Don't use nullptr return from simplify_gen_subreg

Check nullptr return from simplify_gen_subreg.  Don't use it if it is
nullptr.

	PR middle-end/90773
	* builtins.c (builtin_memset_gen_str): Don't use return from
	simplify_gen_subreg.

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 2d6bf4a65b4da53780eaaa0b798a3a67bcf819b0..4613aecfe6eb4a3ddb3c87afe00d0eba4dca1801 100644 (file)
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -6628,7 +6628,9 @@ builtin_memset_gen_str (void *data, void *prevp,
       if (prev->mode == mode)
        return prev->data;
 
-      return simplify_gen_subreg (mode, prev->data, prev->mode, 0);
+      target = simplify_gen_subreg (mode, prev->data, prev->mode, 0);
+      if (target != nullptr)
+       return target;
     }
 
   size = GET_MODE_SIZE (mode);