[PATCH] Add testcase for PR tree-optimization/88739

[Jakub Jelinek]

Hi!

The following testcase distilled from https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88739#c0
aborts on s390x-linux when compiled with trunk -O2 with r268332 reverted (or
e.g. with -O2 and gcc 7.x) and succeeds with trunk -O2, or -O0 with any of
those compilers.  Tested also on x86_64-linux with -m32/-m64 make check.

Ok for trunk?

2019-02-08  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/88739
	* gcc.c-torture/execute/pr88739.c: New test.

--- gcc/testsuite/gcc.c-torture/execute/pr88739.c.jj	2019-01-27 12:44:12.526219828 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr88739.c	2019-02-08 18:48:25.880556579 +0100
@@ -0,0 +1,59 @@
+/* PR tree-optimization/88739 */
+#if __SIZEOF_SHORT__ == 2 &&  __SIZEOF_INT__ == 4 && __CHAR_BIT__ == 8
+struct A
+{
+  unsigned int a, b, c;
+  unsigned int d : 30;
+  unsigned int e : 2;
+};
+
+union U
+{
+  struct A f;
+  unsigned int g[4];
+  unsigned short h[8];
+  unsigned char i[16];
+};
+volatile union U v = { .f.d = 0x4089 };
+
+__attribute__((noipa)) void
+bar (int x)
+{
+  static int i;
+  switch (i++)
+    {
+    case 0: if (x != v.f.d) __builtin_abort (); break;
+    case 1: if (x != v.f.e) __builtin_abort (); break;
+    case 2: if (x != v.g[3]) __builtin_abort (); break;
+    case 3: if (x != v.h[6]) __builtin_abort (); break;
+    case 4: if (x != v.h[7]) __builtin_abort (); break;
+    default: __builtin_abort (); break;
+    }
+}
+
+void
+foo (unsigned int x)
+{
+  union U u;
+  u.f.d = x >> 2;
+  u.f.e = 0;
+  bar (u.f.d);
+  bar (u.f.e);
+  bar (u.g[3]);
+  bar (u.h[6]);
+  bar (u.h[7]);
+}
+
+int
+main ()
+{
+  foo (0x10224);
+  return 0;
+}
+#else
+int
+main ()
+{
+  return 0;
+}
+#endif

	Jakub