2012-09-21 Richard Guenther <rguenther@suse.de>

	PR tree-optimization/54647
	* tree-ssa-pre.c (compute_avail): Do not put COND_EXPR
	or VEC_COND_EXPR into EXP_GEN again.

	* g++.dg/torture/pr54647.C: New testcase.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@191613 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8fd0221..648eb10 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-09-21  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/54647
+       * tree-ssa-pre.c (compute_avail): Do not put COND_EXPR
+       or VEC_COND_EXPR into EXP_GEN again.
+
 2012-09-21  Jakub Jelinek  <jakub@redhat.com>
 
        PR tree-optimization/54629

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9616b89..3723d6b 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-09-21  Richard Guenther  <rguenther@suse.de>
+
+       PR tree-optimization/54647
+       * g++.dg/torture/pr54647.C: New testcase.
+
 2012-09-21  Marc Glisse  <marc.glisse@inria.fr>
 
        PR c++/54427

diff --git a/gcc/testsuite/g++.dg/torture/pr54647.C b/gcc/testsuite/g++.dg/torture/pr54647.C
new file mode 100644 (file)
index 0000000..2177ecd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr54647.C
@@ -0,0 +1,25 @@
+// { dg-do compile }
+
+class A
+{
+};
+template <class type> struct D:A
+{
+  type & operator[](int);
+};
+struct B
+{
+  typedef D <int *>Row;
+  struct C
+    {
+      Row *row;
+    };
+};
+B::C a;
+B::Row & b = *a.row;
+void
+fn1 ()
+{
+  while (1)
+    b[0] = b[0] ? (int *) -1 : 0;
+}

diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c
index ab9f2f4..d1d97b6 100644 (file)
--- a/gcc/tree-ssa-pre.c
+++ b/gcc/tree-ssa-pre.c
@@ -3981,9 +3981,18 @@ compute_avail (void)
                  {
                  case VN_NARY:
                    {
+                     enum tree_code code = gimple_assign_rhs_code (stmt);
                      vn_nary_op_t nary;
+
+                     /* COND_EXPR and VEC_COND_EXPR are awkward in
+                        that they contain an embedded complex expression.
+                        Don't even try to shove those through PRE.  */
+                     if (code == COND_EXPR
+                         || code == VEC_COND_EXPR)
+                       continue;
+
                      vn_nary_op_lookup_pieces (gimple_num_ops (stmt) - 1,
-                                               gimple_assign_rhs_code (stmt),
+                                               code,
                                                gimple_expr_type (stmt),
                                                gimple_assign_rhs1_ptr (stmt),
                                                &nary);