Add GSI_LAST_NEW_STMT iterator update

Currently when adding a sequence before there's no way to get the
iterator placed at the last added stmt which results in convoluted
code in the if-conversion usecase.  The following adds
GSI_LAST_NEW_STMT and corrects one obvious mistake in
execute_update_addresses_taken as well as tries to avoid the
just filed PR102726 by biasing the enum values to be outside of
the boolean 0/1 range.

2021-10-13  Richard Biener  <rguenther@suse.de>

	* gimple-iterator.h (gsi_iterator_update): Add GSI_LAST_NEW_STMT,
	start at integer value 2.
	* gimple-iterator.c (gsi_insert_seq_nodes_before): Update
	the iterator for GSI_LAST_NEW_STMT.
	(gsi_insert_seq_nodes_after): Likewise.
	* tree-if-conv.c (predicate_statements): Use GSI_LAST_NEW_STMT.
	* tree-ssa.c (execute_update_addresses_taken): Correct bogus
	arguments to gsi_replace.

diff --git a/gcc/gimple-iterator.c b/gcc/gimple-iterator.c
index da8c212..ee4e63a 100644 (file)
--- a/gcc/gimple-iterator.c
+++ b/gcc/gimple-iterator.c
@@ -162,6 +162,9 @@ gsi_insert_seq_nodes_before (gimple_stmt_iterator *i,
     case GSI_CONTINUE_LINKING:
       i->ptr = first;
       break;
+    case GSI_LAST_NEW_STMT:
+      i->ptr = last;
+      break;
     case GSI_SAME_STMT:
       break;
     default:
@@ -271,6 +274,7 @@ gsi_insert_seq_nodes_after (gimple_stmt_iterator *i,
     case GSI_NEW_STMT:
       i->ptr = first;
       break;
+    case GSI_LAST_NEW_STMT:
     case GSI_CONTINUE_LINKING:
       i->ptr = last;
       break;

diff --git a/gcc/gimple-iterator.h b/gcc/gimple-iterator.h
index 6047a73..0e384f7 100644 (file)
--- a/gcc/gimple-iterator.h
+++ b/gcc/gimple-iterator.h
@@ -46,8 +46,8 @@ struct gphi_iterator : public gimple_stmt_iterator
  
 enum gsi_iterator_update
 {
-  GSI_NEW_STMT,                /* Only valid when single statement is added, move
-                          iterator to it.  */
+  GSI_NEW_STMT = 2,    /* Move the iterator to the first statement added.  */
+  GSI_LAST_NEW_STMT,   /* Move the iterator to the last statement added.  */
   GSI_SAME_STMT,       /* Leave the iterator at the same statement.  */
   GSI_CONTINUE_LINKING /* Move iterator to whatever position is suitable
                           for linking other statements in the same

diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index 6a67acf..0b6b07c 100644 (file)
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -2582,11 +2582,7 @@ predicate_statements (loop_p loop)
            {
              gsi_remove (&gsi, true);
              gsi_insert_seq_before (&gsi, rewrite_to_defined_overflow (stmt),
-                                    GSI_SAME_STMT);
-             if (gsi_end_p (gsi))
-               gsi = gsi_last_bb (gimple_bb (stmt));
-             else
-               gsi_prev (&gsi);
+                                    GSI_LAST_NEW_STMT);
            }
          else if (gimple_vdef (stmt))
            {

diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c
index 0fba404..fde13de 100644 (file)
--- a/gcc/tree-ssa.c
+++ b/gcc/tree-ssa.c
@@ -2079,7 +2079,7 @@ execute_update_addresses_taken (void)
                            gcall *call
                              = gimple_build_call_internal (IFN_ASAN_POISON, 0);
                            gimple_call_set_lhs (call, var);
-                           gsi_replace (&gsi, call, GSI_SAME_STMT);
+                           gsi_replace (&gsi, call, true);
                          }
                        else
                          {
@@ -2088,7 +2088,7 @@ execute_update_addresses_taken (void)
                               previous out of scope value.  */
                            tree clobber = build_clobber (TREE_TYPE (var));
                            gimple *g = gimple_build_assign (var, clobber);
-                           gsi_replace (&gsi, g, GSI_SAME_STMT);
+                           gsi_replace (&gsi, g, true);
                          }
                        continue;
                      }