Hi!
As mentioned in the PR, the expander now requires that calls with
TREE_ADDRESSABLE result type have lhs set (so that a temporary of the
type doesn't have to be created by the middle-end).
The first 3 hunks (gimplify.c and cgraphunit.c) are to fix noreturn
functions with such return types, by making sure they have the lhs.
The ipa-split.c changes force the *.part.N function to have void
return if we don't need the return value from the split function.
If the split part contains any MEM_REFs that refer to the DECL_BY_REFERENCE
RESULT_DECL SSA_NAME, then consider_split will already mark them
split_point->split_part_set_retval, and if we just the SSA_NAME otherwise,
we (missed optimization) give up on fn splitting in that case earlier (could
force split_point->split_part_set_retval instead and even that would be
handled well in this case).
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2016-02-03 Jakub Jelinek <ja...@redhat.com>
Patrick Palka <ppa...@gcc.gnu.org>
PR ipa/69241
PR c++/69649
* gimplify.c (gimplify_modify_expr): Set lhs even for noreturn
calls if the return type is TREE_ADDRESSABLE.
* cgraphunit.c (cgraph_node::expand_thunk): Likewise.
* ipa-split.c (split_function): Fix doubled "we" in comment.
Use void return type for the split part even if
!split_point->split_part_set_retval.
* g++.dg/ipa/pr69241-1.C: New test.
* g++.dg/ipa/pr69241-2.C: New test.
* g++.dg/ipa/pr69241-3.C: New test.
* g++.dg/ipa/pr69649.C: New test.
--- gcc/gimplify.c.jj 2016-02-02 20:42:00.000000000 +0100
+++ gcc/gimplify.c 2016-02-03 11:04:06.400757668 +0100
@@ -4828,7 +4828,8 @@ gimplify_modify_expr (tree *expr_p, gimp
}
}
notice_special_calls (call_stmt);
- if (!gimple_call_noreturn_p (call_stmt))
+ if (!gimple_call_noreturn_p (call_stmt)
+ || TREE_ADDRESSABLE (TREE_TYPE (*to_p)))
gimple_call_set_lhs (call_stmt, *to_p);
assign = call_stmt;
}
--- gcc/cgraphunit.c.jj 2016-01-20 10:55:15.000000000 +0100
+++ gcc/cgraphunit.c 2016-02-03 11:04:41.034279370 +0100
@@ -1703,7 +1703,8 @@ cgraph_node::expand_thunk (bool output_a
bsi = gsi_start_bb (bb);
/* Build call to the function being thunked. */
- if (!VOID_TYPE_P (restype) && !alias_is_noreturn)
+ if (!VOID_TYPE_P (restype)
+ && (!alias_is_noreturn || TREE_ADDRESSABLE (restype)))
{
if (DECL_BY_REFERENCE (resdecl))
{
@@ -1770,7 +1771,7 @@ cgraph_node::expand_thunk (bool output_a
|| DECL_BY_REFERENCE (resdecl)))
gimple_call_set_return_slot_opt (call, true);
- if (restmp && !alias_is_noreturn)
+ if (restmp)
{
gimple_call_set_lhs (call, restmp);
gcc_assert (useless_type_conversion_p (TREE_TYPE (restmp),
--- gcc/ipa-split.c.jj 2016-01-04 14:55:52.000000000 +0100
+++ gcc/ipa-split.c 2016-02-03 13:01:45.905136051 +0100
@@ -1254,7 +1254,7 @@ split_function (basic_block return_bb, s
else
main_part_return_p = true;
}
- /* The main part also returns if we we split on a fallthru edge
+ /* The main part also returns if we split on a fallthru edge
and the split part returns. */
if (split_part_return_p)
FOR_EACH_EDGE (e, ei, split_point->entry_bb->preds)
@@ -1364,8 +1364,9 @@ split_function (basic_block return_bb, s
/* Now create the actual clone. */
cgraph_edge::rebuild_edges ();
node = cur_node->create_version_clone_with_body
- (vNULL, NULL, args_to_skip, !split_part_return_p, split_point->split_bbs,
- split_point->entry_bb, "part");
+ (vNULL, NULL, args_to_skip,
+ !split_part_return_p || !split_point->split_part_set_retval,
+ split_point->split_bbs, split_point->entry_bb, "part");
node->split_part = true;
--- gcc/testsuite/g++.dg/ipa/pr69241-1.C.jj 2016-02-03 10:56:10.624328263
+0100
+++ gcc/testsuite/g++.dg/ipa/pr69241-1.C 2016-02-03 11:01:18.600075039
+0100
@@ -0,0 +1,12 @@
+// PR ipa/69241
+// { dg-do compile }
+// { dg-options "-O2" }
+
+struct R { R (const R &) {} };
+__attribute__ ((noreturn)) R bar ();
+
+R
+foo ()
+{
+ bar ();
+}
--- gcc/testsuite/g++.dg/ipa/pr69241-2.C.jj 2016-02-03 10:56:07.996364556
+0100
+++ gcc/testsuite/g++.dg/ipa/pr69241-2.C 2016-02-03 11:01:42.958738639
+0100
@@ -0,0 +1,18 @@
+// PR ipa/69241
+// { dg-do compile }
+// { dg-options "-O2" }
+
+__attribute__((noreturn)) void foo (int);
+struct R { R (const R &) {} };
+
+R
+bar ()
+{
+ foo (0);
+}
+
+R
+baz ()
+{
+ foo (0);
+}
--- gcc/testsuite/g++.dg/ipa/pr69241-3.C.jj 2016-02-03 11:00:39.840610317
+0100
+++ gcc/testsuite/g++.dg/ipa/pr69241-3.C 2016-02-03 11:01:02.044303678
+0100
@@ -0,0 +1,12 @@
+// PR ipa/69241
+// { dg-do compile }
+// { dg-options "-O2" }
+
+struct R { int x[100]; };
+__attribute__ ((noreturn)) R bar ();
+
+void
+foo ()
+{
+ bar ();
+}
--- gcc/testsuite/g++.dg/ipa/pr69649.C.jj 2016-02-03 13:19:00.850845887
+0100
+++ gcc/testsuite/g++.dg/ipa/pr69649.C 2016-02-03 13:18:43.000000000 +0100
@@ -0,0 +1,36 @@
+// PR c++/69649
+// { dg-do compile }
+// { dg-options "-O2" }
+
+struct A { virtual void m1 (); };
+struct C : A { void m1 () { m1 (); } };
+template <class T> struct B
+{
+ T *t;
+ B (T *x) : t (x) { if (t) t->m1 (); }
+ B (const B &);
+};
+struct D : public C {};
+struct F : public D
+{
+ virtual B<D> m2 ();
+ virtual B<D> m3 ();
+ int m4 ();
+};
+struct G : F
+{
+ B<D> m2 ();
+ B<D> m3 ();
+};
+B<D> G::m2 ()
+{
+ if (m4 () == 0)
+ return this;
+ return 0;
+}
+B<D> G::m3 ()
+{
+ if (m4 () == 0)
+ return this;
+ return 0;
+}
Jakub
