cp_gimplify_r doesn't always get to see the contents of a CONSTRUCTOR,
so it can miss lowering PTRMEM_CSTs there. cp_genericize_r does look
into CONSTRUCTORs, and lowering them earlier is fine.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit fff4c8804414258331785f08435259ecfdb7311c
Author: Jason Merrill <ja...@redhat.com>
Date: Tue Apr 12 17:00:42 2016 -0400
PR c++/70615
* cp-gimplify.c (cp_genericize_r): Expand PTRMEM_CST here.
(cp_gimplify_expr): Not here.
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index 13f7b7c..30ac660 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -576,11 +576,6 @@ cp_gimplify_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p)
switch (code)
{
- case PTRMEM_CST:
- *expr_p = cplus_expand_constant (*expr_p);
- ret = GS_OK;
- break;
-
case AGGR_INIT_EXPR:
simplify_aggr_init_expr (expr_p);
ret = GS_OK;
@@ -1388,6 +1383,13 @@ cp_genericize_r (tree *stmt_p, int *walk_subtrees, void *data)
|| TREE_CODE (stmt) == OMP_SIMD
|| TREE_CODE (stmt) == OMP_DISTRIBUTE)
genericize_omp_for_stmt (stmt_p, walk_subtrees, data);
+ else if (TREE_CODE (stmt) == PTRMEM_CST)
+ {
+ /* By the time we get here we're handing off to the back end, so we don't
+ need or want to preserve PTRMEM_CST anymore. */
+ *stmt_p = cplus_expand_constant (stmt);
+ *walk_subtrees = 0;
+ }
else if ((flag_sanitize
& (SANITIZE_NULL | SANITIZE_ALIGNMENT | SANITIZE_VPTR))
&& !wtd->no_sanitize_p)
diff --git a/gcc/testsuite/g++.dg/opt/ptrmem7.C b/gcc/testsuite/g++.dg/opt/ptrmem7.C
new file mode 100644
index 0000000..7d9e9b1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/ptrmem7.C
@@ -0,0 +1,31 @@
+// PR c++/70615
+// { dg-options -O }
+
+struct C
+{
+ virtual void f () {}
+};
+
+struct B
+{
+ virtual ~B () {}
+};
+
+class D : public B, public C
+{
+public:
+ D () {}
+};
+
+typedef void (C::*FP) ();
+typedef void (D::*D_f) ();
+
+int
+main ()
+{
+ D *d = new D ();
+ C *c = d;
+ const FP fptr = (FP) & D::f;
+ (d->*(D_f) fptr) ();
+ return 0;
+}
