--- /dev/null
+/* Problem originally visible on ia64.
+
+ There is a partial redundancy of "in + 1" that makes GCSE want to
+ transform the final while loop to
+
+ p = in + 1;
+ tmp = p;
+ ...
+ goto start;
+ top:
+ tmp = tmp + 1;
+ start:
+ in = tmp;
+ if (in < p) goto top;
+
+ We miscalculate the number of loop iterations as (p - tmp) = 0
+ instead of (p - in) = 1, which results in overflow in the doloop
+ optimization. */
+
+static const char *
+test (const char *in, char *out)
+{
+ while (1)
+ {
+ if (*in == 'a')
+ {
+ const char *p = in + 1;
+ while (*p == 'x')
+ ++p;
+ if (*p == 'b')
+ return p;
+ while (in < p)
+ *out++ = *in++;
+ }
+ }
+}
+
+int main ()
+{
+ char out[4];
+ test ("aab", out);
+ return 0;
+}