[ARC] Make D0, D1 double regs fix when not used.

gcc/
2017-04-25  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (arc_conditional_register_usage): Make D0, D1
	double regs fix when not used.

From-SVN: r247198

gcc/ChangeLog

 2017-04-25  Claudiu Zissulescu  <claziss@synopsys.com>
 
+	* config/arc/arc.c (arc_conditional_register_usage): Make D0, D1
+	double regs fix when not used.
+
+2017-04-25  Claudiu Zissulescu  <claziss@synopsys.com>
+
 	* config/arc/arc.h (REGNO_OK_FOR_BASE_P): Consider also extension
 	core registers.
 	(REG_OK_FOR_INDEX_P_NONSTRICT): Likewise.

gcc/config/arc/arc.c

@@ -1543,6 +1543,11 @@ arc_conditional_register_usage (void)
       arc_regno_reg_class[42] = ALL_REGS;
       arc_regno_reg_class[43] = ALL_REGS;
 
+      fixed_regs[40] = 1;
+      fixed_regs[41] = 1;
+      fixed_regs[42] = 1;
+      fixed_regs[43] = 1;
+
       arc_hard_regno_mode_ok[40] = 0;
       arc_hard_regno_mode_ok[42] = 0;