Re: [PATCH v3 07/16] target/i386: floatx80: avoid compound literals in static initializers

[Richard Henderson]

On 7/23/20 11:45 PM, Alex Bennée wrote:
> From: Laszlo Ersek <lersek@redhat.com>
> 
> 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),
>>      ^
> 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
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> Cc: Aurelien Jarno <aurelien@aurel32.net>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Cc: Joseph Myers <joseph@codesourcery.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Richard Henderson <rth@twiddle.net>
> 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
> Message-Id: <20200716144251.23004-1-lersek@redhat.com>
> Message-Id: <20200722062902.24509-8-alex.bennee@linaro.org>
> ---
>  include/fpu/softfloat.h  |   1 +
>  target/i386/fpu_helper.c | 426 +++++++++++++++++++--------------------
>  2 files changed, 214 insertions(+), 213 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~