re PR rtl-optimization/20527 (Mishandling of postincrement causes bzip2 miscompilation.)

	PR rtl-optimization/20527
	* gcc.c-torture/execute/pr20527-1.c: New test.

From-SVN: r96852

gcc/testsuite/ChangeLog

+2005-03-22  Hans-Peter Nilsson  <hp@axis.com>
+
+	PR rtl-optimization/20527
+	* gcc.c-torture/execute/pr20527-1.c: New test.
+
 2005-03-22  Ben Elliston  <bje@au.ibm.com>
 
 	* gcc.misc-tests/options.exp (check_for_options): Create a real C

gcc/testsuite/gcc.c-torture/execute/pr20527-1.c

+/* PR rtl-optimization/20527
+   Mishandled postincrement.  This test-case is derived from the
+   function BZ2_hbCreateDecodeTables in the file huffman.c from
+   bzip2-1.0.2, hence requiring the following disclaimer copied here:  */
+
+/*--
+  This file is a part of bzip2 and/or libbzip2, a program and
+  library for lossless, block-sorting data compression.
+
+  Copyright (C) 1996-2002 Julian R Seward.  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+
+  1. Redistributions of source code must retain the above copyright
+     notice, this list of conditions and the following disclaimer.
+
+  2. The origin of this software must not be misrepresented; you must 
+     not claim that you wrote the original software.  If you use this 
+     software in a product, an acknowledgment in the product 
+     documentation would be appreciated but is not required.
+
+  3. Altered source versions must be plainly marked as such, and must
+     not be misrepresented as being the original software.
+
+  4. The name of the author may not be used to endorse or promote 
+     products derived from this software without specific prior written 
+     permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+  Julian Seward, Cambridge, UK.
+  jseward@acm.org
+  bzip2/libbzip2 version 1.0 of 21 March 2000
+
+  This program is based on (at least) the work of:
+     Mike Burrows
+     David Wheeler
+     Peter Fenwick
+     Alistair Moffat
+     Radford Neal
+     Ian H. Witten
+     Robert Sedgewick
+     Jon L. Bentley
+
+  For more information on these sources, see the manual.
+--*/
+
+void f (long *limit, long *base, long minLen, long maxLen) __attribute__ ((__noinline__));
+void f (long *limit, long *base, long minLen, long maxLen)
+{
+  long i;
+  long vec;
+  vec = 0;
+  for (i = minLen; i <= maxLen; i++) {
+    vec += (base[i+1] - base[i]);
+    limit[i] = vec-1;
+  }
+}
+extern void abort (void);
+extern void exit (int);
+long b[] = {1, 5, 11, 23};
+int main (void)
+{
+  long l[3];
+  f (l, b, 0, 2);
+  if (l[0] != 3 || l[1] != 9 || l[2] != 21)
+    abort ();
+  exit (0);
+}