[Mesa-dev] [PATCH v3 072/104] nir/vars_to_ssa: Rework to entirely use deref instructions
Jason Ekstrand
jason at jlekstrand.net
Tue Apr 3 18:33:39 UTC 2018
This commit reworks nir_lower_vars_to_ssa to use deref instructions and
deref paths internally instead of deref chains. We also drop support
for the old load/store/copy_var intrinsics.
---
src/compiler/nir/nir_lower_vars_to_ssa.c | 352 ++++++++++++++-----------------
1 file changed, 158 insertions(+), 194 deletions(-)
diff --git a/src/compiler/nir/nir_lower_vars_to_ssa.c b/src/compiler/nir/nir_lower_vars_to_ssa.c
index 5718018..98ba2a2 100644
--- a/src/compiler/nir/nir_lower_vars_to_ssa.c
+++ b/src/compiler/nir/nir_lower_vars_to_ssa.c
@@ -27,6 +27,7 @@
#include "nir.h"
#include "nir_builder.h"
+#include "nir_deref.h"
#include "nir_phi_builder.h"
#include "nir_vla.h"
@@ -38,10 +39,10 @@ struct deref_node {
bool lower_to_ssa;
/* Only valid for things that end up in the direct list.
- * Note that multiple nir_deref_vars may correspond to this node, but they
- * will all be equivalent, so any is as good as the other.
+ * Note that multiple nir_deref_instrs may correspond to this node, but
+ * they will all be equivalent, so any is as good as the other.
*/
- nir_deref_var *deref;
+ struct nir_deref_path path;
struct exec_node direct_derefs_link;
struct set *loads;
@@ -106,7 +107,6 @@ deref_node_create(struct deref_node *parent,
struct deref_node *node = rzalloc_size(mem_ctx, size);
node->type = type;
node->parent = parent;
- node->deref = NULL;
exec_node_init(&node->direct_derefs_link);
node->is_direct = is_direct;
@@ -139,84 +139,84 @@ get_deref_node_for_var(nir_variable *var, struct lower_variables_state *state)
* table of of fully-qualified direct derefs.
*/
static struct deref_node *
-get_deref_node(nir_deref_var *deref, struct lower_variables_state *state)
+get_deref_node_recur(nir_deref_instr *deref,
+ struct lower_variables_state *state)
{
- /* Start at the base of the chain. */
- struct deref_node *node = get_deref_node_for_var(deref->var, state);
- assert(deref->deref.type == node->type);
+ if (deref->deref_type == nir_deref_type_var)
+ return get_deref_node_for_var(deref->var, state);
- for (nir_deref *tail = deref->deref.child; tail; tail = tail->child) {
- switch (tail->deref_type) {
- case nir_deref_type_struct: {
- nir_deref_struct *deref_struct = nir_deref_as_struct(tail);
+ struct deref_node *parent =
+ get_deref_node_recur(nir_deref_instr_parent(deref), state);
- assert(deref_struct->index < glsl_get_length(node->type));
+ switch (deref->deref_type) {
+ case nir_deref_type_struct:
+ assert(glsl_type_is_struct(parent->type));
+ assert(deref->strct.index < glsl_get_length(parent->type));
- if (node->children[deref_struct->index] == NULL) {
- node->children[deref_struct->index] =
- deref_node_create(node, tail->type, node->is_direct,
- state->dead_ctx);
- }
-
- node = node->children[deref_struct->index];
- break;
+ if (parent->children[deref->strct.index] == NULL) {
+ parent->children[deref->strct.index] =
+ deref_node_create(parent, deref->type, parent->is_direct,
+ state->dead_ctx);
}
- case nir_deref_type_array: {
- nir_deref_array *arr = nir_deref_as_array(tail);
-
- switch (arr->deref_array_type) {
- case nir_deref_array_type_direct:
- /* This is possible if a loop unrolls and generates an
- * out-of-bounds offset. We need to handle this at least
- * somewhat gracefully.
- */
- if (arr->base_offset >= glsl_get_length(node->type))
- return NULL;
-
- if (node->children[arr->base_offset] == NULL) {
- node->children[arr->base_offset] =
- deref_node_create(node, tail->type, node->is_direct,
- state->dead_ctx);
- }
-
- node = node->children[arr->base_offset];
- break;
+ return parent->children[deref->strct.index];
+
+ case nir_deref_type_array: {
+ nir_const_value *const_index = nir_src_as_const_value(deref->arr.index);
+ if (const_index) {
+ uint32_t index = const_index->u32[0];
+ /* This is possible if a loop unrolls and generates an
+ * out-of-bounds offset. We need to handle this at least
+ * somewhat gracefully.
+ */
+ if (index >= glsl_get_length(parent->type))
+ return NULL;
+
+ if (parent->children[index] == NULL) {
+ parent->children[index] =
+ deref_node_create(parent, deref->type, parent->is_direct,
+ state->dead_ctx);
+ }
- case nir_deref_array_type_indirect:
- if (node->indirect == NULL) {
- node->indirect = deref_node_create(node, tail->type, false,
- state->dead_ctx);
- }
+ return parent->children[index];
+ } else {
+ if (parent->indirect == NULL) {
+ parent->indirect =
+ deref_node_create(parent, deref->type, false, state->dead_ctx);
+ }
- node = node->indirect;
- break;
+ return parent->indirect;
+ }
+ break;
+ }
- case nir_deref_array_type_wildcard:
- if (node->wildcard == NULL) {
- node->wildcard = deref_node_create(node, tail->type, false,
- state->dead_ctx);
- }
+ case nir_deref_type_array_wildcard:
+ if (parent->wildcard == NULL) {
+ parent->wildcard =
+ deref_node_create(parent, deref->type, false, state->dead_ctx);
+ }
- node = node->wildcard;
- break;
+ return parent->wildcard;
- default:
- unreachable("Invalid array deref type");
- }
- break;
- }
- default:
- unreachable("Invalid deref type");
- }
+ default:
+ unreachable("Invalid deref type");
}
+}
- assert(node);
+static struct deref_node *
+get_deref_node(nir_deref_instr *deref, struct lower_variables_state *state)
+{
+ struct deref_node *node = get_deref_node_recur(deref, state);
+ if (!node)
+ return NULL;
- /* Only insert if it isn't already in the list. */
+ /* Insert the node in the direct derefs list. We only do this if it's not
+ * already in the list and we only bother for deref nodes which are used
+ * directly in a load or store.
+ */
if (node->is_direct && state->add_to_direct_deref_nodes &&
node->direct_derefs_link.next == NULL) {
- node->deref = deref;
+ nir_deref_path_init(&node->path, deref, state->dead_ctx);
assert(deref->var != NULL);
exec_list_push_tail(&state->direct_deref_nodes,
&node->direct_derefs_link);
@@ -227,44 +227,43 @@ get_deref_node(nir_deref_var *deref, struct lower_variables_state *state)
/* \sa foreach_deref_node_match */
static bool
-foreach_deref_node_worker(struct deref_node *node, nir_deref *deref,
+foreach_deref_node_worker(struct deref_node *node, nir_deref_instr **path,
bool (* cb)(struct deref_node *node,
struct lower_variables_state *state),
struct lower_variables_state *state)
{
- if (deref->child == NULL) {
+ if (*path == 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;
- }
+ switch ((*path)->deref_type) {
+ case nir_deref_type_struct:
+ if (node->children[(*path)->strct.index] &&
+ !foreach_deref_node_worker(node->children[(*path)->strct.index],
+ path + 1, cb, state))
+ return false;
- case nir_deref_type_struct: {
- nir_deref_struct *str = nir_deref_as_struct(deref->child);
- if (node->children[str->index] &&
- !foreach_deref_node_worker(node->children[str->index],
- deref->child, cb, state))
- return false;
+ return true;
- return true;
- }
+ case nir_deref_type_array: {
+ nir_const_value *const_index = nir_src_as_const_value((*path)->arr.index);
+ assert(const_index);
+ uint32_t index = const_index->u32[0];
- default:
- unreachable("Invalid deref child type");
- }
+ if (node->children[index] &&
+ !foreach_deref_node_worker(node->children[index],
+ path + 1, cb, state))
+ return false;
+
+ if (node->wildcard &&
+ !foreach_deref_node_worker(node->wildcard,
+ path + 1, cb, state))
+ return false;
+
+ return true;
+ }
+
+ default:
+ unreachable("Unsupported deref type");
}
}
@@ -281,66 +280,62 @@ foreach_deref_node_worker(struct deref_node *node, nir_deref *deref,
* or indirects) deref chain.
*/
static bool
-foreach_deref_node_match(nir_deref_var *deref,
+foreach_deref_node_match(struct nir_deref_path *path,
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, state);
+ assert(path->path[0]->deref_type == nir_deref_type_var);
+ struct deref_node *node = get_deref_node_for_var(path->path[0]->var, state);
if (node == NULL)
return false;
- return foreach_deref_node_worker(node, &deref->deref, cb, state);
+ return foreach_deref_node_worker(node, &path->path[1], cb, state);
}
/* \sa deref_may_be_aliased */
static bool
-deref_may_be_aliased_node(struct deref_node *node, nir_deref *deref,
- struct lower_variables_state *state)
+path_may_be_aliased_node(struct deref_node *node, nir_deref_instr **path,
+ struct lower_variables_state *state)
{
- if (deref->child == NULL) {
+ if (*path == 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;
- /* If there is an indirect at this level, we're aliased. */
- if (node->indirect)
- return true;
+ switch ((*path)->deref_type) {
+ case nir_deref_type_struct:
+ if (node->children[(*path)->strct.index]) {
+ return path_may_be_aliased_node(node->children[(*path)->strct.index],
+ path + 1, state);
+ } else {
+ return false;
+ }
- assert(arr->deref_array_type == nir_deref_array_type_direct);
+ case nir_deref_type_array: {
+ nir_const_value *const_index = nir_src_as_const_value((*path)->arr.index);
+ if (!const_index)
+ return true;
- if (node->children[arr->base_offset] &&
- deref_may_be_aliased_node(node->children[arr->base_offset],
- deref->child, state))
- return true;
+ uint32_t index = const_index->u32[0];
- if (node->wildcard &&
- deref_may_be_aliased_node(node->wildcard, deref->child, state))
- return true;
+ /* If there is an indirect at this level, we're aliased. */
+ if (node->indirect)
+ return true;
- return false;
- }
+ if (node->children[index] &&
+ path_may_be_aliased_node(node->children[index],
+ path + 1, state))
+ return true;
- 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;
- }
- }
+ if (node->wildcard &&
+ path_may_be_aliased_node(node->wildcard, path + 1, state))
+ return true;
- default:
- unreachable("Invalid nir_deref child type");
- }
+ return false;
+ }
+
+ default:
+ unreachable("Unsupported deref type");
}
}
@@ -359,44 +354,22 @@ deref_may_be_aliased_node(struct deref_node *node, nir_deref *deref,
* references.
*/
static bool
-deref_may_be_aliased(nir_deref_var *deref,
- struct lower_variables_state *state)
-{
- return deref_may_be_aliased_node(get_deref_node_for_var(deref->var, state),
- &deref->deref, state);
-}
-
-static struct deref_node *
-get_deref_node_for_instr(nir_intrinsic_instr *instr, unsigned idx,
- struct lower_variables_state *state)
+path_may_be_aliased(struct nir_deref_path *path,
+ struct lower_variables_state *state)
{
- switch (instr->intrinsic) {
- case nir_intrinsic_load_var:
- case nir_intrinsic_store_var:
- case nir_intrinsic_copy_var:
- return get_deref_node(instr->variables[idx], state);
-
- case nir_intrinsic_load_deref:
- case nir_intrinsic_store_deref:
- case nir_intrinsic_copy_deref: {
- assert(instr->src[idx].is_ssa);
- nir_deref_instr *deref_instr =
- nir_instr_as_deref(instr->src[idx].ssa->parent_instr);
- nir_deref_var *deref_var =
- nir_deref_instr_to_deref(deref_instr, state->dead_ctx);
- return get_deref_node(deref_var, state);
- }
+ assert(path->path[0]->deref_type == nir_deref_type_var);
+ nir_variable *var = path->path[0]->var;
- default:
- unreachable("Unhanded instruction type");
- }
+ return path_may_be_aliased_node(get_deref_node_for_var(var, state),
+ &path->path[1], state);
}
static void
register_load_instr(nir_intrinsic_instr *load_instr,
struct lower_variables_state *state)
{
- struct deref_node *node = get_deref_node_for_instr(load_instr, 0, state);
+ nir_deref_instr *deref = nir_src_as_deref(load_instr->src[0]);
+ struct deref_node *node = get_deref_node(deref, state);
if (node == NULL)
return;
@@ -411,7 +384,8 @@ static void
register_store_instr(nir_intrinsic_instr *store_instr,
struct lower_variables_state *state)
{
- struct deref_node *node = get_deref_node_for_instr(store_instr, 0, state);
+ nir_deref_instr *deref = nir_src_as_deref(store_instr->src[0]);
+ struct deref_node *node = get_deref_node(deref, state);
if (node == NULL)
return;
@@ -427,8 +401,8 @@ 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_for_instr(copy_instr, idx, state);
+ nir_deref_instr *deref = nir_src_as_deref(copy_instr->src[idx]);
+ struct deref_node *node = get_deref_node(deref, state);
if (node == NULL)
continue;
@@ -452,17 +426,14 @@ register_variable_uses_block(nir_block *block,
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
switch (intrin->intrinsic) {
- case nir_intrinsic_load_var:
case nir_intrinsic_load_deref:
register_load_instr(intrin, state);
break;
- case nir_intrinsic_store_var:
case nir_intrinsic_store_deref:
register_store_instr(intrin, state);
break;
- case nir_intrinsic_copy_var:
case nir_intrinsic_copy_deref:
register_copy_instr(intrin, state);
break;
@@ -492,13 +463,11 @@ lower_copies_to_load_store(struct deref_node *node,
set_foreach(node->copies, copy_entry) {
nir_intrinsic_instr *copy = (void *)copy_entry->key;
- if (copy->intrinsic == nir_intrinsic_copy_var)
- nir_lower_var_copy_instr(copy, state->shader);
- else
- nir_lower_deref_copy_instr(&b, copy);
+ nir_lower_deref_copy_instr(&b, copy);
for (unsigned i = 0; i < 2; ++i) {
- struct deref_node *arg_node = get_deref_node_for_instr(copy, i, state);
+ nir_deref_instr *arg_deref = nir_src_as_deref(copy->src[i]);
+ struct deref_node *arg_node = get_deref_node(arg_deref, state);
/* Only bother removing copy entries for other nodes */
if (arg_node == NULL || arg_node == node)
@@ -538,10 +507,9 @@ rename_variables(struct lower_variables_state *state)
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
switch (intrin->intrinsic) {
- case nir_intrinsic_load_var:
case nir_intrinsic_load_deref: {
- struct deref_node *node =
- get_deref_node_for_instr(intrin, 0, state);
+ nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
+ struct deref_node *node = get_deref_node(deref, state);
if (node == NULL) {
/* If we hit this path then we are referencing an invalid
* value. Most likely, we unrolled something and are
@@ -586,19 +554,12 @@ rename_variables(struct lower_variables_state *state)
break;
}
- case nir_intrinsic_store_var:
case nir_intrinsic_store_deref: {
- struct deref_node *node =
- get_deref_node_for_instr(intrin, 0, state);
+ nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
+ struct deref_node *node = get_deref_node(deref, state);
- nir_ssa_def *value;
- if (intrin->intrinsic == nir_intrinsic_store_var) {
- assert(intrin->src[0].is_ssa);
- value = intrin->src[0].ssa;
- } else {
- assert(intrin->src[1].is_ssa);
- value = intrin->src[1].ssa;
- }
+ assert(intrin->src[1].is_ssa);
+ nir_ssa_def *value = intrin->src[1].ssa;
if (node == NULL) {
/* Probably an out-of-bounds array store. That should be a
@@ -717,14 +678,17 @@ nir_lower_vars_to_ssa_impl(nir_function_impl *impl)
foreach_list_typed_safe(struct deref_node, node, direct_derefs_link,
&state.direct_deref_nodes) {
- nir_deref_var *deref = node->deref;
+ struct nir_deref_path *path = &node->path;
+
+ assert(path->path[0]->deref_type == nir_deref_type_var);
+ nir_variable *var = path->path[0]->var;
- if (deref->var->data.mode != nir_var_local) {
+ if (var->data.mode != nir_var_local) {
exec_node_remove(&node->direct_derefs_link);
continue;
}
- if (deref_may_be_aliased(deref, &state)) {
+ if (path_may_be_aliased(path, &state)) {
exec_node_remove(&node->direct_derefs_link);
continue;
}
@@ -732,7 +696,7 @@ nir_lower_vars_to_ssa_impl(nir_function_impl *impl)
node->lower_to_ssa = true;
progress = true;
- foreach_deref_node_match(deref, lower_copies_to_load_store, &state);
+ foreach_deref_node_match(path, lower_copies_to_load_store, &state);
}
if (!progress)
@@ -761,7 +725,7 @@ nir_lower_vars_to_ssa_impl(nir_function_impl *impl)
memset(store_blocks, 0,
BITSET_WORDS(state.impl->num_blocks) * sizeof(*store_blocks));
- assert(node->deref->var->constant_initializer == NULL);
+ assert(node->path.path[0]->var->constant_initializer == NULL);
if (node->stores) {
struct set_entry *store_entry;
--
2.5.0.400.gff86faf
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