--- /dev/null
+/* Inspired by 'libgomp.oacc-c-c++-common/nvptx-sese-1.c'. */
+
+/* { dg-additional-options -O1 } */
+/* { dg-additional-options -fdump-tree-dom3-raw } */
+
+
+extern int
+__attribute__((const))
+foo1 (int);
+
+int f1 (int r)
+{
+ if (foo1 (r)) /* If this first 'if' holds... */
+ r *= 2; /* ..., 'r' now has a zero-value lower-most bit... */
+
+ if (r & 1) /* ..., so this second 'if' can never hold... */
+ { /* ..., so this is unreachable. */
+ /* In constrast, if the first 'if' does not hold ('foo1 (r) == 0'), the
+ second 'if' may hold, but we know ('foo1' being 'const') that
+ 'foo1 (r) == 0', so don't have to re-evaluate it here: */
+ r += foo1 (r);
+ }
+
+ return r;
+}
+/* Thus, if optimizing, we only ever expect one call of 'foo1'.
+ { dg-final { scan-tree-dump-times {gimple_call <foo1,} 1 dom3 } } */
+
+
+extern int
+__attribute__((const))
+foo2 (int);
+
+int f2 (int r)
+{
+ if (foo2 (r))
+ r *= 8;
+
+ if (r & 7)
+ r += foo2 (r);
+
+ return r;
+}
+/* { dg-final { scan-tree-dump-times {gimple_call <foo2,} 1 dom3 } } */
+
+
+extern int
+__attribute__((const))
+foo3 (int);
+
+int f3 (int r)
+{
+ if (foo3 (r))
+ r <<= 4;
+
+ if ((r & 64) && ((r & 8) || (r & 4) || (r & 2) || (r & 1)))
+ r += foo3 (r);
+
+ return r;
+}
+/* { dg-final { scan-tree-dump-times {gimple_call <foo3,} 1 dom3 } } */
+
+
+extern int
+__attribute__((const))
+foo4 (int);
+
+int f4 (int r)
+{
+ if (foo4 (r))
+ r *= 8;
+
+ if ((r >> 1) & 2)
+ r += foo4 (r);
+
+ return r;
+}
+/* { dg-final { scan-tree-dump-times {gimple_call <foo4,} 1 dom3 } } */
+
+
+extern int
+__attribute__((const))
+foo5 (int);
+
+int f5 (int r) /* Works for both 'signed' and 'unsigned'. */
+{
+ if (foo5 (r))
+ r *= 2;
+
+ if ((r % 2) != 0)
+ r += foo5 (r);
+
+ return r;
+}
+/* { dg-final { scan-tree-dump-times {gimple_call <foo5,} 1 dom3 } } */
+
+
+extern int
+__attribute__((const))
+foo6 (int);
+
+int f6 (unsigned int r) /* 'unsigned' is important here. */
+{
+ if (foo6 (r))
+ r *= 2;
+
+ if ((r % 2) == 1)
+ r += foo6 (r);
+
+ return r;
+}
+/* { dg-final { scan-tree-dump-times {gimple_call <foo6,} 1 dom3 } } */