PR target/79890: S/390: Fix crash.

builtin_eh_return requires the return address to be saved on the
stack.  The patch prevents using an FPR for that.

gcc/ChangeLog:

2017-04-05  Dominik Vogt  <vogt@linux.vnet.ibm.com>

	PR target/79890
	* config/s390/s390.c (s390_register_info_gprtofpr): Return if
	call_eh_return is true.

gcc/testsuite/ChangeLog:

2017-04-05  Dominik Vogt  <vogt@linux.vnet.ibm.com>

	PR target/79890
	* gcc.target/s390/pr79890.c: New test case.

From-SVN: r246701

gcc/ChangeLog

+2017-04-05  Dominik Vogt  <vogt@linux.vnet.ibm.com>
+
+	PR target/79890
+	* config/s390/s390.c (s390_register_info_gprtofpr): Return if
+	call_eh_return is true.
+
 2017-04-05  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
 
 	* config/s390/s390-c.c (s390_resolve_overloaded_builtin):

gcc/config/s390/s390.c

@@ -9512,6 +9512,12 @@ s390_register_info_gprtofpr ()
   if (!TARGET_Z10 || !TARGET_HARD_FLOAT || !crtl->is_leaf)
     return;
 
+  /* builtin_eh_return needs to be able to modify the return address
+     on the stack.  It could also adjust the FPR save slot instead but
+     is it worth the trouble?!  */
+  if (crtl->calls_eh_return)
+    return;
+
   for (i = 15; i >= 6; i--)
     {
       if (cfun_gpr_save_slot (i) == SAVE_SLOT_NONE)

gcc/testsuite/ChangeLog

+2017-04-05  Dominik Vogt  <vogt@linux.vnet.ibm.com>
+
+	PR target/79890
+	* gcc.target/s390/pr79890.c: New test case.
+
 2017-04-05  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/80310

gcc/testsuite/gcc.target/s390/pr79890.c

+/* { dg-do compile } */
+/* { dg-options "-Wno-pedantic" } */
+
+void bar (void);
+
+void
+foo (int x)
+{
+  __builtin_unwind_init ();
+  __builtin_eh_return (x, bar);
+}