[PATCH v2 7/8] [PowerPC] Fix inclusion of dfp pseudoregs in tdep

[Pedro Franco de Carvalho]

Previously, decimal floating point pseudoregisters were always included
in the target if it had a floating point unit.

This patch changes this to only include them if the target description
indicates that they are present, i.e. if the FPSCR register has more
than 32 bits.

gdb/ChangeLog:
yyyy-mm-dd  Pedro Franco de Carvalho  <pedromfc@linux.vnet.ibm.com>

	* rs6000-tdep.c (rs6000_gdbarch_init): Assign 1 to have_dfp only
	if the size of fpscr is larger than 32 bits.
---
 gdb/rs6000-tdep.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c
index 0a56c7890a..ff4699c191 100644
--- a/gdb/rs6000-tdep.c
+++ b/gdb/rs6000-tdep.c
@@ -5981,14 +5981,16 @@ rs6000_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 	      return NULL;
 	    }
 	  have_fpu = 1;
+
+	  /* The fpscr register was expanded in isa 2.05 to 64 bits
+	     along with the addition of the decimal floating point
+	     facility.  */
+	  if (tdesc_register_size (feature, "fpscr") > 32)
+	    have_dfp = 1;
 	}
       else
 	have_fpu = 0;
 
-      /* The DFP pseudo-registers will be available when there are floating
-         point registers.  */
-      have_dfp = have_fpu;
-
       feature = tdesc_find_feature (tdesc,
 				    "org.gnu.gdb.power.altivec");
       if (feature != NULL)
-- 
2.13.6