2009-09-09 Basile Starynkevitch <basile@starynkevitch.net>

	MELT branch merged with trunk rev 151544



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/melt-branch@151549 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 12 insertions, 55 deletions

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index 05988636489..42b2ef36252 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -5297,42 +5297,6 @@ create_new_ivs (struct ivopts_data *data, struct iv_ca *set)
     }
 }
 
-/* Returns the phi-node in BB with result RESULT.  */
-
-static gimple
-get_phi_with_result (basic_block bb, tree result)
-{
-  gimple_stmt_iterator i = gsi_start_phis (bb);
-
-  for (; !gsi_end_p (i); gsi_next (&i))
-    if (gimple_phi_result (gsi_stmt (i)) == result)
-      return gsi_stmt (i);
-
-  gcc_unreachable ();
-  return NULL;
-}
-
-
-/* Removes statement STMT (real or a phi node).  If INCLUDING_DEFINED_NAME
-   is true, remove also the ssa name defined by the statement.  */
-
-static void
-remove_statement (gimple stmt, bool including_defined_name)
-{
-  if (gimple_code (stmt) == GIMPLE_PHI)
-    {
-      gimple bb_phi = get_phi_with_result (gimple_bb (stmt), 
-					 gimple_phi_result (stmt));
-      gimple_stmt_iterator bsi = gsi_for_stmt (bb_phi);
-      remove_phi_node (&bsi, including_defined_name);
-    }
-  else
-    {
-      gimple_stmt_iterator bsi = gsi_for_stmt (stmt);
-      gsi_remove (&bsi, true);
-      release_defs (stmt); 
-    }
-}
 
 /* Rewrites USE (definition of iv used in a nonlinear expression)
    using candidate CAND.  */
@@ -5435,7 +5399,9 @@ rewrite_use_nonlinear_expr (struct ivopts_data *data,
     {
       ass = gimple_build_assign (tgt, op);
       gsi_insert_before (&bsi, ass, GSI_SAME_STMT);
-      remove_statement (use->stmt, false);
+
+      bsi = gsi_for_stmt (use->stmt);
+      remove_phi_node (&bsi, false);
     }
   else
     {
@@ -5611,7 +5577,11 @@ remove_unused_ivs (struct ivopts_data *data)
 {
   unsigned j;
   bitmap_iterator bi;
+  bitmap toremove = BITMAP_ALLOC (NULL);
 
+  /* Figure out an order in which to release SSA DEFs so that we don't
+     release something that we'd have to propagate into a debug stmt
+     afterwards.  */
   EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi)
     {
       struct version_info *info;
@@ -5622,25 +5592,12 @@ remove_unused_ivs (struct ivopts_data *data)
 	  && !info->inv_id
 	  && !info->iv->have_use_for
 	  && !info->preserve_biv)
-	{
-	  if (MAY_HAVE_DEBUG_STMTS)
-	    {
-	      gimple stmt;
-	      imm_use_iterator iter;
-
-	      FOR_EACH_IMM_USE_STMT (stmt, iter, info->iv->ssa_name)
-		{
-		  if (!gimple_debug_bind_p (stmt))
-		    continue;
-
-		  /* ??? We can probably do better than this.  */
-		  gimple_debug_bind_reset_value (stmt);
-		  update_stmt (stmt);
-		}
-	    }
-	  remove_statement (SSA_NAME_DEF_STMT (info->iv->ssa_name), true);
-	}
+	bitmap_set_bit (toremove, SSA_NAME_VERSION (info->iv->ssa_name));
     }
+
+  release_defs_bitset (toremove);
+
+  BITMAP_FREE (toremove);
 }
 
 /* Frees data allocated by the optimization of a single loop.  */