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Diffstat (limited to 'gcc/testsuite/gcc.dg/nrv4.c')
-rw-r--r--gcc/testsuite/gcc.dg/nrv4.c33
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" } } */
+