* tree-scalar-evolution.c (scev_const_prop):

	* tree-phinodes.c (remove_phi_node): Add argument
	RELEASE_LHS_P.  If given, release the SSA name on the LHS of
	the PHI node.
	Update all users.
	* tree-ssa-dce.c: Remove forward declarations for static
	functions.  Re-arrange functions bodies as needed.
	(find_obviously_necessary_stmts): Never mark PHI nodes as
	obviously necessary.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@119740 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 12 insertions, 5 deletions

diff --git a/gcc/tree-phinodes.c b/gcc/tree-phinodes.c
index 98b011f89e6..344770e700a 100644
--- a/gcc/tree-phinodes.c
+++ b/gcc/tree-phinodes.c
@@ -233,6 +233,7 @@ make_phi_node (tree var, int len)
       imm->next = NULL;
       imm->stmt = phi;
     }
+
   return phi;
 }
 
@@ -301,7 +302,6 @@ resize_phi_node (tree *phi, int len)
       imm->stmt = new_phi;
     }
 
-
   *phi = new_phi;
 }
 
@@ -343,6 +343,7 @@ reserve_phi_args_for_new_edge (basic_block bb)
     }
 }
 
+
 /* Create a new PHI node for variable VAR at basic block BB.  */
 
 tree
@@ -362,6 +363,7 @@ create_phi_node (tree var, basic_block bb)
   return phi;
 }
 
+
 /* Add a new argument to PHI node PHI.  DEF is the incoming reaching
    definition and E is the edge through which DEF reaches PHI.  The new
    argument is added at the end of the argument list.
@@ -394,6 +396,7 @@ add_phi_arg (tree phi, tree def, edge e)
   SET_PHI_ARG_DEF (phi, e->dest_idx, def);
 }
 
+
 /* Remove the Ith argument from PHI's argument list.  This routine
    implements removal by swapping the last alternative with the
    alternative we want to delete and then shrinking the vector, which
@@ -406,7 +409,6 @@ remove_phi_arg_num (tree phi, int i)
 
   gcc_assert (i < num_elem);
 
-
   /* Delink the item which is being removed.  */
   delink_imm_use (&(PHI_ARG_IMM_USE_NODE (phi, i)));
 
@@ -428,6 +430,7 @@ remove_phi_arg_num (tree phi, int i)
   PHI_NUM_ARGS (phi)--;
 }
 
+
 /* Remove all PHI arguments associated with edge E.  */
 
 void
@@ -439,11 +442,14 @@ remove_phi_args (edge e)
     remove_phi_arg_num (phi, e->dest_idx);
 }
 
+
 /* Remove PHI node PHI from basic block BB.  If PREV is non-NULL, it is
-   used as the node immediately before PHI in the linked list.  */
+   used as the node immediately before PHI in the linked list.  If
+   RELEASE_LHS_P is true, the LHS of this PHI node is released into
+   the free pool of SSA names.  */
 
 void
-remove_phi_node (tree phi, tree prev)
+remove_phi_node (tree phi, tree prev, bool release_lhs_p)
 {
   tree *loc;
 
@@ -465,7 +471,8 @@ remove_phi_node (tree phi, tree prev)
   /* If we are deleting the PHI node, then we should release the
      SSA_NAME node so that it can be reused.  */
   release_phi_node (phi);
-  release_ssa_name (PHI_RESULT (phi));
+  if (release_lhs_p)
+    release_ssa_name (PHI_RESULT (phi));
 }