Subject: subtract_array()
From: Michael Sporn <sporn@mathematik.hu-berlin.de>
Date: Tue, 16 Mar 1999 17:19:59 +0100 (MET)
Type: Patch
State: Done - applied in 3.2-dev.56

Hallo Lars,

ich hab mir meine subtract_array() - optimierung noch mal angeschaut und
noch eine Verbesserung eingebaut: Fuer Subtrahenden der Groesse 1 wird jetzt
auch das assoc() vermieden, was die Geschwindigkeit bei string-arrays nochmal
auf mehr als das Dreifache, bei normalen arrays auf das Doppelte steigen
laesst.

Ciao, Michael
--
Michael Sporn <sporn@mathematik.hu-berlin.de>


--- ldmud-dev48/array.c	Sat Mar  6 01:01:43 1999
+++ ldmud-dev/array.c	Tue Mar 16 16:53:35 1999
@@ -704,33 +704,30 @@
 }

 /*-------------------------------------------------------------------------*/
-static INLINE void
-alist_canonify (struct svalue *svp)

-/* Bring <svp> into the format expected/created by order_alist: unshared
- * strings are made shared, destructed objects are replaced by svalue-0.
- * <*svp> is modified in-place.
- */
+static int
+compare_aux (struct svalue *p1, struct vector *v)
+
+/*
+ * compare *p1 and v->item[0], return 0 if equal, else -1
+ */

 {
-    if (svp->type == T_STRING)
-    {
-        if (svp->x.string_type != STRING_SHARED)
-        {
-            char *str = make_shared_string(svp->u.string);
-            free_string_svalue(svp);
-            svp->x.string_type = STRING_SHARED;
-            svp->u.string = str;
-        }
-    }
-    else if (svp->type == T_OBJECT)
-    {
-        if (svp->u.ob->flags & O_DESTRUCTED)
-        {
-            free_object_svalue(svp);
-            svp->type = T_NUMBER;
-            svp->u.number = 0;
-        }
+    struct svalue *p2 = &v->item[0];
+
+    if (p1->type != p2->type) return -1;
+    if (p1->type == T_STRING)
+        return strcmp(p1->u.string, p2->u.string) ? -1 : 0;
+
+    if (p1->u.number != p2->u.number) return -1;
+    switch (p1->type) {
+        case T_FLOAT:
+        case T_CLOSURE:
+        case T_SYMBOL:
+        case T_QUOTED_ARRAY:
+            return p1->x.generic != p2->x.generic ? -1 : 0;
+        default:
+            return 0;
     }
 }

@@ -758,6 +755,10 @@
     struct vector *vtmpp;         /* {( Ordered <subtrahend> }) */
     struct svalue *source, *dest; /* Pointers into minuend
                                      and difference vector */
+
+    /* function used to find an svalue in a (sorted) vector */
+    int (*assoc_function) (struct svalue*, struct vector*);
+
     mp_int i;
     mp_int minuend_size    = VEC_SIZE(minuend);
     mp_int subtrahend_size = VEC_SIZE(subtrahend);
@@ -778,7 +779,12 @@
     /* Order the subtrahend */
     if (subtrahend_size == 1)
     {
-        alist_canonify( &subtrahend->item[0] );
+        if (subtrahend->item[0].type == T_OBJECT
+                && subtrahend->item[0].u.ob->flags & O_DESTRUCTED)
+        {
+            assign_svalue(&subtrahend->item[0], &const0);
+        }
+        assoc_function = &compare_aux;
         vtmpp = subtrahend;
     }
     else
@@ -786,6 +792,7 @@
         ltmp.u.vec = subtrahend;
         vtmpp = order_alist(&ltmp, 1, 1);
         free_vector(ltmp.u.vec);
+        assoc_function = &assoc;
         subtrahend = vtmpp->item[0].u.vec;
     }

@@ -800,13 +807,13 @@
         {
             if (source->type == T_OBJECT && source->u.ob->flags & O_DESTRUCTED)
                 assign_svalue(source, &const0);
-            if ( assoc(source, subtrahend) >-1 ) break;
+            if ( (*assoc_function)(source, subtrahend) >-1 ) break;
         }
         for (dest = source++; i-->0 ; source++)
         {
             if (source->type == T_OBJECT && source->u.ob->flags & O_DESTRUCTED)
                 assign_svalue(source, &const0);
-            if ( assoc(source, subtrahend) < 0 )
+            if ( (*assoc_function)(source, subtrahend) < 0 )
                 assign_svalue(dest++, source);
         }
         free_vector(vtmpp);
@@ -821,7 +828,7 @@
         ; source++) {
         if (source->type == T_OBJECT && source->u.ob->flags & O_DESTRUCTED)
             assign_svalue(source, &const0);
-        if ( assoc(source, subtrahend) < 0 )
+        if ( (*assoc_function)(source, subtrahend) < 0 )
             assign_svalue_no_free(dest++, source);
     }