passes: Fix up subobject __bos [PR101419]

The following testcase is miscompiled, because VN during cunrolli changes
__bos argument from address of a larger field to address of a smaller field
and so __builtin_object_size (, 1) then folds into smaller value than the
actually available size.
copy_reference_ops_from_ref has a hack for this, but it was using
cfun->after_inlining as a check whether the hack can be ignored, and
cunrolli is after_inlining.

This patch uses a property to make it exact (set at the end of objsz
pass that doesn't do insert_min_max_p) and additionally based on discussions
in the PR moves the objsz pass earlier after IPA.

2021-07-13  Jakub Jelinek  <jakub@redhat.com>
	    Richard Biener  <rguenther@suse.de>

	PR tree-optimization/101419
	* tree-pass.h (PROP_objsz): Define.
	(make_pass_early_object_sizes): Declare.
	* passes.def (pass_all_early_optimizations): Rename pass_object_sizes
	there to pass_early_object_sizes, drop parameter.
	(pass_all_optimizations): Move pass_object_sizes right after pass_ccp,
	drop parameter, move pass_post_ipa_warn right after that.
	* tree-object-size.c (pass_object_sizes::execute): Rename to...
	(object_sizes_execute): ... this.  Add insert_min_max_p argument.
	(pass_data_object_sizes): Move after object_sizes_execute.
	(pass_object_sizes): Likewise.  In execute method call
	object_sizes_execute, drop set_pass_param method and insert_min_max_p
	non-static data member and its initializer in the ctor.
	(pass_data_early_object_sizes, pass_early_object_sizes,
	make_pass_early_object_sizes): New.
	* tree-ssa-sccvn.c (copy_reference_ops_from_ref): Use
	(cfun->curr_properties & PROP_objsz) instead of cfun->after_inlining.

	* gcc.dg/builtin-object-size-10.c: Pass -fdump-tree-early_objsz-details
	instead of -fdump-tree-objsz1-details in dg-options and adjust names
	of dump file in scan-tree-dump.
	* gcc.dg/pr101419.c: New test.

1 files changed, 73 insertions, 41 deletions

diff --git a/gcc/tree-object-size.c b/gcc/tree-object-size.c
index 13be7f4..744748d 100644
--- a/gcc/tree-object-size.c
+++ b/gcc/tree-object-size.c
@@ -1304,45 +1304,6 @@ fini_object_sizes (void)
     }
 }
 
-
-/* Simple pass to optimize all __builtin_object_size () builtins.  */
-
-namespace {
-
-const pass_data pass_data_object_sizes =
-{
-  GIMPLE_PASS, /* type */
-  "objsz", /* name */
-  OPTGROUP_NONE, /* optinfo_flags */
-  TV_NONE, /* tv_id */
-  ( PROP_cfg | PROP_ssa ), /* properties_required */
-  0, /* properties_provided */
-  0, /* properties_destroyed */
-  0, /* todo_flags_start */
-  0, /* todo_flags_finish */
-};
-
-class pass_object_sizes : public gimple_opt_pass
-{
-public:
-  pass_object_sizes (gcc::context *ctxt)
-    : gimple_opt_pass (pass_data_object_sizes, ctxt), insert_min_max_p (false)
-  {}
-
-  /* opt_pass methods: */
-  opt_pass * clone () { return new pass_object_sizes (m_ctxt); }
-  void set_pass_param (unsigned int n, bool param)
-    {
-      gcc_assert (n == 0);
-      insert_min_max_p = param;
-    }
-  virtual unsigned int execute (function *);
-
- private:
-  /* Determines whether the pass instance creates MIN/MAX_EXPRs.  */
-  bool insert_min_max_p;
-}; // class pass_object_sizes
-
 /* Dummy valueize function.  */
 
 static tree
@@ -1351,8 +1312,8 @@ do_valueize (tree t)
   return t;
 }
 
-unsigned int
-pass_object_sizes::execute (function *fun)
+static unsigned int
+object_sizes_execute (function *fun, bool insert_min_max_p)
 {
   basic_block bb;
   FOR_EACH_BB_FN (bb, fun)
@@ -1453,6 +1414,38 @@ pass_object_sizes::execute (function *fun)
   return 0;
 }
 
+/* Simple pass to optimize all __builtin_object_size () builtins.  */
+
+namespace {
+
+const pass_data pass_data_object_sizes =
+{
+  GIMPLE_PASS, /* type */
+  "objsz", /* name */
+  OPTGROUP_NONE, /* optinfo_flags */
+  TV_NONE, /* tv_id */
+  ( PROP_cfg | PROP_ssa ), /* properties_required */
+  PROP_objsz, /* properties_provided */
+  0, /* properties_destroyed */
+  0, /* todo_flags_start */
+  0, /* todo_flags_finish */
+};
+
+class pass_object_sizes : public gimple_opt_pass
+{
+public:
+  pass_object_sizes (gcc::context *ctxt)
+    : gimple_opt_pass (pass_data_object_sizes, ctxt)
+  {}
+
+  /* opt_pass methods: */
+  opt_pass * clone () { return new pass_object_sizes (m_ctxt); }
+  virtual unsigned int execute (function *fun)
+  {
+    return object_sizes_execute (fun, false);
+  }
+}; // class pass_object_sizes
+
 } // anon namespace
 
 gimple_opt_pass *
@@ -1460,3 +1453,42 @@ make_pass_object_sizes (gcc::context *ctxt)
 {
   return new pass_object_sizes (ctxt);
 }
+
+/* Early version of pass to optimize all __builtin_object_size () builtins.  */
+
+namespace {
+
+const pass_data pass_data_early_object_sizes =
+{
+  GIMPLE_PASS, /* type */
+  "early_objsz", /* name */
+  OPTGROUP_NONE, /* optinfo_flags */
+  TV_NONE, /* tv_id */
+  ( PROP_cfg | PROP_ssa ), /* properties_required */
+  0, /* properties_provided */
+  0, /* properties_destroyed */
+  0, /* todo_flags_start */
+  0, /* todo_flags_finish */
+};
+
+class pass_early_object_sizes : public gimple_opt_pass
+{
+public:
+  pass_early_object_sizes (gcc::context *ctxt)
+    : gimple_opt_pass (pass_data_early_object_sizes, ctxt)
+  {}
+
+  /* opt_pass methods: */
+  virtual unsigned int execute (function *fun)
+  {
+    return object_sizes_execute (fun, true);
+  }
+}; // class pass_object_sizes
+
+} // anon namespace
+
+gimple_opt_pass *
+make_pass_early_object_sizes (gcc::context *ctxt)
+{
+  return new pass_early_object_sizes (ctxt);
+}