* tree-ssa-dom.c (cprop_into_successor_phis): Remove code to

	find the index of a PHI argument.  Use e->dest_idx instead.
	Replace hint with index.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@91166 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 82a31f1..f6e30d9 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2004-11-23  Kazu Hirata  <kazu@cs.umass.edu>
+
+       * tree-ssa-dom.c (cprop_into_successor_phis): Remove code to
+       find the index of a PHI argument.  Use e->dest_idx instead.
+       Replace hint with index.
+
 2004-11-24  Diego Novillo  <dnovillo@redhat.com>
 
        * tree-ssa-alias.c (merge_pointed_to_info): Fix comment

diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
index d88d683..f257d2d 100644 (file)
--- a/gcc/tree-ssa-dom.c
+++ b/gcc/tree-ssa-dom.c
@@ -2290,8 +2290,7 @@ cprop_into_successor_phis (basic_block bb, bitmap nonzero_vars)
   FOR_EACH_EDGE (e, ei, bb->succs)
     {
       tree phi;
-      int phi_num_args;
-      int hint;
+      int index;
 
       /* If this is an abnormal edge, then we do not want to copy propagate
         into the PHI alternative associated with this edge.  */
@@ -2302,46 +2301,16 @@ cprop_into_successor_phis (basic_block bb, bitmap nonzero_vars)
       if (! phi)
        continue;
 
-      /* There is no guarantee that for any two PHI nodes in a block that
-        the phi alternative associated with a particular edge will be
-        at the same index in the phi alternative array.
-
-        However, it is very likely they will be the same.  So we keep
-        track of the index of the alternative where we found the edge in
-        the previous phi node and check that index first in the next
-        phi node.  If that hint fails, then we actually search all
-        the entries.  */
-      phi_num_args = PHI_NUM_ARGS (phi);
-      hint = phi_num_args;
+      index = e->dest_idx;
       for ( ; phi; phi = PHI_CHAIN (phi))
        {
-         int i;
          tree new;
          use_operand_p orig_p;
          tree orig;
 
-         /* If the hint is valid (!= phi_num_args), see if it points
-            us to the desired phi alternative.  */
-         if (hint != phi_num_args && PHI_ARG_EDGE (phi, hint) == e)
-           ;
-         else
-           {
-             /* The hint was either invalid or did not point to the
-                correct phi alternative.  Search all the alternatives
-                for the correct one.  Update the hint.  */
-             for (i = 0; i < phi_num_args; i++)
-               if (PHI_ARG_EDGE (phi, i) == e)
-                 break;
-             hint = i;
-           }
-
-         /* If we did not find the proper alternative, then something is
-            horribly wrong.  */
-         gcc_assert (hint != phi_num_args);
-
          /* The alternative may be associated with a constant, so verify
             it is an SSA_NAME before doing anything with it.  */
-         orig_p = PHI_ARG_DEF_PTR (phi, hint);
+         orig_p = PHI_ARG_DEF_PTR (phi, index);
          orig = USE_FROM_PTR (orig_p);
          if (TREE_CODE (orig) != SSA_NAME)
            continue;
@@ -2349,7 +2318,7 @@ cprop_into_successor_phis (basic_block bb, bitmap nonzero_vars)
          /* If the alternative is known to have a nonzero value, record
             that fact in the PHI node itself for future use.  */
          if (bitmap_bit_p (nonzero_vars, SSA_NAME_VERSION (orig)))
-           PHI_ARG_NONZERO (phi, hint) = true;
+           PHI_ARG_NONZERO (phi, index) = true;
 
          /* If we have *ORIG_P in our constant/copy table, then replace
             ORIG_P with its value in our constant/copy table.  */