sven Verdoolaege, * Ecole Normale Superieure, 45 rue d'Ulm, 75230 Paris, France */ #include #include #include #include #include "gpu_tree.h" /* The functions in this file are used to navigate part of a schedule tree * that is mapped to blocks. Initially, this part consists of a linear * branch segment with a mark node with name "kernel" on the outer end * and a mark node with name "thread" on the inner end. * During the mapping to blocks, branching may be introduced, but only * one of the elements in each sequence contains the "thread" mark. * The filter of this element (and only this filter) contains * domain elements identified by the "core" argument of the functions * that move down this tree. * * Synchronization statements have a name that starts with "sync" and * a user pointer pointing to the kernel that contains the synchronization. * The functions inserting or detecting synchronizations take a ppcg_kernel * argument to be able to create or identify such statements. * They may also use two fields in this structure, the "core" field * to move around in the tree and the "n_sync" field to make sure that * each synchronization has a different name (within the kernel). */ /* Is "node" a mark node with an identifier called "name"? */ static int is_marked(__isl_keep isl_schedule_node *node, const char *name) { isl_id *mark; int has_name; if (!node) return -1; if (isl_schedule_node_get_type(node) != isl_schedule_node_mark) return 0; mark = isl_schedule_node_mark_get_id(node); if (!mark) return -1; has_name = !strcmp(isl_id_get_name(mark), name); isl_id_free(mark); return has_name; } /* Is "node" a mark node with an identifier called "kernel"? */ int gpu_tree_node_is_kernel(__isl_keep isl_schedule_node *node) { return is_marked(node, "kernel"); } /* Is "node" a mark node with an identifier called "shared"? */ static int node_is_shared(__isl_keep isl_schedule_node *node) { return is_marked(node, "shared"); } /* Is "node" a mark node with an identifier called "thread"? */ static int node_is_thread(__isl_keep isl_schedule_node *node) { return is_marked(node, "thread"); } /* Insert a mark node with identifier "shared" in front of "node". */ static __isl_give isl_schedule_node *insert_shared( __isl_take isl_schedule_node *node) { isl_ctx *ctx; isl_id *id; ctx = isl_schedule_node_get_ctx(node); id = isl_id_alloc(ctx, "shared", NULL); node = isl_schedule_node_insert_mark(node, id); return node; } /* Insert a "shared" mark in front of the "thread" mark * provided the linear branch between "node" and the "thread" mark * does not contain such a "shared" mark already. * * As a side effect, this function checks that the subtree at "node" * actually contains a "thread" mark and that there is no branching * in between "node" and this "thread" mark. */ __isl_give isl_schedule_node *gpu_tree_insert_shared_before_thread( __isl_take isl_schedule_node *node) { int depth0, depth; int any_shared = 0; if (!node) return NULL; depth0 = isl_schedule_node_get_tree_depth(node); for (;;) { int is_thread; int n; if (!any_shared) { any_shared = node_is_shared(node); if (any_shared < 0) return isl_schedule_node_free(node); } is_thread = node_is_thread(node); if (is_thread < 0) return isl_schedule_node_free(node); if (is_thread) break; n = isl_schedule_node_n_children(node); if (n == 0) isl_die(isl_schedule_node_get_ctx(node), isl_error_invalid, "no thread marker found", return isl_schedule_node_free(node)); if (n > 1) isl_die(isl_schedule_node_get_ctx(node), isl_error_invalid, "expecting single thread marker", return isl_schedule_node_free(node)); node = isl_schedule_node_child(node, 0); } if (!any_shared) node = insert_shared(node); depth = isl_schedule_node_get_tree_depth(node); node = isl_schedule_node_ancestor(node, depth - depth0); return node; } /* Assuming "node" is a filter node, does it correspond to the branch * that contains the "thread" mark, i.e., does it contain any elements * in "core"? */ static int node_is_core(__isl_keep isl_schedule_node *node, __isl_keep isl_union_set *core) { int disjoint; isl_union_set *filter; filter = isl_schedule_node_filter_get_filter(node); disjoint = isl_union_set_is_disjoint(filter, core); isl_union_set_free(filter); if (disjoint < 0) return -1; return !disjoint; } /* Move to the only child of "node" that has the "thread" mark as descendant, * where the branch containing this mark is identified by the domain elements * in "core". * * If "node" is not a sequence, then it only has one child and we move * to that single child. * Otherwise, we check each of the filters in the children, pick * the one that corresponds to "core" and return a pointer to the child * of the filter node. */ static __isl_give isl_schedule_node *core_child( __isl_take isl_schedule_node *node, __isl_keep isl_union_set *core) { int i, n; if (isl_schedule_node_get_type(node) != isl_schedule_node_sequence) return isl_schedule_node_child(node, 0); n = isl_schedule_node_n_children(node); for (i = 0; i < n; ++i) { int is_core; node = isl_schedule_node_child(node, i); is_core = node_is_core(node, core); if (is_core < 0) return isl_schedule_node_free(node); if (is_core) return isl_schedule_node_child(node, 0); node = isl_schedule_node_parent(node); } isl_die(isl_schedule_node_get_ctx(node), isl_error_internal, "core child not found", return isl_schedule_node_free(node)); } /* Move down the branch between "kernel" and "thread" until * the "shared" mark is reached, where the branch containing the "shared" * mark is identified by the domain elements in "core". */ __isl_give isl_schedule_node *gpu_tree_move_down_to_shared( __isl_take isl_schedule_node *node, __isl_keep isl_union_set *core) { int is_shared; while ((is_shared = node_is_shared(node)) == 0) node = core_child(node, core); if (is_shared < 0) node = isl_schedule_node_free(node); return node; } /* Move down the branch between "kernel" and "thread" until * the "thread" mark is reached, where the branch containing the "thread" * mark is identified by the domain elements in "core". */ __isl_give isl_schedule_node *gpu_tree_move_down_to_thread( __isl_take isl_schedule_node *node, __isl_keep isl_union_set *core) { int is_thread; while ((is_thread = node_is_thread(node)) == 0) node = core_child(node, core); if (is_thread < 0) node = isl_schedule_node_free(node); return node; } /* Move up the tree underneath the "thread" mark until * the "thread" mark is reached. */ __isl_give isl_schedule_node *gpu_tree_move_up_to_thread( __isl_take isl_schedule_node *node) { int is_thread; while ((is_thread = node_is_thread(node)) == 0) node = isl_schedule_node_parent(node); if (is_thread < 0) node = isl_schedule_node_free(node); return node; } /* Move up the tree underneath the "kernel" mark until * the "kernel" mark is reached. */ __isl_give isl_schedule_node *gpu_tree_move_up_to_kernel( __isl_take isl_schedule_node *node) { int is_kernel; while ((is_kernel = gpu_tree_node_is_kernel(node)) == 0) node = isl_schedule_node_parent(node); if (is_kernel < 0) node = isl_schedule_node_free(node); return node; } /* Move down from the "kernel" mark (or at least a node with schedule * depth smaller than or equal to "depth") to a band node at schedule * depth "depth". The "thread" mark is assumed to have a schedule * depth greater than or equal to "depth". The branch containing the * "thread" mark is identified by the domain elements in "core". * * If the desired schedule depth is in the middle of band node, * then the band node is split into two pieces, the second piece * at the desired schedule depth. */ __isl_give isl_schedule_node *gpu_tree_move_down_to_depth( __isl_take isl_schedule_node *node, int depth, __isl_keep isl_union_set *core) { int is_shared; int is_thread = 0; while (node && isl_schedule_node_get_schedule_depth(node) < depth) { if (isl_schedule_node_get_type(node) == isl_schedule_node_band) { int node_depth, node_dim; node_depth = isl_schedule_node_get_schedule_depth(node); node_dim = isl_schedule_node_band_n_member(node); if (node_depth + node_dim > depth) node = isl_schedule_node_band_split(node, depth - node_depth); } node = core_child(node, core); } while ((is_shared = node_is_shared(node)) == 0 && (is_thread = node_is_thread(node)) == 0 && isl_schedule_node_get_type(node) != isl_schedule_node_band) node = core_child(node, core); if (is_shared < 0 || is_thread < 0) node = isl_schedule_node_free(node); return node; } /* Create a union set containing a single set with a tuple identifier * called "syncX" and user pointer equal to "kernel". */ static __isl_give isl_union_set *create_sync_domain(struct ppcg_kernel *kernel) { isl_space *space; isl_id *id; char name[40]; space = isl_space_set_alloc(kernel->ctx, 0, 0); snprintf(name, sizeof(name), "sync%d", kernel->n_sync++); id = isl_id_alloc(kernel->ctx, name, kernel); space = isl_space_set_tuple_id(space, isl_dim_set, id); return isl_union_set_from_set(isl_set_universe(space)); } /* Is "id" the identifier of a synchronization statement inside "kernel"? * That is, does its name start with "sync" and does it point to "kernel"? */ int gpu_tree_id_is_sync(__isl_keep isl_id *id, struct ppcg_kernel *kernel) { const char *name; name = isl_id_get_name(id); if (!name) return 0; else if (strncmp(name, "sync", 4)) return 0; return isl_id_get_user(id) == kernel; } /* Does "domain" consist of a single set with a tuple identifier * corresponding to a synchronization for "kernel"? */ static int domain_is_sync(__isl_keep isl_union_set *domain, struct ppcg_kernel *kernel) { int is_sync; isl_id *id; isl_set *set; if (isl_union_set_n_set(domain) != 1) return 0; set = isl_set_from_union_set(isl_union_set_copy(domain)); id = isl_set_get_tuple_id(set); is_sync = gpu_tree_id_is_sync(id, kernel); isl_id_free(id); isl_set_free(set); return is_sync; } /* Does "node" point to a filter selecting a synchronization statement * for "kernel"? */ static int node_is_sync_filter(__isl_keep isl_schedule_node *node, struct ppcg_kernel *kernel) { int is_sync; enum isl_schedule_node_type type; isl_union_set *domain; if (!node) return -1; type = isl_schedule_node_get_type(node); if (type != isl_schedule_node_filter) return 0; domain = isl_schedule_node_filter_get_filter(node); is_sync = domain_is_sync(domain, kernel); isl_union_set_free(domain); return is_sync; } /* Is "node" part of a sequence with a previous synchronization statement * for "kernel"? * That is, is the parent of "node" a filter such that there is * a previous filter that picks out exactly such a synchronization statement? */ static int has_preceding_sync(__isl_keep isl_schedule_node *node, struct ppcg_kernel *kernel) { int found = 0; node = isl_schedule_node_copy(node); node = isl_schedule_node_parent(node); while (!found && isl_schedule_node_has_previous_sibling(node)) { node = isl_schedule_node_previous_sibling(node); if (!node) break; found = node_is_sync_filter(node, kernel); } if (!node) found = -1; isl_schedule_node_free(node); return found; } /* Is "node" part of a sequence with a subsequent synchronization statement * for "kernel"? * That is, is the parent of "node" a filter such that there is * a subsequent filter that picks out exactly such a synchronization statement? */ static int has_following_sync(__isl_keep isl_schedule_node *node, struct ppcg_kernel *kernel) { int found = 0; node = isl_schedule_node_copy(node); node = isl_schedule_node_parent(node); while (!found && isl_schedule_node_has_next_sibling(node)) { node = isl_schedule_node_next_sibling(node); if (!node) break; found = node_is_sync_filter(node, kernel); } if (!node) found = -1; isl_schedule_node_free(node); return found; } /* Does the subtree rooted at "node" (which is a band node) contain * any synchronization statement for "kernel" that precedes * the core computation of "kernel" (identified by the elements * in kernel->core)? */ static int has_sync_before_core(__isl_keep isl_schedule_node *node, struct ppcg_kernel *kernel) { int has_sync = 0; int is_thread; node = isl_schedule_node_copy(node); while ((is_thread = node_is_thread(node)) == 0) { node = core_child(node, kernel->core); has_sync = has_preceding_sync(node, kernel); if (has_sync < 0 || has_sync) break; } if (is_thread < 0 || !node) has_sync = -1; isl_schedule_node_free(node); return has_sync; } /* Does the subtree rooted at "node" (which is a band node) contain * any synchronization statement for "kernel" that follows * the core computation of "kernel" (identified by the elements * in kernel->core)? */ static int has_sync_after_core(__isl_keep isl_schedule_node *node, struct ppcg_kernel *kernel) { int has_sync = 0; int is_thread; node = isl_schedule_node_copy(node); while ((is_thread = node_is_thread(node)) == 0) { node = core_child(node, kernel->core); has_sync = has_following_sync(node, kernel); if (has_sync < 0 || has_sync) break; } if (is_thread < 0 || !node) has_sync = -1; isl_schedule_node_free(node); return has_sync; } /* Insert (or extend) an extension on top of "node" that puts * a synchronization node for "kernel" before "node". * Return a pointer to the original node in the updated schedule tree. */ static __isl_give isl_schedule_node *insert_sync_before( __isl_take isl_schedule_node *node, struct ppcg_kernel *kernel) { isl_union_set *domain; isl_schedule_node *graft; if (!node) return NULL; domain = create_sync_domain(kernel); graft = isl_schedule_node_from_domain(domain); node = isl_schedule_node_graft_before(node, graft); return node; } /* Insert (or extend) an extension on top of "node" that puts * a synchronization node for "kernel" afater "node". * Return a pointer to the original node in the updated schedule tree. */ static __isl_give isl_schedule_node *insert_sync_after( __isl_take isl_schedule_node *node, struct ppcg_kernel *kernel) { isl_union_set *domain; isl_schedule_node *graft; if (!node) return NULL; domain = create_sync_domain(kernel); graft = isl_schedule_node_from_domain(domain); node = isl_schedule_node_graft_after(node, graft); return node; } /* Insert an extension on top of "node" that puts a synchronization node * for "kernel" before "node" unless there already is * such a synchronization node. */ __isl_give isl_schedule_node *gpu_tree_ensure_preceding_sync( __isl_take isl_schedule_node *node, struct ppcg_kernel *kernel) { int has_sync; has_sync = has_preceding_sync(node, kernel); if (has_sync < 0) return isl_schedule_node_free(node); if (has_sync) return node; return insert_sync_before(node, kernel); } /* Insert an extension on top of "node" that puts a synchronization node * for "kernel" after "node" unless there already is * such a synchronization node. */ __isl_give isl_schedule_node *gpu_tree_ensure_following_sync( __isl_take isl_schedule_node *node, struct ppcg_kernel *kernel) { int has_sync; has_sync = has_following_sync(node, kernel); if (has_sync < 0) return isl_schedule_node_free(node); if (has_sync) return node; return insert_sync_after(node, kernel); } /* Insert an extension on top of "node" that puts a synchronization node * for "kernel" after "node" unless there already is such a sync node or * "node" itself already * contains a synchronization node following * the core computation of "kernel". */ __isl_give isl_schedule_node *gpu_tree_ensure_sync_after_core( __isl_take isl_schedule_node *node, struct ppcg_kernel *kernel) { int has_sync; has_sync = has_sync_after_core(node, kernel); if (has_sync < 0) return isl_schedule_node_free(node); if (has_sync) return node; has_sync = has_following_sync(node, kernel); if (has_sync < 0) return isl_schedule_node_free(node); if (has_sync) return node; return insert_sync_after(node, kernel); } /* Move left in the sequence on top of "node" to a synchronization node * for "kernel". * If "node" itself contains a synchronization node preceding * the core computation of "kernel", then return "node" itself. * Otherwise, if "node" does not have a preceding synchronization node, * then create one first. */ __isl_give isl_schedule_node *gpu_tree_move_left_to_sync( __isl_take isl_schedule_node *node, struct ppcg_kernel *kernel) { int has_sync; int is_sync; has_sync = has_sync_before_core(node, kernel); if (has_sync < 0) return isl_schedule_node_free(node); if (has_sync) return node; node = gpu_tree_ensure_preceding_sync(node, kernel); node = isl_schedule_node_parent(node); while ((is_sync = node_is_sync_filter(node, kernel)) == 0) node = isl_schedule_node_previous_sibling(node); if (is_sync < 0) node = isl_schedule_node_free(node); node = isl_schedule_node_child(node, 0); return node; } /* Move right in the sequence on top of "node" to a synchronization node * for "kernel". * If "node" itself contains a synchronization node following * the core computation of "kernel", then return "node" itself. * Otherwise, if "node" does not have a following synchronization node, * then create one first. */ __isl_give isl_schedule_node *gpu_tree_move_right_to_sync( __isl_take isl_schedule_node *node, struct ppcg_kernel *kernel) { int has_sync; int is_sync; has_sync = has_sync_after_core(node, kernel); if (has_sync < 0) return isl_schedule_node_free(node); if (has_sync) return node; node = gpu_tree_ensure_following_sync(node, kernel); node = isl_schedule_node_parent(node); while ((is_sync = node_is_sync_filter(node, kernel)) == 0) node = isl_schedule_node_next_sibling(node); if (is_sync < 0) node = isl_schedule_node_free(node); node = isl_schedule_node_child(node, 0); return node; }