diff options
| -rw-r--r-- | src/glsl/Makefile.sources | 1 | ||||
| -rw-r--r-- | src/glsl/nir/nir.h | 2 | ||||
| -rw-r--r-- | src/glsl/nir/nir_lower_variables.c | 1066 |
3 files changed, 1069 insertions, 0 deletions
diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources index 84245bc..1d3b049 100644 --- a/src/glsl/Makefile.sources +++ b/src/glsl/Makefile.sources @@ -24,6 +24,7 @@ NIR_FILES = \ $(GLSL_SRCDIR)/nir/nir_lower_atomics.c \ $(GLSL_SRCDIR)/nir/nir_lower_samplers.cpp \ $(GLSL_SRCDIR)/nir/nir_lower_system_values.c \ + $(GLSL_SRCDIR)/nir/nir_lower_variables.c \ $(GLSL_SRCDIR)/nir/nir_lower_variables_scalar.c \ $(GLSL_SRCDIR)/nir/nir_lower_vec_to_movs.c \ $(GLSL_SRCDIR)/nir/nir_metadata.c \ diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h index 8664fc8..9d207bd 100644 --- a/src/glsl/nir/nir.h +++ b/src/glsl/nir/nir.h @@ -1358,6 +1358,8 @@ void nir_dump_cfg(nir_shader *shader, FILE *fp); void nir_split_var_copies(nir_shader *shader); +void nir_lower_variables(nir_shader *shader); + void nir_lower_variables_scalar(nir_shader *shader, bool lower_globals, bool lower_io, bool add_names, bool native_integers); diff --git a/src/glsl/nir/nir_lower_variables.c b/src/glsl/nir/nir_lower_variables.c new file mode 100644 index 0000000..ed3e0fd --- /dev/null +++ b/src/glsl/nir/nir_lower_variables.c @@ -0,0 +1,1066 @@ +/* + * Copyright © 2014 Intel Corporation + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + * + * Authors: + * Jason Ekstrand (jason@jlekstrand.net) + * + */ + +#include "nir.h" + +struct deref_node { + struct deref_node *parent; + const struct glsl_type *type; + + bool lower_to_ssa; + + struct set *loads; + struct set *stores; + struct set *copies; + + nir_ssa_def **def_stack; + nir_ssa_def **def_stack_tail; + + struct deref_node *wildcard; + struct deref_node *indirect; + struct deref_node *children[0]; +}; + +struct lower_variables_state { + void *mem_ctx; + void *dead_ctx; + nir_function_impl *impl; + + /* A hash table mapping variables to deref_node data */ + struct hash_table *deref_var_nodes; + /* A hash table mapping dereference leaves to deref_node data */ + struct hash_table *deref_leaves; + + /* A hash table mapping phi nodes to deref_state data */ + struct hash_table *phi_table; +}; + +/* The following two functions implement a hash and equality check for + * variable dreferences. When the hash or equality function encounters an + * array, all indirects are treated as equal and are never equal to a + * direct dereference or a wildcard. + */ +static uint32_t +hash_deref(const void *void_deref) +{ + const nir_deref *deref = void_deref; + + uint32_t hash; + if (deref->child) { + hash = hash_deref(deref->child); + } else { + hash = 2166136261ul; + } + + switch (deref->deref_type) { + case nir_deref_type_var: + hash ^= _mesa_hash_pointer(nir_deref_as_var(deref)->var); + break; + case nir_deref_type_array: { + nir_deref_array *array = nir_deref_as_array(deref); + hash += 268435183 * array->deref_array_type; + if (array->deref_array_type == nir_deref_array_type_direct) + hash ^= array->base_offset; /* Some prime */ + break; + } + case nir_deref_type_struct: + hash ^= nir_deref_as_struct(deref)->index; + break; + } + + return hash * 0x01000193; +} + +static bool +derefs_equal(const void *void_a, const void *void_b) +{ + const nir_deref *a = void_a; + const nir_deref *b = void_b; + + if (a->deref_type != b->deref_type) + return false; + + switch (a->deref_type) { + case nir_deref_type_var: + if (nir_deref_as_var(a)->var != nir_deref_as_var(b)->var) + return false; + break; + case nir_deref_type_array: { + nir_deref_array *a_arr = nir_deref_as_array(a); + nir_deref_array *b_arr = nir_deref_as_array(b); + + if (a_arr->deref_array_type != b_arr->deref_array_type) + return false; + + if (a_arr->deref_array_type == nir_deref_array_type_direct && + a_arr->base_offset != b_arr->base_offset) + return false; + break; + } + case nir_deref_type_struct: + if (nir_deref_as_struct(a)->index != nir_deref_as_struct(b)->index) + return false; + break; + default: + unreachable("Invalid dreference type"); + } + + assert((a->child == NULL) == (b->child == NULL)); + if (a->child) + return derefs_equal(a->child, b->child); + else + return true; +} + +static int +type_get_length(const struct glsl_type *type) +{ + switch (glsl_get_base_type(type)) { + case GLSL_TYPE_STRUCT: + case GLSL_TYPE_ARRAY: + return glsl_get_length(type); + case GLSL_TYPE_FLOAT: + case GLSL_TYPE_INT: + case GLSL_TYPE_UINT: + case GLSL_TYPE_BOOL: + if (glsl_type_is_matrix(type)) + return glsl_get_matrix_columns(type); + else + return glsl_get_vector_elements(type); + default: + unreachable("Invalid deref base type"); + } +} + +static struct deref_node * +deref_node_create(struct deref_node *parent, + const struct glsl_type *type, void *mem_ctx) +{ + size_t size = sizeof(struct deref_node) + + type_get_length(type) * sizeof(struct deref_node *); + + struct deref_node *node = rzalloc_size(mem_ctx, size); + node->type = type; + node->parent = parent; + + return node; +} + +static struct deref_node * +get_deref_node(nir_deref_var *deref, bool add_to_leaves, + struct lower_variables_state *state) +{ + bool is_leaf = true; + struct deref_node *parent = NULL; + nir_deref *tail = &deref->deref; + while (tail) { + struct deref_node *node; + + switch (tail->deref_type) { + case nir_deref_type_var: { + assert(tail == &deref->deref); + assert(parent == NULL); + + struct hash_entry *entry = + _mesa_hash_table_search(state->deref_var_nodes, deref->var); + if (entry) { + node = entry->data; + } else { + node = deref_node_create(NULL, tail->type, state->dead_ctx); + _mesa_hash_table_insert(state->deref_var_nodes, deref->var, node); + } + break; + } + + case nir_deref_type_struct: { + assert(parent != NULL); + + nir_deref_struct *deref_struct = nir_deref_as_struct(tail); + assert(deref_struct->index < type_get_length(parent->type)); + if (parent->children[deref_struct->index]) { + node = parent->children[deref_struct->index]; + } else { + node = deref_node_create(parent, tail->type, state->dead_ctx); + parent->children[deref_struct->index] = node; + } + break; + } + + case nir_deref_type_array: { + assert(parent != NULL); + + nir_deref_array *arr = nir_deref_as_array(tail); + switch (arr->deref_array_type) { + case nir_deref_array_type_direct: + if (arr->base_offset >= type_get_length(parent->type)) { + /* This is possible if a loop unrolls and generates an + * out-of-bounds offset. We need to handle this at least + * somewhat gracefully. + */ + return NULL; + } else if (parent->children[arr->base_offset]) { + node = parent->children[arr->base_offset]; + } else { + node = deref_node_create(parent, tail->type, state->dead_ctx); + parent->children[arr->base_offset] = node; + } + break; + case nir_deref_array_type_indirect: + if (parent->indirect) { + node = parent->indirect; + } else { + node = deref_node_create(parent, tail->type, state->dead_ctx); + parent->indirect = node; + } + is_leaf = false; + break; + case nir_deref_array_type_wildcard: + if (parent->wildcard) { + node = parent->wildcard; + } else { + node = deref_node_create(parent, tail->type, state->dead_ctx); + parent->wildcard = node; + } + is_leaf = false; + break; + default: + unreachable("Invalid array deref type"); + } + break; + } + default: + unreachable("Invalid deref type"); + } + + parent = node; + tail = tail->child; + } + + assert(parent); + + if (is_leaf && add_to_leaves) + _mesa_hash_table_insert(state->deref_leaves, deref, parent); + + return parent; +} + +static void +register_load_instr(nir_intrinsic_instr *load_instr, bool create_node, + struct lower_variables_state *state) +{ + struct deref_node *node = get_deref_node(load_instr->variables[0], + create_node, state); + if (node == NULL) + return; + + if (node->loads == NULL) + node->loads = _mesa_set_create(state->dead_ctx, + _mesa_key_pointer_equal); + + _mesa_set_add(node->loads, _mesa_hash_pointer(load_instr), load_instr); +} + +static void +register_store_instr(nir_intrinsic_instr *store_instr, bool create_node, + struct lower_variables_state *state) +{ + struct deref_node *node = get_deref_node(store_instr->variables[0], + create_node, state); + if (node == NULL) + return; + + if (node->stores == NULL) + node->stores = _mesa_set_create(state->dead_ctx, + _mesa_key_pointer_equal); + + _mesa_set_add(node->stores, _mesa_hash_pointer(store_instr), store_instr); +} + +static void +register_copy_instr(nir_intrinsic_instr *copy_instr, bool create_node, + 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); + if (node == NULL) + continue; + + if (node->copies == NULL) + node->copies = _mesa_set_create(state->dead_ctx, + _mesa_key_pointer_equal); + + _mesa_set_add(node->copies, _mesa_hash_pointer(copy_instr), copy_instr); + } +} + +static bool +foreach_deref_node_worker(struct deref_node *node, nir_deref *deref, + bool (* cb)(struct deref_node *node, + struct lower_variables_state *state), + struct lower_variables_state *state) +{ + if (deref->child == NULL) { + return cb(node, state); + } else { + switch (deref->child->deref_type) { + case nir_deref_type_array: { + nir_deref_array *arr = nir_deref_as_array(deref->child); + assert(arr->deref_array_type == nir_deref_array_type_direct); + if (node->children[arr->base_offset] && + !foreach_deref_node_worker(node->children[arr->base_offset], + deref->child, cb, state)) + return false; + + if (node->wildcard && + !foreach_deref_node_worker(node->wildcard, + deref->child, cb, state)) + return false; + + return true; + } + + case nir_deref_type_struct: { + nir_deref_struct *str = nir_deref_as_struct(deref->child); + return foreach_deref_node_worker(node->children[str->index], + deref->child, cb, state); + } + + default: + unreachable("Invalid deref child type"); + } + } +} + +static bool +foreach_deref_node_match(nir_deref_var *deref, + bool (* cb)(struct deref_node *node, + struct lower_variables_state *state), + struct lower_variables_state *state) +{ + nir_deref_var var_deref = *deref; + var_deref.deref.child = NULL; + struct deref_node *node = get_deref_node(&var_deref, false, state); + + if (node == NULL) + return false; + + return foreach_deref_node_worker(node, &deref->deref, cb, state); +} + +/* This question can only be asked about leaves. Searching down the tree + * is much harder than searching up. + */ +static bool +deref_may_be_aliased_node(struct deref_node *node, nir_deref *deref, + struct lower_variables_state *state) +{ + if (deref->child == NULL) { + return false; + } else { + switch (deref->child->deref_type) { + case nir_deref_type_array: { + nir_deref_array *arr = nir_deref_as_array(deref->child); + if (arr->deref_array_type == nir_deref_array_type_indirect) + return true; + + assert(arr->deref_array_type == nir_deref_array_type_direct); + + if (node->children[arr->base_offset] && + deref_may_be_aliased_node(node->children[arr->base_offset], + deref->child, state)) + return true; + + if (node->wildcard && + deref_may_be_aliased_node(node->wildcard, deref->child, state)) + return true; + + return false; + } + + case nir_deref_type_struct: { + nir_deref_struct *str = nir_deref_as_struct(deref->child); + if (node->children[str->index]) { + return deref_may_be_aliased_node(node->children[str->index], + deref->child, state); + } else { + return false; + } + } + + default: + unreachable("Invalid nir_deref child type"); + } + } +} + +static bool +deref_may_be_aliased(nir_deref_var *deref, + struct lower_variables_state *state) +{ + nir_deref_var var_deref = *deref; + var_deref.deref.child = NULL; + struct deref_node *node = get_deref_node(&var_deref, false, state); + + /* An invalid dereference can't be aliased. */ + if (node == NULL) + return false; + + return deref_may_be_aliased_node(node, &deref->deref, state); +} + +static bool +fill_deref_tables_block(nir_block *block, void *void_state) +{ + struct lower_variables_state *state = void_state; + + nir_foreach_instr_safe(block, instr) { + if (instr->type != nir_instr_type_intrinsic) + continue; + + nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); + + switch (intrin->intrinsic) { + case nir_intrinsic_load_var_vec1: + case nir_intrinsic_load_var_vec2: + case nir_intrinsic_load_var_vec3: + case nir_intrinsic_load_var_vec4: + register_load_instr(intrin, true, state); + break; + + case nir_intrinsic_store_var_vec1: + case nir_intrinsic_store_var_vec2: + case nir_intrinsic_store_var_vec3: + case nir_intrinsic_store_var_vec4: + register_store_instr(intrin, true, state); + break; + + case nir_intrinsic_copy_var: + register_copy_instr(intrin, true, state); + break; + + default: + continue; + } + } + + return true; +} + +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; +} + +static nir_deref * +get_deref_tail(nir_deref *deref) +{ + while (deref->child) + deref = deref->child; + + return deref; +} + +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) +{ + 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) { + 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); + assert(length == type_get_length(dest_arr_parent->type)); + assert(length > 0); + + 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 { + /* Base case. Actually do the copy */ + 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_op load_op; + switch (num_components) { + case 1: load_op = nir_intrinsic_load_var_vec1; break; + case 2: load_op = nir_intrinsic_load_var_vec2; break; + case 3: load_op = nir_intrinsic_load_var_vec3; break; + case 4: load_op = nir_intrinsic_load_var_vec4; break; + default: unreachable("Invalid number of components"); break; + } + + nir_intrinsic_instr *load = nir_intrinsic_instr_create(state->mem_ctx, + load_op); + 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_op store_op; + switch (num_components) { + case 1: store_op = nir_intrinsic_store_var_vec1; break; + case 2: store_op = nir_intrinsic_store_var_vec2; break; + case 3: store_op = nir_intrinsic_store_var_vec3; break; + case 4: store_op = nir_intrinsic_store_var_vec4; break; + default: unreachable("Invalid number of components"); break; + } + + nir_intrinsic_instr *store = nir_intrinsic_instr_create(state->mem_ctx, + store_op); + store->variables[0] = nir_deref_as_var(dest_deref); + store->src[0].is_ssa = true; + store->src[0].ssa = &load->dest.ssa; + + if (copy_instr->has_predicate) { + store->has_predicate = true; + store->predicate = nir_src_copy(copy_instr->predicate, state->mem_ctx); + } + + nir_instr_insert_before(©_instr->instr, &store->instr); + register_store_instr(store, false, state); + } +} + +static bool +lower_copies_to_load_store(struct deref_node *node, + struct lower_variables_state *state) +{ + if (!node->copies) + return true; + + struct set_entry *copy_entry; + 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); + + for (unsigned i = 0; i < 2; ++i) { + struct deref_node *arg_node = get_deref_node(copy->variables[i], + false, state); + if (arg_node == NULL) + continue; + + struct set_entry *arg_entry = _mesa_set_search(arg_node->copies, + copy_entry->hash, + copy); + assert(arg_entry); + _mesa_set_remove(node->copies, arg_entry); + } + + nir_instr_remove(©->instr); + } + + return true; +} + +static nir_load_const_instr * +get_const_initializer_load(const nir_deref_var *deref, + struct lower_variables_state *state) +{ + nir_constant *constant = deref->var->constant_initializer; + const nir_deref *tail = &deref->deref; + unsigned matrix_offset = 0; + while (tail->child) { + switch (tail->child->deref_type) { + case nir_deref_type_array: { + nir_deref_array *arr = nir_deref_as_array(tail->child); + assert(arr->deref_array_type == nir_deref_array_type_direct); + if (glsl_type_is_matrix(tail->type)) { + assert(arr->deref.child == NULL); + matrix_offset = arr->base_offset; + } else { + constant = constant->elements[arr->base_offset]; + } + break; + } + + case nir_deref_type_struct: { + constant = constant->elements[nir_deref_as_struct(tail->child)->index]; + break; + } + + default: + unreachable("Invalid deref child type"); + } + + tail = tail->child; + } + + nir_load_const_instr *load = nir_load_const_instr_create(state->mem_ctx); + load->array_elems = 0; + load->num_components = glsl_get_vector_elements(tail->type); + + matrix_offset *= load->num_components; + for (unsigned i = 0; i < load->num_components; i++) { + switch (glsl_get_base_type(tail->type)) { + case GLSL_TYPE_FLOAT: + case GLSL_TYPE_INT: + case GLSL_TYPE_UINT: + load->value.u[i] = constant->value.u[matrix_offset + i]; + break; + case GLSL_TYPE_BOOL: + load->value.u[i] = constant->value.u[matrix_offset + i] ? + NIR_TRUE : NIR_FALSE; + break; + default: + unreachable("Invalid immediate type"); + } + } + + return load; +} + +static void +def_stack_push(struct deref_node *node, nir_ssa_def *def, + struct lower_variables_state *state) +{ + if (node->def_stack == NULL) { + node->def_stack = ralloc_array(state->dead_ctx, nir_ssa_def *, + state->impl->num_blocks); + node->def_stack_tail = node->def_stack - 1; + } + + if (node->def_stack_tail >= node->def_stack) { + nir_ssa_def *top_def = *node->def_stack_tail; + + if (def->parent_instr->block == top_def->parent_instr->block) { + /* They're in the same block, just replace the top */ + *node->def_stack_tail = def; + return; + } + } + + *(++node->def_stack_tail) = def; +} + +static nir_ssa_def * +get_ssa_def_for_block(struct deref_node *node, nir_block *block, + struct lower_variables_state *state) +{ + if (node->def_stack) { + while (node->def_stack_tail >= node->def_stack) { + nir_ssa_def *def = *node->def_stack_tail; + + for (nir_block *dom = block; dom != NULL; dom = dom->imm_dom) { + if (def->parent_instr->block == dom) + return def; + } + + node->def_stack_tail--; + } + } + + /* If we got here then we don't have a definition that dominates the + * given block. This means that we need to add an undef and use that. + */ + nir_ssa_undef_instr *undef = nir_ssa_undef_instr_create(state->mem_ctx); + nir_ssa_def_init(&undef->instr, &undef->def, + glsl_get_vector_elements(node->type), NULL); + nir_instr_insert_before_cf_list(&state->impl->body, &undef->instr); + def_stack_push(node, &undef->def, state); + return &undef->def; +} + +static void +add_phi_sources(nir_block *block, nir_block *pred, + struct lower_variables_state *state) +{ + nir_foreach_instr(block, instr) { + if (instr->type != nir_instr_type_phi) + break; + + nir_phi_instr *phi = nir_instr_as_phi(instr); + + struct hash_entry *entry = + _mesa_hash_table_search(state->phi_table, phi); + if (!entry) + continue; + + struct deref_node *node = entry->data; + + nir_phi_src *src = ralloc(state->mem_ctx, nir_phi_src); + src->pred = pred; + src->src.is_ssa = true; + src->src.ssa = get_ssa_def_for_block(node, pred, state); + + _mesa_set_add(src->src.ssa->uses, _mesa_hash_pointer(instr), instr); + + exec_list_push_tail(&phi->srcs, &src->node); + } +} + +static bool +lower_deref_to_ssa_block(nir_block *block, void *void_state) +{ + struct lower_variables_state *state = void_state; + + nir_foreach_instr_safe(block, instr) { + if (instr->type == nir_instr_type_phi) { + nir_phi_instr *phi = nir_instr_as_phi(instr); + + struct hash_entry *entry = + _mesa_hash_table_search(state->phi_table, phi); + + /* This can happen if we already have phi nodes in the program + * that were not created in this pass. + */ + if (!entry) + continue; + + struct deref_node *node = entry->data; + + def_stack_push(node, &phi->dest.ssa, state); + } else if (instr->type == nir_instr_type_intrinsic) { + nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); + + switch (intrin->intrinsic) { + case nir_intrinsic_load_var_vec1: + case nir_intrinsic_load_var_vec2: + case nir_intrinsic_load_var_vec3: + case nir_intrinsic_load_var_vec4: { + struct deref_node *node = get_deref_node(intrin->variables[0], + false, state); + unsigned num_chans = + nir_intrinsic_infos[intrin->intrinsic].dest_components; + + if (node == NULL) { + /* If we hit this path then we are referencing an invalid + * value. Most likely, we unrolled something and are + * reading past the end of some array. In any case, this + * should result in an undefined value. + */ + nir_ssa_undef_instr *undef = + nir_ssa_undef_instr_create(state->mem_ctx); + nir_ssa_def_init(&undef->instr, &undef->def, num_chans, NULL); + + nir_instr_insert_before(&intrin->instr, &undef->instr); + nir_instr_remove(&intrin->instr); + + nir_src new_src = { + .is_ssa = true, + .ssa = &undef->def, + }; + + nir_ssa_def_rewrite_uses(&intrin->dest.ssa, new_src, + state->mem_ctx); + continue; + } + + if (!node->lower_to_ssa) + continue; + + nir_alu_instr *mov = nir_alu_instr_create(state->mem_ctx, + nir_op_imov); + mov->src[0].src.is_ssa = true; + mov->src[0].src.ssa = get_ssa_def_for_block(node, block, state); + for (unsigned i = num_chans; i < 4; i++) + mov->src[0].swizzle[i] = 0; + + assert(intrin->dest.is_ssa); + + mov->dest.write_mask = (1 << num_chans) - 1; + mov->dest.dest.is_ssa = true; + nir_ssa_def_init(&mov->instr, &mov->dest.dest.ssa, num_chans, NULL); + + nir_instr_insert_before(&intrin->instr, &mov->instr); + nir_instr_remove(&intrin->instr); + + nir_src new_src = { + .is_ssa = true, + .ssa = &mov->dest.dest.ssa, + }; + + nir_ssa_def_rewrite_uses(&intrin->dest.ssa, new_src, + state->mem_ctx); + break; + } + + case nir_intrinsic_store_var_vec1: + case nir_intrinsic_store_var_vec2: + case nir_intrinsic_store_var_vec3: + case nir_intrinsic_store_var_vec4: { + struct deref_node *node = get_deref_node(intrin->variables[0], + false, state); + + if (node == NULL) { + /* Probably an out-of-bounds array store. That should be a + * no-op. */ + nir_instr_remove(&intrin->instr); + continue; + } + + if (!node->lower_to_ssa) + continue; + + unsigned num_chans = glsl_get_vector_elements(node->type); + + assert(intrin->src[0].is_ssa); + + nir_alu_instr *mov; + if (intrin->has_predicate) { + mov = nir_alu_instr_create(state->mem_ctx, nir_op_bcsel); + mov->src[0].src = nir_src_copy(intrin->predicate, + state->mem_ctx); + memset(mov->src[0].swizzle, 0, sizeof mov->src[0].swizzle); + + mov->src[1].src.is_ssa = true; + mov->src[1].src.ssa = intrin->src[0].ssa; + for (unsigned i = num_chans; i < 4; i++) + mov->src[1].swizzle[i] = 0; + + mov->src[2].src.is_ssa = true; + mov->src[2].src.ssa = get_ssa_def_for_block(node, block, state); + for (unsigned i = num_chans; i < 4; i++) + mov->src[2].swizzle[i] = 0; + + } else { + mov = nir_alu_instr_create(state->mem_ctx, nir_op_imov); + + mov->src[0].src.is_ssa = true; + mov->src[0].src.ssa = intrin->src[0].ssa; + for (unsigned i = num_chans; i < 4; i++) + mov->src[0].swizzle[i] = 0; + } + + mov->dest.write_mask = (1 << num_chans) - 1; + mov->dest.dest.is_ssa = true; + nir_ssa_def_init(&mov->instr, &mov->dest.dest.ssa, num_chans, NULL); + + nir_instr_insert_before(&intrin->instr, &mov->instr); + nir_instr_remove(&intrin->instr); + + def_stack_push(node, &mov->dest.dest.ssa, state); + break; + } + + default: + break; + } + } + } + + if (block->successors[0]) + add_phi_sources(block->successors[0], block, state); + if (block->successors[1]) + add_phi_sources(block->successors[1], block, state); + + return true; +} + +static void +insert_phi_nodes(struct lower_variables_state *state) +{ + unsigned work[state->impl->num_blocks]; + unsigned has_already[state->impl->num_blocks]; + nir_block *W[state->impl->num_blocks]; + + memset(work, 0, sizeof work); + memset(has_already, 0, sizeof has_already); + + unsigned w_start, w_end; + unsigned iter_count = 0; + + struct hash_entry *deref_entry; + hash_table_foreach(state->deref_leaves, deref_entry) { + struct deref_node *node = deref_entry->data; + + if (node->stores == NULL) + continue; + + if (!node->lower_to_ssa) + continue; + + w_start = w_end = 0; + iter_count++; + + struct set_entry *store_entry; + set_foreach(node->stores, store_entry) { + nir_intrinsic_instr *store = (nir_intrinsic_instr *)store_entry->key; + if (work[store->instr.block->index] < iter_count) + W[w_end++] = store->instr.block; + work[store->instr.block->index] = iter_count; + } + + while (w_start != w_end) { + nir_block *cur = W[w_start++]; + struct set_entry *dom_entry; + set_foreach(cur->dom_frontier, dom_entry) { + nir_block *next = (nir_block *) dom_entry->key; + + /* + * If there's more than one return statement, then the end block + * can be a join point for some definitions. However, there are + * no instructions in the end block, so nothing would use those + * phi nodes. Of course, we couldn't place those phi nodes + * anyways due to the restriction of having no instructions in the + * end block... + */ + if (next == state->impl->end_block) + continue; + + if (has_already[next->index] < iter_count) { + nir_phi_instr *phi = nir_phi_instr_create(state->mem_ctx); + phi->dest.is_ssa = true; + nir_ssa_def_init(&phi->instr, &phi->dest.ssa, + glsl_get_vector_elements(node->type), NULL); + nir_instr_insert_before_block(next, &phi->instr); + + _mesa_hash_table_insert(state->phi_table, phi, node); + + has_already[next->index] = iter_count; + if (work[next->index] < iter_count) { + work[next->index] = iter_count; + W[w_end++] = next; + } + } + } + } + } +} + +static bool +nir_lower_variables_impl(nir_function_impl *impl) +{ + struct lower_variables_state state; + + state.mem_ctx = ralloc_parent(impl); + state.dead_ctx = ralloc_context(state.mem_ctx); + state.impl = impl; + + state.deref_var_nodes = _mesa_hash_table_create(state.dead_ctx, + _mesa_hash_pointer, + _mesa_key_pointer_equal); + state.deref_leaves = _mesa_hash_table_create(state.dead_ctx, + hash_deref, derefs_equal); + state.phi_table = _mesa_hash_table_create(state.dead_ctx, + _mesa_hash_pointer, + _mesa_key_pointer_equal); + + nir_foreach_block(impl, fill_deref_tables_block, &state); + + struct set *outputs = _mesa_set_create(state.dead_ctx, + _mesa_key_pointer_equal); + + bool progress = false; + + nir_metadata_require(impl, nir_metadata_block_index); + + struct hash_entry *entry; + hash_table_foreach(state.deref_leaves, entry) { + nir_deref_var *deref = (void *)entry->key; + struct deref_node *node = entry->data; + + if (deref->var->data.mode != nir_var_local) { + _mesa_hash_table_remove(state.deref_leaves, entry); + continue; + } + + if (deref_may_be_aliased(deref, &state)) { + _mesa_hash_table_remove(state.deref_leaves, entry); + continue; + } + + node->lower_to_ssa = true; + progress = true; + + if (deref->var->constant_initializer) { + nir_load_const_instr *load = get_const_initializer_load(deref, &state); + load->dest.is_ssa = true; + nir_ssa_def_init(&load->instr, &load->dest.ssa, + glsl_get_vector_elements(node->type), NULL); + nir_instr_insert_before_cf_list(&impl->body, &load->instr); + def_stack_push(node, &load->dest.ssa, &state); + } + + if (deref->var->data.mode == nir_var_shader_out) + _mesa_set_add(outputs, _mesa_hash_pointer(node), node); + + foreach_deref_node_match(deref, lower_copies_to_load_store, &state); + } + + if (!progress) + return false; + + nir_metadata_require(impl, nir_metadata_dominance); + + insert_phi_nodes(&state); + nir_foreach_block(impl, lower_deref_to_ssa_block, &state); + + nir_metadata_dirty(impl, nir_metadata_block_index | + nir_metadata_dominance); + + ralloc_free(state.dead_ctx); + + return progress; +} + +void +nir_lower_variables(nir_shader *shader) +{ + nir_foreach_overload(shader, overload) { + if (overload->impl) + nir_lower_variables_impl(overload->impl); + } +} |