* stmt.c (expand_case): Speed up code to detect duplicate case

        label targets and count unique case label targets.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@90027 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e71cba6..cbc5bc6 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-11-03 Jeff Law  <law@redhat.com>
+
+       * stmt.c (expand_case): Speed up code to detect duplicate case
+       label targets and count unique case label targets.
+
 2004-11-03  Kazu Hirata  <kazu@cs.umass.edu>
 
        * cppdefault.c, cppdefault.h, timevar.h: Update copyright.

diff --git a/gcc/stmt.c b/gcc/stmt.c
index f9efbfe..08dabde 100644 (file)
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -2317,7 +2317,7 @@ expand_case (tree exp)
 {
   tree minval = NULL_TREE, maxval = NULL_TREE, range = NULL_TREE;
   rtx default_label = 0;
-  struct case_node *n, *m;
+  struct case_node *n;
   unsigned int count, uniq;
   rtx index;
   rtx table_label;
@@ -2354,6 +2354,7 @@ expand_case (tree exp)
   if (index_type != error_mark_node)
     {
       tree elt;
+      bitmap label_bitmap;
 
       /* cleanup_tree_cfg removes all SWITCH_EXPR with their index
         expressions being INTEGER_CST.  */
@@ -2392,6 +2393,7 @@ expand_case (tree exp)
 
       uniq = 0;
       count = 0;
+      label_bitmap = BITMAP_XMALLOC ();
       for (n = case_list; n; n = n->right)
        {
          /* Count the elements and track the largest and smallest
@@ -2412,17 +2414,18 @@ expand_case (tree exp)
          if (! tree_int_cst_equal (n->low, n->high))
            count++;
 
-         /* Count the number of unique case node targets.  */
-          uniq++;
+         /* If we have not seen this label yet, then increase the
+            number of unique case node targets seen.  */
          lab = label_rtx (n->code_label);
-          for (m = case_list; m != n; m = m->right)
-            if (label_rtx (m->code_label) == lab)
-              {
-                uniq--;
-                break;
-              }
+         if (!bitmap_bit_p (label_bitmap, CODE_LABEL_NUMBER (lab)))
+           {
+             bitmap_set_bit (label_bitmap, CODE_LABEL_NUMBER (lab));
+             uniq++;
+           }
        }
 
+      BITMAP_XFREE (label_bitmap);
+
       /* cleanup_tree_cfg removes all SWITCH_EXPR with a single
         destination, such as one with a default case only.  */
       gcc_assert (count != 0);