lib: tests: Add 17-compare-rotated.

* lib/tests/scaffold/17-compare-rotated.c: Add file.
* build-aux/check-mescc.sh (mes_tests): Add it.

build-aux/check-mescc.sh

@@ -64,6 +64,7 @@ lib/tests/scaffold/17-compare-or.c
 lib/tests/scaffold/17-compare-and-or.c
 lib/tests/scaffold/17-compare-assign.c
 lib/tests/scaffold/17-compare-call.c
+lib/tests/scaffold/17-compare-rotated.c
 lib/tests/scaffold/18-assign-shadow.c
 lib/tests/scaffold/20-while.c
 lib/tests/scaffold/21-char-array-simple.c

lib/tests/scaffold/17-compare-rotated.c

@@ -0,0 +1,42 @@
+/* -*-comment-start: "//";comment-end:""-*-
+ * GNU Mes --- Maxwell Equations of Software
+ * Copyright © 2023 Ekaitz Zarraga <ekaitz@elenq.tech>
+ *
+ * This file is part of GNU Mes.
+ *
+ * GNU Mes is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * GNU Mes is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+int
+main ()
+{
+  unsigned u = 0xFFFFFFFF;
+  u = u <<30 >>30;          // higher 30 bits are cleared because they leave
+                            // the register to the left
+  int i = 3;
+  int r = u != i;
+  if (r)
+    return 1;
+
+  unsigned short s = 0xFFFF;
+  s = s <<14 >>14;          // s<<14 is promoted to int, the higher bits are
+                            // not cleared, because there's space in the
+                            // register
+  i = 0xFFFF;
+  r = s != i;
+  if (r)
+    return 2;
+
+  return 0;
+}