[Mesa-dev] [PATCH 2/3] glsl: Use hash tables for brw_fs_vector_splitting().

[Kenneth Graunke]

Cuts compile/link time of the fragment shader in #91857 by 25%
(21.64 -> 16.28).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91857
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 .../drivers/dri/i965/brw_fs_vector_splitting.cpp   | 48 ++++++++++++----------
 1 file changed, 26 insertions(+), 22 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs_vector_splitting.cpp b/src/mesa/drivers/dri/i965/brw_fs_vector_splitting.cpp
index 96d4f37..ef1ff03 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_vector_splitting.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_vector_splitting.cpp
@@ -43,6 +43,7 @@
 #include "glsl/ir_visitor.h"
 #include "glsl/ir_rvalue_visitor.h"
 #include "glsl/glsl_types.h"
+#include "util/hash_table.h"
 
 static bool debug = false;
 
@@ -72,11 +73,13 @@ public:
    ir_vector_reference_visitor(void)
    {
       this->mem_ctx = ralloc_context(NULL);
-      this->variable_list.make_empty();
+      this->ht = _mesa_hash_table_create(mem_ctx, _mesa_hash_pointer,
+                                         _mesa_key_pointer_equal);
    }
 
    ~ir_vector_reference_visitor(void)
    {
+      _mesa_hash_table_destroy(ht, NULL);
       ralloc_free(mem_ctx);
    }
 
@@ -89,7 +92,7 @@ public:
    variable_entry *get_variable_entry(ir_variable *var);
 
    /* List of variable_entry */
-   exec_list variable_list;
+   struct hash_table *ht;
 
    void *mem_ctx;
 };
@@ -119,13 +122,12 @@ ir_vector_reference_visitor::get_variable_entry(ir_variable *var)
       break;
    }
 
-   foreach_in_list(variable_entry, entry, &variable_list) {
-      if (entry->var == var)
-	 return entry;
-   }
+   struct hash_entry *hte = _mesa_hash_table_search(ht, var);
+   if (hte)
+      return (struct variable_entry *) hte->data;
 
    variable_entry *entry = new(mem_ctx) variable_entry(var);
-   this->variable_list.push_tail(entry);
+   _mesa_hash_table_insert(ht, var, entry);
    return entry;
 }
 
@@ -195,9 +197,9 @@ ir_vector_reference_visitor::visit_enter(ir_function_signature *ir)
 
 class ir_vector_splitting_visitor : public ir_rvalue_visitor {
 public:
-   ir_vector_splitting_visitor(exec_list *vars)
+   ir_vector_splitting_visitor(struct hash_table *vars)
    {
-      this->variable_list = vars;
+      this->ht = vars;
    }
 
    virtual ir_visitor_status visit_leave(ir_assignment *);
@@ -205,7 +207,7 @@ public:
    void handle_rvalue(ir_rvalue **rvalue);
    variable_entry *get_splitting_entry(ir_variable *var);
 
-   exec_list *variable_list;
+   struct hash_table *ht;
 };
 
 variable_entry *
@@ -216,13 +218,8 @@ ir_vector_splitting_visitor::get_splitting_entry(ir_variable *var)
    if (!var->type->is_vector())
       return NULL;
 
-   foreach_in_list(variable_entry, entry, variable_list) {
-      if (entry->var == var) {
-	 return entry;
-      }
-   }
-
-   return NULL;
+   struct hash_entry *hte = _mesa_hash_table_search(ht, var);
+   return hte ? (struct variable_entry *) hte->data : NULL;
 }
 
 void
@@ -329,12 +326,16 @@ ir_vector_splitting_visitor::visit_leave(ir_assignment *ir)
 bool
 brw_do_vector_splitting(exec_list *instructions)
 {
+   struct hash_entry *hte;
+
    ir_vector_reference_visitor refs;
 
    visit_list_elements(&refs, instructions);
 
    /* Trim out variables we can't split. */
-   foreach_in_list_safe(variable_entry, entry, &refs.variable_list) {
+   bool ht_empty = true;
+   hash_table_foreach(refs.ht, hte) {
+      struct variable_entry *entry = (struct variable_entry *) hte->data;
       if (debug) {
 	 fprintf(stderr, "vector %s@%p: whole_access %d\n",
                  entry->var->name, (void *) entry->var,
@@ -342,11 +343,13 @@ brw_do_vector_splitting(exec_list *instructions)
       }
 
       if (entry->whole_vector_access) {
-	 entry->remove();
+         _mesa_hash_table_remove(refs.ht, hte);
+      } else {
+         ht_empty = false;
       }
    }
 
-   if (refs.variable_list.is_empty())
+   if (ht_empty)
       return false;
 
    void *mem_ctx = ralloc_context(NULL);
@@ -354,7 +357,8 @@ brw_do_vector_splitting(exec_list *instructions)
    /* Replace the decls of the vectors to be split with their split
     * components.
     */
-   foreach_in_list(variable_entry, entry, &refs.variable_list) {
+   hash_table_foreach(refs.ht, hte) {
+      struct variable_entry *entry = (struct variable_entry *) hte->data;
       const struct glsl_type *type;
       type = glsl_type::get_instance(entry->var->type->base_type, 1, 1);
 
@@ -378,7 +382,7 @@ brw_do_vector_splitting(exec_list *instructions)
       entry->var->remove();
    }
 
-   ir_vector_splitting_visitor split(&refs.variable_list);
+   ir_vector_splitting_visitor split(refs.ht);
    visit_list_elements(&split, instructions);
 
    ralloc_free(mem_ctx);
-- 
2.5.0