Implement new immediate use iterators.

2006-04-27  Andrew MacLeod  <amacleod@redhat.com>

	PR tree-optimization/26854
	* tree-vrp.c (remove_range_assertions): Use new Immuse iterator.
	* doc/tree-ssa.texi: Update immuse iterator documentation.
	* tree-ssa-math-opts.c (execute_cse_reciprocals_1): Use new iterator.
	* tree-ssa-dom.c (propagate_rhs_into_lhs): Use new iterator.
	* tree-flow-inline.h (end_safe_imm_use_traverse, end_safe_imm_use_p,
	first_safe_imm_use, next_safe_imm_use): Remove.
	(end_imm_use_stmt_p): New.  Check for end of immuse stmt traversal.
	(end_imm_use_stmt_traverse): New.  Terminate immuse stmt traversal.
	(move_use_after_head): New.  Helper function to sort immuses in a stmt.
	(link_use_stmts_after): New.  Link all immuses in a stmt consescutively.
	(first_imm_use_stmt): New.  Get first stmt in an immuse list.
	(next_imm_use_stmt): New.  Get next stmt in an immuse list.
	(first_imm_use_on_stmt): New.  Get first immuse on a stmt.
	(end_imm_use_on_stmt_p): New.  Check for end of immuses on a stmt.
	(next_imm_use_on_stmt): New.  Move to next immuse on a stmt.
	* tree-ssa-forwprop.c (forward_propagate_addr_expr): Use new iterator.
	* lambda-code.c (lambda_loopnest_to_gcc_loopnest): Use new iterator.
	(perfect_nestify): Use new iterator.
	* tree-vect-transform.c (vect_create_epilog_for_reduction): Use new 
	iterator.
	* tree-flow.h (struct immediate_use_iterator_d): Add comments.
	(next_imm_name): New field in struct immediate_use_iterator_d.
	(FOR_EACH_IMM_USE_SAFE, BREAK_FROM_SAFE_IMM_USE): Remove.
	(FOR_EACH_IMM_USE_STMT, BREAK_FROM_IMM_USE_STMT, 
	FOR_EACH_IMM_USE_ON_STMT): New immediate use iterator macros.
	* tree-cfg.c (replace_uses_by): Use new iterator.
	* tree-ssa-threadedge.c (lhs_of_dominating_assert): Use new iterator.
	* tree-ssa-operands.c (correct_use_link): Remove.
	(finalize_ssa_use_ops): No longer call correct_use_link.

From-SVN: r113321

1 files changed, 37 insertions, 6 deletions

diff --git a/gcc/tree-flow.h b/gcc/tree-flow.h
index 87e8328..98ed8af 100644
--- a/gcc/tree-flow.h
+++ b/gcc/tree-flow.h
@@ -225,9 +225,15 @@ struct function_ann_d GTY(())
 
 typedef struct immediate_use_iterator_d
 {
+  /* This is the current use the iterator is processing.  */
   ssa_use_operand_t *imm_use;
+  /* This marks the last use in the list (use node from SSA_NAME)  */
   ssa_use_operand_t *end_p;
+  /* This node is inserted and used to mark the end of the uses for a stmt.  */
   ssa_use_operand_t iter_node;
+  /* This is the next ssa_name to visit.  IMM_USE may get removed before
+     the next one is traversed to, so it must be cached early.  */
+  ssa_use_operand_t *next_imm_name;
 } imm_use_iterator;
 
 
@@ -239,18 +245,43 @@ typedef struct immediate_use_iterator_d
        !end_readonly_imm_use_p (&(ITER));			\
        (DEST) = next_readonly_imm_use (&(ITER)))
   
+/* Use this iterator to visit each stmt which has a use of SSAVAR.  */
 
-#define FOR_EACH_IMM_USE_SAFE(DEST, ITER, SSAVAR)		\
-  for ((DEST) = first_safe_imm_use (&(ITER), (SSAVAR));		\
-       !end_safe_imm_use_p (&(ITER));				\
-       (DEST) = next_safe_imm_use (&(ITER)))
+#define FOR_EACH_IMM_USE_STMT(STMT, ITER, SSAVAR)		\
+  for ((STMT) = first_imm_use_stmt (&(ITER), (SSAVAR));		\
+       !end_imm_use_stmt_p (&(ITER));				\
+       (STMT) = next_imm_use_stmt (&(ITER)))
 
-#define BREAK_FROM_SAFE_IMM_USE(ITER)				\
+/* Use this to terminate the FOR_EACH_IMM_USE_STMT loop early.  Failure to 
+   do so will result in leaving a iterator marker node in the immediate
+   use list, and nothing good will come from that.   */
+#define BREAK_FROM_IMM_USE_STMT(ITER)				\
    {								\
-     end_safe_imm_use_traverse (&(ITER));			\
+     end_imm_use_stmt_traverse (&(ITER));			\
      break;							\
    }
 
+
+/* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to 
+   get access to each occurence of ssavar on the stmt returned by
+   that iterator..  for instance:
+
+     FOR_EACH_IMM_USE_STMT (stmt, iter, var)
+       {
+         FOR_EACH_IMM_USE_ON_STMT (use_p, iter)
+	   {
+	     SET_USE (use_p) = blah;
+	   }
+	 update_stmt (stmt);
+       }							 */
+
+#define FOR_EACH_IMM_USE_ON_STMT(DEST, ITER)			\
+  for ((DEST) = first_imm_use_on_stmt (&(ITER));		\
+       !end_imm_use_on_stmt_p (&(ITER));			\
+       (DEST) = next_imm_use_on_stmt (&(ITER)))
+
+
+
 struct stmt_ann_d GTY(())
 {
   struct tree_ann_common_d common;