Uros pointed me out that I should use another target for the PR test.
Here is the patch committed as rev. 242881.
2016-11-25 Vladimir Makarov <vmaka...@redhat.com>
PR rtl-optimization/77541
* gcc.target/i386/pr77541.c: Change target to int128.
Index: gcc.target/i386/pr77541.c
===================================================================
--- gcc.target/i386/pr77541.c (revision 242848)
+++ gcc.target/i386/pr77541.c (working copy)
@@ -1,5 +1,5 @@
/* { dg-do run } */
-/* { dg-require-effective-target lp64 } */
+/* { dg-require-effective-target int128 } */
/* { dg-options "-O2 -Wno-psabi" } */
#define MAGIC 0x0706050403020100
