vxworks.h (VXCPU_FOR_8548): Correct definition for VxWorks 7.

2017-09-06  Olivier Hainque  <hainque@adacore.com>

	* config/powerpcspe/vxworks.h (VXCPU_FOR_8548): Correct definition
	for VxWorks 7.  Adjust surrounding comments.

From-SVN: r251796

gcc/ChangeLog

+2017-09-06  Olivier Hainque  <hainque@adacore.com>
+
+	* config/powerpcspe/vxworks.h (VXCPU_FOR_8548): Correct definition
+	for VxWorks 7.  Adjust surrounding comments.
+
 2017-09-06  Richard Biener  <rguenther@suse.de>
 
 	* gimple-ssa-strength-reduction.c

gcc/config/powerpcspe/vxworks.h

@@ -60,11 +60,17 @@ along with GCC; see the file COPYING3.  If not see
 
 #define SUBTARGET_EXTRA_SPECS /* none needed */
 
-/* VxWorks and VxWorksAE (aka 653) expect different CPU values to designate
-   SPE on 8548.  We define a dedicated macro for the base VxWorks here, which
-   the AE configuration will override.  */
+/* Arrange to infer -DCPU, which VxWorks headers require, from -mcpu.  */
 
+/* Different flavors of VxWorks expect different CPU values to designate SPE
+   on 8548.  We define a dedicated macro for the base VxWorks here, which the
+   AE configuration might also override.  */
+
+#if TARGET_VXWORKS7
+#define VXCPU_FOR_8548 "PPCE500V2"
+#else
 #define VXCPU_FOR_8548 "PPC85XX"
+#endif
 
 /* FIXME: The only reason we allow no -mcpu switch at all is because
    config-ml.in insists on a "." multilib. */