[Mesa-dev] [PATCH 157/133] nir/vars_to_ssa: Use the copy lowering from lower_var_copies
Jason Ekstrand
jason at jlekstrand.net
Wed Jan 14 15:28:37 PST 2015
---
src/glsl/nir/nir_lower_vars_to_ssa.c | 187 +++++++++--------------------------
1 file changed, 46 insertions(+), 141 deletions(-)
diff --git a/src/glsl/nir/nir_lower_vars_to_ssa.c b/src/glsl/nir/nir_lower_vars_to_ssa.c
index 222ddcd..7fe10e9 100644
--- a/src/glsl/nir/nir_lower_vars_to_ssa.c
+++ b/src/glsl/nir/nir_lower_vars_to_ssa.c
@@ -69,6 +69,14 @@ struct lower_variables_state {
*/
struct hash_table *direct_deref_nodes;
+ /* Controls whether get_deref_node will add variables to the
+ * direct_deref_nodes table. This is turned on when we are initially
+ * scanning for load/store instructions. It is then turned off so we
+ * don't accidentally change the direct_deref_nodes table while we're
+ * iterating throug it.
+ */
+ bool add_to_direct_deref_nodes;
+
/* A hash table mapping phi nodes to deref_state data */
struct hash_table *phi_table;
};
@@ -212,12 +220,11 @@ get_deref_node_for_var(nir_variable *var, struct lower_variables_state *state)
/* Gets the deref_node for the given deref chain and creates it if it
* doesn't yet exist. If the deref is fully-qualified and direct and
- * add_to_direct_deref_nodes is true, it will be added to the hash table of
- * of fully-qualified direct derefs.
+ * state->add_to_direct_deref_nodes is true, it will be added to the hash
+ * table of of fully-qualified direct derefs.
*/
static struct deref_node *
-get_deref_node(nir_deref_var *deref, bool add_to_direct_deref_nodes,
- struct lower_variables_state *state)
+get_deref_node(nir_deref_var *deref, struct lower_variables_state *state)
{
bool is_direct = true;
@@ -289,7 +296,7 @@ get_deref_node(nir_deref_var *deref, bool add_to_direct_deref_nodes,
assert(node);
- if (is_direct && add_to_direct_deref_nodes)
+ if (is_direct && state->add_to_direct_deref_nodes)
_mesa_hash_table_insert(state->direct_deref_nodes,
hash_deref(deref), deref, node);
@@ -355,7 +362,7 @@ foreach_deref_node_match(nir_deref_var *deref,
{
nir_deref_var var_deref = *deref;
var_deref.deref.child = NULL;
- struct deref_node *node = get_deref_node(&var_deref, false, state);
+ struct deref_node *node = get_deref_node(&var_deref, state);
if (node == NULL)
return false;
@@ -430,11 +437,10 @@ deref_may_be_aliased(nir_deref_var *deref,
}
static void
-register_load_instr(nir_intrinsic_instr *load_instr, bool create_node,
+register_load_instr(nir_intrinsic_instr *load_instr,
struct lower_variables_state *state)
{
- struct deref_node *node = get_deref_node(load_instr->variables[0],
- create_node, state);
+ struct deref_node *node = get_deref_node(load_instr->variables[0], state);
if (node == NULL)
return;
@@ -446,11 +452,10 @@ register_load_instr(nir_intrinsic_instr *load_instr, bool create_node,
}
static void
-register_store_instr(nir_intrinsic_instr *store_instr, bool create_node,
+register_store_instr(nir_intrinsic_instr *store_instr,
struct lower_variables_state *state)
{
- struct deref_node *node = get_deref_node(store_instr->variables[0],
- create_node, state);
+ struct deref_node *node = get_deref_node(store_instr->variables[0], state);
if (node == NULL)
return;
@@ -462,12 +467,13 @@ register_store_instr(nir_intrinsic_instr *store_instr, bool create_node,
}
static void
-register_copy_instr(nir_intrinsic_instr *copy_instr, bool create_node,
+register_copy_instr(nir_intrinsic_instr *copy_instr,
struct lower_variables_state *state)
{
for (unsigned idx = 0; idx < 2; idx++) {
- struct deref_node *node = get_deref_node(copy_instr->variables[idx],
- create_node, state);
+ struct deref_node *node =
+ get_deref_node(copy_instr->variables[idx], state);
+
if (node == NULL)
continue;
@@ -493,15 +499,15 @@ register_variable_uses_block(nir_block *block, void *void_state)
switch (intrin->intrinsic) {
case nir_intrinsic_load_var:
- register_load_instr(intrin, true, state);
+ register_load_instr(intrin, state);
break;
case nir_intrinsic_store_var:
- register_store_instr(intrin, true, state);
+ register_store_instr(intrin, state);
break;
case nir_intrinsic_copy_var:
- register_copy_instr(intrin, true, state);
+ register_copy_instr(intrin, state);
break;
default:
@@ -512,27 +518,6 @@ register_variable_uses_block(nir_block *block, void *void_state)
return true;
}
-/* Walks down the deref chain and returns the next deref in the chain whose
- * child is a wildcard. In other words, given the chain a[1].foo[*].bar,
- * this function will return the deref to foo. Calling it a second time
- * with the [*].bar, it will return NULL.
- */
-static nir_deref *
-deref_next_wildcard_parent(nir_deref *deref)
-{
- for (nir_deref *tail = deref; tail->child; tail = tail->child) {
- if (tail->child->deref_type != nir_deref_type_array)
- continue;
-
- nir_deref_array *arr = nir_deref_as_array(tail->child);
-
- if (arr->deref_array_type == nir_deref_array_type_wildcard)
- return tail;
- }
-
- return NULL;
-}
-
/* Returns the last deref in the chain.
*/
static nir_deref *
@@ -544,96 +529,6 @@ get_deref_tail(nir_deref *deref)
return deref;
}
-/* This function recursively walks the given deref chain and replaces the
- * given copy instruction with an equivalent sequence load/store
- * operations.
- *
- * @copy_instr The copy instruction to replace; new instructions will be
- * inserted before this one
- *
- * @dest_head The head of the destination variable deref chain
- *
- * @src_head The head of the source variable deref chain
- *
- * @dest_tail The current tail of the destination variable deref chain;
- * this is used for recursion and external callers of this
- * function should call it with tail == head
- *
- * @src_tail The current tail of the source variable deref chain;
- * this is used for recursion and external callers of this
- * function should call it with tail == head
- *
- * @state The current variable lowering state
- */
-static void
-emit_copy_load_store(nir_intrinsic_instr *copy_instr,
- nir_deref_var *dest_head, nir_deref_var *src_head,
- nir_deref *dest_tail, nir_deref *src_tail,
- struct lower_variables_state *state)
-{
- /* Find the next pair of wildcards */
- nir_deref *src_arr_parent = deref_next_wildcard_parent(src_tail);
- nir_deref *dest_arr_parent = deref_next_wildcard_parent(dest_tail);
-
- if (src_arr_parent || dest_arr_parent) {
- /* Wildcards had better come in matched pairs */
- assert(dest_arr_parent && dest_arr_parent);
-
- nir_deref_array *src_arr = nir_deref_as_array(src_arr_parent->child);
- nir_deref_array *dest_arr = nir_deref_as_array(dest_arr_parent->child);
-
- unsigned length = type_get_length(src_arr_parent->type);
- /* The wildcards should represent the same number of elements */
- assert(length == type_get_length(dest_arr_parent->type));
- assert(length > 0);
-
- /* Walk over all of the elements that this wildcard refers to and
- * call emit_copy_load_store on each one of them */
- src_arr->deref_array_type = nir_deref_array_type_direct;
- dest_arr->deref_array_type = nir_deref_array_type_direct;
- for (unsigned i = 0; i < length; i++) {
- src_arr->base_offset = i;
- dest_arr->base_offset = i;
- emit_copy_load_store(copy_instr, dest_head, src_head,
- &dest_arr->deref, &src_arr->deref, state);
- }
- src_arr->deref_array_type = nir_deref_array_type_wildcard;
- dest_arr->deref_array_type = nir_deref_array_type_wildcard;
- } else {
- /* In this case, we have no wildcards anymore, so all we have to do
- * is just emit the load and store operations. */
- src_tail = get_deref_tail(src_tail);
- dest_tail = get_deref_tail(dest_tail);
-
- assert(src_tail->type == dest_tail->type);
-
- unsigned num_components = glsl_get_vector_elements(src_tail->type);
-
- nir_deref *src_deref = nir_copy_deref(state->mem_ctx, &src_head->deref);
- nir_deref *dest_deref = nir_copy_deref(state->mem_ctx, &dest_head->deref);
-
- nir_intrinsic_instr *load =
- nir_intrinsic_instr_create(state->mem_ctx, nir_intrinsic_load_var);
- load->num_components = num_components;
- load->variables[0] = nir_deref_as_var(src_deref);
- load->dest.is_ssa = true;
- nir_ssa_def_init(&load->instr, &load->dest.ssa, num_components, NULL);
-
- nir_instr_insert_before(©_instr->instr, &load->instr);
- register_load_instr(load, false, state);
-
- nir_intrinsic_instr *store =
- nir_intrinsic_instr_create(state->mem_ctx, nir_intrinsic_store_var);
- store->num_components = num_components;
- store->variables[0] = nir_deref_as_var(dest_deref);
- store->src[0].is_ssa = true;
- store->src[0].ssa = &load->dest.ssa;
-
- nir_instr_insert_before(©_instr->instr, &store->instr);
- register_store_instr(store, false, state);
- }
-}
-
/* Walks over all of the copy instructions to or from the given deref_node
* and lowers them to load/store intrinsics.
*/
@@ -648,14 +543,12 @@ lower_copies_to_load_store(struct deref_node *node,
set_foreach(node->copies, copy_entry) {
nir_intrinsic_instr *copy = (void *)copy_entry->key;
- emit_copy_load_store(copy, copy->variables[0], copy->variables[1],
- ©->variables[0]->deref,
- ©->variables[1]->deref,
- state);
+ nir_lower_var_copy_instr(copy, state->mem_ctx);
for (unsigned i = 0; i < 2; ++i) {
- struct deref_node *arg_node = get_deref_node(copy->variables[i],
- false, state);
+ struct deref_node *arg_node =
+ get_deref_node(copy->variables[i], state);
+
if (arg_node == NULL)
continue;
@@ -873,8 +766,8 @@ rename_variables_block(nir_block *block, struct lower_variables_state *state)
switch (intrin->intrinsic) {
case nir_intrinsic_load_var: {
- struct deref_node *node = get_deref_node(intrin->variables[0],
- false, state);
+ struct deref_node *node =
+ get_deref_node(intrin->variables[0], state);
if (node == NULL) {
/* If we hit this path then we are referencing an invalid
@@ -930,8 +823,8 @@ rename_variables_block(nir_block *block, struct lower_variables_state *state)
}
case nir_intrinsic_store_var: {
- struct deref_node *node = get_deref_node(intrin->variables[0],
- false, state);
+ struct deref_node *node =
+ get_deref_node(intrin->variables[0], state);
if (node == NULL) {
/* Probably an out-of-bounds array store. That should be a
@@ -1010,8 +903,7 @@ rename_variables_block(nir_block *block, struct lower_variables_state *state)
if (intrin->intrinsic != nir_intrinsic_store_var)
continue;
- struct deref_node *node = get_deref_node(intrin->variables[0],
- false, state);
+ struct deref_node *node = get_deref_node(intrin->variables[0], state);
if (!node)
continue;
@@ -1157,6 +1049,8 @@ nir_lower_vars_to_ssa_impl(nir_function_impl *impl)
state.phi_table = _mesa_hash_table_create(state.dead_ctx,
_mesa_key_pointer_equal);
+ /* Build the initial deref structures and direct_deref_nodes table */
+ state.add_to_direct_deref_nodes = true;
nir_foreach_block(impl, register_variable_uses_block, &state);
struct set *outputs = _mesa_set_create(state.dead_ctx,
@@ -1166,6 +1060,9 @@ nir_lower_vars_to_ssa_impl(nir_function_impl *impl)
nir_metadata_require(impl, nir_metadata_block_index);
+ /* We're about to iterate through direct_deref_nodes. Don't modify it. */
+ state.add_to_direct_deref_nodes = false;
+
struct hash_entry *entry;
hash_table_foreach(state.direct_deref_nodes, entry) {
nir_deref_var *deref = (void *)entry->key;
@@ -1203,6 +1100,14 @@ nir_lower_vars_to_ssa_impl(nir_function_impl *impl)
nir_metadata_require(impl, nir_metadata_dominance);
+ /* We may have lowered some copy instructions to load/store
+ * instructions. The uses from the copy instructions hav already been
+ * removed but we need to rescan to ensure that the uses from the newly
+ * added load/store instructions are registered. We need this
+ * information for phi node insertion below.
+ */
+ nir_foreach_block(impl, register_variable_uses_block, &state);
+
insert_phi_nodes(&state);
rename_variables_block(impl->start_block, &state);
--
2.2.1
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