Is this ok for backport to GCC 6?
On 02/06/2017 03:20 PM, Kelvin Nilsen wrote:
>
> The test g++.dg/cpp1y/vla-initlist1.C makes assumptions that the memory
> used to represent the private temporary variables of neighboring control
> blocks at the same control nesting level is:
>
> 1. found at the same address, and
> 2. not overwritten between when the first block ends and the second
> block begins.
>
> While these assumptions are valid with some optimization choices on some
> architectures, these assumptions do not hold universally.
>
> With optimization disabled on the power architecture, the
> g++.dg/cpp1y/vla-initlist1.C test program runs initialization code to
> allocate the variable-length array a[] before entry into the second of
> two neighboring control blocks. This initialization code overwrites the
> first two cells of the array i[] that were initialized by the first of
> the two neighboring control blocks. Thus, the initialization value
> stored into i[1] is no longer present when this value is subsequently
> fetched as a[1].i from within the second control block.
>
> This patch disables this particular test case on power hardware.
>
> The patch has been bootstrapped and tested on
> powerpc64le-unknown-linux with no regressions.
>
> Is this ok for trunk?
>
> gcc/testsuite/ChangeLog:
>
> 2017-02-06 Kelvin Nilsen <kel...@gcc.gnu.org>
>
> PR target/68972
> * g++.dg/cpp1y/vla-initlist1.C: Add dg-skip-if directive to
> disable this test on power architecture.
>
> Index: gcc/testsuite/g++.dg/cpp1y/vla-initlist1.C
> ===================================================================
> --- gcc/testsuite/g++.dg/cpp1y/vla-initlist1.C (revision 245156)
> +++ gcc/testsuite/g++.dg/cpp1y/vla-initlist1.C (working copy)
> @@ -1,4 +1,5 @@
> // { dg-do run { target c++11 } }
> +// { dg-skip-if "power overwrites two slots of array i" { "power*-*-*"
> } { "*" } { "" } }
> // { dg-options "-Wno-vla" }
>
> #include <initializer_list>
>
>
--
Kelvin Nilsen, Ph.D. kdnil...@linux.vnet.ibm.com
home office: 801-756-4821, cell: 520-991-6727
IBM Linux Technology Center - PPC Toolchain
