nir: use nir_shader_instructions_pass in nir_split_per_member_structs

Changes:
- nir_metadata_preserve(..., nir_metadata_block_index | nir_metadata_dominance)
  is called only when pass makes progress
- nir_metadata_preserve(..., nir_metadata_all) is called when pass doesn't
  make progress

Reviewed-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12282>

diff --git a/src/compiler/nir/nir_split_per_member_structs.c b/src/compiler/nir/nir_split_per_member_structs.c
index b5cf32b..2e92012 100644 (file)
--- a/src/compiler/nir/nir_split_per_member_structs.c
+++ b/src/compiler/nir/nir_split_per_member_structs.c
@@ -115,13 +115,18 @@ build_member_deref(nir_builder *b, nir_deref_instr *deref, nir_variable *member)
    }
 }
 
-static void
-rewrite_deref_instr(nir_builder *b, nir_deref_instr *deref,
-                    struct hash_table *var_to_member_map)
+static bool
+rewrite_deref_instr(nir_builder *b, nir_instr *instr, void *cb_data)
 {
+   if (instr->type != nir_instr_type_deref)
+      return false;
+
+   nir_deref_instr *deref = nir_instr_as_deref(instr);
+   struct hash_table *var_to_member_map = cb_data;
+
    /* We must be a struct deref */
    if (deref->deref_type != nir_deref_type_struct)
-      return;
+      return false;
 
    nir_deref_instr *base;
    for (base = nir_deref_instr_parent(deref);
@@ -130,12 +135,12 @@ rewrite_deref_instr(nir_builder *b, nir_deref_instr *deref,
 
       /* If this struct is nested inside another, bail */
       if (base->deref_type == nir_deref_type_struct)
-         return;
+         return false;
    }
 
    /* We must be on a variable with members */
    if (!base || base->var->num_members == 0)
-      return;
+      return false;
 
    nir_variable *member = find_var_member(base->var, deref->strct.index,
                                           var_to_member_map);
@@ -149,6 +154,8 @@ rewrite_deref_instr(nir_builder *b, nir_deref_instr *deref,
 
    /* The referenced variable is no longer valid, clean up the deref */
    nir_deref_instr_remove_if_unused(deref);
+
+   return true;
 }
 
 bool
@@ -175,25 +182,10 @@ nir_split_per_member_structs(nir_shader *shader)
       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) {
-            if (instr->type == nir_instr_type_deref) {
-               rewrite_deref_instr(&b, nir_instr_as_deref(instr),
-                                   var_to_member_map);
-            }
-         }
-      }
-
-      nir_metadata_preserve(function->impl,
-                            nir_metadata_block_index |
-                            nir_metadata_dominance);
-   }
+   nir_shader_instructions_pass(shader, rewrite_deref_instr,
+                                nir_metadata_block_index |
+                                nir_metadata_dominance,
+                                var_to_member_map);
 
    ralloc_free(dead_ctx);