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

[Jeff Law <law at redhat dot com>]

On 06/22/2015 09:38 AM, Nick Clifton wrote:
> 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  <nickc@redhat.com>
>
> 	* gcc.dg/graphite/isl-ast-gen-if-1.c (foo): Prevent writing after
> 	the end of the array.
I'd tend to prefer to change the size of the array -- adding another 
conditional in the loop may have unintended consequences that possibly 
scramble things just enough to compromise the test.

jeff