PR tree-optimization/51466

	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Also copy
	TREE_SIDE_EFFECTS.

	* gcc.c-torture/execute/pr51466.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@182136 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 58 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index acf73da830a..c2a3cee6344 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2011-12-08  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/51466
+	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Also copy
+	TREE_SIDE_EFFECTS.
+
 2011-12-08  Richard Guenther  <rguenther@suse.de>
 
 	* tree-ssa-operands.c (add_stmt_operand): Do not mark stmts
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 30f16099369..ed2428d8c16 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-12-08  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/51466
+	* gcc.c-torture/execute/pr51466.c: New test.
+
 2011-12-08  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/50815
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr51466.c b/gcc/testsuite/gcc.c-torture/execute/pr51466.c
new file mode 100644
index 00000000000..aa0b7fd4fb9
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr51466.c
@@ -0,0 +1,43 @@
+/* PR tree-optimization/51466 */
+
+extern void abort (void);
+
+__attribute__((noinline, noclone)) int
+foo (int i)
+{
+  volatile int v[4];
+  int *p;
+  v[i] = 6;
+  p = (int *) &v[i];
+  return *p;
+}
+
+__attribute__((noinline, noclone)) int
+bar (int i)
+{
+  volatile int v[4];
+  int *p;
+  v[i] = 6;
+  p = (int *) &v[i];
+  *p = 8;
+  return v[i];
+}
+
+__attribute__((noinline, noclone)) int
+baz (int i)
+{
+  volatile int v[4];
+  int *p;
+  v[i] = 6;
+  p = (int *) &v[0];
+  *p = 8;
+  return v[i];
+}
+
+int
+main ()
+{
+  if (foo (3) != 6 || bar (2) != 8 || baz (0) != 8 || baz (1) != 6)
+    abort ();
+  return 0;
+}
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index 6ab47317770..20821ef8b98 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -929,10 +929,12 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
 	  *def_rhs_basep = build2 (MEM_REF, TREE_TYPE (*def_rhs_basep),
 				   new_base, new_offset);
 	  TREE_THIS_VOLATILE (*def_rhs_basep) = TREE_THIS_VOLATILE (lhs);
+	  TREE_SIDE_EFFECTS (*def_rhs_basep) = TREE_SIDE_EFFECTS (lhs);
 	  TREE_THIS_NOTRAP (*def_rhs_basep) = TREE_THIS_NOTRAP (lhs);
 	  new_lhs = unshare_expr (TREE_OPERAND (def_rhs, 0));
 	  gimple_assign_set_lhs (use_stmt, new_lhs);
 	  TREE_THIS_VOLATILE (new_lhs) = TREE_THIS_VOLATILE (lhs);
+	  TREE_SIDE_EFFECTS (new_lhs) = TREE_SIDE_EFFECTS (lhs);
 	  *def_rhs_basep = saved;
 	  tidy_after_forward_propagate_addr (use_stmt);
 	  /* Continue propagating into the RHS if this was not the
@@ -1011,10 +1013,12 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
 	  *def_rhs_basep = build2 (MEM_REF, TREE_TYPE (*def_rhs_basep),
 				   new_base, new_offset);
 	  TREE_THIS_VOLATILE (*def_rhs_basep) = TREE_THIS_VOLATILE (rhs);
+	  TREE_SIDE_EFFECTS (*def_rhs_basep) = TREE_SIDE_EFFECTS (rhs);
 	  TREE_THIS_NOTRAP (*def_rhs_basep) = TREE_THIS_NOTRAP (rhs);
 	  new_rhs = unshare_expr (TREE_OPERAND (def_rhs, 0));
 	  gimple_assign_set_rhs1 (use_stmt, new_rhs);
 	  TREE_THIS_VOLATILE (new_rhs) = TREE_THIS_VOLATILE (rhs);
+	  TREE_SIDE_EFFECTS (new_rhs) = TREE_SIDE_EFFECTS (rhs);
 	  *def_rhs_basep = saved;
 	  fold_stmt_inplace (use_stmt_gsi);
 	  tidy_after_forward_propagate_addr (use_stmt);