obtained gcc-4.6.4.tar.bz2 from upstream website;upstream

verified gcc-4.6.4.tar.bz2.sig;
imported gcc-4.6.4 source tree from verified upstream tarball.

downloading a git-generated archive based on the 'upstream' tag
should provide you with a source tree that is binary identical
to the one extracted from the above tarball.

if you have obtained the source via the command 'git clone',
however, do note that line-endings of files in your working
directory might differ from line-endings of the respective
files in the upstream repository.

1 files changed, 33 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/nrv4.c b/gcc/testsuite/gcc.dg/nrv4.c
new file mode 100644
index 000000000..e213d860e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/nrv4.c
@@ -0,0 +1,33 @@
+/* Verify that NRV optimizations are prohibited when the LHS is an
+   indirect reference to something that may be call-clobbered. */
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+typedef struct { int x[20]; void *y; } S;
+S nrv_candidate (void);
+void use_result (S);
+void make_escape (S *);
+S global_S;
+void foo (void)
+{
+  S *result;
+  S local_S;
+
+  /* We can't perform return slot optimization because global_S is
+     global and may be clobbered by nrv_candidate.  */
+  result = &global_S;
+  *result = nrv_candidate ();
+  use_result (*result);
+
+  /* We can't perform return slot optimization because local_S is
+     call_clobbered (its address escapes prior to invoking
+     nrv_candidate).  */
+  make_escape (&local_S);
+  result = &local_S;
+  *result = nrv_candidate ();
+  use_result (*result);
+}
+
+/* { dg-final { scan-tree-dump-times "return slot optimization" 0 "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
+