Philippe Mathieu-Daudé <phi...@redhat.com> writes:
> On 7/17/20 6:46 PM, Laszlo Ersek wrote:
>> On 07/17/20 11:26, Laszlo Ersek wrote:
>>> On 07/16/20 17:09, Philippe Mathieu-Daudé wrote:
>>>> On 7/16/20 4:42 PM, Laszlo Ersek wrote:
>>>>> Quoting ISO C99 6.7.8p4, "All the expressions in an initializer for an
>>>>> object that has static storage duration shall be constant expressions or
>>>>> string literals".
>>>>>
>>>>> The compound literal produced by the make_floatx80() macro is not such a
>>>>> constant expression, per 6.6p7-9. (An implementation may accept it,
>>>>> according to 6.6p10, but is not required to.)
>>>>>
>>>>> Therefore using "floatx80_zero" and make_floatx80() for initializing
>>>>> "f2xm1_table" and "fpatan_table" is not portable. And gcc-4.8 in RHEL-7.6
>>>>> actually chokes on them:
>>>>>
>>>>>> target/i386/fpu_helper.c:871:5: error: initializer element is not
>>>>>> constant
>>>>>> { make_floatx80(0xbfff, 0x8000000000000000ULL),
>>>>>> ^
>>>>
>>>> This reminds me of:
>>>>
>>>> commit 6fa9ba09dbf4eb8b52bcb47d6820957f1b77ee0b
>>>> Author: Kamil Rytarowski <n...@gmx.com>
>>>> Date: Mon Sep 4 23:23:06 2017 +0200
>>>>
>>>> target/m68k: Switch fpu_rom from make_floatx80() to
>>>> make_floatx80_init()
>>>>
>>>> GCC 4.7.2 on SunOS reports that the values assigned to array members
>>>> are not
>>>> real constants:
>>>>
>>>> target/m68k/fpu_helper.c:32:5: error: initializer element is not
>>>> constant
>>>> target/m68k/fpu_helper.c:32:5: error: (near initialization for
>>>> 'fpu_rom[0]')
>>>> rules.mak:66: recipe for target 'target/m68k/fpu_helper.o' failed
>>>>
>>>> Convert the array to make_floatx80_init() to fix it.
>>>> Replace floatx80_pi-like constants with make_floatx80_init() as they
>>>> are
>>>> defined as make_floatx80().
>>>>
>>>> Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
>>>>
>>>>>
>>>>> We've had the make_floatx80_init() macro for this purpose since commit
>>>>> 3bf7e40ab914 ("softfloat: fix for C99", 2012-03-17), so let's use that
>>>>> macro again.
>>>>>
>>>>> Fixes: eca30647fc07
>>>>> Fixes: ff57bb7b6326
>>>>> Link: https://lists.gnu.org/archive/html/qemu-devel/2017-08/msg06566.html
>>>>> Link: https://lists.gnu.org/archive/html/qemu-devel/2020-07/msg04714.html
>>>>> Cc: Alex Bennée <alex.ben...@linaro.org>
>>>>> Cc: Aurelien Jarno <aurel...@aurel32.net>
>>>>> Cc: Eduardo Habkost <ehabk...@redhat.com>
>>>>> Cc: Joseph Myers <jos...@codesourcery.com>
>>>>> Cc: Paolo Bonzini <pbonz...@redhat.com>
>>>>> Cc: Peter Maydell <peter.mayd...@linaro.org>
>>>>> Cc: Richard Henderson <r...@twiddle.net>
>>>>> Signed-off-by: Laszlo Ersek <ler...@redhat.com>
>>>>> ---
>>>>>
>>>>> Notes:
>>>>> I can see that there are test cases under "tests/tcg/i386", but I
>>>>> don't
>>>>> know how to run them.
>>>>
>>>> Yeah it is not easy to figure...
>>>>
>>>> Try 'make run-tcg-tests-i386-softmmu'
>>>> but you need docker :^)
>>>
>>> That worked, thanks! Even without Docker: I just had to add
>>>
>>> --cross-cc-i386=gcc
>>>
>>> to my ./configure flags.
>>>
>>
>> Also -- I meant to, but I forgot to put "for-5.1" in the subject prefix;
>> sorry about that.
>
> Alex, as Paolo is not available, can this go via your tree?
Ok queued to for-5.1/fixes-for-rc1-v2, thanks.
>
>>
>> Laszlo
>>
--
Alex Bennée
