[Mesa-dev] [PATCH 3/3] nir: simplify node matching code when lowering to SSA

[Caio Marcelo de Oliveira Filho]

The matching code doesn't make real use of the return value. The main
function return value is ignored, and while the worker function
propagate its return value, the actual callback never returns false.
---
 src/compiler/nir/nir_lower_vars_to_ssa.c | 73 +++++++++++-------------
 1 file changed, 32 insertions(+), 41 deletions(-)

diff --git a/src/compiler/nir/nir_lower_vars_to_ssa.c b/src/compiler/nir/nir_lower_vars_to_ssa.c
index 4c41dd69cf..f84ad067ee 100644
--- a/src/compiler/nir/nir_lower_vars_to_ssa.c
+++ b/src/compiler/nir/nir_lower_vars_to_ssa.c
@@ -217,45 +217,40 @@ get_deref_node(nir_deref_var *deref, struct lower_variables_state *state)
 }
 
 /* \sa foreach_deref_node_match */
-static bool
+static void
 foreach_deref_node_worker(struct deref_node *node, nir_deref *deref,
-                          bool (* cb)(struct deref_node *node,
+                          void (* 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;
-      }
+      cb(node, state);
+      return;
+   }
 
-      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;
+   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);
+      if (node->wildcard)
+         foreach_deref_node_worker(node->wildcard, deref->child, cb, state);
+      break;
+   }
 
-         return true;
-      }
+   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);
+      break;
+   }
 
-      default:
-         unreachable("Invalid deref child type");
-      }
+   default:
+      unreachable("Invalid deref child type");
    }
 }
 
@@ -271,9 +266,9 @@ foreach_deref_node_worker(struct deref_node *node, nir_deref *deref,
  * The given deref must be a full-length and fully qualified (no wildcards
  * or indirects) deref chain.
  */
-static bool
+static void
 foreach_deref_node_match(nir_deref_var *deref,
-                         bool (* cb)(struct deref_node *node,
+                         void (* cb)(struct deref_node *node,
                                      struct lower_variables_state *state),
                          struct lower_variables_state *state)
 {
@@ -281,10 +276,8 @@ foreach_deref_node_match(nir_deref_var *deref,
    var_deref.deref.child = NULL;
    struct deref_node *node = get_deref_node(&var_deref, state);
 
-   if (node == NULL)
-      return false;
-
-   return foreach_deref_node_worker(node, &deref->deref, cb, state);
+   if (node)
+      foreach_deref_node_worker(node, &deref->deref, cb, state);
 }
 
 /* \sa deref_may_be_aliased */
@@ -440,12 +433,12 @@ register_variable_uses_block(nir_block *block,
 /* Walks over all of the copy instructions to or from the given deref_node
  * and lowers them to load/store intrinsics.
  */
-static bool
+static void
 lower_copies_to_load_store(struct deref_node *node,
                            struct lower_variables_state *state)
 {
    if (!node->copies)
-      return true;
+      return;
 
    struct set_entry *copy_entry;
    set_foreach(node->copies, copy_entry) {
@@ -470,8 +463,6 @@ lower_copies_to_load_store(struct deref_node *node,
    }
 
    node->copies = NULL;
-
-   return true;
 }
 
 /* Performs variable renaming
-- 
2.17.0