* tree-if-conv.c (find_phi_replacement_condition): Return true edge block.

        (replace_phi_with_cond_modify_expr): Select conditional expr args based on
        true edge basic block.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@87194 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 23 insertions, 17 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 348924547ca..3108964bfa2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2004-09-08  Devang Patel  <dpatel@apple.com>
+
+	* tree-if-conv.c (find_phi_replacement_condition): Return true edge block.
+	(replace_phi_with_cond_modify_expr): Select conditional expr args based on
+	true edge basic block.
+	
 2004-09-08  Jan Hubicka  <jh@suse.cz>
 
 	* tree-ssa-operands.c (add_stmt_operand): Use V_MUST_DEF even for
diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index daca885f64a..1e2fd76e3a9 100644
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -117,9 +117,9 @@ static void add_to_predicate_list (basic_block, tree);
 static tree add_to_dst_predicate_list (struct loop * loop, tree, tree, tree,
 				       block_stmt_iterator *);
 static void clean_predicate_lists (struct loop *loop);
-static bool find_phi_replacement_condition (basic_block, tree *,
-                                            block_stmt_iterator *);
-static void replace_phi_with_cond_modify_expr (tree, tree, bool,
+static basic_block find_phi_replacement_condition (basic_block, tree *,
+						   block_stmt_iterator *);
+static void replace_phi_with_cond_modify_expr (tree, tree, basic_block,
                                                block_stmt_iterator *);
 static void process_phi_nodes (struct loop *);
 static void combine_blocks (struct loop *);
@@ -671,17 +671,17 @@ clean_predicate_lists (struct loop *loop)
 }
 
 /* Basic block BB has two predecessors. Using predecessor's aux field, set
-   appropriate condition COND for the PHI node replacement. Return true if
-   phi arguments are condition is selected from second predecessor.  */
+   appropriate condition COND for the PHI node replacement. Return true block
+   whose phi arguments are selected when cond is true.  */
 
-static bool
+static basic_block
 find_phi_replacement_condition (basic_block bb, tree *cond,
                                 block_stmt_iterator *bsi)
 {
   edge e;
   basic_block p1 = NULL;
   basic_block p2 = NULL;
-  bool switch_args = false;
+  basic_block true_bb = NULL; 
   tree tmp_cond;
 
   for (e = bb->pred; e; e = e->pred_next)
@@ -700,12 +700,12 @@ find_phi_replacement_condition (basic_block bb, tree *cond,
   if (TREE_CODE (tmp_cond) == TRUTH_NOT_EXPR)
     {
       *cond  = p2->aux;
-      switch_args = true;
+      true_bb = p2;
     }
   else
     {
       *cond  = p1->aux;
-      switch_args = false;
+      true_bb = p1;
     }
 
   /* Create temp. for the condition. Vectorizer prefers to have gimple
@@ -727,7 +727,7 @@ find_phi_replacement_condition (basic_block bb, tree *cond,
     abort ();
 #endif
 
-  return switch_args;
+  return true_bb;
 }
 
 
@@ -738,18 +738,18 @@ find_phi_replacement_condition (basic_block bb, tree *cond,
    is converted into,
      S2: A = cond ? x1 : x2;
    S2 is inserted at the top of basic block's statement list.
-   PHI arguments are switched if SWITCH_ARGS is true.
+   When COND is true, phi arg from TRUE_BB is selected.
 */
 
 static void
-replace_phi_with_cond_modify_expr (tree phi, tree cond, bool switch_args,
+replace_phi_with_cond_modify_expr (tree phi, tree cond, basic_block true_bb,
                                    block_stmt_iterator *bsi)
 {
   tree new_stmt;
   basic_block bb;
   tree rhs;
   tree arg_0, arg_1;
-
+  
 #ifdef ENABLE_CHECKING
   if (TREE_CODE (phi) != PHI_NODE)
     abort ();
@@ -767,7 +767,7 @@ replace_phi_with_cond_modify_expr (tree phi, tree cond, bool switch_args,
   arg_1 = NULL_TREE;
 
   /* Use condition that is not TRUTH_NOT_EXPR in conditional modify expr.  */
-  if (switch_args)
+  if (PHI_ARG_EDGE(phi, 1)->src == true_bb)
     {
       arg_0 = PHI_ARG_DEF (phi, 1);
       arg_1 = PHI_ARG_DEF (phi, 0);
@@ -820,7 +820,7 @@ process_phi_nodes (struct loop *loop)
     {
       tree phi, cond;
       block_stmt_iterator bsi;
-      bool switch_args = false;
+      basic_block true_bb = NULL;
       bb = ifc_bbs[i];
 
       if (bb == loop->header || bb == loop->latch)
@@ -832,12 +832,12 @@ process_phi_nodes (struct loop *loop)
       /* BB has two predecessors. Using predecessor's aux field, set
 	 appropriate condition for the PHI node replacement.  */
       if (phi)
-	switch_args = find_phi_replacement_condition (bb, &cond, &bsi);
+	true_bb = find_phi_replacement_condition (bb, &cond, &bsi);
 
       while (phi)
 	{
 	  tree next = TREE_CHAIN (phi);
-	  replace_phi_with_cond_modify_expr (phi, cond, switch_args, &bsi);
+	  replace_phi_with_cond_modify_expr (phi, cond, true_bb, &bsi);
 	  release_phi_node (phi);
 	  phi = next;
 	}