Re: [Google/gcc-4_9][PATCH][target/x86_64] PR 63538

[Sriraman Tallam <tmsriram at google dot com>]

On Mon, Oct 20, 2014 at 12:59 PM, Xinliang David Li <davidxl@google.com> wrote:
> On Mon, Oct 20, 2014 at 11:59 AM, Sriraman Tallam <tmsriram@google.com> wrote:
>> On Mon, Oct 20, 2014 at 10:51 AM, Andrew Pinski <pinskia@gmail.com> wrote:
>>> On Mon, Oct 20, 2014 at 10:46 AM, Sriraman Tallam <tmsriram@google.com> wrote:
>>>> On Mon, Oct 20, 2014 at 10:42 AM, Xinliang David Li <davidxl@google.com> wrote:
>>>>> Why removing the tree_code check?
>>>>
>>>> The actual problem happens because STRING_CSTs (end up in .lrodata)
>>>> are not set a far address as they dont match the VAR_DECL check here.
>>>> Futher,  "ix86_in_large_data_p" call has the TREE_CODE check to do the
>>>> right thing so this seems unnecessary & buggy here.
>>>
>>> I think he is asking because TREE_STATIC (decl) || DECL_EXTERNAL
>>> (decl) might be an issue for STRING_CSTs.
>>
>> TREE_STATIC is true for STRING_CSTs and DECL_EXTERNAL false, that looks ok.
>
> The values for STRING_CST make sense, but it is not documented in
> tree.h for use with STRING_CST. Maybe do this:
>
>  if (((TREE_CODE (decl) == VAR_DECL&& (TREE_STATIC (decl) ||
> DECL_EXTERNAL (decl))
>        ||TREE_CODE (decl) == STRING_CST)
>       && ix86_in_large_data_p (decl))
>
> which can be simplified to:
>
>  if ((TREE_CODE (decl) == VAR_DECL && is_global_var (decl) ||TREE_CODE
> (decl) == STRING_CST)
>   && ix86_in_large_data_p (decl))

Patch updated.

Thanks
Sri

>      ...
>
> David
>>
>> Thanks
>> Sri
>>
>>>
>>> Thanks,
>>> Andrew
>>>
>>>
>>>>
>>>> Thanks
>>>> Sri
>>>>
>>>>>
>>>>> David
>>>>>
>>>>> On Mon, Oct 20, 2014 at 10:35 AM, Sriraman Tallam <tmsriram@google.com> wrote:
>>>>>> Hi,
>>>>>>
>>>>>>    This patch is under review for trunk GCC :
>>>>>> https://gcc.gnu.org/ml/gcc-patches/2014-10/msg01638.html.
>>>>>>
>>>>>>     In the mean time, is this ok for google/gcc-4_9 branch?  Without
>>>>>> this, -mcmodel=medium is unusable if .lrodata goes beyond the 2G
>>>>>> boundary.
>>>>>>
>>>>>> Thanks
>>>>>> Sri

Attachment: pr63538.txt
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