re PR tree-optimization/83843 (wrong code at -O2)

	PR tree-optimization/83843
	* gcc.dg/store_merging_18.c: Don't expect "Merging successful" on arm.
	* gcc.dg/store_merging_19.c: New test.

From-SVN: r256783

gcc/testsuite/ChangeLog

+2018-01-17  Jakub Jelinek  <jakub@redhat.com>
+
+	PR tree-optimization/83843
+	* gcc.dg/store_merging_18.c: Don't expect "Merging successful" on arm.
+	* gcc.dg/store_merging_19.c: New test.
+
 2018-01-17  Kyrylo Tkachov <kyrylo.tkachov@arm.com>
 
 	* gcc.target/arm/xor-and.c: Fix armv6 effective target checks

gcc/testsuite/gcc.dg/store_merging_18.c

 /* PR tree-optimization/83843 */
 /* { dg-do run } */
 /* { dg-options "-O2 -fdump-tree-store-merging" } */
-/* { dg-final { scan-tree-dump-times "Merging successful" 3 "store-merging" { target store_merge } } } */
+/* { dg-final { scan-tree-dump-times "Merging successful" 3 "store-merging" { target { store_merge && { ! arm*-*-* } } } } } */
 
 __attribute__((noipa)) void
 foo (unsigned char *buf, unsigned char *tab)

gcc/testsuite/gcc.dg/store_merging_19.c

+/* PR tree-optimization/83843 */
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-store-merging" } */
+/* { dg-final { scan-tree-dump-times "Merging successful" 3 "store-merging" { target store_merge } } } */
+
+__attribute__((noipa)) void
+foo (unsigned char *buf, unsigned char *tab)
+{
+  tab = __builtin_assume_aligned (tab, 2);
+  buf = __builtin_assume_aligned (buf, 2);
+  unsigned v = tab[1] ^ (tab[0] << 8);
+  buf[0] = ~(v >> 8);
+  buf[1] = ~v;
+}
+
+__attribute__((noipa)) void
+bar (unsigned char *buf, unsigned char *tab)
+{
+  tab = __builtin_assume_aligned (tab, 2);
+  buf = __builtin_assume_aligned (buf, 2);
+  unsigned v = tab[1] ^ (tab[0] << 8);
+  buf[0] = (v >> 8);
+  buf[1] = ~v;
+}
+
+__attribute__((noipa)) void
+baz (unsigned char *buf, unsigned char *tab)
+{
+  tab = __builtin_assume_aligned (tab, 2);
+  buf = __builtin_assume_aligned (buf, 2);
+  unsigned v = tab[1] ^ (tab[0] << 8);
+  buf[0] = ~(v >> 8);
+  buf[1] = v;
+}
+
+int
+main ()
+{
+  volatile unsigned char l1 = 0;
+  volatile unsigned char l2 = 1;
+  unsigned char buf[2] __attribute__((aligned (2)));
+  unsigned char tab[2] __attribute__((aligned (2))) = { l1 + 1, l2 * 2 };
+  foo (buf, tab);
+  if (buf[0] != (unsigned char) ~1 || buf[1] != (unsigned char) ~2)
+    __builtin_abort ();
+  buf[0] = l1 + 7;
+  buf[1] = l2 * 8;
+  bar (buf, tab);
+  if (buf[0] != 1 || buf[1] != (unsigned char) ~2)
+    __builtin_abort ();
+  buf[0] = l1 + 9;
+  buf[1] = l2 * 10;
+  baz (buf, tab);
+  if (buf[0] != (unsigned char) ~1 || buf[1] != 2)
+    __builtin_abort ();
+  return 0;
+}