gcc/testsuite/gcc.dg/pr47381-1.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2" } */
   3
   4 typedef unsigned IPos;
   5 typedef unsigned char uch;
   6 extern uch window[];
   7 unsigned max_chain_length;
   8 unsigned strstart;
   9 int longest_match(IPos cur_match, int len, int best_len)
  10 {
  11     unsigned chain_length = max_chain_length;
  12     register uch *scan = window + strstart;
  13     register uch *match;
  14     register uch scan_end1 = scan[best_len-1];
  15     register uch scan_end = scan[best_len];
  16     do {
  17         ;
  18         match = window + cur_match;
  19         if (match[best_len] != scan_end ||
  20             match[best_len-1] != scan_end1 ||
  21             *match != *scan ||
  22             *++match != scan[1]) continue;
  23             best_len = len;
  24     } while ( --chain_length != 0);
  25     return best_len;
  26 }