Mesa (main): symbol_table: Store the symbol name in the same allocation as the symbol entry.

[GitLab Mirror]

Module: Mesa
Branch: main
Commit: 6db7d72b4bf802779f392988315f6202bee22b8d
URL:    
http://cgit.freedesktop.org/mesa/mesa/commit/?id=6db7d72b4bf802779f392988315f6202bee22b8d

Author: Emma Anholt <e...@anholt.net>
Date:   Wed Apr 12 11:30:24 2023 -0700

symbol_table: Store the symbol name in the same allocation as the symbol entry.

Saves an extra malloc.  Release Mesa build runtime of
KHR-Single-GL46.arrays_of_arrays_gl.SizedDeclarationsPrimitive (which is a
lot of GLSL 4.60 builtin vars symbol table setup) -5.15821% +/- 3.19636%
(n=13).

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzw...@collabora.com>
Reviewed-by: Marek Olšák <marek.ol...@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22451>

---

 src/mesa/program/symbol_table.c | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/src/mesa/program/symbol_table.c b/src/mesa/program/symbol_table.c
index 2a544e03635..ccf611a4e48 100644
--- a/src/mesa/program/symbol_table.c
+++ b/src/mesa/program/symbol_table.c
@@ -106,7 +106,6 @@ _mesa_symbol_table_pop_scope(struct _mesa_symbol_table 
*table)
            hte->data = sym->next_with_same_name;
         } else {
            _mesa_hash_table_remove(table->ht, hte);
-           free(sym->name);
         }
 
         free(sym);
@@ -183,7 +182,7 @@ _mesa_symbol_table_add_symbol(struct _mesa_symbol_table 
*table,
    if (sym && sym->depth == table->depth)
       return -1;
 
-   new_sym = calloc(1, sizeof(*sym));
+   new_sym = calloc(1, sizeof(*sym) + (sym ? 0 : (strlen(name) + 1)));
    if (new_sym == NULL) {
       _mesa_error_no_memory(__func__);
       return -1;
@@ -194,12 +193,8 @@ _mesa_symbol_table_add_symbol(struct _mesa_symbol_table 
*table,
       new_sym->next_with_same_name = sym;
       new_sym->name = sym->name;
    } else {
-      new_sym->name = strdup(name);
-      if (new_sym->name == NULL) {
-         free(new_sym);
-         _mesa_error_no_memory(__func__);
-         return -1;
-      }
+      new_sym->name = (char *)(new_sym + 1);
+      strcpy(new_sym->name, name);
    }
 
    new_sym->next_with_same_scope = table->current_scope->symbols;
@@ -252,7 +247,7 @@ _mesa_symbol_table_add_global_symbol(struct 
_mesa_symbol_table *table,
       /* empty */
    }
 
-   sym = calloc(1, sizeof(*sym));
+   sym = calloc(1, sizeof(*sym) + (inner_sym ? 0 : strlen(name) + 1));
    if (sym == NULL) {
       _mesa_error_no_memory(__func__);
       return -1;
@@ -266,12 +261,8 @@ _mesa_symbol_table_add_global_symbol(struct 
_mesa_symbol_table *table,
 
       sym->name = inner_sym->name;
    } else {
-      sym->name = strdup(name);
-      if (sym->name == NULL) {
-         free(sym);
-         _mesa_error_no_memory(__func__);
-         return -1;
-      }
+      sym->name = (char *)(sym + 1);
+      strcpy(sym->name, name);
    }
 
    sym->next_with_same_scope = top_scope->symbols;