* tree-ssa-dom.c (thread_across_edge): Do not use local_fold.

	Strip away all type conversions after simplifying the
	condition.

        * tree-cfgcleanup.c (merge_phi_nodes): Allow merging in some
        cases the forwarder block dominates the destination.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@108833 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2bd2e7c..69bfe7a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2005-12-19  Jeff Law  <law@redhat.com>
+
+       * tree-ssa-dom.c (thread_across_edge): Do not use local_fold.
+       Strip away all type conversions after simplifying the
+       condition.
+
+        * tree-cfgcleanup.c (merge_phi_nodes): Allow merging in some
+        cases the forwarder block dominates the destination.
+
 2005-12-19  DJ Delorie  <dj@redhat.com>
 
        * reload1.c (spill_failure): Dump reload data to dump file.

diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c
index 7e719c1..6f8b1c0 100644 (file)
--- a/gcc/tree-cfgcleanup.c
+++ b/gcc/tree-cfgcleanup.c
@@ -743,6 +743,39 @@ merge_phi_nodes (void)
             nodes at BB.  */
          *current++ = bb;
        }
+      else
+       {
+         tree phi;
+
+         /* BB dominates DEST.  There may be many users of the PHI
+            nodes in BB.  However, there is still a trivial case we
+            can handle.  If the result of every PHI in BB is used
+            only by a PHI in DEST, then we can trivially merge the
+            PHI nodes from BB into DEST.  */
+         for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
+           {
+             tree result = PHI_RESULT (phi);
+             int num_uses = num_imm_uses (result);
+             use_operand_p imm_use;
+             tree use_stmt;
+
+             /* If the PHI's result is never used, then we can just
+                ignore it.  */
+             if (num_uses == 0)
+               continue;
+
+             /* Get the single use of the result of this PHI node.  */
+             if (!single_imm_use (result, &imm_use, &use_stmt)
+                 || TREE_CODE (use_stmt) != PHI_NODE
+                 || bb_for_stmt (use_stmt) != dest)
+               break;
+           }
+
+         /* If the loop above iterated thorugh all the PHI nodes
+            in BB, then we can merge the PHIs from BB into DEST.  */
+         if (!phi)
+           *current++ = bb;
+       }
     }
 
   /* Now let's drain WORKLIST.  */

diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
index b6257d3..45a5b7d 100644 (file)
--- a/gcc/tree-ssa-dom.c
+++ b/gcc/tree-ssa-dom.c
@@ -892,9 +892,14 @@ thread_across_edge (struct dom_walk_data *walk_data, edge e)
              TREE_OPERAND (COND_EXPR_COND (dummy_cond), 1) = op1;
            }
 
-         /* If the conditional folds to an invariant, then we are done,
-            otherwise look it up in the hash tables.  */
-         cached_lhs = local_fold (COND_EXPR_COND (dummy_cond));
+         /* We absolutely do not care about any type conversions
+            we only care about a zero/nonzero value.  */
+         cached_lhs = fold (COND_EXPR_COND (dummy_cond));
+         while (TREE_CODE (cached_lhs) == NOP_EXPR
+                || TREE_CODE (cached_lhs) == CONVERT_EXPR
+                || TREE_CODE (cached_lhs) == NON_LVALUE_EXPR)
+           cached_lhs = TREE_OPERAND (cached_lhs, 0);
+           
          if (! is_gimple_min_invariant (cached_lhs))
            {
              cached_lhs = lookup_avail_expr (dummy_cond, false);