Changeset 1853 for trunk/src/kmk/read.c

Timestamp:

Oct 13, 2008, 3:46:35 AM (17 years ago)

Author:

bird

Message:

kmk: Optimized the dependency hashing done by uniquize_deps() by making it take advantage of the fact that all strings are in the strcache.

File:

• trunk/src/kmk/read.c (modified) (3 diffs)

trunk/src/kmk/read.c

@@ -2124 +2124 @@
 
 /* Remove duplicate dependencies in CHAIN.  */
+#ifndef CONFIG_WITH_VALUE_LENGTH
 
 static unsigned long
@@ -2154 +2155 @@
 }
 
+#else  /* CONFIG_WITH_VALUE_LENGTH */
+
+/* Exploit the fact that all names are in the string cache. This means equal
+   names shall have the same storage and there is no need for hashing or
+   comparing. Use the address as the first hash, avoiding any touching of
+   the name, and the length as the second. */
+
+static unsigned long
+dep_hash_1 (const void *key)
+{
+  const char *name = dep_name ((struct dep const *) key);
+  assert (strcache_iscached (name));
+  return (size_t) name / sizeof(void *);
+}
+
+static unsigned long
+dep_hash_2 (const void *key)
+{
+  const char *name = dep_name ((struct dep const *) key);
+  return strcache_get_len (name);
+}
+
+static int
+dep_hash_cmp (const void *x, const void *y)
+{
+  struct dep *dx = (struct dep *) x;
+  struct dep *dy = (struct dep *) y;
+  const char *dxname = dep_name (dx);
+  const char *dyname = dep_name (dy);
+  int cmp = dxname == dyname ? 0 : 1;
+
+  /* check preconds: both cached and the cache contains no duplicates. */
+  assert (strcache_iscached (dxname));
+  assert (strcache_iscached (dyname));
+  assert (cmp == 0 || strcmp (dxname, dyname) != 0);
+
+  /* If the names are the same but ignore_mtimes are not equal, one of these
+     is an order-only prerequisite and one isn't.  That means that we should
+     remove the one that isn't and keep the one that is.  */
+
+  if (!cmp && dx->ignore_mtime != dy->ignore_mtime)
+    dx->ignore_mtime = dy->ignore_mtime = 0;
+
+  return cmp;
+}
+
+#endif /* CONFIG_WITH_VALUE_LENGTH */
 
 void
@@ -2467 +2515 @@
           /* Single-colon.  Combine these dependencies
              with others in file's existing record, if any.  */
+#ifndef KMK
           f = enter_file (strcache_add (name));
+#else  /* KMK - the name is already in the cache, don't waste time.  */
+          f = enter_file (name);
+#endif
 
           if (f->double_colon)