[PATCH] Fix devirtualization ICE (PR tree-optimization/59622, take 5)

Richard Biener rguenther@suse.de
Thu Jan 9 20:15:00 GMT 2014


Jakub Jelinek <jakub@redhat.com> wrote:
>On Thu, Jan 09, 2014 at 02:27:40PM +0100, Richard Biener wrote:
>> > Perhaps, if you don't like the !gimple_in_ssa_p (cfun) in the
>condition
>> > we can just drop the lhs always in that case, just doing what we do
>for
>> > __builtin_unreachable if lhs is SSA_NAME:
>> >   tree var = create_tmp_var (TREE_TYPE (lhs), NULL);
>> >   tree def = get_or_create_ssa_default_def (cfun, var);
>> >   gsi_insert_after (gsi, gimple_build_assign (lhs, def),
>GSI_NEW_STMT);
>> 
>> That works for me.
>
>So like this?
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok?

Ok,
Thanks.

>2014-01-09  Jakub Jelinek  <jakub@redhat.com>
>
>	PR tree-optimization/59622
>	* gimple-fold.c (gimple_fold_call): Fix a typo in message.  For
>	__builtin_unreachable replace the OBJ_TYPE_REF call with a call to
>	__builtin_unreachable and add if needed a setter of the lhs SSA_NAME.
>	Don't devirtualize for inplace at all.  For targets.length () == 1,
>	if the call is noreturn and cfun isn't in SSA form yet, clear lhs.
>
>	* g++.dg/opt/pr59622-2.C: New test.
>	* g++.dg/opt/pr59622-3.C: New test.
>	* g++.dg/opt/pr59622-4.C: New test.
>	* g++.dg/opt/pr59622-5.C: New test.
>
>--- gcc/gimple-fold.c.jj	2014-01-08 17:44:57.690582374 +0100
>+++ gcc/gimple-fold.c	2014-01-09 14:34:40.816149806 +0100
>@@ -1167,7 +1167,7 @@ gimple_fold_call (gimple_stmt_iterator *
>                                        (OBJ_TYPE_REF_EXPR (callee)))))
> 	    {
> 	      fprintf (dump_file,
>-		       "Type inheritnace inconsistent devirtualization of ");
>+		       "Type inheritance inconsistent devirtualization of ");
> 	      print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
> 	      fprintf (dump_file, " to ");
> 	      print_generic_expr (dump_file, callee, TDF_SLIM);
>@@ -1177,24 +1177,45 @@ gimple_fold_call (gimple_stmt_iterator *
> 	  gimple_call_set_fn (stmt, OBJ_TYPE_REF_EXPR (callee));
> 	  changed = true;
> 	}
>-      else if (flag_devirtualize && virtual_method_call_p (callee))
>+      else if (flag_devirtualize && !inplace && virtual_method_call_p
>(callee))
> 	{
> 	  bool final;
> 	  vec <cgraph_node *>targets
> 	    = possible_polymorphic_call_targets (callee, &final);
> 	  if (final && targets.length () <= 1)
> 	    {
>+	      tree lhs = gimple_call_lhs (stmt);
> 	      if (targets.length () == 1)
> 		{
> 		  gimple_call_set_fndecl (stmt, targets[0]->decl);
> 		  changed = true;
>+		  /* If the call becomes noreturn, remove the lhs.  */
>+		  if (lhs && (gimple_call_flags (stmt) & ECF_NORETURN))
>+		    {
>+		      if (TREE_CODE (lhs) == SSA_NAME)
>+			{
>+			  tree var = create_tmp_var (TREE_TYPE (lhs), NULL);
>+			  tree def = get_or_create_ssa_default_def (cfun, var);
>+			  gimple new_stmt = gimple_build_assign (lhs, def);
>+			  gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
>+			}
>+		      gimple_call_set_lhs (stmt, NULL_TREE);
>+		    }
> 		}
>-	      else if (!inplace)
>+	      else
> 		{
> 		  tree fndecl = builtin_decl_implicit (BUILT_IN_UNREACHABLE);
> 		  gimple new_stmt = gimple_build_call (fndecl, 0);
> 		  gimple_set_location (new_stmt, gimple_location (stmt));
>-		  gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
>+		  if (lhs && TREE_CODE (lhs) == SSA_NAME)
>+		    {
>+		      tree var = create_tmp_var (TREE_TYPE (lhs), NULL);
>+		      tree def = get_or_create_ssa_default_def (cfun, var);
>+		      gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
>+		      update_call_from_tree (gsi, def);
>+		    }
>+		  else
>+		    gsi_replace (gsi, new_stmt, true);
> 		  return true;
> 		}
> 	    }
>--- gcc/testsuite/g++.dg/opt/pr59622-2.C.jj	2014-01-09
>10:57:46.246694025 +0100
>+++ gcc/testsuite/g++.dg/opt/pr59622-2.C	2014-01-09 10:57:46.246694025
>+0100
>@@ -0,0 +1,21 @@
>+// PR tree-optimization/59622
>+// { dg-do compile }
>+// { dg-options "-O2" }
>+
>+namespace
>+{
>+  struct A
>+  {
>+    A () {}
>+    virtual A *bar (int) = 0;
>+    A *baz (int x) { return bar (x); }
>+  };
>+}
>+
>+A *a;
>+
>+void
>+foo ()
>+{
>+  a->baz (0);
>+}
>--- gcc/testsuite/g++.dg/opt/pr59622-3.C.jj	2014-01-09
>10:57:46.247694040 +0100
>+++ gcc/testsuite/g++.dg/opt/pr59622-3.C	2014-01-09 10:57:46.247694040
>+0100
>@@ -0,0 +1,21 @@
>+// PR tree-optimization/59622
>+// { dg-do compile }
>+// { dg-options "-O2" }
>+
>+struct C { int a; int b; };
>+
>+namespace
>+{
>+  struct A
>+  {
>+    virtual C foo ();
>+    C bar () { return foo (); }
>+  };
>+}
>+
>+C
>+baz ()
>+{
>+  A a;
>+  return a.bar ();
>+}
>--- gcc/testsuite/g++.dg/opt/pr59622-4.C.jj	2014-01-09
>10:57:46.247694040 +0100
>+++ gcc/testsuite/g++.dg/opt/pr59622-4.C	2014-01-09 10:57:46.247694040
>+0100
>@@ -0,0 +1,23 @@
>+// PR tree-optimization/59622
>+// { dg-do compile }
>+// { dg-options "-O2" }
>+
>+struct C { int a; int b; };
>+
>+namespace
>+{
>+  struct A
>+  {
>+    A () {}
>+    virtual C bar (int) = 0;
>+    C baz (int x) { return bar (x); }
>+  };
>+}
>+
>+A *a;
>+
>+C
>+foo ()
>+{
>+  return a->baz (0);
>+}
>--- gcc/testsuite/g++.dg/opt/pr59622-5.C.jj	2014-01-09
>11:06:11.862133398 +0100
>+++ gcc/testsuite/g++.dg/opt/pr59622-5.C	2014-01-09 10:54:04.000000000
>+0100
>@@ -0,0 +1,26 @@
>+// PR tree-optimization/59622
>+// { dg-do compile }
>+// { dg-options "-O2" }
>+
>+namespace
>+{
>+  struct A
>+  {
>+    A () {}
>+    virtual A *bar (int);
>+    A *baz (int x) { return bar (x); }
>+  };
>+
>+  __attribute__((noreturn)) A *A::bar (int)
>+  {
>+    __builtin_exit (0);
>+  }
>+}
>+
>+A *a;
>+
>+void
>+foo ()
>+{
>+  a->baz (0);
>+}
>
>
>	Jakub




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