tree-inline: Simplify IPA-CP type conversion (PR 93385)

when callers and callees do not quite agree on the type of a
parameter, usually with ill-defined K&R or with smilarly wrong LTO
input, IPA-CP can attempt to try and substitute a wrong type for a
parameter (see e.g. gcc.dg/torture/pr48063.c).  Function
tree_function_versioning attempts to handle this in order not to
create invalid gimple but it then creates the mapping using
setup_one_parameter which also handles the same situation to avoid
similar problems when inlining and in more defined way.

So this patch simply removes the conversion attempts in
tree_function_versioning itself.  It is helpful for my upcoming fix of
PR 93385 because then I do not need to teach
ipa_param_body_adjustments to distinguish between successful and
unsuccessful mappings - setup_one_parameter uses force_value_to_type
for conversions which simly maps the worst cases to zero.

2020-05-04  Martin Jambor  <mjambor@suse.cz>

	PR ipa/93385
	* tree-inline.c (tree_function_versioning): Leave any type conversion
	of replacements to setup_one_parameter and its friend
	force_value_to_type.

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a549d453731c94f89759c4a11755ae7c4313e5bc..42c4af762cdf270b2994d00afba8dd6c83ce2e11 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2020-05-04  Martin Jambor  <mjambor@suse.cz>
+
+       PR ipa/93385
+       * tree-inline.c (tree_function_versioning): Leave any type conversion
+       of replacements to setup_one_parameter and its friend
+       force_value_to_type.
+
 2020-05-04  Uroš Bizjak  <ubizjak@gmail.com>
 
        PR target/94650

diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index 69ca8e99109ed9bae74f8099789049a251abe9b9..32c49ae03efd1467ad513f871ab1c62242233f9a 100644 (file)
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -6261,46 +6261,14 @@ tree_function_versioning (tree old_decl, tree new_decl,
          p = new_param_indices[p];
 
        tree parm;
-       tree req_type, new_type;
-
        for (parm = DECL_ARGUMENTS (old_decl); p;
             parm = DECL_CHAIN (parm))
          p--;
-       tree old_tree = parm;
-       req_type = TREE_TYPE (parm);
-       new_type = TREE_TYPE (replace_info->new_tree);
-       if (!useless_type_conversion_p (req_type, new_type))
-         {
-           if (fold_convertible_p (req_type, replace_info->new_tree))
-             replace_info->new_tree
-               = fold_build1 (NOP_EXPR, req_type, replace_info->new_tree);
-           else if (TYPE_SIZE (req_type) == TYPE_SIZE (new_type))
-             replace_info->new_tree
-               = fold_build1 (VIEW_CONVERT_EXPR, req_type,
-                              replace_info->new_tree);
-           else
-             {
-               if (dump_file)
-                 {
-                   fprintf (dump_file, "    const ");
-                   print_generic_expr (dump_file,
-                                       replace_info->new_tree);
-                   fprintf (dump_file,
-                            "  can't be converted to param ");
-                   print_generic_expr (dump_file, parm);
-                   fprintf (dump_file, "\n");
-                 }
-               old_tree = NULL;
-             }
-         }
-
-       if (old_tree)
-         {
-           init = setup_one_parameter (&id, old_tree, replace_info->new_tree,
-                                       id.src_fn, NULL, &vars);
-           if (init)
-             init_stmts.safe_push (init);
-         }
+       gcc_assert (parm);
+       init = setup_one_parameter (&id, parm, replace_info->new_tree,
+                                   id.src_fn, NULL, &vars);
+       if (init)
+         init_stmts.safe_push (init);
       }
 
   ipa_param_body_adjustments *param_body_adjs = NULL;