RE: [r15-2196 Regression] FAIL: c-c++-common/dfp/convert-bfp-6.c -std=gnu++98 execution test on Linux/x86_64

[Jiang, Haochen via Gcc-regression]

> -----Original Message-----
> From: Jakub Jelinek <ja...@redhat.com>
> Sent: Wednesday, July 24, 2024 1:09 PM
> To: Jiang, Haochen <haochen.ji...@intel.com>
> Cc: j...@ventanamicro.com; gcc-regression@gcc.gnu.org; gcc-
> patc...@gcc.gnu.org
> Subject: Re: [r15-2196 Regression] FAIL: c-c++-common/dfp/convert-bfp-6.c
> -std=gnu++98 execution test on Linux/x86_64
> 
> On Wed, Jul 24, 2024 at 01:49:06AM +0000, Jiang, Haochen wrote:
> > It might be a false positive timeout alert. Please ignore that first.
> 
> It is not.  I'm seeing it too consistently on i686-linux:
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++11
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++14
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++17
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++20
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++23
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++26
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++98
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++11
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++14
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++17
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++20
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++23
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++26
> execution test
> obj49/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++98
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++11
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++14
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++17
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++20
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++23
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++26
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-10.c  -std=c++98
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++11
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++14
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++17
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++20
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++23
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++26
> execution test
> obj51/LOGT:FAIL: c-c++-common/dfp/convert-bfp-6.c  -std=gnu++98
> execution test
> 
> The compilation of convert-bfp-6.c itself is identical between the older 
> (where
> it didn't fail) and newer (where it fails) builds, what has changed is 
> libgcc.a.
> In particular, what matters is libgcc/bid_binarydecimal.o.
> If I link all objects from libgcc from older (good libgcc) but 
> bid_binarydecimal.o
> (that one from newer bad libgcc), convert-bfp-6 still aborts, if I link all 
> objects
> from libgcc from newer (bad libgcc) but bid_binarydecimal.o (that one from
> older good libgcc), convert-bfp-6 works.

I see. If it is not a false alarm, then it seems to me that 
gcc-15-2212-gad642d2c950
from Jeff might fix the problem from the regression report. But I am not sure 
if it
really fix the problem or happen to be right.

Thx,
Haochen

> 
>       Jakub