s390.c (MIN_UNROLL_PROBES): Define.

	* config/s390/s390.c (MIN_UNROLL_PROBES): Define.
	(allocate_stack_space): New function, partially extracted from
	s390_emit_prologue.
	(s390_emit_prologue): Track offset to most recent stack probe.
	Code to allocate space moved into allocate_stack_space.
	Dump actions when no stack is allocated.
	(s390_prologue_plus_offset): New function.
	(s390_emit_stack_probe): Likewise.

	* gcc.dg/stack-check-5.c:  Add argument for s390.
	* lib/target-supports.exp:
	(check_effective_target_supports_stack_clash_protection): Enable for
	s390/s390x targets.

Co-Authored-By: Jeff Law <law@redhat.com>

From-SVN: r253049

gcc/ChangeLog

+2017-09-20  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
+	    Jeff Law  <law@redhat.com>
+
+	* config/s390/s390.c (MIN_UNROLL_PROBES): Define.
+	(allocate_stack_space): New function, partially extracted from
+	s390_emit_prologue.
+	(s390_emit_prologue): Track offset to most recent stack probe.
+	Code to allocate space moved into allocate_stack_space.
+	Dump actions when no stack is allocated.
+	(s390_prologue_plus_offset): New function.
+	(s390_emit_stack_probe): Likewise.
+
 2017-09-20  Alexandre Oliva <aoliva@redhat.com>
 
 	* common.opt (Wa, Wl, Wp, g, gz=): Add

gcc/testsuite/ChangeLog

+2017-09-20  Andreas Krebbel  <krebbel@linux.vnet.ibm.com>
+	    Jeff Law  <law@redhat.com>
+
+	* gcc.dg/stack-check-5.c:  Add argument for s390.
+	* lib/target-supports.exp: 
+	(check_effective_target_supports_stack_clash_protection): Enable for
+	s390/s390x targets.
+
 2017-09-20  Martin Sebor  <msebor@redhat.com>
 
 	PR c/81854

gcc/testsuite/gcc.dg/stack-check-5.c

@@ -3,6 +3,10 @@
 /* { dg-require-effective-target supports_stack_clash_protection } */
 
 
+/* Otherwise the S/390 back-end might save the stack pointer in f2 ()
+   into an FPR.  */
+/* { dg-additional-options "-msoft-float" { target { s390x-*-* } } } */
+
 extern void foo (char *);
 extern void bar (void);
 

gcc/testsuite/lib/target-supports.exp

@@ -8640,12 +8640,12 @@ proc check_effective_target_supports_stack_clash_protection { } {
 
    # Temporary until the target bits are fully ACK'd.
 #  if { [istarget aarch*-*-*]
-#       || [istarget s390*-*-*]
 #       || [istarget powerpc*-*-*] || [istarget rs6000*-*-*] } {
 #	return 1
 #  }
 
-    if { [istarget x86_64-*-*] || [istarget i?86-*-*] } {
+    if { [istarget x86_64-*-*] || [istarget i?86-*-*] 
+	  || [istarget s390*-*-*] } {
 	return 1
     }
   return 0