llvm-project/polly/lib/External/ppcg/gpu_tree.c

641 lines
18 KiB
C

/*
* 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 <string.h>
#include <isl/set.h>
#include <isl/union_set.h>
#include <isl/space.h>
#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;
}