On Sat, Nov 30, 2013 at 6:24 PM, Eric Botcazou <ebotca...@adacore.com> wrote:
> Hi,
>
> this test started to fail very recently on 32-bit platforms with 64-bit HWI.
> Not sure exactly why, but the issue is straightforward and was latent.
>
> For the following reference, a call to ao_ref_init_from_ptr_and_size yields:
>
> (gdb) p debug_generic_expr((tree_node *) 0x7ffff6e01200)
> &a[0 ...]{lb: 4294967292 sz: 4}
> (gdb) p debug_generic_expr(size)
> 20
> (gdb) p dref
> $36 = {ref = 0x0, base = 0x7ffff6dfd260, offset = -137438953344, size = 160,
> max_size = 160, ref_alias_set = 0, base_alias_set = 0, volatile_p = false}
>
> The offset is bogus. 'a' is an array with lower bound -4 so {lb: 4294967292
> sz: 4} is actually {lb: -4 sz: 4}. The computation of the offset goes wrong
> in get_addr_base_and_unit_offset_1 because it is not done in sizetype.
>
> Fixed by copying the relevant bits from get_ref_base_and_extent, where the
> computation is correctly done in sizetype.
>
> Tested on x86_64-suse-linux, OK for the mainline?
Ok, though the whole function needs double-int-ization ...
Thanks,
Richard.
>
> 2013-11-30 Eric Botcazou <ebotca...@adacore.com>
>
> * tree-dfa.h (get_addr_base_and_unit_offset_1) <case ARRAY_REF>: Do
> the
> offset computation using the precision of the index type.
>
>
> 2013-11-30 Eric Botcazou <ebotca...@adacore.com>
>
> * gnat.dg/opt30.adb: New test.
>
>
> --
> Eric Botcazou
