re PR middle-end/67651 (Optimizer assumes nothing can reside at address 0…

re PR middle-end/67651 (Optimizer assumes nothing can reside at address 0 despite -fno-delete-null-pointer-checks)

2015-09-21  Richard Biener  <rguenther@suse.de>

	PR middle-end/67651
	* rtlanal.c (nonzero_address_p): SYMBOL_REFs may have zero
	address with -fno-delete-null-pointer-checks.

From-SVN: r227968

gcc/ChangeLog

+2015-09-21  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/67651
+	* rtlanal.c (nonzero_address_p): SYMBOL_REFs may have zero
+	address with -fno-delete-null-pointer-checks.
+
 2015-09-21  Alan Lawrence  <alan.lawrence@arm.com>
 
 	* config/rs6000/altivec.md (reduc_splus_<mode>): Rename to...

gcc/rtlanal.c

@@ -723,7 +723,7 @@ nonzero_address_p (const_rtx x)
   switch (code)
     {
     case SYMBOL_REF:
-      return !SYMBOL_REF_WEAK (x);
+      return flag_delete_null_pointer_checks && !SYMBOL_REF_WEAK (x);
 
     case LABEL_REF:
       return true;