[LRA] Relax one gcc_assert in lra-eliminate for fixed register

  gcc/
    * lra-eliminations.c (update_reg_eliminate): Relax gcc_assert for fixed
    registers.

From-SVN: r217691

gcc/ChangeLog

+2014-11-18  Jiong Wang  <jiong.wang@arm.com>
+
+	* lra-eliminations.c (update_reg_eliminate): Relax gcc_assert for fixed
+	registers.
+
 2014-11-18  Marat Zakirov  <m.zakirov@samsung.com>
 
 	* opts.c (finish_options): Disable aggressive opts for sanitizer.  

gcc/lra-eliminations.c

@@ -1199,7 +1199,9 @@ update_reg_eliminate (bitmap insns_with_changed_offsets)
 		     ep->from, ep->to);
 	  /* If after processing RTL we decides that SP can be used as
 	     a result of elimination, it can not be changed.  */
-	  gcc_assert (ep->to_rtx != stack_pointer_rtx);
+	  gcc_assert ((ep->to_rtx != stack_pointer_rtx)
+		      || (ep->from < FIRST_PSEUDO_REGISTER
+			  && fixed_regs [ep->from]));
 	  /* Mark that is not eliminable anymore.  */
 	  elimination_map[ep->from] = NULL;
 	  for (ep1 = ep + 1; ep1 < &reg_eliminate[NUM_ELIMINABLE_REGS]; ep1++)