Re: [PATCH] Don't build 32-bit libatomic with -march=i486 on x86-64

[Uros Bizjak <ubizjak at gmail dot com>]

On Tue, Apr 19, 2016 at 8:08 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Tue, Apr 19, 2016 at 8:45 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
>> On Tue, Apr 19, 2016 at 5:07 PM, H.J. Lu <hongjiu.lu@intel.com> wrote:
>>> Gcc uses the same -march= for both -m32 and -m64 on x86-64 unless
>>> --with-arch-32= is used.  There is no need for -march=i486 to compile
>>> 32-bit libatomic on x86-64.
>>>
>>> Tested on x86-64.  OK for trunk?
>>>
>>> H.J.
>>> ---
>>>         PR target/70454
>>>         * configure.tgt (XCFLAGS): Don't add -march=i486 to compile
>>>         32-bit x86 target library on x86-64.
>>> ---
>>>  libatomic/configure.tgt | 10 ++--------
>>>  1 file changed, 2 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/libatomic/configure.tgt b/libatomic/configure.tgt
>>> index c5470d7..bbb93fc 100644
>>> --- a/libatomic/configure.tgt
>>> +++ b/libatomic/configure.tgt
>>> @@ -81,14 +81,8 @@ case "${target_cpu}" in
>>>         try_ifunc=yes
>>>         ;;
>>>    x86_64)
>>> -       case " ${CC} ${CFLAGS} " in
>>> -         *" -m32 "*)
>>> -           XCFLAGS="${XCFLAGS} -march=i486 -mtune=generic"
>>> -           XCFLAGS="${XCFLAGS} -fomit-frame-pointer"
>>> -           ;;
>>> -         *)
>>> -           ;;
>>> -       esac
>>> +       # Since 64-bit arch > i486, we can use the same -march= to build
>>> +       # both 32-bit and 64-bit target libraries.
>>>         ARCH=x86
>>>         # ??? Detect when -mcx16 is already enabled.
>>>         try_ifunc=yes
>>> --
>>> 2.5.5
>>>
>>
>> No, this is wrong. My build with default options defaults to i386. So,
>> the difference between
>>
>
> How was your GCC configured?  Did you use
>
> --with-arch_32=i386

Nope, just:

~/gcc-svn/trunk/configure

Uros.