RFA: Fix isl-ast-gen-if-1.c test

[Nick Clifton]

Hi Guys,

  The test file gcc/testsuite/gcc.dg/graphite/isl-ast-gen-if-1.c file
  was generating an unexpected failure for the RX.  When I investigated
  I found that a return address on the stack was being corrupted, and I
  tracked it down to the foo() function:

    foo (int a[], int n)
    {
      int i;
      for (i = 0; i < n; i++)
        {
          if (i < 25)
            a[i] = i;
          a[n - i] = 1;
        }
    }

  The problem is that when i is 0, the line a[n - i] writes to a[50]
  which is beyond the end of the a array.  (In the RX case it writes
  over the return address on the stack).

  The patch below fixes the problem, although it could also be solved by
  increasing the size of the a array when it is declared in main().

  OK to apply ?

Cheers
  Nick

gcc/testsuite/ChangeLog
2015-06-22  Nick Clifton  <ni...@redhat.com>

        * gcc.dg/graphite/isl-ast-gen-if-1.c (foo): Prevent writing after
        the end of the array.

Index: gcc/testsuite/gcc.dg/graphite/isl-ast-gen-if-1.c
===================================================================
--- gcc/testsuite/gcc.dg/graphite/isl-ast-gen-if-1.c    (revision 224722)
+++ gcc/testsuite/gcc.dg/graphite/isl-ast-gen-if-1.c    (working copy)
@@ -10,7 +10,8 @@
     {
       if (i < 25)
         a[i] = i;
-      a[n - i] = 1;
+      if (i > 0)
+       a[n - i] = 1;
     }
 }