[Mesa-dev] [PATCH v3 045/104] nir: Add a concept of per-member structs and a lowering pass
Jason Ekstrand
jason at jlekstrand.net
Tue Apr 3 18:33:12 UTC 2018
This adds a concept of "members" to a variable with an interface type.
It allows you to specify the full variable data for each member of the
interface instead of once for the variable. We also add a lowering pass
to lower those variables to a sequence of variables and rewrite all the
derefs accordingly.
---
src/compiler/Makefile.sources | 1 +
src/compiler/nir/meson.build | 1 +
src/compiler/nir/nir.h | 12 +
src/compiler/nir/nir_clone.c | 8 +
src/compiler/nir/nir_serialize.c | 12 +
src/compiler/nir/nir_split_per_member_structs.c | 289 ++++++++++++++++++++++++
src/compiler/nir/nir_validate.c | 7 +
7 files changed, 330 insertions(+)
create mode 100644 src/compiler/nir/nir_split_per_member_structs.c
diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
index a7c9bb6..5a1b948 100644
--- a/src/compiler/Makefile.sources
+++ b/src/compiler/Makefile.sources
@@ -284,6 +284,7 @@ NIR_FILES = \
nir/nir_search_helpers.h \
nir/nir_serialize.c \
nir/nir_serialize.h \
+ nir/nir_split_per_member_structs.c \
nir/nir_split_var_copies.c \
nir/nir_sweep.c \
nir/nir_to_lcssa.c \
diff --git a/src/compiler/nir/meson.build b/src/compiler/nir/meson.build
index 42adae9..01d75f5 100644
--- a/src/compiler/nir/meson.build
+++ b/src/compiler/nir/meson.build
@@ -179,6 +179,7 @@ files_libnir = files(
'nir_search_helpers.h',
'nir_serialize.c',
'nir_serialize.h',
+ 'nir_split_per_member_structs.c',
'nir_split_var_copies.c',
'nir_sweep.c',
'nir_to_lcssa.c',
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index df7002b..514af53 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -368,6 +368,17 @@ typedef struct nir_variable {
* \sa ir_variable::location
*/
const struct glsl_type *interface_type;
+
+ /**
+ * Description of per-member data for per-member struct variables
+ *
+ * This is used for variables which are actually an amalgamation of
+ * multiple entities such as a struct of built-in values or a struct of
+ * inputs each with their own layout specifier. This is only allowed on
+ * variables with a struct or array of array of struct type.
+ */
+ unsigned num_members;
+ struct nir_variable_data *members;
} nir_variable;
#define nir_foreach_variable(var, var_list) \
@@ -2586,6 +2597,7 @@ void nir_dump_cfg(nir_shader *shader, FILE *fp);
int nir_gs_count_vertices(const nir_shader *shader);
bool nir_split_var_copies(nir_shader *shader);
+bool nir_split_per_member_structs(nir_shader *shader);
bool nir_lower_returns_impl(nir_function_impl *impl);
bool nir_lower_returns(nir_shader *shader);
diff --git a/src/compiler/nir/nir_clone.c b/src/compiler/nir/nir_clone.c
index 20eaaff..b4c6965 100644
--- a/src/compiler/nir/nir_clone.c
+++ b/src/compiler/nir/nir_clone.c
@@ -161,6 +161,14 @@ nir_variable_clone(const nir_variable *var, nir_shader *shader)
}
nvar->interface_type = var->interface_type;
+ nvar->num_members = var->num_members;
+ if (var->num_members) {
+ nvar->members = ralloc_array(nvar, struct nir_variable_data,
+ var->num_members);
+ memcpy(nvar->members, var->members,
+ var->num_members * sizeof(*var->members));
+ }
+
return nvar;
}
diff --git a/src/compiler/nir/nir_serialize.c b/src/compiler/nir/nir_serialize.c
index 834a65b..e2147b6 100644
--- a/src/compiler/nir/nir_serialize.c
+++ b/src/compiler/nir/nir_serialize.c
@@ -149,6 +149,11 @@ write_variable(write_ctx *ctx, const nir_variable *var)
blob_write_uint32(ctx->blob, !!(var->interface_type));
if (var->interface_type)
encode_type_to_blob(ctx->blob, var->interface_type);
+ blob_write_uint32(ctx->blob, var->num_members);
+ if (var->num_members > 0) {
+ blob_write_bytes(ctx->blob, (uint8_t *) var->members,
+ var->num_members * sizeof(*var->members));
+ }
}
static nir_variable *
@@ -180,6 +185,13 @@ read_variable(read_ctx *ctx)
var->interface_type = decode_type_from_blob(ctx->blob);
else
var->interface_type = NULL;
+ var->num_members = blob_read_uint32(ctx->blob);
+ if (var->num_members > 0) {
+ var->members = ralloc_array(var, struct nir_variable_data,
+ var->num_members);
+ blob_copy_bytes(ctx->blob, (uint8_t *) var->members,
+ var->num_members * sizeof(*var->members));
+ }
return var;
}
diff --git a/src/compiler/nir/nir_split_per_member_structs.c b/src/compiler/nir/nir_split_per_member_structs.c
new file mode 100644
index 0000000..98aaaca
--- /dev/null
+++ b/src/compiler/nir/nir_split_per_member_structs.c
@@ -0,0 +1,289 @@
+/*
+ * Copyright © 2018 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.
+ */
+
+#include "nir.h"
+#include "nir_deref.h"
+
+struct split_struct_state {
+ void *dead_ctx;
+
+ struct hash_table *var_to_member_map;
+};
+
+static nir_variable *
+find_var_member(struct nir_variable *var, unsigned member,
+ struct hash_table *var_to_member_map)
+{
+ struct hash_entry *map_entry =
+ _mesa_hash_table_search(var_to_member_map, var);
+ if (map_entry == NULL)
+ return NULL;
+
+ nir_variable **members = map_entry->data;
+ assert(member < var->num_members);
+ return members[member];
+}
+
+static const struct glsl_type *
+member_type(const struct glsl_type *type, unsigned index)
+{
+ if (glsl_type_is_array(type)) {
+ const struct glsl_type *elem =
+ member_type(glsl_get_array_element(type), index);
+ return glsl_get_array_instance(elem, glsl_get_length(type));
+ } else {
+ assert(glsl_type_is_struct(type));
+ assert(index < glsl_get_length(type));
+ return glsl_get_struct_field(type, index);
+ }
+}
+
+static void
+split_variable(struct nir_variable *var, nir_shader *shader,
+ struct hash_table *var_to_member_map, void *dead_ctx)
+{
+ assert(var->state_slots == NULL);
+
+ /* Constant initializers are currently not handled */
+ assert(var->constant_initializer == NULL);
+
+ nir_variable **members =
+ ralloc_array(dead_ctx, nir_variable *, var->num_members);
+
+ for (unsigned i = 0; i < var->num_members; i++) {
+ char *member_name = NULL;
+ if (var->name) {
+ /* Calculate a reasonable variable name */
+ member_name = ralloc_strdup(dead_ctx, var->name);
+ const struct glsl_type *t = var->type;
+ while (glsl_type_is_array(t)) {
+ ralloc_strcat(&member_name, "[*]");
+ t = glsl_get_array_element(t);
+ }
+ const char *field_name = glsl_get_struct_elem_name(t, i);
+ if (field_name) {
+ member_name = ralloc_asprintf(dead_ctx, "%s.%s",
+ member_name, field_name);
+ } else {
+ member_name = ralloc_asprintf(dead_ctx, "%s.@%d", member_name, i);
+ }
+ }
+
+ members[i] =
+ nir_variable_create(shader, var->members[i].mode,
+ member_type(var->type, i), member_name);
+ if (var->interface_type) {
+ members[i]->interface_type =
+ glsl_get_struct_field(var->interface_type, i);
+ }
+ members[i]->data = var->members[i];
+ }
+
+ _mesa_hash_table_insert(var_to_member_map, var, members);
+}
+
+static bool
+split_variables_in_list(struct exec_list *var_list, nir_shader *shader,
+ struct hash_table *var_to_member_map, void *dead_ctx)
+{
+ bool progress = false;
+
+ nir_foreach_variable_safe(var, var_list) {
+ if (var->num_members == 0)
+ continue;
+
+ split_variable(var, shader, var_to_member_map, dead_ctx);
+ exec_node_remove(&var->node);
+ progress = true;
+ }
+
+ return progress;
+}
+
+static nir_deref_instr *
+build_member_deref(nir_builder *b, nir_deref_instr *deref, nir_variable *member)
+{
+ if (deref->deref_type == nir_deref_type_var) {
+ return nir_build_deref_var(b, member);
+ } else {
+ nir_deref_instr *parent =
+ build_member_deref(b, nir_deref_instr_parent(deref), member);
+ return nir_build_deref_follower(b, parent, deref);
+ }
+}
+
+static void
+rewrite_deref_instr(nir_builder *b, nir_deref_instr *deref,
+ struct hash_table *var_to_member_map)
+{
+ /* We must be a struct deref */
+ if (deref->deref_type != nir_deref_type_struct)
+ return;
+
+ nir_deref_instr *base;
+ for (base = nir_deref_instr_parent(deref);
+ base && base->deref_type != nir_deref_type_var;
+ base = nir_deref_instr_parent(base)) {
+
+ /* If this struct is nested inside another, bail */
+ if (base->deref_type == nir_deref_type_struct)
+ return;
+ }
+
+ /* We must be on a variable with members */
+ if (!base || base->var->num_members == 0)
+ return;
+
+ nir_variable *member = find_var_member(base->var, deref->strct.index,
+ var_to_member_map);
+ assert(member);
+
+ b->cursor = nir_before_instr(&deref->instr);
+ nir_deref_instr *member_deref =
+ build_member_deref(b, nir_deref_instr_parent(deref), member);
+ nir_ssa_def_rewrite_uses(&deref->dest.ssa,
+ nir_src_for_ssa(&member_deref->dest.ssa));
+
+ nir_deref_instr_cleanup(deref);
+}
+
+static void
+rewrite_deref_var(nir_instr *instr, nir_deref_var **deref,
+ struct hash_table *var_to_member_map)
+{
+ if ((*deref)->var->members == 0)
+ return;
+
+ nir_deref_struct *strct = NULL;
+ for (nir_deref *d = (*deref)->deref.child; d; d = d->child) {
+ if (d->deref_type == nir_deref_type_struct) {
+ strct = nir_deref_as_struct(d);
+ break;
+ }
+ }
+ assert(strct);
+
+ nir_variable *member = find_var_member((*deref)->var, strct->index,
+ var_to_member_map);
+
+ nir_deref_var *head = nir_deref_var_create(ralloc_parent(*deref), member);
+ nir_deref *tail = &head->deref;
+ for (nir_deref *d = (*deref)->deref.child;
+ d != &strct->deref; d = d->child) {
+ nir_deref_array *arr = nir_deref_as_array(d);
+
+ nir_deref_array *narr = nir_deref_array_create(tail);
+ narr->deref.type = glsl_get_array_element(tail->type);
+ narr->deref_array_type = arr->deref_array_type;
+ narr->base_offset = arr->base_offset;
+
+ if (arr->deref_array_type == nir_deref_array_type_indirect)
+ nir_instr_move_src(instr, &narr->indirect, &arr->indirect);
+
+ assert(tail->child == NULL);
+ tail->child = &narr->deref;
+ tail = &narr->deref;
+ }
+
+ ralloc_steal(tail, strct->deref.child);
+ tail->child = strct->deref.child;
+
+ ralloc_free(*deref);
+ *deref = head;
+}
+
+static void
+rewrite_intrinsic_instr(nir_intrinsic_instr *intrin,
+ struct hash_table *var_to_member_map)
+{
+ for (unsigned i = 0;
+ i < nir_intrinsic_infos[intrin->intrinsic].num_variables; i++) {
+ rewrite_deref_var(&intrin->instr, &intrin->variables[i],
+ var_to_member_map);
+ }
+}
+
+static void
+rewrite_tex_instr(nir_tex_instr *tex, struct hash_table *var_to_member_map)
+{
+ if (tex->texture)
+ rewrite_deref_var(&tex->instr, &tex->texture, var_to_member_map);
+ if (tex->sampler)
+ rewrite_deref_var(&tex->instr, &tex->sampler, var_to_member_map);
+}
+
+bool
+nir_split_per_member_structs(nir_shader *shader)
+{
+ bool progress = false;
+ void *dead_ctx = ralloc_context(NULL);
+ struct hash_table *var_to_member_map =
+ _mesa_hash_table_create(dead_ctx, _mesa_hash_pointer,
+ _mesa_key_pointer_equal);
+
+ progress |= split_variables_in_list(&shader->inputs, shader,
+ var_to_member_map, dead_ctx);
+ progress |= split_variables_in_list(&shader->outputs, shader,
+ var_to_member_map, dead_ctx);
+ progress |= split_variables_in_list(&shader->system_values, shader,
+ var_to_member_map, dead_ctx);
+ if (!progress)
+ return false;
+
+ nir_foreach_function(function, shader) {
+ if (!function->impl)
+ continue;
+
+ nir_builder b;
+ nir_builder_init(&b, function->impl);
+ nir_foreach_block(block, function->impl) {
+ nir_foreach_instr_safe(instr, block) {
+ switch (instr->type) {
+ case nir_instr_type_deref:
+ rewrite_deref_instr(&b, nir_instr_as_deref(instr),
+ var_to_member_map);
+ break;
+
+ case nir_instr_type_intrinsic:
+ rewrite_intrinsic_instr(nir_instr_as_intrinsic(instr),
+ var_to_member_map);
+ break;
+
+ case nir_instr_type_tex:
+ rewrite_tex_instr(nir_instr_as_tex(instr), var_to_member_map);
+ break;
+
+ case nir_instr_type_call:
+ unreachable("Functions must be inlined before this pass");
+
+ default:
+ break;
+ }
+ }
+ }
+ }
+
+ ralloc_free(dead_ctx);
+
+ return progress;
+}
diff --git a/src/compiler/nir/nir_validate.c b/src/compiler/nir/nir_validate.c
index 655d430..89cf4c2 100644
--- a/src/compiler/nir/nir_validate.c
+++ b/src/compiler/nir/nir_validate.c
@@ -1114,6 +1114,13 @@ validate_var_decl(nir_variable *var, bool is_global, validate_state *state)
}
}
+ if (var->num_members > 0) {
+ const struct glsl_type *without_array = glsl_without_array(var->type);
+ validate_assert(state, glsl_type_is_struct(without_array));
+ validate_assert(state, var->num_members == glsl_get_length(without_array));
+ validate_assert(state, var->members != NULL);
+ }
+
/*
* TODO validate some things ir_validate.cpp does (requires more GLSL type
* support)
--
2.5.0.400.gff86faf
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